Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2006
Publication Date: 12/5/2006
Citation: Risatti, G.R., Holinka, L.G., Carillo, C., Kutish, G.F., Lu, Z., Tulman, E.R., Fernandez-Sainz, I., Borca, M.V. 2006. Identification of a Novel Virulence Determinant Within the E2 Structural Glycoprotein of Classical Swine Fever Virus. Conference of Research Workers in Animal Disease (CRWAD) annual meeting, Chicago, IL, December 3-5, 2006, page 201.
Technical Abstract: Classical Swine Fever Virus (CSFV) E2 glycoprotein contains a discrete epitope (TAVSPTTLR, residues 829-837 of CSFV polyprotein) recognized by monoclonal antibody (mAb) WH303, used to differentiate CSFV from related ruminant Pestiviruses, Bovine Viral Diarrhea Virus (BVDV) and Border Disease Virus (BDV), that infect swine without causing disease. Progressive mutations were introduced into mAb WH303 epitope in CSFV virulent strain Brescia (BIC virus) to obtain the homologous amino acid sequence of BVDV strain NADL E2 (TSFNMDTLA). In vitro growth of mutants T1 virus(TSFSPTTLR), T2 virus (TSFNPTTLR), T3 virus (TSFNMTTLR) was similar to parental BIC virus, while mutants T4 virus (TSFNMDTLR) and T5 virus (TSFNMDTLA) exhibited a 10-fold decrease in virus yield and reduced plaque size. In vivo, T1 virus, T2 virus or T3 virus induced lethal disease, T4 virus induced mild and transient disease, and T5 virus induced mild clinical signs. Protection against BIC virus challenge was observed at 3 and 21 days post T5 virus infection. These results indicate that E2 residues TAVSPTTLR play a significant role in CSFV virulence.