Srinivasan Mathangi, Frauwirth Kenneth A
Department of Cell Biology and Molecular Genetics, University of Maryland, Bldg. 231 Room 2113, College Park, MD 20742, USA.
Cytokine. 2009 May;46(2):147-59. doi: 10.1016/j.cyto.2009.01.010. Epub 2009 Mar 5.
The establishment and maintenance of T cell tolerance to self- and non-pathogenic foreign antigens is critical for immune homeostasis. Thymic deletion of self-reactive T cells is an important component of tolerance, but it is incomplete, and does not establish tolerance to most foreign antigens. Thus, mechanisms of peripheral tolerance are also required. This is especially true for CD8(+) T cells, which are able to encounter their cognate antigens presented by nearly any cell type. Upon differentiating into cytotoxic T lymphocytes (CTL), CD8(+) T cells do not require costimulation for their cytotoxic function, reinforcing the importance of tolerance in these cells. In this review, we will discuss the modes of peripheral tolerance in CD8(+) T cells, covering both naïve and effector T cells. We will examine the antigen and signaling requirements for tolerance induction and maintenance, and will also touch on similarities and potential differences between CD8(+) and CD4(+) tolerance mechanisms.
T细胞对自身和非致病性外来抗原耐受性的建立与维持对免疫稳态至关重要。自身反应性T细胞的胸腺清除是耐受性的一个重要组成部分，但并不完全，且无法建立对大多数外来抗原的耐受性。因此，外周耐受性机制也是必需的。对于CD8(+) T细胞而言尤其如此，它们能够接触到几乎任何细胞类型所呈递的同源抗原。在分化为细胞毒性T淋巴细胞（CTL）后，CD8(+) T细胞的细胞毒性功能并不需要共刺激，这凸显了这些细胞中耐受性的重要性。在这篇综述中，我们将讨论CD8(+) T细胞外周耐受性的模式，涵盖初始T细胞和效应T细胞。我们将研究耐受性诱导和维持所需的抗原及信号要求，还将探讨CD8(+) 和CD4(+) 耐受性机制之间的异同。
