中枢神经系统（CNS）是公认的免疫赦免区，但又必须能对致病原的入侵做出快速反应。组织驻留淋巴细胞在许多器官都发挥着快速识别致病原的作用。CNS中是否也天然存在组织驻留淋巴细胞，国际上尚属空白。我们前期通过“联体共生”模型已初步鉴定出Naïve小鼠脑组织中存在驻留gamma delta T细胞。在小鼠冠状病毒嗜神经株J2.2感染引起的脑脊髓炎模型中，当特异性T细胞应答受到抑制时，这群细胞高度活化，并显示出免疫致病性。但这些细胞具有怎样的表型？定位在哪里？如何维持稳态？通过怎样的机制行使功能？等一系列问题均有待阐明。本项目拟通过血管内抗体标记法、联体共生实验、单细胞转录组学等方法深入研究，力图解决上述问题。此开创性研究有望填补相关科学领域的空白、拓展人们对CNS免疫监视系统的认识，揭示脑驻留gamma delta T细胞的作用机制，为相关疾病的治疗提供新思路。

The central nervous system (CNS) has long been recognized as an “immune privilege” site, but it must respond rapidly to pathogen invasion. Resident lymphoid cells are predicted to contribute to pathogen recognition, but such cells have not been identified and characterized in the brain of naïve mice. Recently，we identified a previously undescribed brain-resident gamma delta T cell population. In the setting of a neurotropic coronavirus infection, these cells were highly activated and pathogenic if virus-specific CD8 and CD4 T cell responses were transiently ablated using the chemotherapeutic agent etoposide. However, nothing is known about their phenotypes, tissue localizations, homeostasis and mechanisms underlying their functions. Here, we are going to address these questions using methods such as intravascular staining, parabiosis and 10x genomics single cell sequencing. This study will provide new insight into the CNS immune surveillance network, elucidate mechanisms underlying the functions of brain-resident gamma delta T cells, and provide new strategies for disease therapy.