Jiang Janina, Kelly Kathleen A
Department of Pathology and Lab Medicine, David Geffen School of Medicine at University of California, Los Angeles, CA 90095, USA.
Curr Trends Immunol. 2011;12:89-94.
T cells with the specialized ability to suppress both adaptive and innate immune responses have been identified and called T regulatory cells (Tregs). The primary function of Tregs is to maintain a balance between immunity (foreign Ag) and tolerance (self Ag) to tissues. Tregs prevent autoimmune disease, maintain immune homeostasis and modulate protective responses against infection. Tregs function in two ways; 1) limiting the magnitude of effector responses which influence the adequate control of infection and 2) control collateral tissue damage caused by vigorous antimicrobial responses against pathogens. Initially, the immune suppressive ability of CD4 T cells was predicted by expression of the forkhead box p3 (Foxp3) transcription factor. However, many reports have demonstrated immune suppressive function in an array of other T cells which include iT(R)35, CD8+, NKT cells, especially in mucosal tissues. The immune suppressive mechanisms of Tregs include contact-dependent, cytokine secretion and regulation of immune cell migration. The expanded group of Tregs is crucial for protecting the function of mucosal tissues such as the gut, respiratory and genital tracts, as these tissues are routinely exposed to foreign pathogens.
具有抑制适应性免疫反应和先天性免疫反应特殊能力的T细胞已被识别，并被称为调节性T细胞（Tregs）。Tregs的主要功能是维持机体对组织的免疫（外来抗原）和耐受（自身抗原）之间的平衡。Tregs可预防自身免疫性疾病，维持免疫稳态，并调节针对感染的保护性反应。Tregs通过两种方式发挥作用：1）限制效应反应的强度，这影响对感染的充分控制；2）控制由针对病原体的强烈抗菌反应引起的附带组织损伤。最初，CD4 T细胞的免疫抑制能力是通过叉头框p3（Foxp3）转录因子的表达来预测的。然而，许多报告表明，一系列其他T细胞，包括诱导性调节性T细胞（iT(R)35）、CD8+、自然杀伤T细胞（NKT细胞），尤其是在粘膜组织中，也具有免疫抑制功能。Tregs的免疫抑制机制包括接触依赖性、细胞因子分泌和免疫细胞迁移的调节。Tregs的扩增群体对于保护肠道、呼吸道和生殖道等粘膜组织的功能至关重要，因为这些组织经常暴露于外来病原体。
