title: Cell-based analysis of Chikungunya virus membrane fusion using baculovirus-expression vectors.
abstract: Chikungunya virus infection has emerged in many countries over the past decade. There are no effective drugs for controlling the disease. To develop cell-based system for screening anti-virus drugs, a bi-cistronic baculovirus expression system was utilized to co-express viral structural proteins C (capsid), E2 and E1 and the enhanced green fluorescence protein (EGFP) in Spodoptera frugiperda insect cells (Sf21). The EGFP-positive Sf21 cells fused with each other and with uninfected cells to form a syncytium, allowing characterization of cholesterol and low pH requirements for syncytium formation. Western blot analysis showed three structural proteins were expressed in baculovirus infected cells. The structural proteins of Chikungunya virus that is required for cell fusion was determined with various recombinant baculoviruses bearing different lengths of the viral structural protein genes. Protein E1 was required for cell fusion and indicating that Chikungunya viral membrane fusion was a class II membrane fusion. It was also demonstrated that the heterologous expression of alphavirus monomeric E1 can induce insect cell fusions. Furthermore, this cell-based system provides a model for studying class II viral membrane fusion.
authors.affiliation: Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan 333, Taiwan.
authors.forename: Szu-Cheng
authors.initials: SC
authors.lastname: Kuo
authors.forename: Ying-Ju
authors.initials: YJ
authors.lastname: Chen
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Wang
authors.forename: Ming-Der
authors.initials: MD
authors.lastname: Kuo
authors.forename: Tzyy-Rong
authors.initials: TR
authors.lastname: Jinn
authors.forename: Wen-Shuo
authors.initials: WS
authors.lastname: Chen
authors.forename: Yen-Chung
authors.initials: YC
authors.lastname: Chang
authors.forename: Kuo-Lun
authors.initials: KL
authors.lastname: Tung
authors.forename: Tzong-Yuan
authors.initials: TY
authors.lastname: Wu
authors.forename: Szecheng J
authors.initials: SJ
authors.lastname: Lo
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics*; D018929:Cell Culture Techniques; D002459:Cell Fusion; D002460:Cell Line; D002646:Chikungunya virus / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D018411:Spodoptera; D015678:Viral Structural Proteins / Q000096:biosynthesis* / Q000235:genetics; D053586:Virus Internalization
chemical_list: D011993:Recombinant Fusion Proteins; D015678:Viral Structural Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins