The blood-brain barrier (BBB), which protects the CNS from pathogens, is composed of specialized brain microvascular endothelial cells (BMECs) joined by tight junctions and ensheathed by pericytes and astrocyte endfeet. The stability of the BBB structure and function is of great significance for the maintenance of brain homeostasis. When a neurotropic virus invades the CNS via a hematogenous or non-hematogenous route, it may cause structural and functional disorders of the BBB, and also activate the BBB anti-inflammatory or pro-inflammatory innate immune response. This article focuses on the structural and functional changes that occur in the three main components of the BBB (endothelial cells, astrocytes, and pericytes) in response to infection with neurotropic viruses transmitted by hematogenous routes, and also briefly describes the supportive effect of three cells on the BBB under normal physiological conditions. For example, all three types of cells express several PRRs, which can quickly sense the virus and make corresponding immune responses. The pro-inflammatory immune response will exacerbate the destruction of the BBB, while the anti-inflammatory immune response, based on type I IFN, consolidates the stability of the BBB. Exploring the details of the interaction between the host and the pathogen at the BBB during neurotropic virus infection will help to propose new treatments for viral encephalitis. Enhancing the defense function of the BBB, maintaining the integrity of the BBB, and suppressing the pro-inflammatory immune response of the BBB provide more ideas for limiting the neuroinvasion of neurotropic viruses. In the future, these new treatments are expected to cooperate with traditional antiviral methods to improve the therapeutic effect of viral encephalitis.

保护中枢神经系统免受病原体侵害的血脑屏障（BBB）由专门的大脑微血管内皮细胞（BMEC）组成，这些内皮细胞通过紧密的连接连接，并被周细胞和星形胶质细胞的足部包裹。BBB结构和功能的稳定性对于维持脑稳态具有重要意义。当嗜神经性病毒通过血源性或非血源性途径侵入中枢神经系统时，它可能引起BBB的结构和功能异常，并激活BBB抗炎或促炎性先天免疫应答。本文着眼于BBB的三个主要成分（内皮细胞，星形胶质细胞和周细胞）发生的结构和功能变化，这些变化是对通过血源性途径传播的嗜神经病毒感染的反应，并简要介绍了三种细胞在正常生理条件下对血脑屏障的支持作用。例如，所有三种类型的细胞都表达几种PRR，它们可以快速感知病毒并做出相应的免疫反应。促炎性免疫反应将加剧BBB的破坏，而基于I型IFN的抗炎性免疫反应则巩固了BBB的稳定性。探索在嗜神经性病毒感染期间宿主与BBB病原体之间相互作用的细节，将有助于为病毒性脑炎提出新的治疗方法。增强血脑屏障的防御功能，维持血脑屏障的完整性和抑制血脑屏障的促炎性免疫反应为限制神经营养性病毒的神经入侵提供了更多的思路。在将来，