双阴性调节性T细胞在免疫抑制中的作用及其机制

αβTCR+CD3+CD4-CD8-双阴性调节性T细胞(DN Treg细胞）被证实具有通过对效应性T细胞的直接杀伤作用从而抑制免疫应答的能力。DN Treg细胞与特异性抗原接触后增加其调节活性，该过程部分通过其对抗原呈递细胞表面MHC抗原肽复合物的识别作用介导。DN Treg细胞与靶细胞接触后可通过Fas和Fas配体之间的交互作用介导其杀伤效应。对DN Treg细胞功能特性、分子表达方式及其激活机制的深入研究将有助于探索临床新的治疗手段。

T cells in the suppression of immune responses

Role and mechanisms of CD4-CD8- regulatory various types of Treg cell subsets have been reported in a variety of disease models. Among these subsets, αβTCR+CD3+CD4-CD8- double negative (DN) Treg cells are defined by their capability of inhibiting immune responses via directly killing effector T cells in an antigen specific fashion. Furthermore, DN Treg cells have been shown to develop regulatory activity after encountering specific antigens, partially mediated by the acquisition of MHC-peptide complexes from antigen presenting cells (APCs). Once DN Treg and target cells have come into contact, killing is then mediated by Fas/Fas-ligand interactions. Further characterization of the functions, molecular expression and mechanisms of activation of DN Treg cells will be helpful in the development of novel therapies to induce antigen specific tolerance to self and foreign antigens.