抗BST-1抗体刺激介导的髓系细胞酪氨酸磷酸化及FcyR表达的研究

Study of Tyrosine Phosphorylation and FcyR Expression of Myeloid Cells after Stimulation by Anti-BST-1 Antibody

目的 探讨髓系细胞表面BST 1(骨髓基质细胞抗原 1) /CD15 7分子能否作为一受体介导信号传导和调节细胞表面FcγR的表达。方法 制备兔抗人BST 1多克隆抗体及其F(ab’) 2 片段 ,以其刺激U937细胞后 ,用免疫沉淀及免疫印迹法研究胞内蛋白酪氨酸磷酸化水平的变化 ;用FACS法检测细胞表面FcγR的表达。结果 抗人BST 1抗体刺激U937细胞可介导胞内多种蛋白的酪氨酸磷酸化水平增高 ,包括Mr 为 12 0× 10 3 的c cbl原癌蛋白 ;并可下调细胞表面CD6 4的表达。抗BST 1抗体的这些作用呈抗体Fc段依赖性。结论 髓系细胞表面BST 1分子可作为一受体介导细胞信号传导 ;抗BST 1抗体刺激U937细胞可下调其表面CD6

Purpose To examine whether BST?1/CD157 expressed on myeloid cells can function as a receptor molecule to mediate signal into cells and regulate the expression of FcγR on cells. Methods The tyrosine phosphorylation of U937 cells stimulated by immunoprecipitation and immunoblotting method;FcγR expression level on U937 cells stimulated by anti BST antibody was analyzed by FACS. Results Stimulation of U937 cells by anti BST?1 polyclonal antibody resulted in protein tyrosine phosphorylation of U937 cells,including M r 120×10 3 c cbl onco protein,and the down regulation of CD64 expression on U937 cells.The activities of anti BST?1 antibody depended on its Fc portion. Conclusions BST?1 molecules expressed on myeloid cells can function as a receptor molecule to mediate signal into cells.Stimulation of U937 cells by anti BST?1 antibody down regulate the expression of CD64.