St. Jude Children's Research Hospital, Memphis, TN, USA.
Immunol Rev. 2018 Jul;284(1):79-90. doi: 10.1111/imr.12668.
Over the last several decades, novel populations of unconventional T cells have been identified; defined by an invariant (or nearly invariant) T cell receptor (TCR) with a fixed specificity to non-canonical antigens and major histocompatibility (MHC) molecules, they form large, functionally monoclonal populations tasked with surveying for their specific antigens. With residence in both lymphoid and non-lymphoid tissues coupled with their ability to rapidly produce a spectrum of cytokines and effector molecules, the unconventional T cells are poised as some of the first responders to infection/damage and are thought to provide critical coverage before more focused, conventional T cell responses are mobilized. However, new technologies for the measurement and characterization of TCR repertoires have identified an underappreciated amount of TCR diversity in the unconventional T cells. In many cases, the specificities of these diverse TCRs converge on the same or similar antigens as their invariant counterparts, while others have yet to be defined. Here, we will review the current knowledge of the TCR repertoires of unconventional T cells and discuss how repertoires might be used as a framework for their organization, and further our understanding of their role not only during an immune response, but also their contribution in maintaining homeostasis.
在过去的几十年中，已经鉴定出了新型非常规 T 细胞群体；它们的特征是具有不变（或几乎不变）的 T 细胞受体（TCR），对非经典抗原和主要组织相容性（MHC）分子具有固定的特异性，形成了具有特定抗原特异性的大型、功能单克隆群体。非常规 T 细胞在淋巴组织和非淋巴组织中都有驻留，并且能够快速产生一系列细胞因子和效应分子，因此它们是对感染/损伤的最早反应者之一，并且在更集中的常规 T 细胞反应被动员之前，被认为提供了重要的保护。然而，用于 TCR 库测量和表征的新技术已经确定了非常规 T 细胞中 TCR 多样性的未被充分认识的程度。在许多情况下，这些多样化 TCR 的特异性与不变型对应物相同或相似的抗原趋同，而其他的特异性尚未确定。在这里，我们将回顾非常规 T 细胞 TCR 库的现有知识，并讨论如何将库用作其组织的框架，并进一步了解它们在免疫反应期间的作用，以及它们在维持体内平衡中的贡献。
