Control of Japanese encephalitis by Japanese Researchers

乙脑病毒引起人类和马的脑炎以及怀孕猪的流产。全面研究乙脑病毒的感染机制，从器官、细胞和分子水平阐明乙脑病毒动力学。分别表达DC-SIGN、DC-SIGNR和LSECtin使Daudi细胞易受乙脑病毒感染，而它们的作用取决于用于制备乙脑病毒的细胞系的来源以及表达的分子。乙脑病毒包膜(E)蛋白的分子量在不同细胞系间存在差异，而E蛋白上糖链的结构差异尚不清楚。甘露聚糖或G1cNAcB1-2Man特异性抑制凝集素介导的感染。这些结果提示了乙脑病毒在体内的动力学模型：乙脑病毒通过被感染蚊子的皮肤叮咬侵入并感染表达DC-SIGN分子的树突状细胞。树突状细胞产生的乙脑病毒进入血液并感染其他细胞，如表达DC-SIGNR和/或LSECtin的内皮细胞。乙脑病毒E蛋白的糖修饰可能取决于被感染的细胞类型，也可能影响下一个靶标。胎盘内皮细胞感染可导致猪流产。体内可能存在产生乙脑病毒的细胞，这些细胞容易感染中枢神经元系统。

JEV causes encephalitis in humans and horses and abortion in pregnant pigs. The infection mechanism of JEV was comprehensively studied to clarify JEV dynamics at the levels of organs, cells, and molecular levels.Expression of DC-SIGN, DC-SIGNR, and LSECtin, separately, made Daudi cells susceptible to JEV infection, while their effects depended on the origins of cell lines used for JEV preparation as well as the molecules expressed. Molecular weights of JEV envelope (E) protein were different among cell lines used, while structural differences of sugar chains on the E protein were unclear. Lectin-mediated infection was specifically inhibited by mannan or G1cNAcB1-2Man.These results suggest a model of JEV dynamics in vivo: JEV invades via skin-bites of infected mosquitoes and infects dendritic cells expressing DC-SIGN molecules. JEV produced by dendritic cells enters blood stream and infects other cells such as endothelial cells which express DC-SIGNR and/or LSECtin. Sugar modification of JEV E protein may depend on cell types infected and also affect a next target. Infection of placental endothelial cells may result in abortion of pigs. Cells producing JEV which tends to infect the central neuron system well could exist in vivo.