CD14在脾脏生发中心凋亡淋巴细胞清除中的作用

Clearance of apoptotic lymphocytes during a splenic germinal center reaction:role of CD14

目的通过体内实验证实CD14在巨噬细胞吞噬凋亡小体过程中是否起决定性的作用。方法用T细胞依赖抗原2-苯基唑酮连接载运蛋白鸡血清白蛋白后分别免疫CD14-/-和CD14-/+的小鼠,免疫后第12、14、17天切除小鼠脾脏并作三色荧光免疫组织化学染色,分析CD14-/-小鼠巨噬细胞是否能清除生发中心反应过程中产生的凋亡小体。结果CD14-/-小鼠脾脏显示为正常的生发中心反应过程,没有看到凋亡小体的堆积,而且免疫组织化学染色显示凋亡小体被CD14-/-巨噬细胞所吞噬。结论实验结果说明CD14-/-巨噬细胞能够清除生发中心反应过程中产生的凋亡小体,CD14在巨噬细胞吞噬凋亡小体的过程中并非起着决定性的作用。

Objective The removal of apoptotic cells is affected by macrophages. Defective apoptotic cell clearance is associated with pathogenesis of tumor and autoimmune disease, Surface molecule CD14 has been suggested to be involved in the recognition and engulfment of apoptotic cells. The aim of this study is to determine whether CD14 is essential for in vivo phagocytosis of apoptotic cells. Methods Mice for CD14 deficient mice （CD14） and heterozygous mice （CD14） were immunized with T cell dependent antigen 2-phenyl-oxazolone coupled to chicken serum al- bumin （carrier protein）. At days 12, 14 and 17 after immunization, spleens were removed and analyzed by immunohis-tochemistry. Staining with fluorescent labeled reagents allows demonstrating whether CD14 macrophages can phagocyrose the apoptotic debris generated in the germinal center reaction. Results CD14 mice showed normal germinal centre development. There was no accumulation of cell debris. Furthermore, immunohistology showed that apoptotic cells were engulfed by CD14 macrophages. Conclusion The experiment demonstrated that CD14 macrophages are capable of clearing the apoptotic debris generated in the germinal center reaction. CD14 may not be essential for phagocytosis of cell debris by macrophages.