Immunization with a recombinant fowlpox virus expressing a hepatitis C virus core–E1 polyprotein variant, protects mice and African green monkeys (Chlorocebus aethiops sabaeus) against challenge with a surrogate vaccinia virus

Abstract

HCV (hepatitis C virus) is a worldwide health problem nowadays. No preventive vaccine is available against this pathogen, and therapeutic treatments currently in use have important drawbacks, including limited efficacy. In the present work a recombinant fowlpox virus, FPCoE1, expressing a truncated HCV core-E1 polyprotein, was generated. FPCoE1 virus generally failed to elicit a humoral immune response against HCV antigens in BALB/c mice. By contrast, mice inoculated with FPCoE1 elicited a positive interferon-gamma secretion response against HCV core in ex-vivo ELISPOT (enzyme-linked immunospot) assays. Remarkably, mice inoculated with FPCoE1 significantly controlled viraemia in a surrogate challenge model with vvRE, a recombinant vaccinia virus expressing HCV structural antigens. In fact, 40% of the mice had no detectable levels of vvRE in their ovaries. Administration of FPCoE1 in vervet monkeys [Chlorocebus (formerly Cercophitecus) aethiops sabaeus] induced lymphoproliferative response against HCV core and E1 proteins in 50% of immunized animals. Monkeys immunized with FPCoE1 had no detectable levels of vvRE in their blood, whereas monkeys inoculated with FP9, the negative control virus, had detectable levels of vvRE in blood up to 7 days after challenge. In conclusion, recombinant fowlpox virus FPCoE1 is able to induce an anti-HCV immune response in mice and monkeys. This ability could be rationally employed to develop effective strategies against HCV infection by using FPCoE1 in combination with other vaccine candidates or antiviral treatments.

Recombinant adenovirus expressing the haemagglutinin of peste des petits ruminants virus (PPRV) protects goats against challenge with pathogenic virus; a DIVA vaccine for PPR

“…We have sought to evaluate two alternative vectors for expression of the PPRV H and F glycoproteins, fowlpox virus (FP) and replication-defective human adenovirus type 5 (Ad). Recombinant FP-based vaccines have been proven to be effective when used in mammals, despite their inability to replicate in mammalian cells [5,6]. Replication-defective adenovirus vectors have been shown to be a promising platform for delivery of vaccine antigens in a number of species.…”

Viremia and antibody response in green monkeys (Chlorocebus aethiops sabaeus) infected with dengue virus type 2: A potential model for vaccine testing

“…In parallel, their costs have risen significantly, with current prices for a rhesus macaque reaching over $5000 (10, 11). In this context, green monkeys ( Chlorocebus [formerly Cercopithecus ] aethiops sabaeus ), which have proven useful as a model for several infectious diseases (12–15), could offer a less expensive and more readily available alternative for the evaluation of candidates for dengue vaccines. In this study, we assessed the capacity of green monkeys to allow replication of DEN2 virus, as a potential model for vaccine testing.…”