Figure 5

IgA production requires IL-10 and TGF-β1. (a) In the presence of LPS (1 μg/ml), NASC and MDSCs were cultured alone or in a co-culture for 16 h before the cytokines in the supernatants were determined with CBA (IL-10, IFN-γ, MCP-1, IL-6 and TNF) or with ELISA (TGF-β1). (b) Non-adherent spleen cells were co-cultured with MDSCs and LPS (1 μg/ml) alone or in the presence of anti-IL-10 (10 ng/ml), anti-TGF-β (100 ng/ml) or the TGFβRI inhibitor, SD208 (1 μM) for 72 h. The IgA and IgM antibody concentrations within the supernatants were detected with specific ELISA. (c, d) Non-adherent spleen cells were co-cultured for 16 h or 72 h with MDSCs and LPS (1 μg/ml) alone or in the presence of antibodies that specifically blocked TNFR2 (100 ng/ml), TNF (100 ng/ml) or TNFR1 (1 μg/ml). IL-10 and TGF-β1 at 16 h (c) as well as IgM and IgA antibodies at 72 h (d) were detected from the supernatants with ELISA or CBA (IL-10). For a and c, the mean values±s.e.m. of at least 5 wells per group are shown. This experiment was repeated at least 4 times. *P<0.05 and **P<0.01, as determined with Student’s t-test. Panels b and d summarize three independent experiments with triplicate determinations. *P<0.05 and **P<0.01, as determined with the Mann-Whitney test. CBA, cytometric bead array; ELISA, enzyme-linked immunosorbent assay; Ig, immunoglobulin; IFN, interferon; IL, interleukin; MCP, monocyte chemotactic protein; MDSCs, myeloid-derived suppressor cells; NASC, non-adherent splenocytes, TGFβRI, TGFβ receptor-1; TNF, tumor necrosis factor; TNFR, tumor necrosis factor receptor.