title: Vaccination with recombinant Semliki Forest virus particles expressing translation initiation factor 3 of Brucella abortus induces protective immunity in BALB/c mice.
abstract: Recombinant replicons of Semliki Forest virus (SFV) can be used to induce high-level, transient expression of heterologous proteins in vivo. We constructed infectious but replication-deficient SFV particles carrying recombinant RNA encoding the Brucella abortus translation initiation factor 3 (IF3). The recombinant SFV particles (SFV-IF3 particles) were then evaluated for their ability to induce immune responses and to protect BALB/c mice against a challenge with B. abortus 2308 following vaccination. Animals inoculated with SFV-IF3 developed IF3-specific IgM antibodies at day 14 post-immunization. In vitro stimulation of splenocytes from vaccinated mice with either recombinant IF3 (rIF3) or crude Brucella protein extracts resulted in a T-cell proliferative response and induction of interferon gamma secretion, but not interleukin-4. In addition, mice immunized with SFV-IF3 exhibited a significant level of resistance against challenge with the virulent B. abortus strain 2308 (P<0.01). These findings indicate that an SFV-based vector carrying RNA encoding Brucella IF3 has potential for use as a vaccine to induce protection against B. abortus infections.
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepcion, Chile.
authors.forename: Alex
authors.initials: A
authors.lastname: Cabrera
authors.forename: Darwin
authors.initials: D
authors.lastname: Sáez
authors.forename: Sandra
authors.initials: S
authors.lastname: Céspedes
authors.forename: Edilia
authors.initials: E
authors.lastname: Andrews
authors.forename: Angel
authors.initials: A
authors.lastname: Oñate
mesh_terms: D018354:Alphavirus Infections / Q000276:immunology* / Q000517:prevention & control; D000818:Animals; D002003:Brucella abortus / Q000235:genetics; D039642:Eukaryotic Initiation Factors / Q000235:genetics / Q000276:immunology*; D005818:Genetic Engineering; D007110:Immunity, Active / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D039665:Prokaryotic Initiation Factor-3 / Q000235:genetics / Q000276:immunology*; D011995:Recombination, Genetic; D012672:Semliki forest virus / Q000276:immunology* / Q000472:pathogenicity; D014611:Vaccination; D014774:Virulence
chemical_list: D039642:Eukaryotic Initiation Factors; D039665:Prokaryotic Initiation Factor-3