成年小鼠中自反应T细胞的清除机制

Investigation on the deletion mechanism of self-reactive T cells in adult mice

目的研究成年小鼠自反应Ｔ细胞的清除机制，阐明成年小鼠自身耐受的发生方法胸腺摘除成年小鼠静脉注射ＭＬｓ＋的活化Ｂ细胞．在注射后不同时间点，利用流式细胞技术观察淋巴结中ＣＤＶβ６＋ＣＤＶβ８＋、ＣＤＶβ６＋、和ＣＤＶβ８＋细胞百分比的变化，局部ＧＶＨＲ和抗活化Ｂ细胞混合淋巴细胞反应．结果在胸腺摘除的成年小鼠中静脉注射ＭＬｓ＋的活化Ｂ细胞可诱导ＭＬｓ特异性免疫耐受．来源于ＣＤＦ１小鼠的脾脏Ｂ淋巴细胞经抗ＩｇＭ抗体加ＩＬ—４刺激，静脉注射给摘除胸腺的成年ＢＡＬＢ／Ｃ小鼠（ＭＬ－Ｉｂ）后第７、１１、１５天，淋巴结中ＣＤＶβ６＋细胞显著减少，而ＣＤＶβ８＋细胞数无明显改变；在注射后第３无ＣＤＶβ６＋细胞增加，但对ＭＬＳ抗原的反应性明显低于对照组．结论自反应Ｔ细胞不但在胸腺被排除或功能性“排除”，而且在外周通过同样的机制维持自身耐受．

Objective To investigate the deletion mechanism of self-reactive T cells and self-tolerance mechanism in adult mice. Method MLs+ B blast were injected intravenously into thymectomized adult mice. Percentages of CD Vβ6+.CD Vβ8+. CDV β6+and CDVβ8+T cellsin lymph node were recorded by means of flow cytometry at different time points after intravenous injection. In vivo local GvHR and anti-B blast MLR were observed at different time points after intravenous injectic n.Results When B cells stimulated with anti-IgM antibody plus IL-4 (B blasts)from CDF1mice (MLS-lb/a) were injected into thyrnectomized adult BALB / cmice (MLS-lb), Vβ6+in the CDT cell subset, but not CD T cell subset, were significantly dcreased in the lymph nodes 7, 1 1,15,days. arter the injection. At 3 days Vβ6+ CD T cells were slightly increased as compared to the untreated controls, the reactivity of these cells tO ALs-la antigen was lower than that of the control at any days examined, in both in vivo local GvH res po uses and in vitro MLR Conclusion The self- reactive T cells are actually deleted or functionally 'delted' not only in the thymus but in the periphery to maintain self-tolerance.