TLR3, RIG-Ⅰ Pathway In Microglia Inflammatory Response Induced By Japanese Encephalitis Virus

Japanese encephalitis (JE) is a zoonosis caused by Japanese encephalitis virus (JEV). Patients may be with multiple manifestations like fever, diarrhea, headache, nausea, decreased level of consciousness, trembling and action abnormality, and reproductive disorder has been always performed in infected pigs. The key point of death in human and animals caused by JEV is targeting the central nervous system (CNS) and causing its inflammation response. Meanwhile, the excessive activation of microglia and inflammatory secretion induced by activated microglia is important for brain inflammation in JE. However, the exact signaling pathway via which JEV activated microglia and its molecular mechanism are still not clear.This study starts with TLR.3and RIG-Ⅰ signaling pathway and focuses on inflammatory mediators’expression after microglia activation, which stimulated by Japanese encephalitis virus.The main projects are as follows:Mouse microglia cell line BV-2was set as a model in vitro. To detect Japanese encephalitis virus infection of the cells, it was performed JEV showed proliferation in BV-2cells but with less than10-fold copies of C gene increase. Upregulation of TNF-a, IL-6and CCL-2appeared in both mRNA and protein level expression which stimulated by JEV. Meanwhile, the result of Western Blot demonstrated that JEV infection could effectively stimulate TLR3and RIG-Ⅰ expression, and phosphorylation of ERK, p38MAPK protein was increased significantly after infection. Then shRNA transfection of TLR3and RIG-Ⅰ was used for interference, changes of the above indicators were observed. We found that phosphorylation of ERK, p38MAPK protein, the expression of transcription factor NF-κB, AP-1in cell nuclear and the expression of inflammatory factors were restrained in varying degrees, and proliferation of JEV was increased, which suggests that TLR3and RIG-Ⅰ play important roles in inflammatory response and viral replication of Japanese encephalitis virus activated microglia, and the role of RIG-I does more significantly than TLR3.