In addition, microglia can also exert an antiviral effect by inducing autophagy or secreting cytokines. Microglia can exert a direct antiviral effect by producing type 1 interferon (IFN-1) to induce IFN-stimulated gene (ISG) expression of themselves or indirect antiviral effects by IFN-1 acting on other cells to activate corresponding signaling pathways. On the one hand, microglia can sense ATP signals through the purinergic receptor P2Y12 and are recruited around infected neurons to exert phagocytic activity. Studies have shown that microglia also act as a double-edged sword during viral encephalitis. Microglia, as resident cells of the central nervous system (CNS), can respond quickly to various CNS injuries including trauma, ischemia, and infection and maintain the homeostasis of CNS, but this response is not always good sometimes, it will exacerbate damage. At present, people are studying the role of the innate immune system in viral encephalitis. Some patients cannot get effective relief or suffer from serious sequelae. Viral encephalitis is still very prominent around the world, and traditional antiviral therapies still have shortcomings.
