Orsay δ Protein Is Required for Nonlytic Viral Egress

An important step of the viral life cycle is how viruses exit from host cells to spread to other cells. Certain nonenveloped viruses can exit cultured cells in nonlytic ways; however, such nonlytic exit has not been demonstratedin vivo . In addition, it is not clear how such nonlytic exit is achieved mechanisticallyin vivo . Orsay virus is a nonenveloped RNA virus that infects the intestine cells of the nematodeC. elegans . It is currently the only virus known to naturally infectC. elegans . Using thisin vivo model, we show that the δ protein encoded by Orsay virus facilitates the nonlytic exit of the virus, possibly by interacting with host actin on the apical side of worm intestine cells.