virulence determinant within classical fever virus structural glycoprotein e2

摘要

DETERMINANT OF VIDRULENCE WITHIN THE STRUCTURAL GLYCOPROTEIN E2 OF THE CLASSIC SWINE FEVER VIRUS. The classical swine fever virus (CSFV) E2 glycoprotein is a major inducer of neutralizing antibodies and protective immunity in pigs. E2 mediates the adsorption of viruses in target cells and harbors genetic determinants associated with the virulence of the virus. CSFV E2 also contains, between residues 829 and 837, one is a distinct pitope (TAVSTTLR) recognized by the monoclonal antibody (mAb) WH303, being to differentiate CSFV from Pestiviruses Bovine Viral Diarrhea Virus (BVDV) and Spot Disease Virus (BDV). In that report, an infectious CSFV clone from the virulent isolate Brescia (BICv) was used to perform progressive mutations in the WH303 epitope of the CSFV E2 mAb to the homologous amino acid sequence of the BVDV NADL strain (TSFNMDTLA). Although the resulting viral mutants T1v (TSFSTTLR) T2v (TSIWTTLR), T3v (TSFNMTTLR) demonstrated similar in vitro growth characteristics to those of the precursor BICv, T4v (TSFNMDTLR) and T5v (TSFNMDTLA) mutants exhibited a 10-fold decrease in production and a significant decrease in plaque size compared to precursor BICv. Immunohistochemistry reactivity with WH303 was lost only in T3v, T4v and T5v.