McHugh Rebecca S, Shevach Ethan M
Cellular Immunology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
J Allergy Clin Immunol. 2002 Nov;110(5):693-702. doi: 10.1067/mai.2002.129339.
Suppressor T cells play important roles in the regulation of immune responses and the mediation of dominant immunologic tolerance. Studies of suppressor T-cell function have been hampered until their recent identification as a minor fraction (approximately 10%) of CD4 ( +) T cells that coexpress CD25. CD4(+)CD25(+ ) T cells have been shown to play a critical role in the prevention of organ- specific autoimmunity and allograft rejection. Because tumor antigens are self- antigens, it is not surprising that CD4(+)CD25(+) T cells also inhibit the induction of tumor immunity. The spectrum of activity of CD4(+ ) CD25(+) cells extends to non-self-antigens, including infectious agents. Indeed, T cell-mediated suppression might be responsible for the low level of chronic infection seen with many pathogens. Interestingly, however, this persistent level of infection might be beneficial to the host and needed for maintenance of immunologic memory. Although CD4(+ ) CD25(+) T cells are capable of inhibiting T(H)2 responses, their role in the suppression of allergic responses has not been firmly established. Depending on the desired immune response, enhancement or restraint of suppressor T-cell function might be required. Therefore immunologic or pharmacologic manipulation of regulatory T-cell populations represents an important future approach to immunotherapy of a wide range of immune responses.
抑制性T细胞在免疫反应的调节和主导免疫耐受的介导中发挥着重要作用。直到最近将其鉴定为共表达CD25的CD4(+) T细胞中的一小部分（约10%），抑制性T细胞功能的研究一直受到阻碍。已证明CD4(+)CD25(+) T细胞在预防器官特异性自身免疫和同种异体移植排斥中起关键作用。由于肿瘤抗原是自身抗原，所以CD4(+)CD25(+) T细胞也抑制肿瘤免疫的诱导也就不足为奇了。CD4(+)CD25(+)细胞的活性谱扩展到非自身抗原，包括感染因子。实际上，T细胞介导的抑制作用可能是许多病原体所致慢性感染水平较低的原因。然而，有趣的是，这种持续的感染水平可能对宿主有益，并且是维持免疫记忆所必需的。虽然CD4(+)CD25(+) T细胞能够抑制Th2反应，但其在抑制过敏反应中的作用尚未得到确凿证实。根据所需的免疫反应，可能需要增强或抑制抑制性T细胞的功能。因此，对调节性T细胞群体进行免疫或药物操纵是未来广泛免疫反应免疫治疗的重要方法。
