Effects of mutations in the VP2/VP4 cleavage site of Swine vesicular disease virus on RNA encapsidation and viral infectivity

Abstract

We studied VP0 cleavage of Swine vesicular disease virus (SVDV), a member of the Picornaviridae using a full-length cDNA copy of the Dutch SVDV isolate. The influences of mutations, introduced at the cleavage site of SVDV, on VP0 cleavage, RNA encapsidation and viral infection were studied. Double mutations at asparagine (VP0 aa 69) and serine (VP0 aa 70) resulted in no cleavage of VP0 and 100% inhibition of virus production. Mutation of the asparagine into threonine or phenylalanine resulted in a low amount of cleaved VP0 and infectious virus was found. After passage of this mutated virus VP0 cleavage became more efficient and the growth rate of the virus became similar to wild-type SVDV. The passaged virus had mutated at the asparagine site; the threonine had changed into an alanine and the phenylalanine into a cysteine. When the serine was mutated no maturation cleavage was observed and no infectious virus could be derived. All the mutations resulted in RNA encapsidation. We conclude that in the case of SVDV the cleavage site between VP2 and VP4 is essential for the formation of infectious virus which is comparable to poliovirus. The serine of the VP0 site was more important than the asparagine in this respect.

Report of a novel C1483W mutation in the hepatitis E virus polymerase in patients with acute liver failure

“…Earlier studies have reported about the significance of mutation in Cysteine having higher probability in causing disease (Vitkup et al, 2003). Besides, the asparagine into threonine mutation had been stated to trigger a decreased amount of cleaved VP0, one of the structural proteins of the Swine vesicular disease virus (SVDV),a nonenveloped single positive stranded RNA virus (Rebel et al, 2003). Thus, based on the results obtained, the present study reports for the first time the possible association of C1483W and N1530T mutations with high viral load in ALF and disease severity in pregnant women.…”

Noninfectious Virus-Like Particle Antigen for Detection of Swine Vesicular Disease Virus Antibodies in Pigs by Enzyme-Linked Immunosorbent Assay

“…4, our VLP-ELISA using neutralizing antibody 3H10 did not detect SVDV-specific antibodies in the (5,24). Several epitopes involved in neutralization of SVDV have been identified on the capsid surface (5,23,25,29,34), and although immune response in pigs is induced by linear epitopes (24), conformational epitopes are known to be the most immunogenic (5). In preliminary work, neutralizing antibodies (VN titers of up to 1:1,000) were developed in BALB/c mice vaccinated with our VLPs in Freund's adjuvant, although high neutralizing antibody titers were elicited by inactivated SVDV antigen (VN titers Ͼ 1:3,200) in mice (data not shown).…”

“…These structural proteins can then self-assemble to form empty capsid particles, which are composed of 60 copies of each structural protein (4,36). The final step in virion assembly involves cleavage of structural protein VP0 into VP4 and VP2 during encapsidation of viral RNA (4,34,36).…”

Characterization of porcine sapelovirus isolated from Japanese swine with PLC/PRF/5 cells

“…In contrast, the particles with a density of 1.285 g/cm 3 were empty particles (Figure d) that did not contain the virus genome. Empty virus particles are known to be produced as a natural product in most picornavirus‐infected cells, and these particles are usually generated without cleavage of the precursor (VP0) into VP2 and VP4 (Basavappa et al., ; Curry et al., ; Rebel, Leendertse, Dekker, & Moormann, ). In the present study, we found three protein bands—that is VP1, VP3 and an unknown protein band with a molecular mass of ~32 kDa—but bands corresponding to VP2 and VP4 were not found.…”