title: Cloning, expression and immunogenicity of the translation initiation factor 3 homologue of Brucella abortus.
abstract: The infC gene of Brucella abortus encoding the translation initiation factor 3 (IF3) was cloned, sequenced and expressed in Escherichia coli. The amino acid sequence analysis predicted a product with 74-80% identity with the IF3 proteins from Mesorhizobium loti, Sinorhizobium meliloti, Aurantimona sp. and Mesorhizobium sp. This protein also show 54% amino acid sequence identity with the E. coli IF3, sharing most of the residues which were described as responsible for the biological activity of this protein. Since we have previously reported the immunoprotective capacity of this Brucella protein, we stimulated lymphoid cells from animals immunized with purified recombinant Brucella IF3 protein "in vitro" with this antigen. The lymphocytes were able to mount a strong proliferative response with concomitant production of gamma interferon, but without the secretion of either IL-4 or antibodies. Thus, immunization with the Brucella recombinant IF3 protein promotes a TH-1 polarized response, allowing us to propose it as a promising candidate antigen for the development of subunit vaccines against Brucella.
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Molecular Immunology Laboratory, Universidad de Concepción, Concepción, Chile.
authors.forename: Marcela
authors.initials: M
authors.lastname: González
authors.forename: Edilia
authors.initials: E
authors.lastname: Andrews
authors.forename: Hugo
authors.initials: H
authors.lastname: Folch
authors.forename: Darwin
authors.initials: D
authors.lastname: Sáez
authors.forename: Alex
authors.initials: A
authors.lastname: Cabrera
authors.forename: Paulina
authors.initials: P
authors.lastname: Salgado
authors.forename: Angel
authors.initials: A
authors.lastname: Oñate
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002004:Brucella Vaccine / Q000235:genetics / Q000276:immunology*; D002003:Brucella abortus / Q000276:immunology*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D005260:Female; D015870:Gene Expression; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D039665:Prokaryotic Initiation Factor-3 / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D016415:Sequence Alignment; D022223:Vaccines, Subunit / Q000235:genetics / Q000276:immunology
chemical_list: D002004:Brucella Vaccine; D039665:Prokaryotic Initiation Factor-3; D011993:Recombinant Fusion Proteins; D022223:Vaccines, Subunit; D015847:Interleukin-4; D007371:Interferon-gamma