Yu Ping, Fu Yang-Xin
1Department of Pathology and Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.
Lab Invest. 2006 Mar;86(3):231-45. doi: 10.1038/labinvest.3700389.
The prognostic significance of tumor-infiltrating lymphocytes (TILs) has been a longstanding topic of debate. In cases where TILs have improved patient outcome, T lymphocytes are recognized as the main effectors of antitumor immune responses. However, recent studies have revealed that a subset of CD4(+) T cells, referred to as CD4(+)CD25(+) regulatory T cells (Treg), may accumulate in the tumor environment and suppress tumor-specific T-cell responses, thereby hindering tumor rejection. Hence, predicting tumor behavior on the basis of an indiscriminate evaluation of tumor-infiltrating T cells may result in inconsistent prognostic accuracy. The presence of infiltrating CD4(+)CD25(+) Treg may be detrimental to the host defense against the tumor, while the presence of effector T lymphocytes, including CD8(+) T cells and non-regulatory CD4(+) helper T cells may be beneficial. Enhanced recruitment of antitumor effector T lymphocytes to tumor tissue in addition to inhibition of local Treg, may therefore be an ideal target for improving cancer immunotherapy. This article reviews the antitumor functions of T-lymphocytes, with special attention given to CD4(+) regulatory T-cells within the tumor environment.
肿瘤浸润淋巴细胞（TILs）的预后意义一直是一个长期争论的话题。在TILs改善患者预后的情况下，T淋巴细胞被认为是抗肿瘤免疫反应的主要效应细胞。然而，最近的研究表明，一种被称为CD4(+)CD25(+)调节性T细胞（Treg）的CD4(+) T细胞亚群可能在肿瘤环境中积聚，并抑制肿瘤特异性T细胞反应，从而阻碍肿瘤排斥反应。因此，基于对肿瘤浸润T细胞的不加区分的评估来预测肿瘤行为可能会导致预后准确性不一致。浸润性CD4(+)CD25(+) Treg的存在可能对宿主抵御肿瘤的防御机制不利，而效应T淋巴细胞的存在，包括CD8(+) T细胞和非调节性CD4(+)辅助性T细胞可能是有益的。因此，除了抑制局部Treg外，增强抗肿瘤效应T淋巴细胞向肿瘤组织的募集可能是改善癌症免疫治疗的理想靶点。本文综述了T淋巴细胞的抗肿瘤功能，特别关注肿瘤环境中的CD4(+)调节性T细胞。
