Mizrahi Meir, Ilan Yaron
Liver Unit, Department of Medicine, Hebrew University-Hadassah Medical Center, Jerusalem, Israel.
Curr Pharm Des. 2009;15(11):1191-202. doi: 10.2174/138161209787846784.
Regulatory T lymphocytes (Tregs) are specialized for immune suppression and are important regulators of the immune response in various settings. Tregs actively suppress enteroantigen-reactive cells and contribute to the maintenance of intestinal immune homeostasis. Distinct Treg subsets coexist in the intestinal mucosa and mesenteric lymph nodes. Disturbances in Treg number and function are associated with immune-mediated disorders. Therefore, Tregs are potential targets for immunotherapies. The gut mucosal immune system is the largest lymphoid organ in the body. This site has continuous antigenic challenges from food antigens, antigens of the abundant normal bacterial flora, and pathogens. Despite this constant antigenic stimulation, controlled inflammatory responses and suppression of inflammation appear to be the rule. The gut immune system differentiates the antigenic signals from the high background noise of food and bacterial antigens. This tight regulation required to maintain homeostasis is achieved through multiple non-immune and immune factors. Oral tolerance is a mechanism in which the gastrointestinal immune system inhibits or promotes its reaction toward an orally administered antigen. Mucosal tolerance is attractive as an approach to the treatment of autoimmune and inflammatory diseases; the benefits of using an oral tolerance approach are: lack of toxicity, ease of administration over time, and antigen-specific mechanisms of action. Multiple mechanisms of tolerance are induced by oral antigen administration. Recent data suggest that oral antigen administration of antigens may promote activation of different types of regulatory T lymphocytes, enabling treatment of immune mediated disorders. This review summarizes the recent data on induction of regulatory T-cells by oral antigen administration as a possible mechanism of oral tolerance.
调节性T淋巴细胞（Tregs）专门负责免疫抑制，是各种情况下免疫反应的重要调节因子。Tregs积极抑制肠抗原反应性细胞，并有助于维持肠道免疫稳态。不同的Treg亚群共存于肠道黏膜和肠系膜淋巴结中。Treg数量和功能的紊乱与免疫介导的疾病有关。因此，Tregs是免疫治疗的潜在靶点。肠道黏膜免疫系统是体内最大的淋巴器官。该部位不断受到来自食物抗原、丰富的正常细菌菌群抗原和病原体的抗原性挑战。尽管存在这种持续的抗原刺激，但受控的炎症反应和炎症抑制似乎是常态。肠道免疫系统从食物和细菌抗原的高背景噪音中区分出抗原信号。维持稳态所需的这种严格调节是通过多种非免疫和免疫因素实现的。口服耐受是一种机制，其中胃肠道免疫系统抑制或促进其对口服抗原的反应。黏膜耐受作为一种治疗自身免疫性和炎性疾病的方法很有吸引力；采用口服耐受方法的好处包括：无毒性、长期给药方便以及抗原特异性作用机制。口服抗原给药可诱导多种耐受机制。最近的数据表明，口服抗原给药可能促进不同类型调节性T淋巴细胞的激活，从而能够治疗免疫介导的疾病。这篇综述总结了关于口服抗原给药诱导调节性T细胞作为口服耐受可能机制的最新数据。
