Bonnefoy J Y, Shields J, Mermod J J
Department of Cell Biology, Glaxo Institute for Molecular Biology, Geneva, Switzerland.
Eur J Immunol. 1990 Jan;20(1):139-44. doi: 10.1002/eji.1830200120.
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.
针对CD23抗原的特异性单克隆抗体（mAb）被用于研究人白细胞介素4（hIL4）诱导血液和扁桃体单个核细胞产生IgE的情况。通过所有抗CD23 mAb的结合检测发现，hIL4刺激的外周血和扁桃体单个核细胞均表达膜CD23。然而，可以区分出两组抗CD23 mAb。第一组包括mAb 25，能够显著降低hIL4诱导的单个核细胞IgE合成。第二组包括EBVCS#1，不影响hIL4诱导的IgE合成。所有抗CD23 mAb都能特异性结合表达重组CD23的人B细胞系。抑制实验表明，两组抗CD23 mAb识别的CD23抗原表位不同。事实上，除EBVCS#1外，所有抗CD23 mAb都能抑制IgE与RPMI 8866细胞上CD23的结合。此外，能降低IgE产生的第一组抗体能够上调hIL4刺激的扁桃体单个核细胞膜CD23的表达。相反，对IgE产生无影响的EBVCS#1不影响hIL4诱导的CD23表达。这些结果表明，CD23在人IgE合成中起关键作用。
