Submitted to: Positive Strand RNA Virus International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/1/2004
Publication Date: 6/1/2004
Citation: Borca, M.V., Risatti, G.R., Kutish, G.F., Lu, Z., Holinka, L.G., French, R.A., Sur, J., Rock, D.L. 2004. A 19mer peptide insertion in the e1 glycoprotein of classical swine fever virus affects viral virulence in swine [abstract]. Positive Strand RNA Virus International Conference Proceedings. p. 109. Interpretive Summary: Poxvirus Meeting.
Technical Abstract: Transposon linker insertion mutagenesis of a full-length infectious clone of the pathogenic classical swine fever virus (CSFV) isolate Brescia (pBIC) was used to identify genetic determinants of CSFV virulence and host range. A virus mutant, RB-C22 (RB-C22v), possessing a 19-residue tag insertion at the carboxyl end of E1 was constructed. RB-C22v and the parental virus pBIC (pBICv) exhibited similar growth characteristics on primary porcine macrophage cell cultures although RB-C22v produced significantly smaller plaques on SK6 cell cultures. In vivo, RB-C22v was markedly attenuated in swine. In contrast with pBIC infection, where mortality was 100%, all RB-C22v- infected pigs survived infection remaining clinically normal. A delay in spread to and decreased replication of RB-C22v in the tonsils were accompanied by a delay in generalization of infection, and a 10(2) to 10(7) log10 reduction in virus titers in lymphoid tissues and blood. These results indicate that a domain of E1 glycoprotein affects swine virulence