树突状细胞对调节性T细胞的调控作用

Controls of regulatory T cell by dendritic cell

树突状细胞（DCs）是目前已知的体内功能最强大的专职性抗原提呈细胞，具有启动免疫应答和诱导免疫耐受的双重特性。近年来树突状细胞对调节性T细胞的调控作用是免疫学领域的一个研究热点。Foxp3’Tregs是二群同时具有免疫低反应性和免疫抑制性功能两大特征的T淋巴细胞，它在维持机体内环境稳定、预防自身免疫性疾病、抑制移植排斥反应等病理生理过程中发挥着重要作用。越来越多的研究结果证实DCs和Tregs二者在维持外周免疫耐受中存在着紧密联系，DCs可以诱导抗原特异性Tregs的生成并增加后者的抑制活性，其中参与该调节机制的分子主要包括相关细胞因子、Toll样受体、共刺激分子及维甲酸等。对DCs在接触共生和致病微生物时诱导和调控Tregs细胞有了一些新发现。

Dendritic cell are the most powerful professional antigen-presenting cells in vivo known at present, the cells have dual characteristics of initiating the immune responses and inducing immune tolerance. Control of regulatory T cells by the dendritic cells is becoming a key point that has been concerned in immunolo- gy research of recent years. Foxp3 ＋regulatory T cells are the T lymph cells that have both the features of hypo- responsive and anergic to antigen stimulation. They play an essential role in the physiological and pathological processes of immunological homeostasis and a variety of disease settings including autoimmunity, allograft rejec- tion, etc. In addition, it has become.increasingly clear that dendritic cells and regulatory T cells contribute to the maintenance of peripheral immune tolerance. Dendritic ceils have the capacity to induce antigen-specific regulatory T cells and increase their suppressive activity. The potential molecules in the process of regulating regulatory T cells include correlated cytokines, Toll-like receptors, eo-stimulatory molecules and retinoic acid, etc. In this review, we discuss some new findings associating dendritic cells with the induction and control of regulatory T cells in the context of exposure to both commensal and pathogenic microbes.