Identification and characterization of host cell factors that determine the susceptibility of human and animal cells to coronavirus IBV

Abstract

DExH/D box helicases have been characterized to contribute to a multitude of functions in the host cells, most knowingly involved in the unwinding of RNA in an ATP-dependent manner. Some of these helicases have been shown to affect virus infectivity. Despite advances in understanding Coronavirus replication, there is neither a vaccine nor anti-viral against it. Identification of three DExH/D box helicases has been implicated to play a role in the pathogenesis of Infectious Bronchitis Coronavirus (IBV), being either suppressive or permissive host factors. Suggestively, DDX3 plays a role in repressing IBV infection, possibly through a type-I interferon dependent manner. Contrastingly, DDX21 and DHX8 have been implicated to transit from a repressive to a permissive factor during IBV replication. It is hinted that DDX21 may be involved with interacting with IBV Nsp14 and DDX1 in facilitating replication. On the other hand, DHX8 might play a role in cell cycle regulation as a favorable G2/M phase is needed for optimal IBV replication, hence DHX8 might be involved in this regulation. Collectively, the mechanistic insight of these DExH/D box helicases not only contributes to understanding Coronavirus replication but may lead to potential therapeutic targets for the development of anti-virals in the future.