Transforming Growth Factor-βModulates Murine Spleen B Cells to Secrete Antigen-specific lgA Antibody

Transforming Growth Factor-βModulates Murine Spleen B Cells to Secrete Antigen-specific lgA Antibody

It has been reported that transforming growth factor-β1 (TGF-β1) increases antigen (Ag)-nonspecific IgA secretion by LPS-stimulated slgA murine spleen B cells, and this effect is further augmented by costimulation with rlL-2. In contrast, IgM and IgG1 secretion are downregulated under the same conditions. The aim of this study was whether TGF-β1 could increase Ag-specific IgA synthesis by whole spleen cells. Mice were immunized with Ustilago maydis (UM) toxin and Ag-specific isotype antibody was measured by ELISA developed by us. TGF-β1 induced a 2-fold or greater increase in UM toxin-specific IgA secretion by LPS-activated whole spleen cells from the immune mouse. Unexpectedly, IgG1 production was also enhanced under the same conditions. In the case of immunization with BSA, TGF-β1 significantly increased BSA-specific IgA production, which was further augmented by IL-2. These results from the present study indicate that TGF-β1 can induce spleen whole cells to secrete Ag-specific IgA production, raising the possibility that TGF-β1 may have important effects on the expression of Ag-specific IgA in vivo.