Rab8, a vesicular traffic regulator, is involved in dengue virus infection in HepG2 cells

Objective: The pathogenesis of dengue virus (DV) has not been completely clarified. Rab8 regulates vesicular traffic from Golgi to plasma membrane where DV is matured and then delivered by exocytosis. In this study, involvement of Rab8 in DV serotype 2 (DV2) infection was investigated in HpeG2 cells. Methods: Distributions of Rab8 and DV2, and the number of infection cells were observed by immunostaining. HepG2(Rab8AM) and HepG2(Rab8DN) cells were constructed to stably express a constitutively active mutant of Rab8 and a dominant negative mutant, respectively, which were assessed by flow cytometry. Production of infectious virions and the amounts of DV2 entry were detected by standard plaque assay. Viral RNA replication was detected by real-time RT-PCR. Results: Rab8 showed high co-localization with DV2 in HpeG2 cells and the amount of DV antigen-positive cells decreased in HepG2(Rab8AM) and HepG2(Rab8DN) cells. Also, progeny virus released from those cells was drastically reduced. Infectious virions produced in cells were also significantly reduced, while the viral RNA replication was downregulated by a different level. Furthermore, viral entry into those cells was reduced by about 80%. Conclusions: Our data suggest that the function of Rab8 is important for DV2 infection, and Rab8 may be involved in DV2 infection. Copyright (C) 2008 S. Karger AG, Basel.