Mechanisms to diversify repertoire and modify T cell activity after infection

描述（由申请方提供）：与B细胞相反，一旦完全成熟的T细胞离开胸腺，T细胞受体库通常被认为是固定的。我们最近开发了一种技术，可以检测和测序来自小鼠和人类单细胞的配对T细胞受体的信息。该方法允许两个重要的观察结果：1）转录两个Tcra链的信息的细胞的比例在急性和记忆免疫应答的过程中显著变化，和2）体内T细胞的克隆谱系证明了外周中受体修正的证据。采用创新的体外单细胞培养平台， 在包括条件性RAG缺陷小鼠的体内模型和一组有价值的纵向人类样本中，我们建议扩展这些观察以评估对病毒感染的最佳T细胞应答需要固有的可塑性外周库的假设。我们的三 目的是测试以下特定假设：1）双TCR等位基因表达通过干扰符合读码框的等位基因转录和/或TCR：CD 3组装来调节TCR信号强度和功能性T细胞活性，2）外周TCR修正在大多数幼稚T细胞中由强TCR信号传导诱导，以及3）双等位基因表达和修正都是急性和慢性感染（流感和mCMV）中最佳T细胞活性所需的。这些研究结合了联合收割机一套新的体外技术和体内模型，将导致对最佳抗病毒T细胞应答如何产生和调节的新理解，对我们理解适应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.