Inhibition of human interleukin 4-induced IgE synthesis by a subset of anti-CD23/Fc epsilon RII monoclonal antibodies.
Specific monoclonal antibodies (mAb) directed against the CD23 antigen were used to study human interleukin 4 (hIL4)-induced IgE production by blood and tonsillar mononuclear cells. Both peripheral blood and tonsillar mononuclear cells stimulated by hIL4 expressed membrane CD23 as detected by the binding of all anti-CD23 mAb. Nevertheless, two sets of anti-CD23 mAb could be distinguished. The first set, including mAb 25, was able to decrease significantly hIL4-induced IgE synthesis by mononuclear cells. The second set, including EBVCS#1, did not affect hIL4-induced IgE synthesis. All the anti-CD23 mAb were able to bind specifically to a human B cell line expressing recombinant CD23. Inhibition experiments revealed that the two sets of anti-CD23 mAb did not recognize the same epitope on the CD23 antigen. In fact, all the anti-CD23 mAb, except EBVCS#1, were able to inhibit IgE binding to CD23 on RPMI 8866 cells. Moreover, the first set of antibodies, which decreased IgE production, was able to up-regulate membrane CD23 expression on hIL4-stimulated tonsillar mononuclear cells. Conversely, EBVCS#1, which had no effect on IgE production, did not affect hIL4-induced CD23 expression. These results indicate that CD23 plays a key role in human IgE synthesis.
Bonnefoy
J Y
JY
Department of Cell Biology, Glaxo Institute for Molecular Biology, Geneva, Switzerland.
Shields
J
J
Mermod
J J
JJ
D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology* / Q000378:metabolism; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D000939:Epitopes; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000494:pharmacology*; D014066:Palatine Tonsil / Q000166:cytology; D011961:Receptors, Fc / Q000276:immunology* / Q000378:metabolism; D017455:Receptors, IgE
D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D000939:Epitopes; D011961:Receptors, Fc; D017455:Receptors, IgE; D015847:Interleukin-4; D007073:Immunoglobulin E