共查询到11条相似文献,搜索用时 125 毫秒
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外周T细胞TCR基因的重排(编辑/修正)与选择 总被引:3,自引:0,他引:3
T细胞在胸腺发育过程中,TCR通过VDJC基因重排(rearrangement)和选择(细胞水平选择或克隆选择,cellorclonalselection),而组成了外周多样性的T细胞库。现证实外周的T细胞存在着TCR的第二次重排(编辑/修正,editing/revision)与选择(受体水平或分子水平的选择,receptorormolecularselection),即外周的T细胞能重新开放RAG酶等进行VDJC基因的重新编排,修正原来的TCR或产生全新的TCR,再一次选择成为产生耐受或特异应答的新的T细胞,这种机制在外周T细胞库的扩展、自身免疫病、T细胞的外周耐受、肿瘤和感染、免疫缺陷和移植等免疫应答机制中发挥重要作用。 相似文献
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Wagner DH 《Clinical immunology (Orlando, Fla.)》2007,123(1):1-6
Protection against the universe of pathogens requires a functional, diverse T cell repertoire. However, the price that is paid for an evolved, effective immune system includes the potential danger of generating autoaggressive T cells. Autoimmune diseases result from inherent breach of tolerance to self-antigens leading to disruption of the regulatory to autoaggressive T cell homeostatic balance. The immune system has evolved mechanisms to control those processes. For T cells, positive and negative selection in the thymus assures that only fully functional, non-self-reactive T cells will populate the periphery. Failure of this central tolerance would result in autoaggressive T cells escaping into the periphery. However, other means of escaping negative selection can occur in the periphery, i.e., TCR revision, or the altering of TCR expression after thymic egress. Here the potential benefits, i.e., expansion and re-shaping of the T cell repertoire as potentiated by TCR editing and revision are considered. Furthermore, the potential to develop autoaggressive TCR and thus enhance autoimmunity is considered. 相似文献