Correspondence re R. Lapointe et al ., CD40-stimulated B Lymphocytes Pulsed with Tumor Antigens Are Effective Antigen-presenting Cells That Can Generate Specific T Cells. Cancer Res 2003;63:2836–43.

Publisher Website
Google Scholar
Abstract
Lapointe et al. (17) addressed this important question in this journal and demonstrated that CD40-B cells generate tumor antigen-specific CD4+ T cells in cancer patients when the B cells are pulsed with lysate from tumor cells (17) . The authors conclude that these findings emphasize the role of CD40-B cells as antigen-presenting cells for immunotherapy. Melanoma antigen-specific T cells were generated from the peripheral blood mononuclear cells of two melanoma patients. Because it is most likely that these melanoma antigen-specific T cells derived from melanoma patients were expanded from a preexisting population of memory T cells, it remains to be shown whether CD40-B cells also prime naïve CD4+ T cells against neoantigens as demonstrated for CD8+ T-cells (2) . This would also extend their potential use to neoantigens such as viral antigens or previously ignored potential tumor antigens. Most likely because of low antigen concentration in tumor lysates, Lapointe et al. reported a rather low efficacy of expansion of CD4+ T cells after stimulation with CD40-B cells, (17) , whereas antigen-specific CD8+ T cell expansion was successful in more than 80% of individuals tested (2 , 6) . Here, we have addressed the induction of naïve CD4+ T-cell responses and the efficacy of ex vivo CD4+ T-cell expansion by stimulation with CD40-B cells.