Biophysical parameters of self-reactive TCR engagement in T1D

T1D 中自反应 TCR 参与的生物物理参数

• 批准号: 10681917
• 负责人: Maria Bettini
• 金额: $ 74.95万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10681917
• 关键词: Affinity; Alleles; Antigen Presentation; Antigens; Autoantigens; Autoimmune; Autoimmune Diabetes; Autoimmune Diseases; Autoimmunity; Beta Cell; Binding; CD4 Positive T Lymphocytes; CDR1 gene; Cell physiology; Cells; Complementarity Determining Regions; Complex; Data; Disease; Disease Progression; Eragrostis; Exhibits; Experimental Animal Model; FOXP3 gene; Failure; Family; Functional disorder; Genetic; Goals; HLA-DR4 Antigen; Histocompatibility; Human; Insulin-Dependent Diabetes Mellitus; Knowledge; Measurement; Measures; Mediating; Modeling; Mus; Outcome; Peptide Receptor; Peptides; Predisposition; Prevalence; Process; Proteins; Public Health; Publishing; Receptor Activation; Regulatory T-Lymphocyte; Risk Factors; Specificity; Structure; Surveys; System; T cell response; T cell therapy; T-Cell Activation; T-Cell Antigen Receptor Specificity; T-Cell Development; T-Cell Receptor; T-Lymphocyte; TCR Activation; Technology; Testing; Therapeutic; Treg therapy; Work; antigen-specific T cells; autoreactive T cell; beta Chain Antigen T Cell Receptor; biophysical properties; design; diabetogenic; effector T cell; humanized mouse; improved; insight; mechanical force; new technology; novel; response

ABSTRACT Major histocompatibility loci (MHC) are the largest genetic contributors to autoimmune susceptibility, including type 1 diabetes. Our novel observations show that biophysical parameters of T cell receptor interactions with peptide-MHC are altered in the context of susceptible MHC alleles. Dissecting the interaction between T cell receptor and self-antigens requires sensitive technologies to measure the affinity and bond lifetimes. T cells apply force to the bond between TCR and pMHC antigenic complex, which is ultimately reflected by changes in how long the proteins interact. We have surveyed affinities, bond lifetimes, and force that form during T cell receptor interaction with model, infectious, and self-antigens presented on non-autoimmune I-Ab and compared these observations with I-Ag7 autoimmune MHC restricted T cells. We consistently observed 2-fold difference in force between effector and Foxp3+ regulatory T cells in non-autoimmune MHC restricted responses, with Tregs pulling higher 20pN force. However, I-Ag7 restricted effector T cells are capable of pulling similar high 20pN force, and Tregs loose the 2-fold force advantage. Moreover, human-derived beta cell antigen specific TCR restricted to autoimmune HLA-DR4 exhibited similar high 20pN force. Our overall hypothesis is that Foxp3+ Treg efficacy is dependent on peak TCR force levels that differ 2-fold from T conventional cells, this difference is absent in the context of autoimmune MHCs. How structural components of autoimmune MHC, peptide, and TCR control the stability of the TCR/pMHC interaction is not fully resolved, especially in the context of force measurements. Our recently published and unpublished observations point to CDR2 loops of the TCR as important in establishing the level of force. Moreover, it is unknown how susceptible MHC effects Treg suppressive function, and why Tregs falter during T1D. Therefore, a thorough understanding of the beta cell- specific reactivity of effector and regulatory T cells is needed to fully understand and potentially exploit their therapeutic potential for treatment of autoimmune diabetes. We have devised two aims to test this hypothesis: Aim 1. Determine TCR biophysical parameters restricted by autoimmune MHC and their impact on autoimmune and regulatory T cell function; and Aim 2. Determine structural components of TCR that specifically regulate the force and bond-lifetime, but do not influence specificity or affinity of the interaction. This project will be the first to investigate various levels of force/bond lifetimes as indicators for T cell function and loss of Treg function in autoimmunity, and connect TCR affinity vs force to the ultimate outcome in disease. Furthermore, it will provide novel insight into the mechanisms governing dysfunction of T cell tolerance during T1D.

抽象的 主要的组织相容性基因座（MHC）是自身免疫性易感性的最大遗传因素，包括 1型糖尿病。我们的新发现表明，T细胞受体相互作用与 在易感的MHC等位基因的背景下，肽-MHC发生了变化。解剖T细胞之间的相互作用 受体和自我抗原需要敏感技术来测量亲和力和键寿命。 T细胞 将力施加在TCR和PMHC抗原复合物之间的键上，最终由变化反映 蛋白质相互作用多长。我们已经调查了T细胞期间形成的亲和力，债券寿命和力量 与非自动免疫I-AB上呈现的模型，感染性和自我抗原的受体相互作用，并比较 这些与I-AG7自身免疫性MHC限制T细胞的观察结果。我们始终观察到2倍差 在非自动免疫MHC中的效应子和Foxp3+调节性T细胞之间的力量，有限制的反应， Tregs拉高20pn力。但是，I-AG7限制效应T细胞能够拉出相似的高 20pn力，Tregs松开了2倍的力优势。此外，人类衍生的β细胞抗原特异性 限于自身免疫性HLA-DR4的TCR表现出相似的20pn力。我们的总体假设是Foxp3+ Treg疗效取决于TCR力水平与TCR的峰值与常规细胞不同2倍，此差异 在自身免疫性MHC的背景下不存在。自身免疫性MHC，肽和 TCR控制TCR/PMHC相互作用的稳定性尚未完全解决，尤其是在力的背景下 测量。我们最近发表和未发表的观察结果指出了TCR的CDR2循环 建立力量水平很重要。此外，尚不清楚如何敏感MHC效应Treg 抑制功能，为什么Treg在T1D期间步履蹒跚。因此，对β细胞的透彻理解 - 需要效应子和调节性T细胞的特定反应性，以充分理解并可能利用其 治疗自身免疫性糖尿病的治疗潜力。我们已经设计了两个目的，以检验这一假设： 目标1。确定受自身免疫性MHC限制的TCR生物物理参数及其对自身免疫的影响 和调节性T细胞功能；和目标2。确定特异性调节的TCR的结构成分 力量和粘合时期，但不影响相互作用的特异性或亲和力。这个项目将是第一个 研究各种水平的力/键寿命作为T细胞功能的指标和Treg功能的丧失 自身免疫性，并将TCR亲和力与力量连接到疾病的最终结果。此外，它将提供 对T1D期间T细胞耐受性功能障碍的机制的新洞察力。