title: B subunit of Escherichia coli heat-labile enterotoxin as adjuvant of humoral immune response in recombinant BCG vaccination.
abstract: The B subunit of Escherichia coli heat-labile enterotoxin (LTB), a nontoxic molecule with potent biological properties, is a powerful mucosal and parenteral adjuvant that induces a strong immune response against co-administered or coupled antigens. In this paper, the effect of LTB on the humoral immune response to recombinant BCG (rBCG) vaccination was evaluated. Isogenic mice were immunized with rBCG expressing the R1 repeat region of the P97 adhesin of Mycoplasma hyopneumoniae alone (rBCG/R1) or fused to LTB (rBCG/LTBR1). Anti-R1 systemic antibody levels (IgG1, IgG2a, IgG2b, IgG3, IgM, and IgA) were measured by ELISA using recombinant R1 as antigen. With the exception of IgM, LTB doubled the anti-R1 antibody levels in rBCG vaccination. The IgG1/IgG2a mean ratio showed that both rBCG/LTBR1 and rBCG/R1 induced a mixed Th1/Th2 immune response. Interestingly, anti-R1 serum IgA was induced only by rBCG/LTBR1. These results demonstrate that LTB has an adjuvant effect on the humoral immune response to recombinant antigens expressed in BCG.
authors.affiliation: Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, Pelotas, RS 96010-900, Brazil.
authors.forename: Andréa
authors.initials: A
authors.lastname: da Silva Ramos Rocha
authors.forename: Fabricio Rochedo
authors.initials: FR
authors.lastname: Conceição
authors.forename: André Alex
authors.initials: AA
authors.lastname: Grassmann
authors.forename: Valeska Lizzi
authors.initials: VL
authors.lastname: Lagranha
authors.forename: Odir Antônio
authors.initials: OA
authors.lastname: Dellagostin
mesh_terms: D018829:Adhesins, Bacterial / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000235:genetics; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000917:Antibody Formation; D001500:BCG Vaccine / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D003001:Cloning, Molecular; D004768:Enterotoxins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D029968:Escherichia coli Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D045705:Mycoplasma hyopneumoniae / Q000235:genetics / Q000276:immunology; D014376:Tuberculosis / Q000517:prevention & control; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D018829:Adhesins, Bacterial; D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D001500:BCG Vaccine; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C092236:P97 protein, Mycoplasma; D014614:Vaccines, Synthetic; C027538:heat-labile enterotoxin, E coli