Antigenic variation in visna virus

SUMMARYAntigenic relatedness between the virion-associated proteins of caprine arthritisencephalitis, visna and progressive pneumonia viruses was examined. Antigenic crossreactivity was assessed by immunoprecipitation of disrupted, radiolabeUed virus with goat, sheep and rabbit antisera, followed by resolution of the immunoprecipitation products by SDS-polyacrylamide gel electrophoresis. The results indicate that antigenic cross-reactivity between the caprine and ovine virus isolates involves all of the major virion-associated proteins and glycoproteins. The common antigenic determinants exhibited by virion structural proteins are immunogenic in goats, sheep and rabbits.

Section: Methodsmentioning

confidence: 99%

Antigenic Cross-reactivity between Caprine Arthritis-Encephalitis, Visna and Progressive Pneumonia Viruses Involves All Virion-associated Proteins and Glycoproteins

Gogolewski¹,

Adams

McGuire³

et al. 1985

“…The antigenic variation in visna virus was shown to result from oligonucleotide changes in the T-terminal region of the viral genome (Clements et al, 1982) which is the region that codes for the envelope glycoproteins of the virus. These proteins have been shown to be at least one of the antigenic targets for neutralization of virus (Scott et al, 1979).…”

Section: Introductionmentioning

confidence: 99%

Antigenic Variation of Caprine Arthritis-Encephalitis Virus during Persistent Infection of Goats

Ellis

Wilcox

Robinson

1987

SUMMARYSix caprine arthritis-encephalitis virus (CAEV)-free goats kept in strict isolation were inoculated intravenously with a cloned CAEV isolate (virus 020). At 78 weeks post-infection a virus (virus 095) isolated from one of the goats was shown to have the characteristics of CAEV, but was antigenically distinct from virus 020 and two other CAEV isolates by serum neutralization tests. Serum from the goat that had the variant virus neutralized the inoculum virus and the variant virus but serum from other inoculated goats neutralized only the inoculum virus. The variant virus and the inoculum virus were shown to co-exist in the infected goat, but the presence of the antigenic variant did not appear to be associated with an increase in severity of lesions compared with other inoculated goats.

“…Studies similar to those presented here have been reported for another retrovirus, visna, which causes a progressive (rather than periodic) disease in sheep. In the case of visna, Scott et al (1979) noted changes in the peptide maps of viral gp135 in antigenically distinct virus isolates, and in another study Clements et al (1980) reported up to seven oligonucleotides with altered mobilities in R N A fingerprints between an infecting virus and serologically distinct isolates from a diseased animal. The degree of genomic mutation reported by Clements et al (1980)for visna is similar to that reported here for E I A V isolates P2-1 and P2-6, between which seven changes were observed.…”

Section: Discussionmentioning

confidence: 99%

Genomic Alterations Associated with Persistent Infections by Equine Infectious Anaemia Virus, a Retrovirus

Payne¹,

Parekh²,

Montelaro

et al. 1984

SUMMARYThe unique periodic nature of equine infectious anaemia (EIA) is believed to result from the ability of the infecting virus, EIAV, to undergo relatively rapid antigenic variations which circumvent host immune responses resulting in distinct virus populations in sequential clinical episodes in the persistently infected horse. This model was examined by oligonucleotide mapping comparisons of the RNA genomes of selected isolates of EIAV. Variations in oligonucleotide maps could be reproducibly demonstrated (i) after adaptation of the laboratory strain of EIAV to replication in a pony, (ii) after serial passage of virus between two ponies, and (iii) after a prolonged persistent infection in a single pony. In the latter case, the two isolates examined were recovered from different clinical episodes and were shown to be antigenic variants. In contrast, no variations in RNA structure could be detected in oligonucleotide maps of virus isolated after prolonged passage in tissue culture. Thus, these results support our concept that EIAV is a highly mutable virus, which may give rise to antigenic variants in the presence of immune pressures. The degree of variation observed between oligonucleotide maps is similar to that observed previously between variants of visna virus. These similarities between EIAV and visna virus suggest that genomic point mutations producing antigenic variants may be a more important mechanism of retrovirus persistence than was previously recognized.