Open AccessIL‐4 and transforming growth factor‐β suppress human immunoglobulin secretion in vitro by surface IgD − B cells
Author(s) -
NINOMIYA C.,
SPIEGELBERG H. L.
Publication year - 1992
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1992.tb06942.x
Subject(s) - immunoglobulin d , immunoglobulin e , biology , immunoglobulin class switching , isotype , secretion , lymphokine , antibody , microbiology and biotechnology , peripheral blood mononuclear cell , interleukin 4 , immunology , b cell , cytokine , immunoglobulin g , transforming growth factor beta , in vitro , transforming growth factor , antigen , endocrinology , monoclonal antibody , biochemistry
SUMMARY The effect of IL‐4 and transforming growth factor‐β (TGF‐β) on immunogiobulin secretion in vitro by peripheral blood mononuclear cells (PBMC) or purified B cells activated with murine EL4 thymoma cells and phorbol myristate acetate (PMA) was investigated. As previously reported. IL‐4 induced IgE and IgG4 secretion by B cells in PBMC preparations and B cells activated with EL4 cells and PMA. However, when B cells, either in PBMC preparations or purified and activated with EL4 cells and PMA, spontaneously secreted large quantities of immunoglobulin, IL‐4 suppressed the immunoglobulin secretion of all isotypes. IL‐4 also suppressed the IgE secretion by B cells from an atopic dermatitis patient. This suppressive effect was not reversed by adding IL‐2 or interferongamma (IFN‐γ) to the cultures. We also showed that TGF‐β suppressed the immunoglobulin secretion by purified B cells activated by EL4 cells and PMA. To investigate whether IL‐4 or TGF‐β suppressed immunoglobulin secretion by in vivo ‘switched’ and isotype‐committed B cells, sIgD‐B cells were isolated, activated with EL4 cells and PMA and cultured with IL‐4 or TGF‐β. Such activated B cells secreted large quantities of IgG1, IgG2, IgG3, IgA1, IgA2 and IgM, and IL‐4 and TGF‐β suppressed all these isotypes by >80%. The data demonstrated that IL‐4 and TGF‐β suppress immunoglobulin secretion in vitro by in vivo isotype‐committed sIgD‐B cells, suggesting that these lymphokines may play a down‐regulatory role on differentiated isotype‐committed B cells in an isotype‐unrestricted manner. The data also showed that IL‐4 and TGF‐β acted directly on isolated B cells.