HSV-1 infected microglia escape immune response by down-regulating TLR3-mediated innate immune response by GM130

Background and Aims: To investigate the mechanism of GM130 regulating the antiviral immune response of TLR3 after HSV-1 infection of microglia cells. To explore the regulatoryof berberine on GM130 and TLR3 mediated immune response. Method The vitro model of HSV-1 infection was established by infecting BV2 cells with HSV-1. The protein levels of GM130 and TLR3 were detected by Immunoblotting. The secretion of inflammatory cytokines IFN-β, TNF-α and IL-6 was detected by enzyme-linked immunosorbent assay. The structural changes of Golgi apparatus were observed by immunofluorescence staining and transmission electron microscopy. Results Compared with the uninfected group, the Golgi apparatus fragmentation and GM130 in the HSV-1 infected group began to decrease at 6h; the level of TLR3 increased at 6h and began to decrease at 12h; the secretion of inflammatory cytokines IFN-β, TNF-α and IL-6 increased at 6h and 12h, but began to decrease at 24h afterinfection.In uninfected group, the Golgi apparatus was fragmented after GM130 knockdown, and the level of TLR3 was significantly reduced. In the HSV-1 infected group, GM130 knockdown aggravated the fragmentation of Golgi apparatus, and caused the level of TLR3 to further decrease, and the virus titer also increased significantly.In the HSV-1 infected group, over-expression of GM130 alleviated the Golgi fragmentation induced by HSV-1 and partially restored the level of TLR3.After GM130 knockdown in HSV-1 infection group, TLR3 excitant was added to partially restore the level of TLR3 and the secretion level of inflammatory factors.After GM130 over-expression in the HSV-1 infected group, treatment with TLR3 inhibitor TLR3i inhibited TLR3 levels and inflammatory factor secretion. Berberine can protect the Golgi apparatus and reverse the down-regulation of GM130 levels, as well as reverse the down-regulation of TLR3 and its downstream factor factorsafter HSV-1 infection, reducing the virus titer. Conclusion In microglia, HSV-1 infection induced Golgi stress response and decreased level of GM130.GM130 affects the secretion levels of inflammatory cytokines IFN-β, TNF-α and IL-6 and viral replication by regulating the levels of TLR3. Berberine protects the Golgi apparatus and enhances TLR3 mediated antiviral immune response.