Molecular mechanisms of cytokine-induced modulation of T cell antigen receptor responsiveness

细胞因子诱导的 T 细胞抗原受体反应性调节的分子机制

• 批准号: RGPIN-2020-04804
• 负责人: Ilangumaran, Subburaj
• 金额: $ 2.33万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=717415
• 关键词: Molecular; mechanisms; cytokine; induced; modulation

The overall objective of this research program is to understand how inflammatory cytokines produced during innate immune responses impact on the adaptive immune responses of cytotoxic T lymphocytes. Cytokine responses are regulated by suppressors of cytokine signaling' (SOCS) family proteins. While studying the deregulated homeostasis of the T cell compartment in mice lacking SOCS1, we made a fortuitous observation: SOCS1-deficient CD8 T cells proliferate robustly in response to cytokines that regulate T cell homeostasis and this is amplified by inflammatory cytokines; while this was not unexpected, CD8 T cells from control mice also proliferated in response to synergistic stimulation by inflammatory and homeostatic cytokines. The latter was unexpected because normal T cells require two signals one via the antigen receptor and the other via a costimulatory receptor. As both inflammatory and homeostatic cytokines can become available during inflammatory conditions (in response to infections or sterile inflammation), we started investigating the physiological significance and pathological consequences of such antigen- and co-stimulation- independent activation of nave T cells. Over the past decade, we have shown that (i) the cytokine-stimulated T cells acquire increased sensitivity to antigens as they respond to limiting amounts of antigens and weakly agonistic antigenic peptides, (ii) such antigen non-specific stimulation can activate autoreactive T cells in vivo, and (iii) this process is regulated by SOCS1. We have also found that the cytokine-primed' T cells display increased metabolic fitness and marked changes in their plasma membrane that could impact T cell antigen receptor (TCR) signaling. In the proposed research, we aim to understand the mechanistic and molecular basis of the increased antigen responsiveness of cytokine-primed T cells. As our candidate approaches have shown very limited scope, we propose to use unbiased genomic (ATACseq, RNAseq) and proteomic (iTRAQ differential proteomics) approaches to gain a comprehensive view of the molecular changes that occur during cytokine priming. The selected candidate genes/proteins/pathways will be tested for their contribution to cytokine priming using in vitro assays and in vivo models. The proposed research program will put emphasis on training students in cutting-edge technologies of genomics and proteomics, and bioinformatics analyses. In addition they will be trained in several immunology techniques related to animal handling, T cell biology, flow cytometry, confocal microscopy, molecular biology techniques and bioinformatics analyses. The trainees will gain knowledge and skill set suitable for both academic career and industry jobs. The outcome of this research will impact on how cytokines could be exploited for boosting immune responses, and how their signaling pathways could be targeted to control aberrant immune responses.

该研究项目的总体目标是了解先天免疫反应过程中产生的炎症细胞因子如何影响细胞毒性 T 淋巴细胞的适应性免疫反应。 细胞因子反应受细胞因子信号传导抑制因子 (SOCS) 家族蛋白的调节。 在研究缺乏 SOCS1 的小鼠 T 细胞区室的稳态失调时，我们偶然观察到：SOCS1 缺陷的 CD8 T 细胞响应调节 T 细胞稳态的细胞因子而剧烈增殖，并且这种情况会被炎症细胞因子放大；虽然这并不出人意料，但对照小鼠的 CD8 T 细胞也会响应炎症和稳态细胞因子的协同刺激而增殖。后者是出乎意料的，因为正常 T 细胞需要两种信号，一种通过抗原受体，另一种通过共刺激受体。由于炎症和稳态细胞因子都可以在炎症条件下（响应感染或无菌炎症）变得可用，我们开始研究这种抗原和共刺激独立的天然 T 细胞激活的生理意义和病理后果。 在过去的十年中，我们已经证明，(i) 细胞因子刺激的 T 细胞对抗原的敏感性增加，因为它们对有限数量的抗原和弱激动性抗原肽做出反应，(ii) 这种抗原非特异性刺激可以激活自身反应性 T 细胞。 (iii) 该过程受 SOCS1 调节。我们还发现，细胞因子引发的 T 细胞表现出更高的代谢适应性，其质膜发生显着变化，这可能会影响 T 细胞抗原受体 (TCR) 信号传导。在拟议的研究中，我们旨在了解细胞因子引发的 T 细胞抗原反应性增强的机制和分子基础。 由于我们的候选方法的范围非常有限，我们建议使用无偏见的基因组（ATACseq、RNAseq）和蛋白质组（iTRAQ 差异蛋白质组）方法来全面了解细胞因子引发过程中发生的分子变化。将使用体外测定和体内模型来测试所选候选基因/蛋白质/途径对细胞因子引发的贡献。 拟议的研究计划将重点培训学生基因组学和蛋白质组学以及生物信息学分析的尖端技术。此外，他们还将接受与动物处理、T 细胞生物学、流式细胞术、共聚焦显微镜、分子生物学技术和生物信息学分析相关的多种免疫学技术的培训。学员将获得适合学术职业和行业工作的知识和技能。 这项研究的结果将影响如何利用细胞因子来增强免疫反应，以及如何靶向其信号通路来控制异常的免疫反应。