On the plasticity of Beta-cell antigen recognition by diabetogenic CD8 T cells

项目摘要 CD 8 T细胞在T1 D发病机制中起重要作用。它们是最丰富的免疫细胞 患者胰岛浸润的人群。在T1 D的非肥胖型糖尿病（NOD）模型中， 糖尿病发展胰岛中自身反应性T细胞的浸润和保留严格依赖于 β细胞抗原的特异性识别。这种自我识别也决定了致糖尿病CD 8 T细胞的 细胞毒性和最终杀死β细胞。然而，关于CD 8 + T细胞如何识别β- 细胞抗原在过去的十年中，我们已经使用新的2D测定来表征T细胞抗原识别 一般而言，揭示2D亲和力和机械力作为确定T细胞中两个限定动力学参数， 应答在目前的提案中，我们将通过以下方式将这些2D方法应用于β细胞抗原识别： 通过单细胞RNA测序，阐明了自身免疫性CD 8 T细胞的潜在分子机制。 我们的初步数据表明，致糖尿病的CD 8 T细胞可以极大地改变自身抗原的亲和力和/或力， 这取决于T细胞的成熟、活化和疾病状态。我们提出两个具体目标， 测试致糖尿病性CD 8 T细胞与β细胞自身抗原弱结合以逃避 耐受机制，但可以上调键强度驱动疾病。在具体目标1中，我们将使用2D 表征整个过程中CD 8 T细胞对β细胞抗原识别的亲和力和力的方法 糖尿病在特定目标2中，我们将使用单细胞转录组分析来阐明分子机制 异常调节β细胞自身抗原识别。该项目将产生关键的，但目前 缺失β细胞自身抗原识别的信息，并为新的干预策略提供信息， 能够特异性靶向致糖尿病的CD 8 T细胞。

Project summary CD8 T cells play an essential role in T1D pathogenesis. They comprise the most abundant immune cell population in patient islet infiltrates. In the non-obese diabetic (NOD) model of T1D, they are required for diabetes development. The infiltration and retention of autoreactive T cells in islets is strictly dependent on specific recognition of beta-cell antigens. Such self-recognition also determines diabetogenic CD8 T cell’s cytotoxicity and ultimate killing of beta-cells. However, little is known about how CD8+ T cells recognize beta- cell antigens. Over the past decade, we have used novel 2D assays to characterize T cell antigen recognition in general, revealing 2D affinity and mechanical force as two defining kinetics parameters in determining T cell responses. In the current proposal, we will apply these 2D methods to beta-cell antigen recognition by autoimmune CD8 T cells and elucidate the underlying molecular mechanisms by single cell RNA sequencing. Our preliminary data show that diabetogenic CD8 T cells can greatly change affinity and/or force of self-antigen recognition depending on T cell maturation, activation, and disease status. We propose two specific aims to test a central hypothesis that diabetogenic CD8 T cells bind to beta-cell self-antigens weakly to evade tolerance mechanisms but can upregulate bond strength to drive disease. In Specific Aim 1, we will use our 2D methods to characterize affinity and force of beta-cell antigen recognition by CD8 T cells throughout the course of diabetes. In Specific Aim 2, we will use single cell transcriptome analysis to elucidate molecular mechanisms that abnormally regulate beta-cell self-antigen recognition. The project will generate critical yet currently missing information on beta-cell self-antigen recognition and inform novel intervention strategies that are capable of specifically targeting diabetogenic CD8 T cells.