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

这项研究的总体目标是了解先天免疫反应中产生的炎性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转导抑制物家族蛋白的调节。在研究缺乏SOCS1的小鼠T细胞室的失控稳态时，我们偶然观察到：SOCS1缺陷的CD8T细胞在调节T细胞稳态的细胞因子的反应下旺盛增殖，这一点被炎性细胞因子放大；虽然这并不出人意料，但对照组小鼠的CD8T细胞也在炎性细胞因子和稳态细胞因子的协同刺激下增殖。后者是出乎意料的，因为正常的T细胞需要两种信号，一种是通过抗原受体，另一种是通过共刺激受体。由于炎症条件下(对感染或无菌炎症的反应)可获得炎性和稳态细胞因子，我们开始研究这种抗原和共刺激无关的NAVE T细胞激活的生理意义和病理后果。 在过去的十年里，我们已经证明：(I)细胞因子刺激的T细胞对有限数量的抗原和弱激动型抗原肽的反应增加了对抗原的敏感性，(Ii)这种抗原的非特异性刺激可以激活体内的自身反应性T细胞，(Iii)这一过程受SOCS1的调控。我们还发现，细胞因子启动的T细胞表现出更强的新陈代谢适应性和显著的质膜变化，这可能会影响T细胞抗原受体(TCR)信号。在这项拟议的研究中，我们的目标是了解细胞因子诱导的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，我们建议使用无偏基因组学(ATACseq，RNAseq)和蛋白质组学(iTRAQ差异蛋白质组学)方法来全面了解细胞因子启动过程中发生的分子变化。选定的候选基因/蛋白质/途径将使用体外分析和体内模型来测试它们对细胞因子启动的贡献。 拟议的研究计划将侧重于培训学生在基因组学和蛋白质组学以及生物信息学分析方面的尖端技术。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有关的几项免疫学技术方面的培训。学员将获得适合学术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，以及如何针对它们的信号通路来控制异常免疫反应。

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.