Characterization of the polyclonal TCR repertoire in TCR-beta transgenic mice

描述（由申请人提供）：T细胞受体（TCR）序列的随机生成确保TCR库能够识别多种病原体。然而，TCR 库的研究因这种巨大的多样性而受到阻碍。为了克服这个问题，我们使用固定的 TCR-β 链模型来促进多克隆 TCR 库的实验研究。该 TCR 库在正常胸腺和外周环境中发育，并受到天然 T 细胞选择力的影响，包括与自身抗原和来自皮肤和肠道共生菌群的外来抗原的潜在相互作用。在之前的研究中，这种固定的 TCR-β 链模型可用于表征正常自然产生的 TCR 库并将其与自身免疫库进行比较。我们在这里提出，固定TCR-β链模型中TCR库的详细知识将有助于T细胞生物学的许多方面的研究。因此，该项目的目标是通过对基于空间和表型变量分离的T细胞的可变TCR-α链进行广泛测序，在个体TCR水平上完整地原位表征该多克隆TCR库。一个特定的重点领域是了解自然产生的记忆 CD4 T 细胞的 TCR 特异性，这种细胞可能是由于遇到自身或共生抗原而产生的，并且可能具有潜在的致病性。我们相信这些数据将成为未来研究自我反应性调节性和非调节性 T 细胞、自身免疫性疾病的遗传模型、记忆性 T 细胞以及 T 细胞运输和稳态的基础。

DESCRIPTION (provided by applicant): The random generation of T cell receptor (TCR) sequences ensures a TCR repertoire capable of recognizing a wide variety of pathogens. However, study of the TCR repertoire is hampered by this great diversity. To overcome this issue, we have used a fixed TCR-beta chain model to facilitate experimental study of a polyclonal TCR repertoire. This TCR repertoire develops in a normal thymic and peripheral environment, and is subject to natural T cell selective forces, including potential interactions with self-antigens and foreign antigens from commensal flora on the skin and intestines. In previous studies, this fixed TCR-beta chain model has been useful in characterizing normal naturally arising TCR repertoires and comparing them with autoimmune repertoires. We propose here that detailed knowledge of the TCR repertoire in a fixed TCR- beta chain model will be useful for study of numerous aspects of T cell biology, Thus, the goal of this project is the complete in situ characterization of this polyclonal TCR repertoire at the individual TCR level by extensive sequencing of the variable TCR-alpha chains from T cells isolated based on spatial and phenotypic variables. One particular area of focus will be to understand the TCR specificity of naturally arising memory CD4+ T cells, which presumably arose due to encounter with self or commensal antigens, and may potentially be pathogenic. We believe these data will serve as the foundation of future studies on self-reactive regulatory and non-regulatory T cells, genetic models of autoimmune disease, memory T cells, and T cell trafficking and homeostasis.