Frade R, Crevon M C, Barel M, Vazquez A, Krikorian L, Charriaut C, Galanaud P
Eur J Immunol. 1985 Jan;15(1):73-6. doi: 10.1002/eji.1830150114.
The C3d receptor is a specific marker of B lymphocytes. Recently we have shown that C3d receptor activity is carried by a gp 140 membrane antigen. A polyclonal antibody has been prepared by immunizing a rabbit with highly purified gp 140 molecule isolated from membranes of the human B lymphoblastoid cell line Raji and its high specificity was previously demonstrated. We tested the effect of this antibody to the C3d receptor on the B cell proliferative response. Purified B cells from human blood were induced to proliferate by a B cell growth factor (BCGF)-containing partially purified supernatant from activated T cells. The anti-C3d receptor F(ab')2 enhanced the BCGF-dependent B cell proliferation. This effect was dose dependent, was observed in the presence of different concentrations of BCGF and did not correspond to a change in the time course of the response. The anti-C3d receptor F(ab')2 had no mitogenic effect in the absence of T cell supernatant. In contrast the undigested anti-C3d receptor IgG suppressed the BCGF-dependent B cell proliferation. These results emphasize the potentialities of anti-gp 140 F(ab')2 to explore the involvement of the C3d receptor in the regulation of B cell response to T cell products.
C3d受体是B淋巴细胞的一种特异性标志物。最近我们发现，C3d受体活性由一种gp 140膜抗原介导。我们用从人B淋巴母细胞系Raji细胞膜中分离出的高度纯化的gp 140分子免疫兔子，制备了一种多克隆抗体，并且之前已证实其具有高度特异性。我们测试了这种针对C3d受体的抗体对B细胞增殖反应的影响。用含有B细胞生长因子（BCGF）的部分纯化的活化T细胞上清液诱导人血中纯化的B细胞增殖。抗C3d受体F(ab')2增强了依赖BCGF的B细胞增殖。这种效应呈剂量依赖性，在不同浓度的BCGF存在下均能观察到，且与反应的时间进程变化无关。在没有T细胞上清液的情况下，抗C3d受体F(ab')2没有促有丝分裂作用。相反，未消化的抗C3d受体IgG抑制了依赖BCGF的B细胞增殖。这些结果强调了抗gp 140 F(ab')2在探究C3d受体参与调节B细胞对T细胞产物反应方面的潜力。
