HI_(47)(CD_(20))单克隆抗体对B细胞活化增殖的影响

Effect of HI_(47) (CD_(20)) monoclonal antibody on human B Iymphocyte activation and proliferation

CD_(20)单克隆抗体(HI_(47))能够抑制SAC诱导B细胞~3H-TdR掺入。进一步研究发现HI_(47)也能抑制SAC诱导B细胞~3H-UdR掺入和母细胞化,但对PHA和Anti-Ig引起的B细胞活化和T、B及髓细胞系的增殖无影响。用相同免疫球蛋白亚类的无关抗体及HI_(47)F(ab′)_2片段试验表明HI_(47)的抑制活性是抗体的特异性作用,与Fc片段无关。通过观察HI_(47)抗原表达与B细胞活化的关系,结果提示HI_(47)对SAC活化途径的抑制作用可能与CD_(20)抗原表达有关。

We have previously reported that a CD_(20) monoclonal antibody (HI_(47)) had obvious inhibition to ~3H-TdR incorporation of tonsil B cells in SAC drived system. This paper describes that McAb HI_(47) also markedly inhibited ~3H-UdR uptake and enlargement of B lymphocytes induced by SAC. However, it had no effect on B cell activation in PMA and anti-immunoglobul in antibody drived systems and the proliferation of established T, B and myeloid cell lines. The non-specific inhibition of HI_(47) Fc fragment had been ruled out by the experiments with irrelative MoAbs, which Ig subclass was same as HI_(47) (IgG_3),and with HI_(47) F (ab')2 fragment. Exposure of tonsil B cell to either SAC or PMA resulted in an increase in expression of HI_(47) antigen. McAb HI_(47), neverthless, induced reduction of HI_(47) antigen expressed on B cells stimulated by SAC. but not by PMA. In conclusion, antigen HI_(47) (CD_(20)) only involved in the SAC-activation pathway. The modulation of HI47 antigen by McAb HI47 may be one of the mechanisms of the depressed SAC activation.