Mechanisms to diversify repertoire and modify T cell activity after infection

描述(申请人提供)：与B细胞不同，一旦完全成熟的T细胞离开胸腺，T细胞受体的谱系通常被认为是固定的。我们最近开发了一项技术，可以从小鼠和人类的单个细胞中检测成对的��T细胞受体的信息并对其进行排序。这一方法允许两个重要的观察：1)在急性和记忆免疫反应过程中，两条TCRA链转录信息的细胞比例显著不同；2)体内T细胞的克隆性谱系证明了外周受体的修订。采用创新的体外单细胞培养平台，独一无二 在活体模型中，包括条件性RAG缺陷小鼠和一组有价值的纵向人类样本，我们建议扩展这些观察，以评估对病毒感染的最佳T细胞反应需要固有的可塑性外周系统的假设。我们的三个 目的验证以下假设：1)双TCRCD3等位基因表达通过干扰帧内等位基因转录和/或TCRCD3组装来调节TcR信号强度和功能T细胞活性；2)大多数NA�ve T细胞外周TcR修饰性是由强TcR信号诱导的；3)在急、慢性感染(流感和巨细胞病毒)中，双等位基因表达和修饰性都是T细胞最佳活性所必需的。这些研究结合了一套新的体外技术和体内模型，将导致对如何产生和调节最佳抗病毒T细胞反应的新理解，对我们理解获得性免疫具有广泛的意义。

DESCRIPTION (provided by applicant): In contrast to B cells, the T cell receptor repertoire is generally considered fixed once fully mature T cells exit the thymus. We recently developed the technology to detect and sequence the message of paired �� T cell receptors from single cells in mice and humans. This approach permitted two important observations: 1) the proportion of cells transcribing message for two Tcra chains varies dramatically over the course of acute and memory immune responses and 2) clonal lineages of T cells in vivo demonstrate evidence of receptor revision in the periphery. Using innovative in vitro single cell culture platforms, unique in vivo models including conditional RAG-deficient mice, and a valuable panel of longitudinal human samples, we propose to extend these observations to assess the hypothesis that optimal T cell responses to viral infections require an inherently plastic peripheral repertoire. Our three aims test the specific hypotheses that 1) Dual TCR� allele expression regulates TCR signal strength and functional T cell activity by interfering with in frame allele transcription and/or TCR:CD3 assembly, 2) Peripheral TCR revision is induced in most na�ve T cells by strong TCR signaling and 3) Both dual allele expression and revision are required for optimal T cell activity in acute and chronic infections (influenza and mCMV). These studies combine a suite of novel in vitro technology and in vivo models that will result in a new understanding of how optimal antiviral T cell responses are generated and regulated, with broad implications for our understanding of adaptive immunity.