Dr. Peera Jaruampornpan
Virology and Antibody Technology Research Unit, National Center for Genetic Engineering and Biotechnology, NSTDA, THAILAND
Abstract:
Nucleocapsid proteins constitute an essential component of most RNA viruses. Their primary roles are to organize the viral genomes and, in most cases, to participate in replication and transcription processes. They are also found to regulate or alter various cellular and immunological processes by interacting with myriads of viral and host factors. Indispensable for viruses, nucleocapsid proteins are usually highly conserved within the virus families and have always been popular as targets for antiviral development. Recently, basic research in our laboratory has suggested nucleocapsid proteins can play other more active roles in combatting infections of avian influenza viruses and porcine epidemic diarrhea virus (PEDV). For influenza viruses, we delineated the mechanism underlying influenza A virus growth suppression by influenza B virus nucleoprotein and attempted to develop a novel anti-avian influenza virus (type A) therapeutics based on type B nucleoprotein. For PEDV, we observed naturally-occurring cleavage of nucleocapsids during infection of some laboratory-adapted PEDV strains and showed that the presence of the cleavage site on nucleocapsid promoted PEDV growth in cell culture. We are now investigating whether the cleavage event plays a role in PEDV cell adaptation, which might be a considerable aid in PEDV live-attenuated vaccine production. Both of these lessons exemplify how we might rethink the use of viral nucleocapsid proteins in the battle against these viruses.