Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2006
Publication Date: 12/5/2006
Citation: Risatti, G., Holinka, L.G., Fernandez-Sainz, I., Carrillo, C., Lu, Z., Borca, M.V. 2006. N-linked glycosylation status of classical swine fever virus strain brescia e2 glycoprotein influences virulence in swine. Conference of Research Workers in Animal Disease (CRWAD) annual meeting, Chicago, IL, December 3-5, 2006, page 200.
Technical Abstract: E2 is one of the three envelope glycoproteins of Classical Swine Fever Virus (CSFV). Previous studies indicate that E2 is involved in several functions including virus attachment and entry to target cells, production of antibodies, induction of protective immune response in swine, and virulence. Here, we have investigated the role of E2 glycosylation of highly virulent CSFV strain Brescia in infection of the natural host. Seven putative glycosylation sites in E2 were modified by site directed mutagenesis of a CSFV Brescia infectious clone (BIC virus). A panel of virus mutants was obtained and used to investigate whether the removal of putative glycosylation sites in the E2 glycoprotein would affect viral virulence/pathogenesis in swine. We observed that rescue of viable virus was completely impaired by removal of all putative glycosylation sites in E2, but restored when mutation N185A reverted to wild-type asparagine producing viable virus (Delta O1N1-N6/N3 virus) that was attenuated in swine. Single mutations of each of the E2 glycosylation sites showed that amino acid N116 (N1 virus) was responsible for BIC virus attenuation. N1v efficiently protected swine from challenge with virulent BIC virus at 3 and 28 days post-infection suggesting that glycosylation of E2 could be modified for development of CSF live-attenuated vaccines.