title: Immunogenicity of the Brucella melitensis recombinant ribosome recycling factor-homologous protein and its cDNA.
abstract: A study was conducted to evaluate the immunogenicity of the Brucella melitensis ribosome recycling factor (RRF)-homologous protein (CP24). The CP24 gene was cloned, expressed in Escherichia coli and purified. The resulting purified recombinant protein (rCP24) produced delayed-type hypersensitivity (DTH) reactions in B. melitensis-infected mice but not in naive controls. Thus, we decided to characterise the immune responses generated with DNA vaccination (pcDNACP24) or immunisation with the rCP24 in adjuvant. Animals injected with pcDNACP24 exhibited a dominance of IgG2a to IgG1 while mice injected with rCP24 developed a higher response of IgG1 than IgG2a. Both immunisation protocols were capable of eliciting CP24-specific gamma interferon (IFN-gamma) producing cells. Spleen cells from pcDNACP24-immunised mice did not produce interleukin (IL)-4, IL-10 or up-regulation of IL-2 mRNA. Cells from rCP24-immunised mice produced IL-10, up-regulated IL-2 mRNA but did not produce IL-4. Neither immunisation with purified CP24 nor injection of pcDNACP24 protected mice against challenge with live smooth B. melitensis. However, the potential of CP24 for a Brucella diagnostic test based on an in vitro antigen (Ag)-specific IFN-gamma production or DTH test would be worth testing.
authors.affiliation: Facultad de Farmacia y Bioquímica, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Universidad de Buenos Aires (UBA), Junín 956, 1113 Buenos Aires, Argentina.
authors.forename: Juliana
authors.initials: J
authors.lastname: Cassataro
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Velikovsky
authors.forename: Guillermo H
authors.initials: GH
authors.lastname: Giambartolomei
authors.forename: Silvia
authors.initials: S
authors.lastname: Estein
authors.forename: Laura
authors.initials: L
authors.lastname: Bruno
authors.forename: Axel
authors.initials: A
authors.lastname: Cloeckaert
authors.forename: Raul A
authors.initials: RA
authors.lastname: Bowden
authors.forename: Moisés
authors.initials: M
authors.lastname: Spitz
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Fossati
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology*; D001483:Base Sequence; D002004:Brucella Vaccine / Q000235:genetics / Q000276:immunology*; D017347:Brucella melitensis / Q000235:genetics* / Q000276:immunology*; D019556:COS Cells; D003001:Cloning, Molecular; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D015870:Gene Expression; D005798:Genes, Bacterial; D006968:Hypersensitivity, Delayed; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014162:Transfection; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002004:Brucella Vaccine; C102461:CP24 protein, Brucella melitensis; D016207:Cytokines; D004269:DNA, Bacterial; D018076:DNA, Complementary; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic