摘要
目的:通过不同的间隔天数,连续多次给予小鼠腹腔注射超抗原葡萄球菌肠毒素A(SEA),观察注射后T细胞的表型变化,并找寻SEA在小鼠体内对T细胞无能的诱导规律。方法:将80只小鼠随机分为4组:间隔3d组、间隔28 d组、阳性对照组和阴性对照组,每组20只小鼠。每组于末次注射后的不同天数,用流式细胞术检测小鼠脾淋巴细胞上CD3、CD4、CD8、CD69、CD25的表达,并将细胞体外继续培养72 h,用单四唑(MTT)法测定细胞的增殖能力。结果:间隔3 d组和间隔28 d组中,连续3次注射SEA后,小鼠脾淋巴细胞中CD3的表达均显著下降(P<0.01),2组中CD8的表达水平基本相似;但间隔3 d组中,CD4的表达在末次注射后3 d内明显降低(P<0.05);末次注射后3 d内,CD25的表达明显高于末次注射后第7 d(P<0.05)。间隔28 d组中CD4的表达较稳定,无显著升降;CD25的表达水平较低。SEA连续3次注射后,间隔3 d组的细胞从第21 d开始出现较弱的增殖反应,至第28 d增殖反应明显提高。间隔28 d组的细胞在第28 d始出现较弱的应答反应。结论:小鼠体内反复注射超抗原SEA可诱导T细胞无能,注射间隔时间的长短可能与无能的触发无关,但影响了CD4亚群的克隆清除,即间隔时间越短,被清除的CD4 T细胞越多;间隔时间越长,CD4 T细胞清除的程度越小。尽管CD25与T细胞无能的诱导密切相关,但CD25可能不参与无能状态的维持。T细胞的免疫无反应性并不是绝对的和持久的,在一定条件下,它可再次对超抗原的刺激出现反应。
Objective ： To evaluate the effects of the superantigen staphylococcal enterotoxin A （SEA） on the anergy of T lymphocytes in vivo by observing the changes of the surface molecule expressions of T cells in mice after repeated injection of SEA at different intervals. Methods ： Eighty mice were equally randomized into 4 groups： 3-day interval, 28-day interval, positive control and negative control.The expressions of CD3, CD4, CD8, CD69 and CD25 in the spleen cells of the mice were detected by FACS at different times after the last SEA injection. The proliferation of the spleen lymphocytes was measured by MTT after cultured for 72 hours. Results ： The expressions of CD3 in the spleen cells of the mice were significantly decreased after three times of SEA injection （P 〈 0.01 ）, but the expressions of CD8 were basically similar in the 3-day and 28-day interval groups. The expression of CD4 was markedly reduced （P 〈 0.05） and that of CD25 remained high at 3 days after the last injection, while at 28 days the former showed no obvious changes and the latter stayed at a low level. A faint response to SEA injection in the proliferation of the anergic T cells was observed at 21 days in the 3-day interval group and at 28 days in the 28-day interval group. Conclusion ： Repeated injection of SEA can induce the anergy of T cells, and the length of injection interval is related with clonal deletion, shorter the interval, the more the CD4 T cells deleted. Although CD25 is closely associated with the induction of anergy, it might not be involved in the maintenance of the anergic state, which is reversible in vivo under certain conditions.
出处
《医学研究生学报》
CAS
2009年第9期904-907,共4页
Journal of Medical Postgraduates
基金
国家自然科学基金资助项目(批准号:30271464)
关键词
超抗原
T细胞
无能
Superantigen
T cell
Anergy
