Abstract: CD40-activated B cells (CD40-B cells) have previously been introduced as an alternative source of antigen-presenting cells for immunotherapy. CD40-B cells can prime naive and expand memory T cells, and they can be generated in large numbers from very small amounts of peripheral blood derived from healthy individuals or cancer patients alike. Administration of CD40-B cells as a cellular adjuvant would require these cells to migrate toward secondary lymphoid organs and attract T cells in situ, processes guided by specific chemokines and chemokine receptors. Here, we demonstrate that primary, human CD40-B cells express a pattern of adhesion molecules and chemokine receptors necessary for homing to secondary lymphoid organs and have the capacity to migrate to cognate ligands. Furthermore, we show that CD40-B cells express important T-cell attractants and induce strong T-cell chemotaxis. These findings further support the use of CD40-B cells as cellular adjuvant for cancer immunotherapy.

Abstract: PURPOSE: To investigate the clinical characteristics and treatment outcome of patients with lymphocyte-rich classical Hodgkin's lymphoma (LRCHL) compared with other histologic subtypes of Hodgkin's lymphoma (HL). PATIENTS AND METHODS: From a total of 2,715 patients with biopsy-proven HL treated within the trials HD7 to HD12 of the German Hodgkin's Study Group, 100 patients (4%) with LRCHL, 145 patients (5%) with lymphocyte-predominant HL (LPHL), 1,688 patients (62%) with nodular sclerosis, 731 patients (27%) with mixed cellularity, and 23 patients (1%) with lymphocyte depletion were identified. Patients with LRCHL had a median age of 38 years (range, 16 to 74 years). RESULTS: Compared with other histologic subtypes, patients with LRCHL are, on average, older and usually present with early stages of disease (stage I, 34%; stage II, 46%). The median time of follow-up was 32.2 months (95% CI, 28.2 to 37.0 months). Complete and partial remission was achieved in 96 patients (96%) and four patients (4%), respectively, with LRCHL. The event-free and overall survival rates were 97% (95% CI, 93% [corrected] to 100% [corrected]) and 97% (95% CI, 93% [corrected] to 100% [corrected]), respectively, at 30 months. Only three patients died; all of the deaths were caused by treatment-related toxicities. CONCLUSION: LRCHL is a distinct subtype of CHL, with features of CHL and LPHL, and is a rare entity accounting for only 4% of HLs. LRCHL has a different pattern of clinical presentation and age and sex distribution than other CHLs. It is associated with an excellent prognosis if treated with current treatment regimens. When treating patients with LRCHL, great attention should be paid to avoid acute toxicities.

Abstract: The major source of natural IgM Abs are B-1 cells, which differ from conventional B cells in their anatomic location, cell surface phenotype, restricted usage of particular V(H) genes and limited use of N-region addition during V-D-J rearrangement. The origin of B-1 cells is unclear. However, they are capable of self-renewal and their development is sensitive to signaling via the B cell receptor, as genetic defects that impair the strength of the signal often result in limited development. These findings suggest that B-1 cells require either an intrinsic signal, or contact with Ag, for positive selection and expansion and/or maintenance in the periphery. In support of interaction with cognate Ag, deficiency in the complement receptors CD21/CD35 results in a 30-40% decrease in the CD5(+) B-1 population. To determine whether this reduction reflects a loss of certain specificities or simply a proportional decline in the repertoire, we examined peritoneal B cells isolated from Cr2(+) and Cr2(def) mice for recognition of a B-1 cell Ag, i.e., phosphatidylcholine, and assayed for injury in an IgM natural Ab-dependent model of reperfusion injury. We found a similar frequency of phosphatidylcholine-specific CD5(+) B-1 cells in the two strains of mice. By contrast, the Cr2(def) mice have reduced injury in the IgM-dependent model of reperfusion injury. Reconstitution of the deficient mice with pooled IgM or adoptive transfer of Cr2(+) peritoneal B cells restored injury. These results suggest that complement receptors CD21/CD35 are important in maintenance of the B-1 cell repertoire to some, but not all, specificities.