A Study on the entry of Japanese encephalitis virus into mosquito cells through V-ATPase-dependent endocytosis

• Main Authors: Wei-Chun Chai, 翟維君
• Other Authors: Wei-June Chen
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/01797666215716279520

碩士 === 長庚大學 === 基礎醫學研究所 === 93 === Japanese encephalitis virus (JEV) is a member of the family Flaviviridae. It has been reported that JEV infection of C6/36 mosquito cells was inhibited by bafilomycin A1, a specific inhibitor of vacuolar type H+-ATPase (V-ATPase). However, electron microscopic studies have demonstrated that JE and type 2 dengue viruses may directly penetrate into C6/36 mosquito cells at physiological pH. It is not generally accepted that direct penetration of virions is the mode of the flavivirus entry in the productive infection. There have been reports that flaviviruses enter the cell by receptor-mediated endocytosis, primarily in mammalian cells. Especially, clathrin-dependent and caveola-dependent pathways were two main pathways in the virus entry mechanism. Endocytic activity of cells can be analysed by using pharmacological agents. We analysed the effects of chlorpromazine on JEV production and its relations with V-ATPase in C6/36 cells. The results showed that acidification of intracellular compartments was dependent on V-ATPase activity in the cells. When JEV infected C6/36 cells, the expression of V-ATPase was raised up at both protein and mRNA levels. The JEV titer in chlorpromazine-treated C6/36 cells was lower than that in untreated cells. These reports demonstrated that JEV was taken up by the cells through a constitutive endocytic pathway, and low pH in the vesicles, presumably regulated by V-ATPase, plays an important role in intracellular translocation of the virions. The inhibition of virus infection in C6/36 cells by chlorpromazine also demonstrated that endocytosis of JEV by mosquito cells is clathrin-dependent.