Abstract: The efficacy of anti-HER2 therapeutics, such as lapatinib and trastuzumab, is limited by primary and acquired resistance. Cellular adaptations that allow breast cancer cell to survive prolonged HER2 inhibition include de-repression of the transcription factor FOXO3A with consequent estrogen receptor activation, and/or increased HER3 signaling. Here, we used low-density arrays, quantitative PCR, and western blotting to determine how HER2 signaling inhibition with lapatinib or PI3K inhibitors affects the expression of genes involved in breast cancer metastatic spread and overall prognosis. Retroviral transgenesis was used to express constitutively active forms of Akt in the HER2(+) breast cancer cell line SKBR3, and Grb7 in MCF7 cells. Specific gene silencing was obtained by siRNAs transfection. A murine BT474 xenograft cancer model was used to assess the effect of lapatinib on gene expression in vivo. We found that lapatinib induces upregulation of Grb7, an adaptor protein involved in receptor tyrosine kinase signaling and promoting cell survival and cell migration. Grb7 upregulation induced by lapatinib was found to occur in cancer cells in vitro and in vivo. We demonstrate that Grb7 upregulation is recreated by PI3K inhibitors while being prevented by constitutively active Akt. Thus, Grb7 is repressed by PI3K signaling and lapatinib-mediated Akt inhibition is responsible for Grb7 de-repression. Finally, we show that Grb7 removal by RNA-interference reduces breast cancer cell viability and increases the activity of lapatinib. In conclusion, Grb7 upregulation is a potentially adverse consequence of HER2 signaling inhibition. Preventing Grb7 accumulation and/or its interaction with receptor tyrosine kinases may increase the benefit of HER2-targeting drugs.
Abstract: Acquired resistance to imatinib in the advanced phase of chronic myeloid leukemia (CML) has been associated with mutations in the kinase domain (KD) of BCR-ABL. On the contrary, the prognostic implication of KD mutations in early chronic phase (CP) patients at diagnosis before imatinib-based therapy has not yet been established. We have reviewed the status of mutations in 43 patients with early CP-CML on the samples collected at diagnosis. Mutations were identified by direct sequencing (DS) with BidDye Terminator v 1.1. cycle sequencing kit and analyzed with a 3130 ABI capillary electrophoresis system. Eight out 13 (61.5%) high Sokal risk patients showed the following mutations: Y253C, S265R, E255K, F359Y, N374S, E255V, E255V, E255V. Three patients progressed during imatinib and second-line inhibitors and died of blastic phase CML at 23, 33, and 69 months. Another patient with intermediate Sokal risk showed D363G mutation at diagnosis, progressed under imatinib, was allografted and he is now alive in major molecular remission (MMR). No low-risk patient carried KD mutation at diagnosis. In conclusion, KD mutations conferring high-level imatinib resistance are present in patients with de novo CML and in some of them lead to disease progression.
Abstract: Lapatinib, a dual HER2 and EGFR tyrosine kinase inhibitor is highly active in HER2+ breast cancer. However, its efficacy is limited by either primary or acquired resistance. Although mutations in ras genes are rarely found in breast cancer, H-ras overexpression is frequently observed. Moreover, genetic alterations that do not directly involve ras such as Brk amplification, ultimately result in increased ras signaling. Using SKBR3 cells, a HER2+ breast cancer cell line that is naturally devoid of mutations in PI3KCA, PTEN, BRAF, and ras we show that both H-ras overexpression and expression of an oncogenic ras allele (ras V12) reduce susceptibility to lapatinib in analogy to what observed with activating PI3KCA mutations and with a constitutively active form of Akt. Importantly, we found that resistance to lapatinib due to ras overexpression or to ras V12 is overcome by MEK inhibition with U0126, suggesting a key role for the MEK-Erk pathway in ras-induced resistance. Similar results were obtained in BT474 cells, another HER+ breast cancer cell line. Therefore, our data indicate that overexpressed/mutated ras may act as a biological modifier of the response to lapatinib. Combining MEK inhibitors with lapatinib may help overcome this form of resistance and increase the efficacy of lapatinib in these tumors.
Abstract: Novel alpha-mannosidase inhibitors of the type (2R,3R,4S)-2-({[(1R)-2-hydroxy-1-arylethyl]amino}methyl)pyrrolidine-3,4-diol have been prepared and assayed for their anticancer activities. Compound 30 with the aryl group=4-trifluoromethylbiphenyl inhibits the proliferation of primary cells and cell lines of different origins, irrespective of Bcl-2 expression levels, inducing a G2/Mcell cycle arrest and by modification of genes involved in cell cycle progression and survival.
Abstract: The current treatment of chronic myelogenous leukemia (CML) is one of the most successful examples of molecularly targeted therapy in cancer. The identification of the fusion oncogene BCR-ABL allowed the discovery of small molecule inhibitors of its tyrosine kinase activity which, in turn, have literally revolutionized the treatment of this disease. However, large part of a successful clinical management of CML relies on appropriate diagnosis, molecular monitoring and identification of mutations potentially leading to drug resistance. These issues are discussed here together with an overview on how patients treated with tyrosine kinase inhibitors should be monitored.
Abstract: Nicotinamide phosphoribosyltransferase (Nampt) inhibitors such as FK866 are potent inhibitors of NAD(+) synthesis that show promise for the treatment of different forms of cancer. Based on Nampt upregulation in activated T lymphocytes and on preliminary reports of lymphopenia in FK866 treated patients, we have investigated FK866 for its capacity to interfere with T lymphocyte function and survival. Intracellular pyridine nucleotides, ATP, mitochondrial function, viability, proliferation, activation markers and cytokine secretion were assessed in resting and in activated human T lymphocytes. In addition, we used experimental autoimmune encephalomyelitis (EAE) as a model of T-cell mediated autoimmune disease to assess FK866 efficacy in vivo. We show that activated, but not resting, T lymphocytes undergo massive NAD(+) depletion upon FK866-mediated Nampt inhibition. As a consequence, impaired proliferation, reduced IFN-gamma and TNF-alpha production, and finally autophagic cell demise result. We demonstrate that upregulation of the NAD(+)-degrading enzyme poly-(ADP-ribose)-polymerase (PARP) by activated T cells enhances their susceptibility to NAD(+) depletion. In addition, we relate defective IFN-gamma and TNF-alpha production in response to FK866 to impaired Sirt6 activity. Finally, we show that FK866 strikingly reduces the neurological damage and the clinical manifestations of EAE. In conclusion, Nampt inhibitors (and possibly Sirt6 inhibitors) could be used to modulate T cell-mediated immune responses and thereby be beneficial in immune-mediated disorders.
Abstract: Summary Molecular monitoring of the BCR-ABL1 transcript in chronic myelogenous leukemia (CML) using quantitative real-time PCR (RQ-PCR) can be performed using either bone marrow (BM) or peripheral blood (PB). However, a recent report by Stock et al. [International Journal of Oncology 28 (2006) 1099] questioned the reliability of PB samples for BCR-ABL1 detection as performed by RQ-PCR. We report a study on 114 CML patients who received allogeneic stem cell transplantation (ASCT), and who were monitored by RQ-PCR using paired samples of BM and PB: the total number of determinations was 428, with a median follow-up after transplant of 8 years. BCR-ABL1 transcript was undetectable or <0.1%, in 106 (49.57%) and 62 (29%) paired determinations, respectively. BCR-ABL1 was >0.1% in 36 (16.8%) paired determinations and was discordant in 10 (4.7%). Agreement between PB and BM results was quantified by the kappa test (k = 0.85; 95% CI 0.76-0.94). This study shows that BCR-ABL1 RQ-PCR monitoring of CML patients after ASCT with PB is concordant with BM in 95.3% of cases, and thus may be used to monitor the disease. This may be relevant when discussing both quality of life issues and the need for post-transplant monitoring with the patient.
Abstract: Cancer immunotherapy aims at eliciting an immune response directed against tumor antigens to help fight off residual tumor cells and thereby improve survival and quality of life of cancer patients. Different immunotherapeutic approaches share the use of dendritic cells (DCs) to present tumor-associated antigens to T-lymphocytes. Ex vivo generated DCs can be loaded with antigens and re-infused to the patients, or they can be used for ex vivo expansion of antitumor lymphocytes. Alternatively, methods exist to target antigens to DCs in vivo without need for ex vivo cell manipulations. The clinical studies have shown that DC administration to patients is safe and induces antigen-specific immunity. However, it seldom elicits objective clinical responses in patients with advanced-stage malignancies. Novel insights into DC and lymphocyte regulation are expected to lead to more effective vaccines in the near future. Meanwhile, efforts are directed at identifying the most appropriate clinical targets for active specific immunotherapies. Data suggests that vaccinations may indeed be beneficial when given in the adjuvant setting rather than to treat metastatic cancers. These issues are discussed here together with an overview of the DC-based antitumor immunotherapy studies.
Abstract: To evaluate the safety and efficacy of pegfilgrastim administered as haematological support after autologous peripheral blood stem cell transplantation, we compared 44 patients with solid tumours and lymphomas receiving a 6-mg single dose of pegfilgrastim on day +5 after transplantation to a historical control group of 25 patients receiving filgrastim 5 microg kg(-1) day(-1) starting on day +5. There were no significant differences in haematological recovery nor in the incidence and duration of neutropenic fever. Median duration of grade 4 neutropenia in the pegfilgrastim and filgrastim group was similar. The incidence of grade III-IV mucositis was lower in pegfilgrastim than in filgrastim group due to the significant difference observed among the patients with solid tumours (p = 0.00). The only adverse event considered to be cytokine related was mild to moderate bone pain occurring during haematological recovery. According to the present study design and taking into account the current prices in our institution, the cost of the two drugs was similar in both treatment groups. In conclusion, a single injection of pegfilgrastim administered at day +5 post-transplantation shows comparable safety and efficacy profiles to daily injections of filgrastim and may be cost effective.
Abstract: Proteasome inhibitors are emerging as effective drugs for the treatment of multiple myeloma and possibly certain subtypes of non-Hodgkin's lymphoma. Bortezomib (Velcade) is the first proteasome inhibitor proven to be clinically useful and will soon be followed by a second generation of small molecule inhibitors with improved pharmacological properties. Although it is now understood that certain types of malignancies have an exquisite dependence on a functional proteasome for their survival, the underlying reason(s) remain unclear as of now. In this context, addiction to nuclear factor-kappaB (NF-kappaB)-induced survival signals, activation of the unfolded protein response as well as a reduced proteasomal activity in differentiated plasma cells have all been proposed to justify proteasome inhibitors' activity in susceptible tissues. In addition to their anticancer properties, bortezomib and related drugs modulate inflammatory and immune responses by affecting function and survival of immune cells such as lymphocytes and dendritic cells. The present review offers an overview of the biological effects that have been involved in proteasome inhibitors' antitumor activity and suggests prospective future applications for these drugs based on their recently characterized anti-inflammatory and immunomodulatory effects.
Abstract: PURPOSE: Histone deacetylases (HDAC) modulate gene transcription and chromatin assembly by modifying histones at the posttranscriptional level. HDAC inhibitors have promising antitumor activity and are presently explored in clinical studies. Cumulating evidence in animal models of immune disorders also suggests immunosuppressive properties for these small molecules, although the underlying mechanisms remain at present poorly understood. Here, we have evaluated the effects of two HDAC inhibitors currently in clinical use, sodium valproate and MS-275, on human monocyte-derived DCs. EXPERIMENTAL DESIGN: DCs were generated from monocytes through incubation with granulocyte macrophage colony-stimulating factor and interleukin-4. DC maturation was induced by addition of polyinosinic-polycytidylic acid. DC phenotype, immunostimulatory capacity, cytokine secretion, and migratory capacity were determined by flow cytometry, mixed leukocyte reaction, ELISA, and Transwell migration assay, respectively. Nuclear translocation of RelB, IFN regulatory factor (IRF)-3, and IRF-8 were determined by immunoblotting. RESULTS: HDAC inhibition skews DC differentiation by preventing the acquisition of the DC hallmark CD1a and by affecting the expression of costimulation and adhesion molecules. In addition, macrophage inflammatory protein-3beta/chemokine, motif CC, ligand 19-induced migration, immunostimulatory capacity, and cytokine secretion by DCs are also profoundly impaired. The observed defects in DC function on exposure to HDAC inhibitors seem to reflect the obstruction of signaling through nuclear factor-kappaB, IRF-3, and IRF-8. CONCLUSIONS: HDAC inhibitors exhibit strong immunomodulatory properties in human DCs. Our results support the evaluation of HDAC inhibitors in inflammatory and autoimmune disorders.
Abstract: The ubiquitin-proteasome pathway is a well-characterized mechanism deputed to the degradation of intracellular proteins. Proteasomal degradation intervenes in the regulation of numerous cellular functions including signal transduction, apoptosis, cell cycle, and antigen presentation. In vitro and in vivo studies have shown that both normal and malignant cells of the immune system are exquisitely affected by inhibition of proteasome activity. This property is currently exploited in the treatment of multiple myeloma and mantle cell lymphoma, two B-cell malignancies that respond to treatment with the proteasome inhibitor bortezomib. Pharmacological inhibitors of the proteasome also affect function and survival of B and T lymphocytes and of dendritic cells and were shown to reduce autoimmune and inflammatory manifestations in several models of immune-mediated disorders. The present review offers an overview of the mechanisms implicated in the immunomodulatory effects of proteasome inhibitors and discusses prospective future applications for these small molecules in immune and inflammatory diseases.
Abstract: Proteasome inhibitors possess potent antitumor activity against a broad spectrum of human malignancies. However, the effects of these compounds on the immune system still have to be clearly determined. In the present study, we have investigated the effects of proteasome inhibitors on dendritic cells (DC), antigen-presenting cells playing a key role in the initiation of immune responses. Exposure to the proteasome inhibitors bortezomib, MG132 or epoxomicin was found to promote apoptosis of human monocyte-derived DC and to reduce the yield of viable DC when given to monocytes early during differentiation to DC. DC apoptosis via proteasome inhibition was accompanied by mitochondria disruption and subsequent activation of the caspase cascade. Up-regulation and intracellular redistribution of Bcl-2-associated X protein (Bax), a pro-apoptotic Bcl-2 family protein, were observed in DC treated with these compounds and represent a suitable mechanism leading to activation of the intrinsic apoptotic pathway. Finally, active protein synthesis was found to represent an upstream prerequisite for DC apoptosis induced by proteasome inhibitors, since the translation inhibitor cycloheximide blocked all of the steps of the observed apoptotic response. In conclusion, induction of apoptosis in DC may represent a novel mechanism by which proteasome inhibitors affect the immune response at the antigen-presenting cell level.
Abstract: In cancer patients, the ability to detect disseminated tumour cells in peripheral blood or bone marrow could improve prognosis and consent both early detection of metastatic disease and monitoring of the efficacy of systemic therapy. These objectives remain elusive mainly due to the lack of specific genetic markers for solid tumours. The use of surrogate tissue-specific markers can reduce the specificity of the assays and give rise to a clinically unacceptable false-positive rate. Mammaglobin (MAM) and maspin are two putative breast tissue-specific markers frequently used for detection of occult tumour cells in the peripheral blood, bone marrow and lymph nodes of breast cancer patients. In this study, it was evaluated whether MAM and maspin gene expression may be induced in the normal blood and bone marrow cells exposed to a panel of cytokines, including chemotactic factors (C5a, interleukin (IL)-8), LPS, proinflammatory cytokines (TNF-alpha, IL-1beta) and growth factors (IL-3, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor). The experimental data show that all cytokines included in the panel, except for IL-8, were able to induce maspin expression; on the contrary, MAM gene was never induced. These results suggest that MAM is more specific than maspin and that the possible interference of cytokines should be taken into account in interpreting molecular assays for detection of isolated tumour cells.
Abstract: Up-regulation of LOX-1 is implicated in apoptosis in both vascular smooth muscle cells and in endothelial cells. We examined the effects of doxorubicin on LOX-1 expression in H9c2 cardiomyocytes and the role played by LOX-1 up-regulation in doxorubicin-induced apoptosis. Reactive oxygen species (ROS) formation was assessed by DCF flow cytometry. LOX-1 mRNA and protein expression was assessed by RT-PCR and Western blotting. Apoptosis was evaluated by flow cytometry with annexin/PI double staining. Doxorubicin-induced LOX-1 expression in a concentration- and time-dependent fashion. The doxorubicin-induced ROS formation and the LOX-1 expression were significantly attenuated by pre-treatment with antioxidants. By exposing cells that had been pre-treated with doxorubicin to oxidized-LDL, a LOX-1 agonist, in the presence or in the absence of k-carrageenan, a LOX-1 receptor antagonist, we documented that doxorubicin-induced LOX-1 expression plays a role in inducing apoptosis. These findings suggest that LOX-1 up-regulation is redox-sensitive and may contribute to doxorubicin-induced cardiotoxicity.
Abstract: The benefits of allografting noted in some malignant diseases might be safely extended to metastatic breast cancer by a combination of cytoreduction with high-dose chemotherapy (HDT) and autologous stem-cell transplant (ASCT) with graft-versus-tumour effect mediated by transplanted donor immune cells with nonmyeloablative allografting (reduced intensity conditioning transplantation, RICT). 17 patients with heavily pretreated disease were given tandem transplants. 13 patients sustained donor engraftment. Three had partial remission after HDT and ASCT and complete remission after RICT; they achieved full chimerism and all developed graft-versus-host disease (GVHD) before regression of cancer. Another patient did not respond to HDT and ASCT but had partial remission after RICT, giving an overall response rate of 24%. Five patients had grade II or higher acute GVHD and five had extensive chronic GVHD. No non-relapse-related deaths occurred during the first 100 days. Five patients (29%) were alive 90-2160 days (median 1320) after RICT. This two-step approach is feasible in patients with metastatic breast cancer.
Abstract: PURPOSE: Bcl-2 overexpression is frequently detected in lymphoid malignancies, being associated with poor prognosis and reduced response to therapy. Here, we evaluated whether Bcl-2 overexpression affects the cytotoxic activity of proteasome inhibitors taken alone or in association with conventional anticancer drugs or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). EXPERIMENTAL DESIGN: Jurkat cells engineered to overexpress Bcl-2 were treated with proteasome inhibitors (MG132, epoxomicin, and bortezomib), anticancer drugs (etoposide and doxorubicin), TRAIL, or combinations of these compounds. Cell death and loss of mitochondrial transmembrane potential were detected by flow cytometry. Cytosolic relocalization of cytochrome c and SMAC/Diablo, caspase cleavage, and Bcl-2 and Mcl-1 levels were determined by immunoblotting. Nuclear factor-kappaB inhibition was done by retroviral transduction with a dominant-negative mutant of IkappaBalpha. RESULTS: Bcl-2 overexpression results in significant inhibition of apoptosis in response to proteasome inhibitors, antiblastics, and TRAIL. Addition of TRAIL to proteasome inhibitors results in a synergistic cytotoxic effect in Bcl-2-overexpressing cells, whereas this result is not reproduced by the combination of proteasome inhibitors with antiblastic drugs. Importantly, proteasome inhibitors plus TRAIL induce mitochondrial dysfunction irrespective of up-regulated Bcl-2. Bcl-2 cleavage to a fragment with putative proapoptotic activity and elimination of antiapoptotic Mcl-1 may both play a role in proteasome inhibitors-TRAIL cooperation. Conversely, nuclear factor-kappaB inhibition by proteasome inhibitors is per se insufficient to explain the observed synergy. CONCLUSIONS: Combined proteasome inhibitors and TRAIL overcome the apoptotic threshold raised by Bcl-2 and may prove useful in the treatment of chemoresistant malignancies with up-regulated Bcl-2.
Abstract: Proteasome inhibitors exhibit antitumor activity against malignancies of different histology. Yet, the mechanisms underlying this effect are poorly understood. Recent evidence indicates that antiapoptotic factors may also accumulate as a consequence of exposure to these drugs, possibly reducing their cytotoxicity. These include the Bcl-2 family member Mcl-1, whose down-regulation has been proposed to initiate apoptosis in response to genotoxic stimuli. In this study, we found that proteasome inhibitors release cyotochrome c and second mitochondria-derived activator of caspase (SMAC)/Diablo and trigger the subsequent apoptotic cascade in spite of concomitant Mcl-1 increase. However, our data indicate that subtraction of Mcl-1 during apoptosis, although not required for early release of proapoptotic factors, is probably relevant in speeding up cell demise, since RNA interference-mediated Mcl-1 silencing is lethal in lymphoma cells. Consistent with this, the cytotoxic effects of proteasome inhibitors are enhanced when Mcl-1 increase is impeded. Thus, this study identifies Mcl-1 accumulation as an unwanted molecular consequence of exposure to proteasome inhibitors, which slows down their proapoptotic effects. Pharmacologic or genetic approaches targeting Mcl-1, including therapeutic RNAi, may increase the effectiveness of these compounds.
Abstract: PURPOSE: Overexpression of antiapoptotic Bcl-2 family members has recently been related to resistance to chemo/radiotherapy in several human malignancies, particularly lymphomas. Hence, innovative approaches bypassing this resistance mechanism are required in the therapeutic approach. This study evaluated whether chemoresistance associated with Bcl-2 and Bcl-x(L) overexpression would be overcome by activating the death receptor pathway by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in the Jurkat cell model EXPERIMENTAL DESIGN: We made use of genetically modified Jurkat cells to evaluate the effect of Bcl-2 or Bcl-x(L) overexpression on the cytotoxic effect produced by the anticancer drugs doxorubicin, etoposide, and oxaliplatin and TRAIL. Caspase activation was detected by cleavage of caspase-8 and -3. The mitochondrial transmambrane potential was assessed by staining with DiOC(6) and flow cytometry. Caspase activity was blocked by the broad-spectrum caspase inhibitor zVAD-fmk. RESULTS: Bcl-2 and Bcl-x(L) overexpression but not lack of caspase-8 protects the Jurkat cells from the anticancer drug-induced cytolysis. However, Bcl-2/Bcl-x(L) Jurkat cells retained some susceptibility to TRAIL-induced cytolysis. A highly synergistic cytotoxic effect of the combination of TRAIL with any of the antiblastic used in this study was detected in the chemoresistant cells. This effect was associated with mitochondrial disassemblage and dependent on caspase activation CONCLUSIONS: The combination of TRAIL with conventional anticancer drugs may prove to be useful in the treatment of antiapoptotic Bcl-2 family proteins-expressing malignancies.
Abstract: The clinical use of doxorubicin, a highly active anticancer drug, is limited by its severe cardiotoxic side effects. Increased oxidative stress and apoptosis have been implicated in the cardiotoxicity of doxorubicin. Carvedilol is an adrenergic blocking agent with potent anti-oxidant activity. In this study we investigated whether carvedilol has protective effects against doxorubicin-induced free radical production and apoptosis in cultured cardiac muscle cells, and we compared the effects of carvedilol to atenolol, a beta-blocker with no anti-oxidant activity. Reactive oxygen species (ROS) generation in cultured cardiac muscle cells (H9c2 cells) was evaluated by flow cytometry using dichlorofluorescein (DCF) and hydroethidine (HE). Apoptosis was assessed by measuring annexin V-FITC/propidium iodide double staining, DNA laddering, levels of expression of the pro-apoptotic protein Bax-alpha and the anti-apoptotic protein Bcl-2, and caspase-3 activity. Pre-treatment with carvedilol significantly attenuated the doxorubicin-induced increases in DCF (P < 0.001 compared to cells not pre-treated with carvedilol) and HE (P < 0.01) fluorescence. Doxorubicin increased the fraction of annexin V-FITC-positive fluorescent cells, while pre-treatment with carvedilol reduced the number of positive fluorescent cells (P < 0.01). Doxorubicin-induced DNA fragmentation to a clear ladder pattern, while carvedilol prevented DNA fragmentation. Doxorubicin-induced a fall in mRNA expression of the anti-apoptotic Bcl-2 and an increase in the expression of the pro-apoptotic Bax-alpha. Carvedilol pre-treatment blunted both the decrease of Bcl-2 (P < 0.01) and the increase of Bax-alpha mRNA expression (P < 0.01). Caspase-3 activity significantly increased after the addition of doxorubicin. Concurrently, carvedilol partially inhibited the doxorubicin-induced activation of caspase-3 (P < 0.01). Atenolol did not produce any effect in preventing doxorubicin-induced ROS generation and cardiac apoptosis. Our results suggest that carvedilol is potentially protective against doxorubicin cardiotoxicity by decreasing free radical release and apoptosis in cardiomyocytes.
Abstract: We studied the safety, activity and peripheral blood progenitor cell mobilizing capability of a dose-dense combination of vinorelbine (VNB) and paclitaxel (PTX) as first-line chemotherapy for patients with metastatic breast cancer (MBC). Forty-three MBC patients were submitted to four cycles of VNB 30 mg/m2 and PTX 175 mg/m2 intravenously, every 2 weeks, as the first induction step of a tandem high-dose chemotherapy program. Granulocyte colony-stimulating factor (G-CSF) 5 microg/kg was administered daily from day +5 to +10 in order to accelerate hematopoietic recovery, or 48h after the last VNB-PTX when a leukapheresis was planned (after the third or fourth cycle). A total of 172 cycles were administered. The mean delivered dose-intensity of VNB and PTX was 14.7 and 86 mg/m2/week, respectively (98% of the planned dose-intensity). The main per-patient toxicities were: peripheral neurotoxicity (G1/2 60%, G3 5%), constipation (G1/2 10%), oral mucositis (G1/2 20%), and asthenia (G1/2 35%). Hematological toxicity was unremarkable, except for anemia with hemoglobin (Hb) values < 10 g/dl (28%), and lymphopenia with lymphocyte counts < 1000/mm3 (28%). Two complete (5.1%) and 24 partial (61.5%) responses were observed in 39 assessable patients, for an overall response rate of 66.6% (95% CI 51.6-80.9). A median of one apheretic procedure (range 1-3) was required to achieve the target number of 6 x 10(6)/kg CD34+ cells. The median number of CD34+ harvested per patient was 15 x 10(6)/kg (range 6.4-36.5). Four cycles of dose dense VNB and PTX showed a favorable toxicity profile, a relevant anti-tumor activity and a high peripheral blood progenitor cell mobilizing activity.
Abstract: Dendritic cells (DC) are the most potent antigen-presenting cells known, currently tested for vaccination studies in cancer patients. The use of tumor-derived RNA to load DC overcomes the requirement of defined HLA types and the identification of tumor antigens expressed by the tumors. Here, we show that human monocyte-derived DC generated under serum-free conditions by GM-CSF, IL-4 and TNF-alpha acquire a mature phenotype and expression of the chemokine receptor CCR-7, which plays a pivotal role in DC migration to the afferent lymph nodes. We demonstrate the feasibility of total RNA transfection into such DC using the renal cell carcinoma (RCC) cell line N43-EGFP, which was stably transfected with an EGFP-encoding vector. Moreover, we show that DC transfected with RNA from colorectal cancer cells present HLA class I-restricted antigenic epitopes to induce a primary antitumor CTL response in vitro. Interestingly, the CTL induced by SW480 RNA also recognized another colon cancer line, HCT116, and the RCC line A498. Our results confirm the feasibility of total RNA transfection of serum-free generated DC for the induction of CTL against colon cancer and RCC cells, and support the relevance of shared tumor rejection epitopes between colorectal cancer and RCC.
Abstract: BACKGROUND AND OBJECTIVES: High-dose chemotherapy (HDT) with autologous peripheral blood progenitor cell (PBPC) transplant has been increasingly used for newly diagnosed multiple myeloma (MM) in recent years. Presently available results suggest an improvement in the complete remission rate and survival as compared to conventional chemotherapy. However, there is no plateau in the survival curves, and experiments with new treatment schedules and conditioning regimens are warranted. DESIGN AND METHODS: In a non-randomised controlled trial, 20 patients underwent three-step HDT following conventional vincristine/doxorubicin/dexamethasone (VAD)-based induction. In the intensification phase patients received high-dose cyclophosphamide (HD-CY), high-dose etoposide (HD-VP), and mitoxantrone (NOV) plus melphalan (L-PAM) with haemopoietic rescue. Maintenance treatment with interferon was given until relapse. Actuarial overall survival (OS) and event-free survival (EFS) curves were plotted according to the method of Kaplan and Meier. In five of the eight patients achieving complete remission (CR), the molecular disease was monitored by polymerase chain reaction technique (PCR). RESULTS: Overall 18/20 (90%) patients responded, with a CR rate of 40%. After an average follow-up of 40 months, median EFS and OS are 25.5 and 44.6 months, respectively. Monoclonal cells were detectable in the post-treatment bone marrow and in the aphereses of the five CR patients monitored by PCR. CONCLUSION: The present three-step HDT regimen, including conditioning with mitoxantrone and melphalan, proved to be feasible and safe. Our results are in agreement with the hypothesis that HDT results in an increased remission rate and in prolonged survival in newly diagnosed MM, but a cure is unlikely.
Abstract: BACKGROUND: Maspin is a molecular marker used for the detection of contaminating breast carcinoma (BC) cells in peripheral blood and lymph nodes. However, its specificity has been questioned recently. The objective of this study was to verify the specificity of this marker and to determine the incidence of positive bone marrow results in patients with BC who are eligible for high-dose chemotherapy (HDT) both in early and advanced disease stages and before and after treatment. METHODS: Bone marrow specimens from 41 patients with BC as well as from 35 normal volunteers and 17 patients with hematologic tumors were examined for maspin transcript expression by a modified nested reverse transcriptase-polymerase chain reaction technique. RESULTS: Maspin transcript was found in all normal and neoplastic breast tissues and in none of the 35 normal bone marrow specimens (specificity, 100%; 95% confidence interval, 90-100%). However, the transcript was found in 40% of the bone marrow samples from patients with hematologic malignancies. Thus, this marker appears very specific for discriminating between normal controls and patients with BC, but it cannot be considered disease specific. Among patients with BC, bone marrow was positive for the maspin transcript in 32% of patients with early-stage disease and in 75% of patients with metastatic disease before chemotherapy. After treatment, in 75% of patients with early-stage disease and in 50% of patients with metastatic disease, the bone marrow results became maspin negative. CONCLUSIONS: On the basis of the current data, although it is not disease specific, maspin is a reliable marker for detecting bone marrow molecular disease in patients with BC and should be considered for prospective studies as a prognostic indicator and as an assay for monitoring residual disease.
Abstract: OBJECTIVES: The purpose of this study was to evaluate the clinical efficacy and tolerability of high-dose (HD) chemotherapy with growth factor support in primary breast cancer with extensive nodal involvement. PATIENTS AND METHODS: Fifty-three patients with ten or more involved nodes were recruited and were given three cycles of standard-dose fluorouracil, epidoxorubicin and cyclophosphamide followed by one single course of high-dose CEP (cyclophosphamide, etoposide and cisplatin). No autologous progenitor support was used. RESULTS: Five-year actuarial disease-free and overall survival were 40 and 60%, respectively. High-dose CEP required a median of 22 days of hospitalization and was associated with grade G3--4 nausea and vomiting in two thirds of the cases. Hematological toxicity was comparable to that of high-dose therapies delivered with autologous progenitor support. No therapy-related mortality was observed. CONCLUSIONS The efficacy of treatment was comparable to the best results of conventional therapy, with only a trend for improved survival. High-dose CEP was feasible with acceptable toxicity. Although this regimen does not require stem cell harvesting and storage, it requires clinical support comparable to autotransplantation procedures and side effects are not so manageable to recommend its use outside specialized units.
Abstract: The aim of this study was to compare both the effects on hematologic recovery and circulating progenitor cell mobilization and the toxicity of three cytokine regimens administered after high-dose non-myeloablative chemotherapy with cyclophosphamide 5 g/m(2), etoposide 1.5 g/m(2) and cisplatin 150 mg/m(2). Thirty-five consecutive patients were non-random sequentially allocated to one of three treatment groups: (1) granulocyte colony-stimulating factor alone (n = 15); (2) granulocyte-macrophage colony-stimulating factor alone (n = 10), and (3) sequential interleukin-3 and granulocyte-macrophage colony-stimulating factor (n = 10). Neutrophil recovery in group 1 was significantly hastened as compared to the two other groups (median 2 days, p < 0.005), while no significant differences were observed between groups 2 and 3. CD34+ cells peaked about 2 days earlier in group 1 compared to the other groups (p = 0.0001), whereas the median peak value of CD34+ cells was similar in the three groups. In all patients, the toxicity related to cytokine administration was low and easily manageable with nonsteroidal anti-inflammatory drugs.
Abstract: The purpose of the present study was to evaluate the feasibility and the efficacy of employing a high-dose chemotherapy (HDT) regimen with tandem peripheral blood progenitor cells (PBPC) supported transplantation in the initial treatment of aggressive non-Hodgkin's lymphoma (NHL). HDT was preceded by a standard course of conventional dose chemotherapy in 17 out of the 25 patients treated, while in 8 cases it was delivered after only one or two cycles. HDT was a three-step procedure which included high-dose (6-7 g/m2) cyclophosphamide (CY) supported by haematopoietic growth factors, the first myeloablative course with mitoxantrone (NOV) 60, 75 or 90 mg/m2 plus melphalan (L-PAM) 140-180 mg/m2 with haematopoietic rescue, and the second myeloablative course with etoposide (VP) and carboplatin (CARBO) given at 1.5 g/m2 each with haematopoietic rescue. PBPC were collected after CY administration. Twenty-two patients (88%) completed the HDT, haematological reconstitution was rapid and complete at each step and there were no toxic deaths. The activity of the treatment was high with a CR rate over 90% in the entire patient population. The 2-year overall survival (OS) and failure-free survival (FFS) rates of patients in both Age-Adjusted International Prognostic Index (A-AIPI) groups 2 and 3 are 79% and the disease-free survival (DFS) rate for the CRs is 85%. In A-AIPI group 1 the 2-year OS and FFS rates are both 91%.
Abstract: The availability of the myeloid hemopoietic growth factors (HGF) granulocyte- and granulocyte/macrophage-colony stimulating factor (G-CSF and GM-CSF) has enhanced the therapeutic index of high-dose chemotherapeutic antitumoral regimens (HDCT), as well as the rate of severe damage to immune competence. We investigated some immune functions before, during and after one course of HDCT for poor-risk breast cancer and compared the effects of G-CSF and GM-CSF on the immune recovery. They exerted different influences on the functions we examined and showed distinctive patterns of both qualitative and quantitative in vivo activities on the immune system. The main findings were that (a) granulocyte and lymphocyte recovery rates were faster in the patients receiving G-CSF; (b) looking at the lymphocyte compartment, this difference was restricted to the CD3(+)/CD8(+) and CD56(+) lymphocyte subsets; (c) the reconstitution rate of CD19(+) lymphocytes was slow in both groups; (d) at the end of follow-up HLA-DR expression by CD3(+) lymphocytes was higher in the GM-CSF group; (e) the lymphocyte proliferative capacity was restored at a faster rate in the GM-CSF group, whereas cytotoxic activities recovered better in the G-CSF group; (f) the early repopulating phase was characterized by higher interleukin-6 serum levels in the GM-CSF group. Overall, GM-CSF seemed to exert an earlier effect on all T lymphocyte subsets, preventing them from a complete drop during the long-lasting "nadir" of the cell count, whereas G-CSF appeared to boost them strongly, though a few days later, hastening their final recovery. The distinct pattern of the cytokine cascade induced by each factor, consistent with the different functional changes, seemed to account for the peculiarities of their immune modulations.
Abstract: PURPOSE: To compare the toxicity and effects on hematologic recovery and circulating progenitor cell mobilization of three cytokine regimens administered after high-dose cyclophosphamide (HD-CTX; 6 g/m(2)), given as the first step of a high-dose sequential chemotherapy. PATIENTS AND METHODS: Forty-eight patients with breast cancer or non-Hodgkin's lymphoma were randomized to receive granulocyte colony-stimulating factor (G-CSF) alone (arm 1), granulocyte-macrophage colony-stimulating factor (GM-CSF) alone (arm 2), or sequential interleukin-3 (IL-3) and GM-CSF (arm 3). Cytokines were administered as a single daily subcutaneous injection at a dose of 5 to 6 microg/kg/d. Progenitor cells were evaluated in peripheral blood as well as in apheretic product as both CD34(+) cells and granulocyte-macrophage colony-forming units (CFU-GM). RESULTS: Neutrophil recovery was faster in arm 1 as compared with arms 2 and 3 (P <.0001); no significant differences were observed between arms 2 and 3. In arm 3, a moderate acceleration of platelet recovery was observed, but it was statistically significant only as compared with arm 1 (P =.028). The peak of CD34(+) cells was hastened in a median of 2 days in arm 1 compared with arms 2 and 3 (P =.0002), whereas the median peak value of CD34(+) cells and CFU-GM was similar in the three patient groups. Administration of IL-3 and GM-CSF resulted in more significant toxicity requiring pharmacologic treatment in 90% of patients. CONCLUSION: The three cytokine regimens administered after HD-CTX are comparably effective in reducing hematologic toxicity and mobilizing the hematopoietic progenitor cells. G-CSF accelerates leukocyte recovery and progenitor mobilization. Although G-CSF-treated patients have somewhat slower platelet recovery, they definitely have fewer side effects.
Abstract: Cytogenetic analysis of 72 consecutive de novo myelodysplastic syndrome patients revealed monosomy 7 in 12 cases. In 4 of these cases, the -7 was the only abnormality, whereas the remaining 8 cases showed additional chromosomal aberrations. Fluorescence in situ hybridization (FISH) utilizing chromosome 7 alpha-satellite and painting probes and other specific probes, when necessary, provided evidence of unusual and unsuspected structural rearrangements involving chromosome 7. FISH analysis showed that the small fragment found in one patient and the ring found in each of two other patients were chromosome 7-derived rings. FISH also revealed the insertion of chromosome 7 sequences into autosomes in three other patients and unusual translocations in the remaining two patients. By comparing the results obtained by using banding techniques to those obtained by using the FISH technique, we deduced the involvement of chromosome 7 with partial deletion of the short arm in all eight examined patients. Our study confirms the ability of FISH to detect chromosomal aberrations that would otherwise not be identified and the tendency of chromosome 7 to be involved in many different rearrangements. From a clinical point of view, we confirm that patients affected by myelodysplastic syndromes with complex karyotypes involving chromosome 7 do not respond to treatment and have a poor prognosis.
Abstract: The first GROCTA trial compared 5-year tamoxifen treatment to ten chemotherapy cycles in a group of 504 pre-/post-menopausal, node-positive, ER-positive breast cancer patients. This study also included an arm combining tamoxifen with chemotherapy. Fifteen-year results showed no difference between tamoxifen and tamoxifen plus chemotherapy, while both treatments were significantly superior to chemotherapy alone. A confirmatory study (GROCTA 02) was performed in 244 pre-/perimenopausal patients by comparing 5 years of tamoxifen treatment (plus 2 years of goserelin) to six CMF cycles. No difference has emerged so far between the tamoxifen and CMF arms at a median follow-up time of 62 months. Post-menopausal women were scheduled to receive 3 years of tamoxifen treatment and then to be randomly allocated to further 2 years of tamoxifen or to 2 years of low-dose aminoglutethimide (GROCTA 04B). So far 662 patients have been entered, 375 of whom have been randomized to tamoxifen (n = 188) or aminoglutethimide (n = 187). Preliminary results (median follow-up time 32 months) show no major difference in patients' outcome. A new trial (ITA trial) with a similar design but employing anastrozole in place of aminoglutethimide has been activated in 1998. The GROCTA 03 study investigated the potential superiority of alternating adjuvant chemotherapy over standard CMF. This study, which included 107 node-positive ER-negative pre-menopausal women, was prematurely closed because more patients allocated to the triple alternated chemotherapy appeared to have relapsed and died at the first interim analysis. The use of high-dose chemotherapy (HDC) was explored by the GROCTA 06 trial which included 53 patients with ten or more involved nodes and a maximum age of 55 years. These patients were scheduled to receive three standard CEF cycles followed by one cycle of HDC (cyclophosphamide 5 g/m2; etoposide 1.5 g/m2; cisplatin 150 mg/m2) without any form of bone marrow rescue. This HDC program proved to be feasible but was not superior to CMF-based chemotherapy we had previously employed in a comparable group of patients in previous GROCTA trials. These findings prompted us to explore new HDC programmes with the use of peripheral stem cell support and in addition the possible value of new drugs such as Taxol and vinorelbine. New-generation trials will also explore the value of new prognostic indicators such as tumor proliferative activity, which are prospectively used to allocate patients to different treatment options.
Abstract: Correct diagnosis of acute promyelocytic leukemia (APL) requires proof of the translocation (15;17)(q24;q11), which appears to be absolutely specific for this particular type of myeloid disorder. We studied the karyotypes of 29 consecutive APL patients at diagnosis: in 5 of them banding techniques failed to detect the t(15;17). In these seemingly cytogenetically negative cases, fluorescence in situ hybridization (FISH) with a chromosome 17 painting probe detected a high percentage of mitoses with 3 hybridization signals: one derived from the intact chromosome 17, and 2 from the rearranged chromosomes 15 and 17. Trisomy 8 (+8) as a secondary chromosomal abnormality was observed in 8 cases (27.5%), confirming that the t(15;17) favors the acquisition of an extra chromosome 8. One of these 8 cases showed a marker that was interpreted by FISH analysis as der(8) with duplication of a segment of the long arm carrying the c-MYC allele. Clinical features of patients with t(15;17) and +8 were no different from patients with t(15;17) alone. The usefulness of FISH to standard banding techniques in the detection of specific structural and/or numerical chromosomal abnormalities is confirmed in this report.
Abstract: Double minute chromosomes (dmin) are small acentric fragments frequently observed when karyotyping human tumor cells. They are considered the cytogenetic manifestation of gene amplification. The finding of dmin in leukemia is a rare event usually associated with progression of the disease and unfavorable prognosis. We present four patients affected by myeloid disorders with an abnormal karyotype and a variable number of dmin. In an attempt to clarify the origin of the dmin and the amplified gene, we utilized a fluorescent in-situ hybridization (FISH) technique and a panel of specific probes. The results of the analysis indicate that, although chromosomes 8 are apparently uninvolved, dmin retained c-MYC sequencs in three cases. By observing previously reported cases, we found that the majority of patients with myeloid disorders and dmin showed an amplified c-MYC gene, regardless of the chromosomal abnormalities. The FISH technique proved to be informative in demonstrating gene amplification in both metaphase and interphase cells. Finally, in the one patient carrying a 20q deletion, FISH allowed the detection of a previously unreported translocation between a 16p and the 20q-, confirming the ability of the technique to understand complex karyotypes.
Abstract: High-dose chemotherapy often requires hematopoietic progenitor cell reinfusion, but drugs with extramedullary dose-limiting toxicity may be administered in the high-dose range by simple growth factor support. In this study, we evaluated the feasibility and toxicity of a three-drug high-dose regimen supported by recombinant human granulocyte colony-stimulating factor (rhG-CSF). Ten patients with histologically proven malignancy were enrolled. Eight had breast cancer, one non-Hodgkin's lymphoma, and one a mediastinal tumor of unknown origin. The regimen included cyclophosphamide (C) 5 g/m2, etoposide (E) 1.5 g/m2, and cisplatin (P) 150 mg/m2 (CEP), administered in a 3-day schedule followed by rhG-CSF, 300 micrograms once a day, beginning from day +5 (36 h after the end of chemotherapy). The cycle was repeated as clinically needed up to three times. After the first course, hematologic recovery was rapid and complete without documented infections, and no relevant extramyeloid toxicities were observed. Eight of 10 patients received a second course with comparably low toxicity, and three of them received a third course. We concluded that CEP therapy can be administered safely and even repeatedly, by simple growth factor support, in good performance status cancer patients.
Abstract: The optimal use of mitoxantrone (NOV) in the high-dose range requires elucidation of its maximum tolerated dose with peripheral blood progenitor cell (PBPC) support and the time interval needed between drug administration and PBPC reinfusion in order to avoid graft toxicity. The aims of this study were: (1) to verify the feasibility and haematological toxicity of escalating NOV up to 90 mg m(-2) with PBPC support; and (2) to verify the safeness of a short (96 h) interval between NOV administration and PBPC reinfusion. Three cohorts of ten patients with breast cancer (BC) or non-Hodgkin's lymphoma (NHL) received escalating doses of NOV, 60, 75 and 90 mg m(-2) plus melphalan (L-PAM), 140-180 mg m(-2), with PBPC rescue 96 h after NOV. Haematological toxicity was evaluated daily (WHO criteria). NOV plasma pharmacokinetics was also evaluated, as well as NOV cytotoxicity against PBPCs. Haematological recovery was rapid and complete at each NOV dose level without statistically significant differences, and there were no major toxicities. NOV plasma concentrations at the time of PBPC reinfusion were below the toxicity threshold against haemopoietic progenitors. It is concluded that, when adequately supported with PBPCs, NOV can be escalated up to 90 mg m(-2) with acceptable haematological toxicity. PBPCs can be safely reinfused as early as 96 h after NOV administration.
Abstract: A case of chronic myelomonocytic leukemia with a reciprocal translocation (12;13)(p13;q14) and other numerical and structural abnormalities is described. Most of the metaphases examined showed duplication of the der(13)t(12;13), leading to trisomy of the translocated segment of chromosome 12. Using fluorescence in situ hybridization we observed that the breakpoint on chromosome 13 is centromeric to the retinoblastoma gene. Since other cases with apparently similar t(12;13) have recently been reported, we conclude that this structural rearrangement may be a rare but non random event in hematologic disorders.
Abstract: BACKGROUND: Elderly patients with acute myeloid leukemia (AML) those refractory to induction chemotherapy and those with so-called secondary leukemia have unfavorable prognoses and require innovative therapeutic approaches. Fludarabine allows an increased accumulation of Ara-CTP in leukemic cells and inhibits DNA repair mechanisms; therefore its association with Ara-C and mitoxantrone results in a synergistic effect. MATERIALS AND METHODS: From May 1993 to February 1996, fludarabine-containing regimens (FLAG and FLANG) were employed as induction therapy in 51 high-risk AML patients. Diagnosis of AML in 22 patients was preceded by a myelodysplastic syndrome lasting more than six months; 8 of the 29 de novo AML cases (28%) were refractory to previous chemotherapy, 9 (31%) were treated for early relapse, 12 (41%) presented poor prognostic factors at diagnosis. The median age was 64 (range 33-76) years and the FAB subtypes were the following: M0 3, M1 5, M2 28, M4 7, M5 8. Forty-eight per cent of patients showed poor prognosis chromosomal abnormalities. FLAG (24 patients) consisted of both fludarabine 30 mg/sqm over 30 minutes followed 4 hours later by Ara-C 2 g/sqm over 4 hours (for 5 days) and G-CSF 300 micrograms/day administered 12 hours before fludarabine, for a total of 5 doses. FLANG (27 patients) had a shorter duration (3 days), reduced Ara-C dosage (1 g/sqm) and administration of mitoxantrone (10 mg/sqm) at the end of Ara-C infusion. RESULTS: Recovery of both neutrophils (PMN > 0.5 x 10(9)/L) and platelets (Plt > 20 x 10(9)/L) required a median of 16 days from the end of therapy. Overall, 30 patients (59%) achieved CR, 6 (11%) PR and 10 (20%) were refractory; 5 (10%) experienced early death (cerebral hemorrhage or infection). The length of complete response ranged from 2 to 26 months with a median follow-up of 8 months. De novo and secondary AML registered 62 and 54% CR rates, respectively. Eight out of 10 patients refractory to conventional schemes achieved CR (80%) but only 3 out of 10 treated for relapse obtained CR (30%). CONCLUSIONS: FLAG and FLANG showed similar activity and toxicity while proving to be highly effective and relatively well-tolerated treatments for high-risk de novo AML. Secondary leukemias seemed to be responsive as well, but the presence of an unfavorable karyotype alteration lowered the response rate.
Abstract: A chronic myelogenous leukemia (CML) patient with a masked Ph chromosome due to the translocation (9;10;22)(q34;q24;q11) is reported. Banding analysis showed a 9q+ chromosome typical of standard t(9;22)(q34;q11), and fluorescence in situ hybridization studies confirmed the involvement of a chromosome 10 in the masked Ph formation and also the presence of 3' ABL-DNA sequences in the der(22). This complex rearrangement could be explained by two consecutive translocations: the first, a standard t(9;22) (q34;q11), the second, a translocation between a chromosome 10 and the der(22) with a breakpoint in sequences derived from chromosome 9 telomeric to the ABL gene. By reverse transcription polymerase chain reaction (RT-PCR), we studied the BCR/ABL transcript junction: a chimeric m-RNA b3-a2, indicating a breakpoint within the major breakpoint cluster region, was found.
Abstract: Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome (MDS) subtype, characterized by monocytosis, dysgranulocytosis and a low number of blast cells in the peripheral blood (PB). The clonal nature of MDS has been demonstrated by various techniques: the stem cell involved initially is capable of myeloid and lymphoid differentiation. Fluorescent in situ hybridization (FISH) is a technique which can be utilized without any pretreatment on whole interphase cells. In this study leukocytes of PB Wright-stained smears from four CMML patients with trisomy 8 (three cases) and 9 (one case) have been analyzed by FISH. Utilizing a probe for the centromere of chromosome 8 and for the heterochromatic region of chromosome 9, we observed the cells involved by trisomy. In each of the four cases neutrophils, eosinophils, basophils and monocytes may show trisomy 8 or 9, whereas lymphocytes resulted disomic. The comparison between leukocytes morphology and genotype suggests that the supernumerary chromosome does not influence cellular differentiation and maturation. We conclude that FISH analysis of PB leukocytes of patients with CMML is informative when studying the clonality of the disease. Chromosomal abnormalities seem to involve a hematopoietic cell committed to myeloid but not lymphoid differentiation. Trisomies 8 and 9 seem to confer some proliferative advantage without influencing the morphologic characteristics of leukocytes. Other causes will be investigated to explain dysmorphisms of neutrophils and monocytes typical of this disease.
Abstract: PURPOSE: High-dose chemotherapy produces high complete remission (CR) rates and some survival advantage in patients with metastatic breast cancer (BC). A current issue is the possibility that these patients may have an even better prognosis with multiple high-dose treatments. In this study, we evaluated the feasibility of a four-step, high-dose sequential chemotherapy (HDSC) with double autologous hematopoietic progenitor-cell rescue. We also tested the hypothesis that peripheral-blood progenitor cells (PBPCs) harvested following a single recruitment with cyclophosphamide (CY) and granulocyte-macrophage colony-stimulating factor (GM-CSF) allow the safe administration of the whole HDSC with closely timed repeated courses of several non-cross-resistant agents. PATIENTS AND METHODS: The treatment plan included CY 7 g/m2, followed by GM-CSF 5 to 7 micrograms/kg/d administered by continuous intravenous (i.v.) infusion on days 2 to 14; PBPCs with or without bone marrow (BM) harvest; mitoxantrone (NOV) 60, 75, or 90 mg/m2 plus melphalan (L-PAM) 140 to 180 mg/m2 with hematopoietic rescue; methotrexate (MTX) 8 g/m2 plus vincristine (VCR) 1.4 mg/m2; and etoposide (VP-16) 1.5 g/m2 plus carboplatin (PP) 1.5 g/m2 with hematopoietic rescue. RESULTS: All 15 patients enrolled completed the entire treatment and there were no toxic deaths. Hematologic reconstitution was good at each step. The median number of days with an absolute neutrophil count (ANC) less than 100/microL and platelet count less than 20,000/microL were 8 and 3, respectively, after NOV plus L-PAM, and 7 and 4, respectively, after VP-16 plus PP. The main non-hematologic toxicity was mucositis, while organ toxicity was mild and reversible. CONCLUSION: This regimen is feasible, with acceptable toxicity. GM-CSF and PBPCs have a pivotal role, as they hasten hematologic reconstitution, abate toxicity, and allow rapid recycling.
Abstract: We examined bone marrow (BM) cells from 6 Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML) patients in advanced phase of the disease using conventional cytogenetic techniques and fluorescence in situ hybridization (FISH) for detection of an extra chromosome 8. All patients showed mosaicism for trisomy 8 as a secondary chromosome abnormality. For FISH, we used the D8Z5 probe specific for the centromeric region of chromosome 8 and analyzed 300 interphase nuclei and a variable number of mitoses for each patient. The percentages of metaphases carrying trisomy 8 were similar with both techniques, whereas the percentage of interphase nuclei showing three hybridization spots indicative of trisomy 8 was significantly lower than that in metaphases. This finding suggests that cells with a supernumerary chromosome 8 may have a cell cycle time shorter than that of disomic cells.
Abstract: This work contains a cytogenetic analysis of 507 consecutive CML patients examined at diagnosis before any therapeutic treatment. Philadelphia chromosome translocations different from the standard t(9;22)(q34;q11) were observed in 28 patients (5.5%). Structural chromosomal abnormalities apparently unrelated to the Ph were found in six patients carrying variant Ph (6 of 28 = 21.4%) and in three patients carrying standard Ph translocations (3 of 472 = 0.6%). This finding confirms that structural abnormalities other than Ph are a rare event at diagnosis but that they occur with significantly different frequencies between the variant and standard Ph translocations, indicating that causes favoring the variant Ph formation may promote additional non-lethal DNA breakpoints.
Abstract: Recombinant human erythropoietin (rhEPO) was administered subcutaneously to 13 anemic (Hb < 10 g/dl) patients with myelodysplasia (MDS). rhEPO was given 3 times a week at doses of 75-250 U/kg body weight, over a maximum period of 24 weeks. Five patients (38%) showed a response to rhEPO treatment. rhEPO was well tolerated and without relevant side effects throughout the study. All responding patients had low but detectable pretreatment circulating erythroid progenitor cells (BFU-E) and the response to rhEPO was associated with a significant increase in BFU-E (p < 0.01); concentrations of serum transferrin receptor (TfR) also consistently rose in all responding patients. Baseline erythropoietin (EPO) concentrations did not significantly differ between responders and nonresponders, although 4 out of the 5 responders had relatively low levels of EPO. In conclusion, subcutaneous rhEPO administration appears to be an effective treatment of anemia in a substantial subset of patients with MDS. Relatively low baseline EPO concentrations, detectable pretreatment circulating BFU-E and an early increase in the serum concentrations of TfR seem to be criteria for predicting response to rhEPO in patients with MDS.
Abstract: We report the results of our in vitro experiments on the effects of an L-Arg terminal synthetic hypoxanthine derivative (ST 789) on human neutrophil function. To verify the hypothesis that the reported immunomodulatory effects of ST 789 in vivo are accounted for, at least in part, by effects on phagocytic cells, we experimented in parallel also with methisoprinol, a well known stimulator of neutrophil chemotaxis, structurally related to ST 789. Our results demonstrate that ST 789 is able to improve the true chemotactic response of human neutrophils without interfering with other phagocytic functions, following a pattern largely shared by methisoprinol. Accordingly, ST 789 may be able, when used in vivo, to prime neutrophils for timely and efficient migration to inflammatory sites, and it could be considered for therapeutic use in patients with impaired inflammatory response or severe infections.
Abstract: BACKGROUND. Several methods for the recruitment of circulating progenitor cells (CPC) to be used for hemopoietic rescue after myeloablative therapy have been described. The present study was designed to verify the effectiveness and safeness of one of such procedures, involving the administration of high-dose cyclophosphamide (HD-CTX) and granulocyte-macrophage colony-stimulating factor (GM-CSF). METHODS. Eight tumor patients were treated with HD-CTX (7 g/m2), followed by GM-CSF (7 mcg/Kg/day, continuous infusion) from day +2 to the completion of leukocyte recovery, when aphereses for CPC harvesting were performed. CPC were evaluated by clonogenic assay for granulocyte-macrophage colony-forming units (CFU-GM), megakaryocyte colony-forming units (CFU-Meg) and erythrocyte burst-forming units (BFU-E) before therapy as well as during the hemopoietic recovery. RESULTS. In each patient, a significant increase of trilineage CPC was observed, at a mean of 14 days from HD-CTX, with peak increment of 224, 268 and 230-fold for CFU-GM, CFU-Meg and BFU-E respectively. The mean duration of leukocyte count < or = 0.5 x 10(9)/l was 6.6 days, with severe thrombocytopenia (grade 4 WHO) lasting 2.8 days in 5 patients. GM-CSF infusion was well tolerated without any need for dose reduction or discontinuation. CONCLUSION. The administration of HD-CTX and GM-CSF induces a significant enhancement of CPC including CFU-Meg other than CFU-GM and BFU-E. The procedure is suitable for the recruitment of CPC in patients with CTX sensitive tumors.
Abstract: Peripheral blood neutrophil polymorphonuclear leukocytes (PMN) from healthy donors were found to inhibit the cytolytic efficiency of interleukin 2 (IL-2)-activated lymphocytes (LAK cells) in a dose-dependent manner. The inhibitory activity of PMN was not merely due to PMN acting as cold alternative targets, PMN ingestion of the label released by target cells or cell overcrowding in test wells. Heat-treated (50 degrees C, 30 min) lysates from PMN maintained their ability to inhibit LAK cell cytotoxicity, whereas PMN supernatants were completely ineffective. Oxidant scavengers (catalase, superoxide, dismutase) did not affect the PMN-mediated inhibition of LAK cell function. The results suggest that PMN contain heat-stable factor(s) able to suppress LAK cytotoxicity and potentially capable of limiting the therapeutic efficacy of IL-2 and/or LAK cells.
Abstract: The lysis of tumor cells, and other nucleated mammalian cells, by neutrophilic polymorphonuclear leukocytes (PMNs) triggered by phorbol myristate acetate (PMA) represents a widely used model system to dissect the PMN cytolytic armamentarium, potentially responsible for the cell damage at tissue sites of PMN activation. Although oxidants are generally considered to be instrumental in the target lysis by PMNs, the mediators actually involved remain a matter of controversy. Moreover, other factors potentially crucial to the lysis have not been clearly identified. In order to reexamine the determinants of the cytolytic process, we studied the events underlying the PMA-triggered PMN-delivered attack against two different targets, selected on the basis of preliminary experiments (B lymphoblastoid Daudi cells and erythroleukemic K 562 cells). The results suggest that the lysis is promoted by hypochlorous acid (HOCl) or a compound with characteristics very similar to HOCl itself. No evidence was obtained for the intervention or contribution of hydrogen peroxide (H2O2), hydroxyl (OH.) radicals, and the major HOCl-derived chloramines. PMNs appeared to use 35% of the generated H2O2 to produce HOCl, while the remainder appears to be consumed by PMNs themselves and target cells as well. Moreover, PMNs and target cells coaggregated at an early step of the cytolytic reaction, through a process efficiently prevented by a monoclonal antibody (MoAb J-90) directed against leukocyte function-associated antigen-1 (LFA-1). The inhibition of the PMN-target aggregation by the MoAb J-90 resulted in the impairment of the lysis, despite a normal generation of HOCl. Thus, the data demonstrate that the PMA-triggered lysis of tumor target cells by PMNs requires at least two events, occurring simultaneously: the LFA-1-mediated effector-target adherence and the PMN production of HOCl. The intervention of the LFA-1-mediated PMN-target adherence in the PMA-triggered lysis is likely to allow PMNs to focus HOCl on the target cell surface and suggests that the process requires a sort of molecule to molecule recognition at the effector-target surface level.
Abstract: The aim of the present study was to investigate the effects of 5-aminosalicyclic acid (5-ASA) on the cell injury mediated by activated neutrophils. We used a system constituted of neutrophils, triggered with phorbol myristate acetate, and 51Cr-labelled Daudi cells as targets. The results show that 5-ASA is capable of efficiently preventing neutrophil-mediated lysis. 5-ASA was up to 10-fold more effective than taurine, which acts as an hypochlorous acid scavenger. Moreover, 5-ASA was found to compete with taurine for the neutrophil derived hypochlorous acid. The results are consistent with the conclusion that 5-ASA is capable of limiting the neutrophil mediated cell damage by scavenging the generated hypochlorous acid. This may represent a potential mechanism for the therapeutic action of 5-ASA in ulcerative colitis.
Abstract: The anti-inflammatory drug nimesulide was found to effectively reduce the availability of hypochlorous acid, the most potent chlorinated oxidant generated by the myeloperoxidase system of activated neutrophils. Such an effect was observed at concentrations achievable in vivo after the oral administration of the drug. Higher concentrations of nimesulide were also found to limit both the oxygen consumption and the superoxide anion/hydrogen peroxide production by neutrophils. Taken together, the results suggest that nimesulide is endowed with a high potential to efficiently control the harmful effects of oxidants produced by neutrophils at inflammatory tissue sites.
Abstract: The Daudi cell lysis by human neutrophils, incubated with phorbol myristate acetate (PMA), was inhibited by amino acids (taurine, methionine), consistent with the involvement of hypoclorous acid (HOCl) in the lytic process. Also, the lysis was inhibited by a monoclonal antibody (mAb J-90) directed against the leukocyte function-associated antigen-1 (LFA-1). The inhibition of the target cell lysis by mAb J-90 is not due to a HOCl-scavenging mechanism, as suggested by the use of control mAb Dako M-1 (anti CD-15). As detected by the microscopic examination of samples from test tubes and measured by monitoring the light transmission from the cell suspensions, neutrophils and Daudi cells were found to co-aggregate during the lytic reaction. Co-aggregation was efficiently inhibited by the mAb J-90. The results suggest that tumour cell lysis by PMA-triggered human neutrophils involves at least two events: production of HOCl and LFA-1-mediated effector-target adhesion.
Abstract: Neutrophilic polymorphonuclear leukocytes (PMNs), triggered by opsonized zymosan (OPZ), lysed chicken red blood cells as measured by a chromium 51 release method. The lysis was prevented by scavengers of hypochlorous acid. When platelets were added to the cytolytic system, a dose-dependent inhibition of the lysis was observed. Moreover, platelets lowered the HOCl recovery from OPZ-triggered PMNs. A positive linear relationship was found between the extent of the lysis mediated by and the amount of HOCl recovered from PMNs. Finally, both the inhibition of the lysis and the reduction of the HOCl recovery induced by platelets were prevented by pulsing platelets with carmustine (BCNU) to block their glutathione cycle. These results suggest that platelets act by consuming via their glutathione cycle significant amounts of PMN-derived hydrogen peroxide, with a consequent impairment of the PMN HOCl production and, in turn, lytic efficiency. Consistent with such a conclusion, platelets were found to consume PMN-derived H2O2 via a BCNU-inhibitable process. Further, the platelet inhibitory activity could be abolished by the addition of an appropriate extra-flux of enzymatically generated H2O2. No evidence for a platelet-induced inhibition of OPZ-PMN interaction, PMN myeloperoxidase release, and H2O2 production was obtained. The present study provides direct evidence for a platelet-dependent mechanism capable of controlling the PMN production of highly reactive oxidants and, in turn, the PMN cytolytic activity.
Abstract: Neutrophil antibody-dependent cellular cytotoxicity (ADCC) against Raji target cells was studied in 32 patients with lung or gastro-intestinal carcinoma and 25 healthy controls. Seventeen of the patients (53%) had defective ADCC. Moreover, neutrophils obtained from patients with defective ADCC were found to bind IgG-coated target cells normally. Thus, the defect responsible for the impaired lysis appears to be distal to the Fc receptor (FcR)-mediated target cell binding by neutrophils.
Abstract: Platelets (PLTs) were found to inhibit the chemiluminescence (CL) response of neutrophils (neutrophilic polymorphonuclear leukocytes, PMNs) activated with phorbol myristate acetate. The inhibition of the PMN CL response could be efficiently prevented by pulsing PLTs with carmustine (BCNU) to block their glutathione cycle. In ancillary experiments, the CL response of PMNs was inhibited by catalase (H2O2-scavenger), -azide (myeloperoxidase-MPO-inhibitor), taurine (hypochlorous acid-HOCl-scavenger) and chloride ion omission. These data suggest that the PMN CL response requires the HOCl production by the following pathway: H2O2 + Cl--MPO----H+ HOCl + H2O. Therefore, the BCNU-preventable PLT-induced inhibition of CL may reflect the consumption of PMN-derived H2O2 by the PLT glutathione cycle with a consequent impairment of the HOCl production. Consistent with such a possibility, PLTs lowered the H2O2 and HOCl recovery from PMNs via a BCNU-inhibitable process. Based on these results, we suggest that PLTs have the capacity of limiting the oxidant production by PMNs. This PLT capacity may represent a natural device for the protection of vascular structures from PMN-mediated oxidative stresses.
Abstract: Human peripheral blood monocytes (M), incubated with opsonized zymosan particles (OPZ), lysed human erythrocyte (RBC) targets, as detected by a 51Cr release method. Conversely, cells derived in vitro from M (monocyte-derived macrophages, MDM) were ineffective. When added to the M-RBC system, MDM enhanced the lysis. The lysis by M and M plus MDM was prevented by catalase, azide and amino acids (alanine, taurine), consistent with the requirement for hypochlorous acid (HOCl). Moreover, MDM per se incapable of generating HOCl augmented the HOCl recovery from the M-RBC system. The results provide evidence for a previously unrecognized form of interaction between two distinct populations of mononuclear phagocytes.
Abstract: Human neutrophils, incubated with phorbol myristate acetate (PMA), caused a rapid and substantial adenosine triphosphate (ATP) depletion in lymphoblastoid Daudi cells without producing lysis. Catalase (which destroys hydrogen peroxide), taurine and methionine (which scavenge hypochlorous acid), and chloride omission from the medium prevented the ATP fall. An ATP depletion comparable to that induced by neutrophils was observed by replacing neutrophils with an appropriate myeloperoxidase-H2O2-Cl- enzymatic system. Together, these data suggest that the neutrophil ATP depleting activity involves the myeloperoxidase-catalyzed transformation of H2O2 into HOCl. Moreover, the free H2O2 remaining in the neutrophil extracellular environment is ineffective. In fact, a comparable amount of enzymatically generated H2O2 did not cause Daudi cell ATP loss. A direct role for H2O2 in the neutrophil-induced Daudi cell ATP depletion was observed only under artificial conditions, that is, in the presence of the heme enzyme inhibitor azide, which prevented the HOCl production but dramatically augmented the extracellular H2O2 level. Similar levels of ATP depletion in Daudi cells were induced by amounts of reagent HOCl comparable to those generated by neutrophils. As the generated HOCl can rapidly react with a variety of neutrophil-derived nitrogenous compounds (primarily ammonia and taurine) to yield chloramines, these chlorinated oxidants might contribute to the neutrophil-mediated ATP depletion. Nevertheless, the main and well-characterized chloramines (ammonia-derived monochloramine, NH2Cl, and taurine monochloramine, TauNHCl) were devoid of ATP-depleting capacity. Thus, the results suggest that the neutrophil-induced ATP depletion in Daudi cells is HOCl-dependent, is not mediated by NH2Cl or TauNHCl, and could be promoted either by HOCl directly or by an unknown derivative oxidant.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: When added to the hypochlorous acid (HOCl)-dependent cytolytic system constituted of opsonized zymosan (OPZ)-triggered neutrophils and chicken erythrocyte (CRBC) targets, human erythrocytes (HRBCs) inhibited the lysis. The replacement of HRBCs with cells pretreated with amino-triazole (AT) to inactivate catalase prevented the HRBC inhibitory effect almost completely. HRBCs, pretreated with carmustine (BCNU) to inhibit glutathione cycle activity, behaved as untreated cells. Thus, HRBCs appear to protect CRBCs via an AT-inhibitable, i.e. catalase-dependent, process. When measured under conditions similar to those used for the lytic assay, both the hydrogen peroxide (H2O2) and the HOCl recovery from the neutrophil-CRBC system was reduced by HRBCs and restored by pulsing HRBCs with AT but not BCNU. The results suggest that HRBC catalase rescues CRBCs from neutrophil-delivered attack by "stealing" H2O2 from the neutrophil HOCl-generating myeloperoxidase (MPO)-H2O2 system.
Abstract: The requirement for serine esterase activity in antibody-dependent cellular cytotoxicity (ADCC) in human neutrophils against Raji target cells has been investigated. The lysis was prevented when the serine esterase inhibitors TPCK and TLCK (chloromethyl-ketone derivatives of tosylamino acids) were introduced into the system. Moreover, neutrophils pretreated with TPCK or TLCK and washed were inhibited as well, via a process unaffected by the presence of adequate amounts of enzymatic substrates. This suggests that the inhibition mediated by TPCK and TLCK is independent of serine esterase blockade, therefore implying the inactivation of some other step crucial to the lysis. The addition of synthetic chymotrypsin substrates (tyrosine and phenylalanine esters) impaired the Raji cell lysis in a dose-related manner without altering the constitution of neutrophil-target conjugates. Trypsin ester substrates were ineffective. These results are in agreement with the involvement of a serine esterase activity with chymotrypsin-like specificity, which should participate in the lysis at a post-binding step. We conclude that neutrophil-mediated ADCC, as developed in our model system, needs the intervention of a serine esterase or esterases, like other systems of cell-mediated cytotoxicity.
Abstract: Neutrophilic polymorphonuclear leukocytes (PMNs) were incubated with opsonized zymosan and lysed human erythrocytes (RBCs) as measured by a 51Cr release method. Conversely, myeloperoxidase (MPO)-negative hydrogen peroxide (H2O2)-generating cells, derived in vitro from human monocytes (monocyte-derived cells (MDCs), were ineffective per se but capable of augmenting the lysis by PMNs. The lysis by PMNs and PMNs plus MDCs was inhibited by catalase, azide, taurine, and alanine, consistent with the requirement for hypochlorous acid (HOCl). As detected under conditions similar to those used for lytic assays, MDCs failed to produce HOCl but augmented the HOCl recovery from the PMN-RBC system. Moreover, when the extent of the lysis was plotted as a function of the HOCl recovery, a positive linear relationship was found. Although the actual size of the H2O2 extracellular pool could not be measured because of the inexistence of a reliable assay to probe our cytolytic model without perturbing the equilibrium of the system, the results presented suggest that MDCs enhance the PMN-mediated lysis by improving the HOCl production, presumably by supplying extra amounts of H2O2 to be handled by PMN MPO. In fact, the events mediated by MDCs could be reproduced by using an appropriate H2O2-generating enzymatic system (glucose-glucose oxidase). The present study provides direct evidence for the possibility of cooperation between MPO-positive and MPO-negative phagocytes in exerting functions (HOCl production and, in turn, cytolysis) possibly relevant to the outcome of inflammatory processes.
Abstract: Neutrophil-mediated antibody-dependent cellular cytotoxicity (ADCC) against Raji target cells and neutrophil degranulation during the ADCC process were evaluated in the presence and in the absence of different agents able to interfere with the neutrophil release of granule components (anion channel blockers, colchicine, isoproterenol, dimethylxanthine, cAMP). When used at concentrations incapable of preventing the target cell recognition by neutrophils, the majority of these agents inhibited both the ADCC and the release of myeloperoxidase (MPO, primary granule marker) and lysozyme (LZM, primary and secondary granule marker). The inhibition of the ADCC correlated strictly with the inhibition of the MPO release. Thus, the results are consistent with the hypothesis that neutrophil primary granules play a major role in the cytolytic process.
Abstract: The erythrocyte (RBC) lysis by human monocytes incubated with opsonized zymosan particles (OPZ), was inhibited by catalase, chloride-free medium, azide and hypochlorous acid (HOCl) scavengers (taurine, alanine). These findings suggest the requirement for the HOCl-generating myeloperoxidase-hydrogen peroxide-chloride system (MPO-H2O2-Cl- system). The HOCl-dependent lysis was increased by inhibiting RBC catalase with aminotriazole (AT). Conversely, the inhibition of RBC glutathione cycle with 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) had no detectable effect. Moreover, the recovery of H2O2 and HOCl from OPZ-triggered monocytes was reduced by the presence of RBCs through a process almost completely preventable by pulsing RBCs with AT but not with BCNU. Thus, it appears that RBC targets protect themselves by consuming, primarily via catalase, significant amounts of monocyte-derived H2O2 with a consequent impairment of the HOCl generation. The results suggest a potential role of target cells in modulating the cytolysin production by monocytes.
Abstract: Neutrophils, triggered by heat-aggregated human IgG (Agg.IgG), were found to lyse chicken red blood cells (CRBC) as determined by a 51Cr release method. The lysis was inhibited by azide, catalase, chloride-free medium and amino acids, suggesting the requirement for myeloperoxidase (MPO), hydrogen peroxide (H2O2), chloride ions (Cl-), and hypochlorous acid (HOC1), respectively. These results indicate that neutrophils lyse CRBC through an HOCl-(ie, MPO-H2O2-Cl-) dependent process. Although HOCl can react with neutrophil-derived nitrogenous (N-) compounds to yield chloramines, the main and well-characterized chloramines did not play a direct role in the lysis of CRBC in our model system. Thus, it appears that lysis is due either to HOCl or to an unknown compound derived from and with characteristics similar to HOCl. When CRBC were replaced with HRBC targets, no lysis could be observed. Treatment of HRBC with carmustine, to inhibit the glutathione cycle, did not affect the cell resistance to lysis by neutrophils. Conversely, the inhibition of HRBC catalase activity with aminotriazole (AT) made the cells susceptible to neutrophil-mediated HOCl-dependent lysis: this suggests that HRBC escape lysis by neutrophils through an AT-inhibitable, ie catalase-dependent, process. Through an identical catalase-dependent process, HRBC were capable of efficiently preventing the H2O2 and HOCl recovery from Agg.IgG-triggered neutrophils, tested under experimental conditions similar to those used for cytolytic assays. Together, these data suggest that HRBC targets, endowed with high catalase activity, escape neutrophil-mediated lysis by consuming (by catalase) neutrophil-derived H2O2, so that HOCl cannot be produced in amounts sufficient to promote lysis. Parallel experiments, performed with AT-treated CRBC, showed that these cells, endowed with a relatively low catalase content, only partially limit neutrophil cytolytic efficiency by a process qualitatively similar to that observed with HRBC targets. The results provide evidence that target cells can restrain neutrophil cytolytic efficiency by interfering with the MPO-H2O2-Cl system through their catalase activity.
Abstract: Mature polymorphonuclear leukocytes (PMN) are capable of mediating phorbol myristate acetate (PMA)- and antibody (A)-dependent cellular cytotoxicity (DCC) against ox red blood cells (ORBC) by using oxidative means. The purpose of the present study was to investigate the acquirement of these cytotoxic functions during PMN ontogeny, using the promyelocytic HL-60 cell line as a model for PMN differentiation. HL-60 cells were induced to differentiate along the PMN pathway by exposure to dimethyl sulfoxide (DMSO). Uninduced HL-60 cells were found to be completely devoid of PMA-DCC and ADCC activity. DMSO-induced cells progressively acquired the capacity to kill ORBC and to undergo the activation of oxidative metabolic burst when triggered by PMA. Despite approximately 40% of them also were capable of binding IgG-sensitized ORBC, no ADCC activity and respiratory burst activation was observed: this finding indicates that maturing HL-60 cells require a more complete maturation than that induced by DMSO to actually exert ADCC. Together the results suggest that: a. the acquirement of both PMA-DCC and ADCC potential is a post-promyelocytic event; b. the cytotoxicity activating stimuli, PMA and IgG-coated targets, follow different post-receptor transductional pathways to trigger the effector cell lytic systems: only the PMA receptor-linked pathway develops during DMSO-driven differentiation of HL-60 cells.
Abstract: The lysis of human red blood cells (HRBC) by neutrophil polymorphonuclear leukocytes (PMN), triggered with opsonized zymosan (OPZ) particles, was inhibited by azide, catalase, Cl- -free medium and amino acids indicating the involvement of myeloperoxidase (MPO), hydrogen peroxide (H2O2), Cl- ions and hypochlorous acid (HOCl) respectively. Thus, the cytolytic process depends on the following reaction: (Formula: see text). Because the oxidizing agent HOCl is also the precursor of the chloramines, a group of oxidants formed by the reaction between HOCl and PMN-derived ammonia (NH4+) or amines (R-NH2), the observed HRBC lysis can be theoretically due to HOCl and/or chloramines. Nevertheless, we found that PMN-mediated cytotoxicity occurs as an unidirectional process, being HRBC targets lysed and PMN unaffected. This finding indicates that the cytotoxin must be relatively more efficient against HRBC as compared with PMN. In fact, reagent HOCl (used at concentrations comparable to those generated by PMN) but not chloramines displayed such a type of property. Taken together, the data suggest that HRBC are killed by PMN-derived HOCl without the requirement for chloramines: this implies that NH4+ and R-NH2, released by PMN, act as down-modulators of the cytotoxic process, serving as HOCl trapping agents.
Abstract: The hypochlorous acid (HOCL)-dependent lysis of human red blood cells (HRBC) targets by neutrophils, activated with opsonized zymosan particles (OPZ), was increased by inhibiting HRBC catalatic activity with aminotriazole (AT; HRBCAT). The inhibition of HRBC glutathione cycle activity with carmustine (BCNU; HRBCBCNU) had no effect. In addition, the recovery of hydrogen peroxide (H2O2) and HOCL from neutrophils, activated under conditions similar to those used for cytotoxicity assay, was reduced by the presence of HRBC and restored by replacing HRBC with HRBCAT, but not with HRBCBCNU. Linear relationships were found between the increments in the neutrophil-mediated lysis, observed by using HRBCAT instead of HRBC, and the increments in the H2O2 or HOCL recovery, detected by replacing HRBC with HRBCAT. Together these data, coupled with the results obtained by probing neutrophil cytolysis with chemical agents, suggest that the increased cytolytic efficiency displayed by neutrophils against HRBCAT, inhibited in their catalatic activity, is due to an enhanced availability of neutrophil-derived H2O2, with a consequent enhancement in the HOCL production (according to the following reaction: (formula; see text). Thus it appears that HRBC catalase restrains the neutrophil cytolytic activity, by interfering with an early step of the pathway through which neutrophils generate cytotoxins.
Abstract: This study investigated the influence of a chemotactic stimulus on the extracellular cytotoxicity mediated by phagocytosing polymorphonuclear neutrophilic leukocytes (PMN). We used N-formyl-methionyl-leucyl-phenylalanine (FMLP) as chemotactic peptide, opsonized zymosan as phagocytosable particle, and ox red blood cells (ORBC) as extracellular bystander targets. Phagocytosing PMN were found to kill ORBC efficiently, as determined by the 51Cr-release assay. FMLP, at the concentration of 100 nM, significantly enhanced the target cell lysis. PMN from two patients with chronic granulomatous disease and normal PMN plus catalase or free radical scavengers (mannitol, benzoate, histidine) were completely devoid of cytolytic activity both in the presence and in the absence of FMLP. The results indicate that the target cell lysis by phagocytosing PMN as well as the chemotactic peptide-related amplification of the lysis itself depend on the expression of the PMN oxidative cytotoxic potential. A similar response to a chemotactic stimulus in vivo could provide a mechanism for regulating PMN-dependent cytotoxic and inflammatory processes.
Abstract: Neutrophil-derived nucleus-and granule-free cytoplasts, consisting of cytosol enclosed by an intact plasma membrane, were able to destroy 51Cr-labelled ox red blood cells (ORBC) in the presence of phorbol myristate acetate (PMA). The slope of the target cell lysis vs the log of the cytoplast number was similar to that observed with neutrophils as effector cells. Nevertheless, a number of cytoplasts 60-80 times higher than that of neutrophils was required to obtain a common level of cytotoxicity. The ability of cytoplasts and neutrophils to lyse ORBC was completely abolished by catalase and unaffected by superoxide dismutase and mannitol, suggesting the involvement of hydrogen peroxide in the target cell damage. Addition of myeloperoxidase (MPO) to cytoplasts increased lysis. The MPO lysis by cytoplasts, except when experiments were carried out in the presence of MPO. The results indicate that neutrophil cytosol and plasma membrane represent the basic requirement for the PMA-dependent cytolytic process, whereas MPO behaves as a device to amplify lysis.
Abstract: Human neutrophils, activated by phorbol-myristate acetate (PMA), (A-neutrophils), were found to suppress lymphocytic killer (K) cell-mediated antibody-dependent cellular cytotoxicity (ADCC). Resting (R) neutrophils, ie, PMA-untreated cells, were completely ineffective. Suppression was optimal when A-neutrophils were added at the beginning of the ADCC assay. Furthermore, A-neutrophils were found to cause an approximately 80% reduction in the number of Raji target cell-bound lymphocytes. These data indicate that A-neutrophils inhibit K cell activity by interfering with the target cell recognition. A-neutrophils were capable of reducing the percentage of Fc receptor (FcR)-bearing lymphocytes with a half-time of 7.2 minutes, through a process preventable by the serine-protease inhibitors tosyl-lysine-chloromethyl ketone (TLCK) and lima bean trypsin inhibitor (LBTI). Conversely, A-neutrophils caused a very slow decrease in the amount of Raji cell-bound antibodies, as detected by the complement-mediated lytic assay. Thus, only lymphocyte FcR structures seem to be highly susceptible to neutrophil-derived TLCK- and LBTI-inhibitable proteases. Furthermore, supernatants from A-neutrophils were found to inhibit K cell ADCC and lymphocyte binding to Raji target cells. In addition, LBTI prevented the A-neutrophil-dependent and the supernatant-dependent inhibition of both K cell ADCC activity and lymphocyte-target cell conjugate formation. Together these data suggest that A-neutrophils suppress K cell function through a protease-mediated impairment of the FcR binding capacity. The results provide evidence that human neutrophils are endowed with mechanisms to regulate K cell ADCC activity.
Abstract: Levamisole, used in vitro at therapeutic concentrations, was found able to restore the defective Fc-receptor activity of cancer patient neutrophils. In addition, the drug prevented the inhibition of normal neutrophils Fc-receptor function by cancer patient sera. The neutrophil Fc-receptor function was also restored in six of seven cancer patients after in vivo administration of levamisole (2.5 mg/Kg/day for 3 days). Due to the central role played by the Fc-receptor function in host defence mechanisms, including phagocytosis as well as antibody dependent cellular cytotoxicity, the capacity of levamisole to restore defective neutrophil Fc-receptor function in cancer patients could contribute to the "immunomodulating" effect of the drug.
Abstract: Human red blood cells (HRBC) were efficiently lysed when incubated with neutrophil polymorphonuclears (PMN) in the presence of phorbol-myristate-acetate (PMA), as detected by a 4-hr 51Cr release assay. The lysis was virtually absent in the presence of catalase, azide or cyanide and in the absence of chloride ions. These findings indicate the involvement of the myeloperoxidase (MPO)-hydrogen peroxide (H2O2)-chloride (Cl-) system in the cytolytic process. As the MPO-H2O2-Cl- system is capable of generating the powerful oxidant hypochlorous acid (HOCl), cytotoxicity assays were performed in the presence of taurine, glycine, serine and valine to scavenge this potentially lytic agent. Each of these compounds efficiently inhibited the HRBC lysis by PMA-triggered PMN, as well as the lysis caused by HOCl in a cell-free system. Thus, the results suggest that HOCl, or an agent with similar reactivity, plays a key role in the PMA-dependent PMN-mediated cytotoxicity against HRBC targets.
Abstract: The impairment of different neutrophil functions has recently been reported in some patients with glycogenosis Ib and neutropenia. However, no satisfactory explanation for these findings has so far been supplied. In order to investigate this problem, we have studied neutrophil functions (random locomotion and chemotaxis, O-2 release, [1-14C]glucose oxidation and cellular cytotoxicity) in two further patients with glycogenosis Ib and neutropenia. The results show that neutrophil dysfunctions related to the involvement of both hexose monophosphate shunt and anaerobic glycolysis were variable. The heterogeneity of neutrophil functional impairment in glycogenosis Ib and their possible relationship with the basic metabolic defect of the disease are discussed.
Abstract: The in vivo migration of neutrophils was evaluated in patients affected by epithelial carcinoma using the quantitative skin-chamber technique. The results demonstrated a significant impairment of the patients' neutrophil migration, which was reduced to approximately 4% of that of the controls. Patients' sera were able to inhibit the chemotactic responsiveness of normal neutrophils in vitro. It is therefore suggested that the defective in vivo migration of neutrophils in cancer patients is related to the presence of humoral cell-directed inhibitory activity. This defect of neutrophil function might contribute to the host-defense impairment of carcinoma patients.
Abstract: The chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP), per se incapable of triggering cytotoxicity, was found to significantly enhance phorbol myristate acetate (PMA)-dependent monocyte-mediated cytolysis of human red blood cell (HRBC) targets. Target cell lysis by PMA triggered monocytes was related to the release of superoxide anion and hydrogen peroxide, since cells from patients with chronic granulomatous disease and cells from normal donors, in the presence of superoxide dismutase or catalase, failed to exert significant cytotoxicity. An increased release of these mediators was found to be responsible for the FMLP-dependent amplification of the cytolytic reaction. The results indicate that chemotactic factors are able to enhance the release of cytotoxic mediators by monocytes and raise the possibility that cellular processes during monocyte chemotaxis could modulate the subsequent cytolytic activity.
Abstract: The purpose of the present study was to investigate the general conditions under which neutrophil polymorphonuclears (PMN) mediate antibody-independent cytolysis in the presence of normal human serum (NHS). Normal PMN were found to kill rabbit red blood cells (RRBC) only when cultured with 1% NHS. NHS was per se incapable of lysing RRBC. PMN from a patient with Chronic Granulomatous Disease did not destroy RRBC targets even in the presence of 1% NHS. In addition, cytotoxicity by normal PMN was significantly reduced by scavengers of oxygen metabolites. The results suggest that the target cell lysis by PMN in the presence of NHS requires a synergistic interaction between at least two mediators: serum factor(s) and oxygen metabolite(s).
Abstract: Normal human neutrophils, incubated with 0.2 mg/ml opsonized zymosan particles, were found to lyse human (H), ox (O) and chicken (C) red blood cell (RBC) targets as determined by the 51Cr release assay. The susceptibility to the lysis of the different target cells was HRBC less than ORBC less than CRBC. An intact neutrophil metabolic burst was essential for the cytotoxic event, since neutrophils from a patient with chronic granulomatous disease failed to kill all three target cells. HRBC and ORBC destruction was prevented by catalase and unaffected by azide, suggesting the requirement of hydrogen peroxide alone in the lethal hit. CRBC destruction was abolished by catalase and azide, suggesting the involvement of the myeloperoxidase-hydrogen peroxide system. Thus, different neutrophil cytolytic systems may become operative and may vary in their efficiency depending on the type of target cells.
Abstract: Leukaemic blast cells from 20 patients with acute leukaemia were examined for their capacity to mediate cytotoxicity against ox red blood cells in the presence of phorbol myristate acetate (PMA), a system widely employed as an in vitro model of tissue damage by metabolically activated mature phagocytes. Blasts from certain patients with myelomonocytic and monocytic leukaemia behaved like efficient killer cells. Conversely, leukaemic myeloblasts and promyelocytes as well as leukaemic lymphoblasts were ineffective. Blast cells capable of inducing the target cell lysis were also capable of mounting an oxidative respiratory burst upon challenge with PMA, as detected by the superoxide anion release. N-ethyl-maleimide, superoxide dismutase and catalase completely inhibited the cytotoxicity by monocytoid blast cells, suggesting the involvement of oxygen reactive products in the lethal hit itself. The cytolytic potential of blasts committed to monocytic differentiation might be an additional factor contributing to the tissue damage in a subpopulation of leukaemic patients.
Abstract: Antibody-dependent cellular cytotoxicity (ADCC) against Raji cells was used as a model system to investigate the polymorphonuclear leukocyte (PMN) mechanisms involved in tumor cell lysis. PMN killed target cells by nonoxidative means, as indicated by the following observations: PMN from patients with chronic granulomatous disease (CGD), defective in their metabolic burst, lysed Raji cells normally; impairment of the oxidative metabolism of normal PMN by phenylbutazone did not affect ADCC. Rosenthal's inhibitor of phospholipase A2 completely prevented the lysis, suggesting the involvement of this enzyme in the target cell damage. The inhibition of the Raji cell glutathione redox cycle by carmustine [1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU)] increased cell susceptibility to PMN-mediated ADCC. This increment of lysis was related to oxidative killing systems. In fact, CGD PMN had an ADCC against BCNU-treated Raji cells lower than that mediated by normal PMN, but comparable to that observed with untreated targets, and phenylbutazone reduced the lysis of BCNU-treated Raji cells by normal PMN to the level observed with the use of untreated targets. The remaining ADCC against BCNU-treated Raji cells mediated by CGD PMN and by normal PMN in the presence of phenylbutazone was suppressed by Rosenthal's inhibitor. Thus PMN killed sensitized BCNU-treated Raji cells by use of both oxidative and nonoxidative means. The results indicate that the interaction of sensitized Raji cells with PMN triggers simultaneously oxidative and non-oxidative potentially lytic systems and the mediator(s) of Raji cell lysis actually operating may depend on the metabolic state of the target cells themselves. Therefore, the lysis of sensitized tumor cells might not reflect the simple effect of PMN tumoricidal systems; rather it should be regarded as a result of an inability of the target cells to escape the various PMN cytolytic mechanisms.
Abstract: Human neutrophils, incubated in the presence of zymosan-activated serum ( ZAS ), were able to damage ox red blood cells ( ORBC ) as assessed by a 4-hr 51Cr-release assay. Cells from a patient with chronic granulomatous disease were incapable of mediating ZAS -induced cytolysis. Cytotoxicity by normal neutrophils was prevented by N-ethyl-maleimide as well as by catalase, but heat-inactivated catalase and superoxide dismutase were completely ineffective. Heme enzyme inhibitors, azide and cyanide, only partially reduced the target cell lysis. The results indicate the involvement of products of the oxidative metabolism, mainly hydrogen peroxide, as cytolytic mediators. These mediators released by neutrophils may contribute to the tissue injury occurring during inflammation.
Abstract: Human neutrophils, triggered by Concanavalin A, were cytotoxic against chicken red blood cell targets as determined by the 51Cr release method. The cytolysis increased with the effector: target ratio, reaching optimal levels when 2-4 neutrophils were available for each chicken red blood cell. The target cell lysis required an optimal release of highly reactive oxygen by-products by neutrophils, since neutrophils from a patient with chronic granulomatous disease failed to exhibit any cytolytic activity. Superoxide dismutase, catalase and inhibitors of heme-containing peroxidases (azide and cyanide) significantly inhibited the neutrophil-mediated cytotoxicity. Together these results indicate that superoxide anion and the myeloperoxidase-hydrogen peroxide system are simultaneously involved in the target cell injury by Concanavalin A-triggered neutrophils.
Abstract: Normal human neutrophils were found to destroy ox red blood-cell targets when incubated on micropore filters coated with aggregated IgG, as determined by the 51Cr release method. An intact neutrophil oxidative metabolism was essential for the cytotoxic event, since cells from patients with chronic granulomatous disease failed to exert any cytolysis. The target-cell destruction was prevented by catalase, azide, and cyanide and was enhanced by superoxide dismutase, suggesting involvement of the myeloperoxidase-hydrogen peroxide system. Neutrophil-mediated cytotoxicity was markedly amplified by the chemotactic peptide N-formyl-methionyl-leucylphenylalanine, as a result of an increased activity of the myeloperoxidase-hydrogen peroxide cytolytic system itself. This system of cytotoxicity provides a direct evidence for the neutrophil capacity of destroying bystander target cells under conditions simulating the in vivo immunologically mediated tissue injury and offers an excellent model to study events occurring during immune complex diseases.
Abstract: Neutrophils activated by phytohemagglutinin (PHA) were cytotoxic to chicken red blood cells (CRBC), as determined by the 51Cr release assay. High levels of cytotoxicity were obtained when one CRBC was available for each effector cell. Neutrophils from patients with Chronic Granulomatous Disease (CGD), incapable of generating potentially toxic oxygen radicals, had a reduced cytotoxicity activity, suggesting the requirement for an intact oxidative metabolism in the PHA-induced neutrophil-mediated cytotoxicity. However, CGD neutrophils maintained approximately 50% of this activity, compared with normal cells. These findings support the conclusion that both oxygen-dependent and oxygen-independent mechanisms are necessary to achieve an efficient cytotoxicity.
Abstract: Human neutrophils were cytotoxic to IgG coated ox erythrocytes as determined by a 51Cr release assay. Target cell phagocytosis was found to take place during the cytotoxic reaction, suggesting that cytolysis occurs as a post-phagocytic event. Studies, performed with neutrophils from patients with chronic granulomatous disease, demonstrated that these cells had an impaired cytotoxic activity, despite their ability to normally ingest target cells. Thus the cytotoxicity of human neutrophils against sensitized ox erythrocytes depends mainly on oxidative mechanisms. Oxygen radical scavengers failed to prevent the target cell lysis, possibly because of their inability to gain access into the killing sites. However, when cytotoxicity was carried out in presence of latex particles, pre-incubated with oxygen radical scavengers, a significant inhibition of target cell lysis by superoxide dismutase and cytochrome c was obtained. As well, in these experimental conditions, catalase had no effect. Furthermore, cytotoxicity was unaffected by hemeprotein inhibitors, cyanide and azide. Together, these results indicate that superoxide anion plays a key role in the neutrophil-mediated cytotoxicity against ox erythrocytes, whereas hydrogen peroxide alone or in combination with myeloperoxidase is unoperative under the experimental conditions employed.
Abstract: A monoclonal antibody (PBM 6.4) to platelet and megakaryocyte glycoproteins IIb and IIIa has been obtained and used to purify human megakaryocytes from sternal bone marrow aspirates by a simple method, consisting of a Percoll gradient centrifugation followed by affinity adherence on PBM 6.4-coated plastic surface, "panning." Megakaryocytes, 80-90% pure and morphologically well preserved, were attached to poly-L-ornithine-coated multi-well microscope slides and immunofluorescence was done using monoclonal antibodies to human Ia-like antigens (DR, DC1). A higher proportion of DR-positive megakaryocytes was found, in comparison to the values reported by others, while DC1 antigen was detected on about 20% of megakaryocytes. The method described has the unique feature of enriching cells of the human megakaryocytic lineage from simple diagnostic sternal aspirates in an amount adequate for immunofluorescent and morphological analysis.
Abstract: Human neutrophils activated by phorbol myristate acetate were cytotoxic to ox erythrocytes, as determined by the 51Cr release method. Maximal cytolysis was obtained with a phorbol myristate acetate concentration of 5 ng/ml and with an effector to target cell ratio of 1:4. An intact neutrophil metabolic burst and production of oxygen-derived-free radicals were essential for the cytotoxic event, since neutrophils from patients with chronic granulomatous disease failed to exhibit any ox erythrocyte lysis. The target cell destruction was completely prevented by catalase, was unaffected by superoxide dismutase, and was reduced approximately to one-third by azide and cyanide. These data suggest that, under our experimental conditions, the ox erythrocyte killing by phorbol myristate acetate-activated neutrophils mainly depends on myeloperoxidase and hydrogen peroxide.
Abstract: Phorbol myristate acetate (PMA)-activated neutrophils were found to destroy B lymphoblast tumour cells (Raji) as determined by the 51Cr release assay. The target cell lysis was prevented by azide, suggesting the involvement of the myeloperoxidase enzyme. Catalase and cytochrome c caused a marked impairment of the neutrophil-mediated cytolysis, whereas superoxide dismutase significantly enhanced the target cell destruction. These data indicate that hydrogen peroxide plays a key role in the target cell injury; superoxide anion appears to be devoid of direct cytotoxic activity, despite its requirement as a precursor of hydrogen peroxide. The target cell destruction required the presence of the iodide ion as oxidizable co-factor for the myeloperoxidase-hydrogen peroxide system. The chloride ion alone was uneffective. Inhibition of target cell metabolic pathways, involved in the cellular defences against oxidative injury, by the anti-neoplastic agent 1,3-bis-(2-chloroethyl)-1-nitrosurea (BCNU) resulted in an increased neutrophil-mediated cytolysis. Under the experimental conditions employed, PMA-activated neutrophils incubated with BCNU-treated Raji cells became cytotoxic also in the presence of the chloride ion alone as myeloperoxidase co-factor. Our results suggest that Raji target cell destruction by PMA-activated neutrophils depends on the myeloperoxidase-hydrogen peroxide-halide system. The cytolytic event is influenced by target cells themselves, which should be regarded as an active component of the cytotoxic system, capable of interfering with the lytic mediators of the effector cells.
Abstract: Ascorbic acid is able to stimulate neutrophil oxidative metabolism in normal neutrophils, as well as other several functions of these cells, either in the normal state or in the defective one. In the present study, we have investigated the effects of ascorbic acid on the hexose monophosphate shunt (HMPS) and on the bactericidal activity of neutrophils from Chronic Granulomatous Disease (CGD) patients. Furthermore, we have investigated the effects of ascorbic acid on the antibody dependent cell cytotoxicity (ADCC) of normal neutrophils. Ascorbic acid in vitro was able to significantly improve both HMPS activity and bacterial killing of CGD neutrophils. Its prolonged administration to such patients led to consistent clinical improvement, possibly related to the enhancement of chemotaxis, although the effects on HMPS and bacterial killing seen in vitro could not be confirmed. Ascorbic acid was also able to interfere with neutrophil ADCC with different results depending on its concentration and the experimental conditions.
Abstract: The purpose of the present study was to investigate the mechanisms by which neutrophil polymorphonuclears (PMN) mediate antibody-dependent cellular cytotoxicity (ADCC). Under experimental conditions which allow target cell phagocytosis, PMN were found to efficiently kill IgG-sensitized ox erythrocytes, as determined by the 51Cr release assay. Inhibition of the target cell ingestion by colchicine did not affect the PMN cytotoxic activity, suggesting that target cell phagocytosis does not represent an essential step in the PMN-mediated ADCC against erythrocytes. PMN from patients with Chronic Granulomatous Disease, who have defective oxidative metabolic burst, displayed an impaired ADCC activity, which was unaffected by changes in the phagocytic capacities induced by colchicine. The results indicate that, under the experimental conditions employed, both the intracellular and the extracellular target cell destruction by PMN involve oxygen-dependent mechanisms.
Abstract: The colony-forming capacity of normal peripheral blood mononuclear cells and of TG-depleted cell suspensions induced by PHA was investigated in the presence of different concentrations of levamisole. The results obtained demonstrate that: (1) the drug enhances significantly the number of colonies formed by both mononuclear cells and TG-depleted cells at concentrations ranging from 5 x 10(-6) to 5 x 10(-8 M; (2) this stimulatory activity results from a direct effect on T cells; and (3) adherent accessory cells are unaffected by the in vitro treatment with levamisole.
Abstract: Ten patients with neutrophil dysfunctions and recurrent pyogenic infections, mainly of the skin middle-ear, and respiratory tract, are described. The most frequently affected functions were chemotaxis and bacterial killing. Pharmacologic restoration of functional defects was tried in all cases. Levamisole was given in two cases and ascorbic acid in the other eight cases. During a follow up of at least 18 months, seven patients showed a complete restoration of neutrophil function and a long-lasting clinical remission. One of the two patients with Chronic Granulomatous Disease has been free from infections for 1 year, despite persistent neutrophil dysfunction, while the other did not display consistent clinical improvement. Another patient, who was given ascorbic acid for a short period only due to non compliance, showed neither laboratory nor clinical improvement.
Abstract: Immunopathological studies in a case of Sweet's syndrome revealed IgM- and IgE-bearing polymorphonuclear leucocytes in involved skin when the direct immunofluorescence technique was used. Circulating polymorphonuclear neutrophils showed defective chemotaxis with normal random migration, phagocytosis, killing, and hexose monophosphate shunt activity.
Abstract: The effects of the sulphydryl group donor N-(2-mercaptopropionyl) glycine on neutrophil locomotion were evaluated in vitro. The drug, when used at a concentration of 10(-3) M was found to stimulate the random migration and chemotaxis of normal neutrophils as a result of an enhanced rate of locomotion. The true chemotactic response was unaffected. N-(2-mercaptopropionyl) glycine appeared to exert its effect on the whole moving cell population.
Abstract: The effects of the sulfydryl donor drug N-(2-mercaptopropionyl)-glycine (MPG) on neutrophil chemotaxis, adhesiveness, phagocytosis, and hexose monophosphate shunt activity were investigated in vitro. The drug significantly enhanced all the neutrophil functions tested when used at appropriate concentrations. The results, which are in accord with the well known inhibition of neutrophil function by sulfydryl-blocking agents, suggest the possible therapeutic usefulness of the drug in clinical conditions with defective neutrophil function.
Abstract: Rosettes with ox erythrocytes coated with purified IgG antibody were used to detect Fc receptors on neutrophils from 60 patients with solid neoplasias and from 55 normal controls. The mean average of the rosettes in the patients was 48.10%, and that in normal controls was 79.42%, with a highly significant difference according to the Wilcoxon test [negative probability, P(w)-4.47 . 10(-5)]. The low proportion of patients' rosettes ws related to the presence of a serum factor, which also inhibited normal neutrophil rosette formation. Patient neutrophils (or normal neutrophils treated with patient sera) recovered their rosetting capacity when cultured in vitro. No correlation was found between low percentages of rosette-forming cells and the level of circulating immune complexes of the individual patients. Additional evidence also supported the finding that IC and the serum factor are probably unrelated.
Abstract: The effects of histamine and cimetidine on neutrophil locomotion were studied in vitro in experimental conditions able to dissociate random from truly directional motility. Histamine 10(-4) mol/l inhibited the true chemotactic response. Cimetidine was able to reverse the histamine-induced inhibition of true chemotaxis. Since histamine-induced inhibition of neutrophil chemotaxis may play a role in allergic patients with repeated infections, and since cimetidine has been shown to enhance cell-mediated immunity in vivo, often impaired in such cases, the use of cimetidine is suggested for the prevention of recurrences in these patients.
Abstract: The in vitro effects of the peptide N-formyl-L-methionyl-L-phenylalanine on granulocytes adhesiveness and chemotaxis were investigated. N-formyl-L-methionyl-L-phenylalanine, when used at concentration chemotactically effective, increased significantly granulocyte adhesiveness. When granulocyte adhesiveness was inhibited by colchicine, the inhibition could not be reversed by subsequent treatment with N-formyl-L-methionyl-L-phenylalanine. These results suggest that microtubular system is involved in the stimulation of granulocyte adhesiveness by N-formyl-L-methionyl-L-phenylalanine.
Abstract: Neutrophil function was studied in several patients with recurrent infections, mainly of the skin. Twelve patients showed impairment of neutrophil functions, either chemotaxis or bacterial killing and phagocytosis. Levamisole was given in four cases: improvement of neutrophil function and long-lasting clinical remission occurred in three of them, whilst in the fourth the drug was not tolerated. Ascorbic acid was administered to three other patients, with satisfactory improvement of neutrophil function and long-lasting clinical remission.
Abstract: 2 children with undue susceptibility to skin infections and isolated defective neutrophil bacterial killing are described. Since the NBT-reducing capabilities of granulocytes were normal, a mild form of chronic granulomatous disease was excluded. Ascorbic acid was effective in delaying and eventually suppressing infectious episodes.
Abstract: Experiments were performed to investigate the in vitro effects of inosiplex on the locomotion and oxidative metabolism of human neutrophils. The drug, when used at the concentration of 500 micrograms/ml, significantly increased neutrophil random migration and chemotaxis. Enhancement of chemotaxis was due to an increased rate of locomotion as well as toan increased true chemotactic response. Inosiplex appeared to exert its effect on the whole migrating cell population. No significant effect on the oxidative metabolism of both resting and phagocytizing neutrophils was found. The results suggest that the effect of inosiplex may be related chiefly to its effect on neutrophil locomotion.
Abstract: The effects of the three synthetic chemotactic N-formyl-L-methionyl peptides, namely f-met-phe, f-met-val and f-met-ala, on neutrophil chemotaxis, adhesiveness, oxidative metabolism, phagocytosis and killing were evaluated in vitro. The three peptides displayed different stimulating properties, with relative activity f-met-phe greater than f-met-val greater than f-met-alal for all functions tested. Experiments performed with chemotactically deactivated neutrophils showed that deactivation does not interfere with neutrophil functions other than chemotaxis and does not prevent further stimulation by the same chemo-attractant. The results demonstrate that the interaction of a single chemotactic agent with neutrophil membrane can trigger different cellular responses, dependent in their type and intensity on the concentrations of the chemotactic factor and on the functional state of the cell.
Abstract: Neutrophils pretreated with a chemotactic factor become deactivated, that is, unresponsive to a subsequent chemotactic stimulus. A decay of surface esterase activity, an increased adhesiveness, an auto-oxidative damage of the cell structures and microtubule hyperpolymerization have been previously proposed as the cause of the chemotactic deactivation. To further understand the cellular mechanisms involved in this process, we have studied the locomotory behaviour of deactivated neutrophils in an experimental system allowing differentiation among the various types of migratory cellular response to chemotactic factors. Thus, we have found that deactivated neutrophils retain a normal capacity of random locomotion, but entirely lose their true chemotactic responsiveness. Diamide, which disrupts assembled microtubules in concanavalin A-treated cells, was able to completely restore the true chemotactic response of deactivated cells. These observations suggest that neutrophil deactivation is a reversible cellular event dependent on the functional state of the microtubular system.
Abstract: The locomotion of human neutrophils deactivated by pretreatment with appropriate concentration of chemoattractant was investigated in experimental conditions capable of dissociating random from truly directional motility. It was shown that deactivated neutrophils lose true chemotactic responsiveness, being unaffected by the rate of locomotion. Ascorbic acid, when present in appropriate concentrations during the deactivation step, completely prevented the loss of true chemotactic responsiveness by cells--that is, their chemotactic deactivation.
Abstract: The effects of ascorbic acid on neutrophil locomotion were studied in experimental conditions able to dissociate random from truly directional motility. It was shown that the significant enhancement of chemotaxis achievable with high ascorbic acid concentrations was due to an increase of the true chemotactic response. With lower concentrations of ascorbic acid, chemotactic values were unaffected as the result of an increase in the rate of neutrophil locomotion with a concomitant inhibition of the true chemotactic response. Ascorbic acid appeared to exert its effect on the whole moving cell population.
Abstract: Chemotaxis, random migration, phagocytosis, spontaneous and stimulated NBT reduction were evaluated in neutrophils from the peripheral blood of 8 patients with acne conglobata and were found to be normal. Only 2 patients had an increased spontaneous NBT reduction, and another exhibited a defect in neutrophil adhesiveness. On this basis, intrinsic defects of the major neutrophil functions, as evaluated in vitro, can be excluded in acne conglobata.
Abstract: A-35-year-old woman with a long-lasting history of neutropenia and recurrent infections was found to have defective neutrophil chemotaxis, random motility, and in vivo migration. Although the bone marrow granulocyte reserve was normal, the patient failed to release an appropriate amount of granulocytes after injection of etiocholanolone. These features are characteristic of the so-called "Lazy leukocyte syndrome". The clinical presentation of the five cases of this syndrome so far reported and its pathophysiological aspects are discussed.
Abstract: Five normal subjects were subjected to leukapheresis by continuous-flow-centrifugation (CFC) in the Aminco Celltrifuge. Granulocyte functional capacities were evaluated on the venous blood samples drawn before apheresis and on the cell-rich plasma collected by CFC, immediately after collection and after short-term storage at 4 degrees C with or without previous irradiation (1500 rad, 50 rad/min). The CFC technique has been shown to provide cells without functional damage. Irradiation did not appear to influence granulocyte function, as evaluated by in vitro studies. The data demonstrate that granulocytes maintain, even after irradiation, functional activities similar to those found immediately after collection for up to 24 hours of storage at 4 degrees C and exhibit only a moderate loss of function after 48 h. Chemotaxis appears to be the most sensitive detector of cellular damage of stored granulocytes, either irradiated or non-irradiated; this technique may be the most useful for assessment of granulocyte function before transfusion.
Abstract: Granulocyte function was studied in 9 patients with untreated, Ph1-positive chronic myelocytic leukemia (CML). The nitroblue tetrazolium reduction by stimulated granulocytes was impaired in all patients; 4 patients also had diminished phagocytosis and 2 others defective chemotaxis. In spite of this variety of polymorphonuclear (PMN) functional impairments, there is little evidence of increased susceptibility to infections in CML patients. This suggests that CML-PMN leucocytes (PMNs) may be successfully used for transfusion into neutropenic recipients, as previously reported. To evaluate the effects of irradiation and liquid storage on CML-PMNs, 5 of our patients were subjected to leukapheresis by continuous-flow centrifugation in the Aminco Celltrifuge, and granulocyte functional capacities were also evaluated on the cell-rich plasma immediately after collection and after short-term storage at 4 degrees C with or without irradiation (1500 rads). As evaluated by in vitro studies, granulocytes maintained, even after irradiation, functional activities similar to those found immediately after collection up to 24 h of storage at 4 degrees C and presented a moderate loss of function after 48 h. Chemotaxis appeared to be the most sensitive detector for cellular damage of stored leucocytes, irradiated and non-irradiated, so that it might be used for assessment of leucocyte function before transfusion.
Abstract: An 11-year-old boy with a life-long history of atopic-like dermatitis and recurrent staphylococcal abscesses was found to have defective neutrophil chemotaxis, impaired-T-lymphocyte functions, hyperimmunoglobulinemia E, and delayed neutrophil bactericidal power. This latter defect has never been found in such patients. The patient's mother revealed a panhypogammaglobulinemia, while his sister and maternal grandmother who had repeated infections were immunologically normal.
Abstract: Host defence mechanisms against microbial invasion requires an adequate number and function of phagocytic cells. There is evidence that vitamin C, which has been claimed to play a role in several aspects of host defence mechanisms, is involved significantly at least in phagocytic function. Vitamin C has been shown to interfere with oxidative metabolism, bactericidal power and chemotaxis of neutrophil granulocytes. The authors present evidence that, in vitro, vitamin C stimulates the true chemotactic response of normal human granulocytes. In addition the results of clinical trials in patients with recurrent infections and primary deficiencies of neutrophil function are presented. In such patients vitamin C therapy induced the restoration of impaired functions. A significant clinical improvement was also seen in the majority of cases. Vitamin C represents the specific therapy for primary defects of phagocytic function in patients with recurrent infections.
Abstract: In a 26-year-old man with Crohn's disease, evaluation of the neutrophil polymorphonuclear (PMN) function showed marked impairment of chemotaxis, while NBT tests, phagocytosis, random migration and adhesiveness were all normal. PMN chemotaxis was found normal after levamisole therapy.
Abstract: An infant girl with chronic eczema, recurrent infections, elevated IgE and impaired neutrophil chemotaxis appeared to belong to the group of patients described by Buckley, Wray & Belmaker (1972). An hereditary influence is suggested by a similar defect found in the patient's mother. Levamisole improved the in vitro defect and the clinical picture.
Abstract: Identification of mouse bone marrow colony growth in soft agar cultures has been realized by layering of the plates with nitroblue tetrazolium at the concentrations of 1 mg/ml. Granulocyte-macrophage colonies appear dark-blue coloured on the yellow surrounding medium and can be fixed, stored at 4 degrees C and counted few days later. This method allows the cultures to be assessed macroscopically and makes a better enumeration of small clusters even if spread and consisting of only 30-40 cells.
Abstract: A case of ulcerative colitis with defective neutrophil chemotaxis, improved after short sulfasalazine therapy, is reported. This is the first case of this disease in which the chemotactic defect was characterized as a serum inhibitor, directed toward autologous and homologous neutrophils and associated with circulating IgA. Preincubation of normal neutrophils with increasing concentrations of patient's serum resulted in a dose-related inhibition, suggesting a stoichiometric relationship between humoral inhibitory power and neutrophils.
