The inhibition of AaSTAT signal transduction by the NS3 protein of Japanese encephalitis virus

• Main Authors: Ya-Chi Chen, 陳雅祺
• Other Authors: Chang-Chi Lin
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/68701787846590599186

碩士 === 國防醫學院 === 微生物及免疫學研究所 === 96 === AaSTAT protein from mosquito, Aedes albopictus, is homologue to those STATs of Drosophila, Anopheles, and mammals, and with similar activities in the host early development and immune functions. Japanese encephalitis virus (JEV) is a member of the mosquito-borne flavivirus that can cause human encephalitis in Asia annually. In the past study, C6/36 cells infected with JEV revealed a decrease of tyrosine phosphorylation and DNA binding activity of AaSTAT, but it didn’t show which viral protein participate this effect. In this study, the NS3 of JEV was found to interact with AaSTAT by immunoprecipitation and Western blotting and colocalized with AaSTAT in the nucleus by confocal Immunofluorescence assay and Western blotting. The NS2B-NS3 full length and NS2B-NS3-N’ 185aa length was constructed in PIZ/His vector into C6/36 cells in order to detect the interaction of JEV NS3 with mosquito AaSTAT. Also pCMV vector expressing NS2B-NS3 full or N’-185aa length combined with pCDNA vector expressing AaSTAT, or AaSTAT-Jak were transfected into mammalian COS-1 cells to evaluate this two protein interaction. This is the first report that NS3 protein of JEV interact with the mosquito AaSTAT in the nucleus. Further investigation: include using EMSA and transactivation assay to verify the decreasing of tyrosine phosphorylation and DNA binding activity of AaSTAT in these construct plasmid in C6/36 and COS-1 cells; and JEV infection of mosquito in vivo by confocal, Western blot, EMSA, and immunoprecipitation assay.