Autonomously Replicating RNAs of Bungowannah Pestivirus: E RNS Is Not Essential for the Generation of Infectious Particles

Abstract

The proteins N PRO and E RNS are unique for the genus Pestivirus , but only N PRO has been demonstrated to be nonessential for in vitro growth. While this was also speculated for E RNS , it has always been previously shown that pestivirus replicons with deletions of the structural proteins E RNS , E1, or E2 did not produce any infectious progeny virus in susceptible host cells. Here, we demonstrated for the first time that BuPV E RNS is dispensable for the generation of infectious virus particles but still important for efficient passaging. The E RNS -defective BuPV particles showed clearly limited growth in cell culture but were capable of several rounds of infection, expression of foreign genes, and highly efficient trans -complementation to rescue virus replicon particles (VRPs). The noncytopathic characteristics and the absence of preexisting immunity to BuPV in human populations and livestock also provide a significant benefit for a possible use, e.g., as a vector vaccine platform.