title: Evaluation of protective effect of DNA vaccines encoding the BAB1_0263 and BAB1_0278 open reading frames of Brucella abortus in BALB/c mice.
abstract: The immunogenicity of two DNA vaccines encoding open reading frames (ORFs) of genomic island 3 (GI-3), specific for Brucella abortus and Brucella melitensis, has been examined. Intramuscular injection of plasmid DNA carrying the BAB1_0263 and BAB1_0278 genes (pVF263 and pVF278, respectively) into BALB/c mice elicited both humoral and cellular immune responses. Mice injected with pVF263 or pVF278 had a dominant immunoglobulin G2a (IgG2a) response. In addition, both DNA vaccines elicited a T-cell-proliferative response, but only pVF263 induced significant levels of interferon gamma (INF-γ) upon restimulation with recombinant 263 protein. Neither DNA vaccine induced interleukin (IL)-10, nor IL-4, upon stimulation with an appropriate recombinant protein or crude Brucella protein, suggesting the induction of a typical T-helper 1 (Th1)-dominated immune response. Furthermore, the pVF278 DNA vaccines induced protection in BALB/c mice against challenge with the virulent strain B. abortus 2308. Taken together, these data suggest that DNA vaccination offers an improved delivery strategy for the BAB1_0278 antigen, and provide the first evidence of a protective effect of this antigen.
authors.affiliation: Molecular Immunology Laboratory, Department of Microbiology, Universidad de Concepción, Concepción, Chile.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Sislema-Egas
authors.forename: Sandra
authors.initials: S
authors.lastname: Céspedes
authors.forename: Pablo
authors.initials: P
authors.lastname: Fernández
authors.forename: Angello
authors.initials: A
authors.lastname: Retamal-Díaz
authors.forename: Darwin
authors.initials: D
authors.lastname: Sáez
authors.forename: Angel
authors.initials: A
authors.lastname: Oñate
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D002004:Brucella Vaccine / Q000008:administration & dosage / Q000276:immunology*; D002003:Brucella abortus / Q000235:genetics / Q000276:immunology*; D017347:Brucella melitensis / Q000235:genetics / Q000276:immunology*; D002006:Brucellosis / Q000517:prevention & control*; D049109:Cell Proliferation; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016366:Open Reading Frames; D013601:T-Lymphocytes / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D002004:Brucella Vaccine; D007074:Immunoglobulin G; D019444:Vaccines, DNA; D007371:Interferon-gamma