Interaction of astrocytes and T cells in physiological and pathological conditions.

The central nervous system (CNS) has long been recognized as a site of ‘immune privilege’ because of the existence of the blood brain barrier (BBB) which presumably isolates CNS from the peripheral immunosurveillance. Different from the peripheral organs, CNS is unique in response to all forms of CNS injury and disease which is mainly mediated by resident microglia and astrocyte. There is increasing evidence that immune cells are not only involved in neuroinflammation process but also the maintenance of CNS homeostasis. T cells, an important immune cell population, are involved in the pathogenesis of some neurological diseases by inducing either innate or adaptive immune responses. Astrocytes, which are the most abundant cell type in the CNS, maintain the integrity of BBB and actively participate in the initiation and progression of neurological diseases. Surprisingly, how astrocytes and T cells interact and the consequences of their interaction are not clear. In this review we briefly summarized T cells diversity and astrocyte function. Then, we examined the evidence for the astrocytes and T cells interaction under physiological and pathological conditions including ischemic stroke, multiple sclerosis, viral infection, and Alzheimer’s disease.

中枢神经系统（CNS）长期以来被认为是一个“免疫特权”部位，因为存在血脑屏障（BBB），据推测它将中枢神经系统与外周免疫监视隔离开来。与外周器官不同，中枢神经系统在对所有形式的中枢神经系统损伤和疾病的反应方面具有独特性，这种反应主要由常驻的小胶质细胞和星形胶质细胞介导。越来越多的证据表明，免疫细胞不仅参与神经炎症过程，还参与中枢神经系统内稳态的维持。T细胞作为一种重要的免疫细胞群，通过诱导先天性或适应性免疫反应参与某些神经系统疾病的发病机制。星形胶质细胞是中枢神经系统中数量最多的细胞类型，它维持血脑屏障的完整性，并积极参与神经系统疾病的发生和发展。令人惊讶的是，星形胶质细胞和T细胞如何相互作用以及它们相互作用的结果尚不清楚。在这篇综述中，我们简要总结了T细胞的多样性和星形胶质细胞的功能。然后，我们研究了在生理和病理条件下，包括缺血性中风、多发性硬化症、病毒感染和阿尔茨海默病中，星形胶质细胞和T细胞相互作用的证据。