Chen Wanjun, Perruche Sylvain, Li Jun
Mucosal Immunology Unit, Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
Curr Med Chem. 2007;14(21):2245-9. doi: 10.2174/092986707781696591.
Three major mucosal systems exist in the body, the oral-gastrointestinal, the respiratory and the genitourinary systems. In particular, the gastrointestinal (GI) tract contains the largest mucosal surface in the body and is the major port of entry for foreign antigens. Therefore, the gut immune system has to differentiate to tolerate dietary antigens and expel infectious and harmful pathogens. During the complex but well-orchestrated immune responses in the mucosal system, T cells play a pivotal role in both immunity and tolerance. Of many T cell subpopulations, CD4(+)CD25(+) T regulatory cells (Tregs) are instrumental in regulation of immune responses in mucosea. Among the multitude of cytokines and factors that are produced in the gut, Transforming Growth Factor-beta (TGF-beta) is probably the most important one in influencing mucosal T cell responses. The interaction and mutual regulation between TGF-beta and CD4(+)CD25(+) Tregs may be the key in maintaining the balance between T cell immunity and tolerance in mucosal system. In this article, we attempt to discuss both beneficial and detrimental effects of TGF-beta and Tregs on oral tolerance, mucosal inflammation and autoimmunity, colon cancer and HIV infection in the gut.
人体存在三大主要黏膜系统，即口腔 - 胃肠道、呼吸道和泌尿生殖系统。特别是胃肠道包含了人体最大的黏膜表面，并且是外来抗原进入的主要入口。因此，肠道免疫系统必须进行分化，以耐受饮食抗原并排出传染性和有害病原体。在黏膜系统复杂但精心编排的免疫反应过程中，T细胞在免疫和耐受方面都发挥着关键作用。在众多T细胞亚群中，CD4(+)CD25(+)调节性T细胞（Tregs）在调节黏膜免疫反应中发挥着重要作用。在肠道产生的众多细胞因子和因子中，转化生长因子 -β（TGF-β）可能是影响黏膜T细胞反应最重要的一种。TGF-β与CD4(+)CD25(+)Tregs之间的相互作用和相互调节可能是维持黏膜系统中T细胞免疫和耐受平衡的关键。在本文中,我们试图讨论TGF-β和Tregs对口服耐受、黏膜炎症和自身免疫、结肠癌以及肠道HIV感染的有益和有害影响。
