Intravital imaging of T cell priming in the gut-associated lymphatic tissue (GALT)

肠道相关淋巴组织 (GALT) 中 T 细胞启动的活体成像

• 批准号: 246754395
• 负责人: Privatdozent Dr. Naoto Kawakami
• 金额: --
• 依托单位: Forschungsbereich Klinische Neuroimmunologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/246754395?language=en
• 关键词: Intravital; imaging; cell; priming; gut

Multiple sclerosis (MS), a common autoimmune disease, is characterized by infiltration of immune cells into the central nervous system (CNS). In my previous work I showed by intravital imaging that the infiltration and activation of autoreactive CD4 positive T cells in the CNS is critical for the initiation of CNS inflammation. However, it is still largely unknown why encephalitogenic T cells start infiltration into the CNS. Although these cells exist normally in healthy immune repertoire, they only start infiltrating into the CNS and induce local inflammatory lesions if triggered to do. Since it was shown that gut microbiota can trigger the onset of experimental autoimmune encephalomyelitis (EAE), an animal model of MS, I hypothesize that the encephalitogenic T cells get primed for CNS infiltration in the gut. To directly test this hypothesis, I have established an intravital imaging that allows to visualize by two-photon microscopy when and where T cells are stimulated in the gut-associated lymphatic tissue (GALT). To do so I will express two activation sensors that I have previously developed in encephalitogenic T cells. Whereas the calcium sensing protein, Twitch, detects changes of the intracellular calcium level that allow a graded assessment of T cell stimulation, the nuclear translocation of the NFAT-GFP fusion protein selectively detects antigen-dependent T cell activation, which is only induced by saturated calcium signaling. To study the consequences of T cell priming in the GALT, the GALT-emigrating cells will be recovered from efferent lymphatics and their phenotype will be analyzed by next-generation sequencing (NGS). Based on the molecular profiling of the GALT-emigrating cells I will define "encephalitogenic switches that can be therapeutically targeted to prevent the subsequent induction of CNS inflammation.

多发性硬化（MS）是一种常见的自身免疫性疾病，其特征在于免疫细胞浸润到中枢神经系统（CNS）中。在我以前的工作中，我通过活体成像表明，CNS中自身反应性CD 4阳性T细胞的浸润和激活对于CNS炎症的启动至关重要。然而，致脑炎性T细胞开始浸润到CNS中的原因在很大程度上仍然未知。虽然这些细胞通常存在于健康的免疫库中，但它们仅开始浸润到CNS中并在触发时诱导局部炎性病变。由于肠道微生物群可以触发实验性自身免疫性脑脊髓炎（EAE）（MS的动物模型）的发作，因此我假设致脑炎T细胞在肠道中为CNS浸润做好准备。为了直接验证这一假设，我建立了一种活体成像，可以通过双光子显微镜观察肠道相关淋巴组织（GALT）中T细胞何时何地受到刺激。为此，我将表达我以前在致脑炎T细胞中开发的两个激活传感器。而钙敏感蛋白Twitch检测细胞内钙水平的变化，允许T细胞刺激的分级评估，NFAT-GFP融合蛋白的核转位选择性地检测抗原依赖性T细胞活化，其仅由饱和钙信号传导诱导。为了研究GALT中T细胞引发的后果，将从传出神经中回收GALT迁移细胞，并通过下一代测序（NGS）分析其表型。基于GALT迁移细胞的分子特征，我将定义“致脑炎开关，可以在治疗上靶向预防随后诱导CNS炎症。