【摘要】 为研究抗CD4 McAb引起胸腺细胞减少的机理,本课题探讨了CD4 McAb诱导胸腺细胞发生凋亡(Apoptosis)的可能性。小鼠注射抗CD4 McAb后,皮质胸腺细胞体积缩小,染色质凝聚;PI染色后经流式细胞计测定,显示大量的亚二倍体细胞(凋亡细胞,Apoptotic cells),与正常小鼠相比P<0.001;片断化DNA的百分比也明显高于正常小鼠,P<0.01。片断化DNA在凝胶电泳上呈现典型的阶梯现象。细胞内钙离子浓度升高。放线菌酮对抗CD4McAb诱导的DNA片断化有一定的抑制作用。上述结果提示抗CD4 McAb促进胸腺细胞凋亡可能是胸腺细胞减少的原因之一。更多还原

【Abstract】 In previous experiments,we found that anti-CD4 McAb administration led to depletion of thymocytes in mice. Here ,we explored the possibility that anti-CD4 McAb could induce apoptosis of thymocytes. It has been shown that cortical thymocytes underwent apoptosis as characterized by morphologic changes with chromatin condensation and DNA fragmentation after anti-CD4 injection in mice. A flow cytometric method for measuring the percentatge of apop-totic nuclei(hypodiploid DNA) after PI staining,and colorimetric methods measure DNA fragmentation in the nuclear extracts, both of them were much higher in anti-CD4 group than thymocytes of normal mice. (P<0. 01 and P< 0. 001). Anti-CD4 induced apoptosis was inhibited by cycloheximide or IL-2. The ladder pattern of DNA fragments, characteristic of apoptosis ,appeared in anti-CD4 group. All results indicated that the anti-CD4 McAb could accelerate apoptosis of thymocytes,therefore the number of thymocytes was decreased.更多还原