title: Salmonella porins induce a sustained, lifelong specific bactericidal antibody memory response.
abstract: We examined the ability of porins from Salmonella enterica serovar typhi to induce a long-term antibody response in BALB/c mice. These porins triggered a strong lifelong production of immunoglobulin G (IgG) antibody in the absence of exogenous adjuvant. Analysis of the IgG subclasses produced during this antibody response revealed the presence of the subclasses IgG2b, IgG1, IgG2a and weak IgG3. Despite the high homology of porins, the long-lasting anti-S. typhi porin sera did not cross-react with S. typhimurium. Notably, the antiporin sera showed a sustained lifelong bactericidal-binding activity to the wild-type S. typhi strain, whereas porin-specific antibody titres measured by enzyme-linked immunosorbent assay (ELISA) decreased with time. Because our porin preparations contained the outer membrane proteins C and F (OmpC and OmpF), we evaluated the individual contribution of each porin to the long-lasting antibody response. OmpC and OmpF induced long-lasting antibody titres, measured by ELISA, which were sustained for 300 days. In contrast, although OmpC induced sustained high bactericidal antibody titres for 300 days, postimmunization, the bactericidal antibody titre induced by OmpF was not detected at day 180. These results indicate that OmpC is the main protein responsible for the antibody-mediated memory bactericidal response induced by porins. Taken together, our results show that porins are strong immunogens that confer lifelong specific bactericidal antibody responses in the absence of added adjuvant.
authors.affiliation: Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México.
authors.forename: Ismael
authors.initials: I
authors.lastname: Secundino
authors.forename: Constantino
authors.initials: C
authors.lastname: López-Macías
authors.forename: Luisa
authors.initials: L
authors.lastname: Cervantes-Barragán
authors.forename: Cristina
authors.initials: C
authors.lastname: Gil-Cruz
authors.forename: Nora
authors.initials: N
authors.lastname: Ríos-Sarabia
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Pastelin-Palacios
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Villasis-Keever
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Becker
authors.forename: José Luis
authors.initials: JL
authors.lastname: Puente
authors.forename: Edmundo
authors.initials: E
authors.lastname: Calva
authors.forename: Armando
authors.initials: A
authors.lastname: Isibasi
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007156:Immunologic Memory; D008070:Lipopolysaccharides / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D018272:Porins / Q000276:immunology*; D012485:Salmonella typhi / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; C113724:OmpC protein; C109237:OmpF protein; D018272:Porins