ABSTRACT
Genetic recombination between different strains of Hepatitis C virus (HCV) was investigated in three chimpanzees inoculated experimentally with factor VIII concentrate containing HCV subgenotypes 1a, 1b, 2b and 3a. A 750 bp long fragment from the HCV envelope region was amplified by RT-PCR and quasispecies were isolated by plasmid cloning. Nucleotide sequences derived from isolated quasispecies were screened for the presence of inter-subgenotypic recombination by using sequence analysis. Recombination between HCV subgenotype 1a and 1b was found in two animals; each recombinant variant differed by location of predicted crossover region or order of subgenotype 1a and 1b sequences.
Subject(s)
Hepacivirus/classification , Hepacivirus/genetics , Hepatitis C/physiopathology , Animal Experimentation , Animals , DNA, Viral/analysis , Genome, Viral , Hepacivirus/isolation & purification , Hepatitis C/transmission , Hepatitis C/virology , Pan troglodytes , Phylogeny , Recombination, Genetic , Sequence Homology, Amino AcidABSTRACT
The protective efficacy of a DNA vaccine against hepatitis E virus (HEV) infection was tested in cynomolgus macaques (cynos) vaccinated with a plasmid containing a full-length HEV open-reading frame 2 (ORF2) sequence (Burmese strain) and subsequently challenged with a heterologous strain of HEV (Mexican strain). Cynos administered vaccine by gene gun developed antibodies to HEV (anti-HEV), whereas cynos administered vaccine by intradermal injections and cynos administered a mock DNA construct did not develop anti-HEV. Anti-HEV-positive cynos were protected from HEV infection after challenge with an inoculum that produced infection in the anti-HEV-negative cynos. These results indicate that DNA vaccine with HEV ORF2 administered by gene gun is protective against a heterologous viral challenge.
Subject(s)
Biolistics/methods , Hepatitis E virus/immunology , Hepatitis E/prevention & control , Vaccines, DNA/immunology , Viral Hepatitis Vaccines/immunology , Animals , Disease Models, Animal , Female , Hepatitis Antibodies/blood , Hepatitis E virus/genetics , Macaca , VaccinationABSTRACT
BACKGROUND: : The feasibility of DNA vaccination against hepatitis E in non-human primates has not been evaluated. In the present study a full-length hepatitis E virus (HEV) open reading frame (ORF)2 (Burmese strain) was assembled, cloned, and used for genetic immunization of cynomolgus macaques (cynos), which were subsequently challenged with a heterologous HEV strain (Mexico). METHODS: : Four cynos were vaccinated intramuscularly with the HEV ORF2 DNA cassette and one animal was vaccinated with a mock DNA construct. RESULTS: : Following vaccination anti-HEV antibodies were detected in the four HEV-DNA-vaccinated cynos, but not in the control animal. When challenged, two of the four HEV-DNA-vaccinated cynos were protected against HEV infection and had no elevated alanine aminotransferase activity, viremia, or fecal shedding. The two other DNA-vaccinated animals developed HEV infection and disease. CONCLUSION: : These findings demonstrate the feasibility of DNA vaccination for the protection of HEV infection and warrant further studies to explore routes other than intramuscular for induction of a stronger and efficacious immune response.
