Tony H P, Schimpl A
Eur J Immunol. 1980 Sep;10(9):726-9. doi: 10.1002/eji.1830100914.
While soluble intact rabbit anti-mouse kappa chain antibodies (RaMK) fail to stimulate [3H] thymidine incorporation in B cells of young mice, the F(ab')2 fragments thereof are stimulatory. This stimulation can be abrogated by the addition of soluble intact RaMK, pointing at the dominance of a negative signal mediated by intact antibodies, probably via their Fc portion. Blocking the interaction between intact antibody, and the Fc receptor of B cells by staphylococcal protein A renders the intact antibodies also stimulatory. Protein A itself is not mitogenic in this system nor does its addition influence B cell activation induced by rabbit F (ab')2 anti-mouse kappa chain antibodies. The data indicate that the Ig receptor of murine B cells can serve as a triggering receptor provided the negative signal mediated by cross-linkage involving the B cells' Fc receptor is avoided.
虽然可溶性完整兔抗小鼠κ链抗体（RaMK）不能刺激幼鼠B细胞掺入[3H]胸腺嘧啶核苷，但其F(ab')2片段具有刺激作用。加入可溶性完整RaMK可消除这种刺激，这表明完整抗体介导的负信号占主导地位，可能是通过其Fc部分。用葡萄球菌蛋白A阻断完整抗体与B细胞Fc受体之间的相互作用，可使完整抗体也具有刺激作用。在该系统中，蛋白A本身无促有丝分裂作用，其添加也不影响兔F(ab')2抗小鼠κ链抗体诱导的B细胞活化。数据表明，只要避免由涉及B细胞Fc受体的交联介导的负信号，小鼠B细胞的Ig受体就可以作为触发受体。
