Increased expression of surface IgM but not IgD or IgG on human B cells in response to IL-4.
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.
Shields
J G
JG
Department of Immunology, Institute of Child Health, London.
Armitage
R J
RJ
Jamieson
B N
BN
Beverley
P C
PC
Callard
R E
RE
D001402:B-Lymphocytes / Q000032:analysis / Q000276:immunology*; D002478:Cells, Cultured; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D015847:Interleukin-4; D007378:Interleukins / Q000276:immunology*; D008213:Lymphocyte Activation; D011947:Receptors, Antigen, B-Cell / Q000032:analysis*; D013755:Tetradecanoylphorbol Acetate
D007075:Immunoglobulin M; D007378:Interleukins; D011947:Receptors, Antigen, B-Cell; D015847:Interleukin-4; D013755:Tetradecanoylphorbol Acetate