Increased expression of surface IgM but not IgD or IgG on human B cells in response to IL-4

• Published in: Immunology 1989-02, Vol.66 (2), p.224-227
• Main Authors: SHIELDS, J. G, ARMITAGE, R. J, JAMIESON, B. N, BEVERLEY, P. C. L, CALLARD, R. E
• Format: Article
• Language: English
• Subjects: B-Lymphocytes - analysis; B-Lymphocytes - immunology; Biological and medical sciences; Cells, Cultured; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immunobiology; Immunoglobulin M - analysis; Interleukin-4; Interleukins - immunology; Lymphocyte Activation; Modulation of the immune response (stimulation, suppression); Receptors, Antigen, B-Cell - analysis; Tetradecanoylphorbol Acetate
• ISSN: 0019-2805; 1365-2567

Surface IgM (sIgM) was increased up to 10 times on human tonsillar B cells activated with IL-4. No change was observed for surface IgD, IgG or IgE. Other activators of human B cells, such as TPA, EBV and anti-IgM resulted in increased expression of the low-affinity receptor for IgE (CD23), but had no effect on sIgM. IL-4 also increased sIgM expression on prolymphocytic leukaemic (PLL) B cells, whereas TPA significantly reduced the level of sIgM. The effect on sIgM thus seems specific for IL-4, and is consistent with the existence of a unique IL-4-dependent B-cell activation pathway. Preincubation with IL-4 did not 'prime' B cells to proliferate in response to subsequent exposure to anti-IgM, and slightly decreased the response to co-stimulation with IL-4 and anti-IgM. The increase in sIgM expression in response to IL-4, therefore, does not seem to be important for proliferation.