Table 1 Proliferation of CD40-activated B cells   Mean (%) SD p Control 197 +/− 52 – IL-10 301 +/− 106 < 0.01 TGF-β 222 +/− 95 Not significant VEGF 197 +/− 70 Not significant Means of the relative increase in cell number of 8 experiments. Migratory ability Migration of APCs to the secondary lymphoid organs is essential for the

induction of CD4+ and CD8+ T cell responses. For CD40-activated B cells of healthy donors and of cancer patients the migration capacity has been shown [28, 31]. We thus studied the influence of IL-10, TGF-β, and VEGF on the migratory ability of CD40-activated B cells towards the important lymph node homing cytokines SDF-1α and SLC in vitro. ACP-196 purchase We used the migration of vehicle treated

CD40-activated B cells as SB203580 molecular weight controls (relative migration =1). The T cell migration of CD40-activated B cells treated with IL-10, TGF-β, or VEGF in comparison to these controls are shown in Figure 3. CD40-activated B cells migrated equally well towards SDF-1α and SLC independent of whether they were treated with vehicle, IL-10, TGF-β, or VEGF. Figure 3 Migratory ability of CD40-activated B cells. 5 × 105 CD40-B cells were added to the upper chamber transwell plates. Varying amounts of the chemokines SDF-1α and SLC (R&D Systems) were added to the lower chamber. After 2 hours selleckchem the cells that had migrated into the lower chamber were counted with a hemacytometer. The migration index is calculated relative to vehicle-treated controls. Shown are the means of 4 independent experiments ± SD. T cell stimulation by CD40-activated B cells In order to assess the impact of tumor-derived immunosuppressive factors on the T cell-stimulatory capacity of CD40-activated B cells we compared the ability of CD40-activated B cells which were treated with IL-10, TGF-β, or VEGF to induce the proliferation of CFSE-labeled CD4+ or CD8+ T lymphocytes from

healthy HLA-mismatched donors. Figure 4 shows the result of the CFSE-proliferation assays comparing vehicle controls with CD40-activated B cells which were exposed to IL-10, TGF-β, or VEGF. We did not observe statistically significant differences in the proliferation of CD4+ or CD8+ T cells between the controls and CD40-activated B cells which Thiamine-diphosphate kinase were cultured in the presence of 40 ng/ml IL-10, 10 ng/ml TGF-β, or 20 ng/ml VEGF. Therefore, neither IL-10, TGF-β, nor VEGF was able to inhibit the capacity CD40-activated B cell to activate CD4+ or CD8+ T lymphocytes. Figure 4 T cell-stimulatory capacity of CD40-activated B cells. 1 x 104 treated and control CD40-activated B cells were incubated with 1 x 105 CFSE-labeled allogeneic T cells. After 5 days the proliferation of the allogeneic CD4+ and CD8+ T cells was assessed by flow cytometery. IL-10, TGF-β, or VEGF did not inhibit the proliferation of allogeneic CFSE-labeled CD4+ (n = 8) and CD8+ T cells (n = 5) in response to CD40-activated B cells.