金葡菌及其L型对小鼠胸腺细胞凋亡的影响

Effect of Staphylococcus aureus L-forms on apoptosis of murine thymocytes

目的:研究金黄色葡萄球菌(金葡菌)及其L型(金葡菌L型)对小鼠胸腺细胞凋亡的影响。方法:用金葡菌、金葡菌L型、肠毒素B(staphylococcal enterotoxin B,SEB)分别作用于小鼠胸腺细胞,同时设立正常对照,于作用后2 h、4 h、6 h、8 h、10 h终止培养。Ann in ix V和PI双染法流式细胞仪检测细胞凋亡。结果:SEB作用2 h、金葡菌作用4 h、金葡菌L型作用6 h后各时间段小鼠胸腺细胞的凋亡率与对照组比较均明显增高(P<0.01),随着诱导时间的延长,胸腺细胞的凋亡率逐渐增加(P<0.01);SEB诱导胸腺细胞凋亡率在6 h、8 h和10 h时均明显弱于原菌(P<0.01)。结论:金葡菌L型和原菌以及SEB均能促进胸腺细胞凋亡,除SEB外,产SEB金葡菌株及其L型诱导胸腺细胞凋亡还可能有其他因素参与。

Objective： To explore the effect of Staphylococcus aureus （S. aureus） L-forms on apoptosis of murine thymocytes. Methods： Murine thymocytes were co-cultured with S. aureus, S. aureus L-forms or staphylococcal enterotoxin B （SEB） in vitro for different times（2 hrs,4 hrs,6 hrs,8 hrs,or 10 hrs） before examination. The apoptotic rates of routine thymocytes were measured by flowcytometry technique and using Annexin V-FITC/PI double staining kit. Results：The apoptotic rates of thymocytes in group of SEB treated for 2 hrs,in group of S. aureus infected for 4 hrs, and in group of S. aureus L-forms infected for 6 hrs were obviously increased compared to that of the control （ all groups showed P 〈 0. 01 ）. The longer the time of incubation, the higher rates of thymocyte apoptosis. Conclusions：Both S. aureus L-forms and S. aureus can induce the apoptosis of murine thymocytes. Except for SEB, other factors might be involved in the apoptosis of thymocytes induced by S. aureus and S. aureus L-forms that producing SEB.