Autoreactive CD4 T cells in healthy mice

健康小鼠的自身反应性 CD4 T 细胞

• 批准号: 10621383
• 负责人: LESZEK IGNATOWICZ
• 金额: $ 39万
• 依托单位: GEORGIA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10621383
• 关键词: Ablation; Acceleration; Agonist; Antigen Receptors; Antigen-Presenting Cells; Autoantigens; Autoimmune Diseases; Autoimmunity; Bar Codes; Binding; Bypass; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; Cells; Chromatin; Development; Devices; Diphtheria Toxin; Disabled Persons; Epigenetic Process; Gene Targeting; Genomics; Homeostasis; Human; Immune response; Individual; Infection; MHC Class I Genes; MHC Class II Genes; Maintenance; Malignant Neoplasms; Microfluidics; Modeling; Mus; Organ; Pathogenicity; Peptides; Peripheral; Protocols documentation; Receptor Activation; Receptor Cell; Regulatory T-Lymphocyte; Reproducibility; Research; Rest; Role; Self Tolerance; Specificity; Stromal Cells; System; T-Lymphocyte; T-Lymphocyte Subsets; Testing; Therapeutic; Thymus Gland; Tissues; Transposase; Visit; autoreactive T cell; autoreactivity; central tolerance; high throughput analysis; lymphoid organ; novel therapeutics; peripheral tolerance; prevent; reconstruction; response; single-cell RNA sequencing; thymocyte; transcriptome

In the thymus, central tolerance should eliminate the majority of immature T cells that express autoreactive, pathogenic antigen receptors (αβTCRs). However, an unknown number of autoreactive cells escape deletion or commit to immunosuppressive, regulatory linage (Tregs). Tregs control peripheral tolerance and sustain dormancy of potentially autoreactive T cells. However, mice and humans with disabled Tregs rapidly develop multiorgan autoimmunity and die young, manifesting polyclonal activation of almost all CD4+ clones. Thus, we hypothesized that the number of autoreactive clones embedded in the peripheral repertoire can be much higher (i.e. over one-third of all CD4+ cells) as compared to what is currently anticipated. In Specific Aim 1, we will examine how the intrathymic expression of different self-peptides supports or prevents an escape of autoreactive T cells from central tolerance. This approach will document that potentially self-reactive CD4+ clones commonly trespass to lymphoid organs of B6 mice as quiescent cells. Next, we will test these cells ex vivo responses to a known set of self-peptides naturally presented by mouse Ab molecules to determine if these clones are triggered by ubiquitous or specific autoantigens. In Specific Aim 2, we will investigate why mice expressing single autoantigen across the body have main autoimmunity manifestation in specific organs and examine the role of non-classical CD4+ T cells in autoimmunity in this model. In Aim 3 we will use a new single-cell RNA seq system from 10X Genomics, to examine in individual CD4+ cells their transcriptomes and native αβTCRs to identify genes targeted by Tregs in potentially autoreactive cells to keep them dormant and prevent autoimmunity. Overall, this application will revisit the relative importance of various mechanisms of tolerance in the maintenance of homeostasis to self- antigens and can reveal new mechanisms of how Tregs control self-reactivity.

在胸腺中，中枢耐受应该消除大部分未成熟的 T 细胞。 表达自身反应性致病性抗原受体（αβTCR）。然而，数量未知 自身反应性细胞逃避缺失或进入免疫抑制性调节谱系 (Treg)。 Tregs 控制外周耐受性并维持潜在自身反应性 T 细胞的休眠。 然而，患有Tregs功能障碍的小鼠和人类会迅速发展出多器官自身免疫并死亡 年轻，几乎所有 CD4+ 克隆都表现出多克隆激活。因此，我们假设 嵌入外围库中的自身反应性克隆的数量可能要高得多（即 与目前的预期相比，超过所有 CD4+ 细胞的三分之一。在具体目标 1 中， 我们将研究不同自肽的胸腺内表达如何支持或预防 自身反应性 T 细胞逃离中枢耐受。这种方法将记录潜在的 自身反应性 CD4+ 克隆通常作为静止细胞侵入 B6 小鼠的淋巴器官。 接下来，我们将测试这些细胞对一组已知的自然呈现的自肽的体外反应 通过小鼠抗体分子来确定这些克隆是由普遍存在的还是特定的 自身抗原。在具体目标 2 中，我们将研究为什么小鼠表达单一自身抗原 全身各部位的自身免疫主要表现在特定器官并检查其作用 该模型中非经典 CD4+ T 细胞在自身免疫中的作用。在目标 3 中，我们将使用新的单细胞 10X Genomics 的 RNA seq 系统，用于检查单个 CD4+ 细胞的转录组 和天然 αβTCR 来识别潜在自身反应细胞中 Tregs 靶向的基因，以保持 它们处于休眠状态并防止自身免疫。总的来说，这个应用程序将重新审视相关的 各种耐受机制在维持自我稳态中的重要性 抗原，并可以揭示 Tregs 如何控制自身反应的新机制。