IL-2, Regulatory T Cells, and Tolerance

作者：Brad H. Nelson · 发表于：The Journal of Immunology · 年份：2004 · DOI：10.4049/jimmunol.172.7.3983 · 被引用次数：560 · 研究领域：T-cell and B-cell Immunology、Immune Cell Function and Interaction、Immunotherapy and Immune Responses

IL-2 is a potent T cell growth factor that for many years was assumed to amplify lymphocyte responses in vivo. Accordingly, IL-2 has been used clinically to enhance T cell immunity in patients with AIDS or cancer, and blocking Abs to the IL-2R are used to inhibit T cell responses against transplanted tissues. It was later shown in mice that, unexpectedly, disruption of the IL-2 pathway results in lymphoid hyperplasia and autoimmunity rather than immune deficiency, indicating that the major physiological function of IL-2 is to limit rather than enhance T cell responses. This apparent paradox has recently been resolved with the discovery that IL-2 is critical for the development and peripheral expansion of CD4(+)CD25(+) regulatory T cells, which promote self-tolerance by suppressing T cell responses in vivo. Our new understanding of IL-2 biology prompts a re-evaluation of how best to clinically manipulate this important immunoregulatory pathway.