title: Protection against lethal leptospirosis after vaccination with LipL32 coupled or coadministered with the B subunit of Escherichia coli heat-labile enterotoxin.
abstract: Leptospirosis, a worldwide zoonosis, lacks an effective, safe, and cross-protective vaccine. LipL32, the most abundant, immunogenic, and conserved surface lipoprotein present in all pathogenic species of Leptospira, is a promising antigen candidate for a recombinant vaccine. However, several studies have reported a lack of protection when this protein is used as a subunit vaccine. In an attempt to enhance the immune response, we used LipL32 coupled to or coadministered with the B subunit of the Escherichia coli heat-labile enterotoxin (LTB) in a hamster model of leptospirosis. After homologous challenge with 5× the 50% lethal dose (LD(50)) of Leptospira interrogans, animals vaccinated with LipL32 coadministered with LTB and LTB::LipL32 had significantly higher survival rates (P < 0.05) than animals from the control group. This is the first report of a protective immune response afforded by a subunit vaccine using LipL32 and represents an important contribution toward the development of improved leptospirosis vaccines.
authors.affiliation: Unidade de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: André A
authors.initials: AA
authors.lastname: Grassmann
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Félix
authors.forename: Carolina Ximendes
authors.initials: CX
authors.lastname: dos Santos
authors.forename: Marta G
authors.initials: MG
authors.lastname: Amaral
authors.forename: Amilton C P
authors.initials: AC
authors.lastname: Seixas Neto
authors.forename: Michel Q
authors.initials: MQ
authors.lastname: Fagundes
authors.forename: Fabiana K
authors.initials: FK
authors.lastname: Seixas
authors.forename: Everton F
authors.initials: EF
authors.lastname: da Silva
authors.forename: Fabricio R
authors.initials: FR
authors.lastname: Conceição
authors.forename: Odir A
authors.initials: OA
authors.lastname: Dellagostin
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000008:administration & dosage / Q000276:immunology*; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006224:Cricetinae; D004195:Disease Models, Animal; D004768:Enterotoxins / Q000008:administration & dosage / Q000276:immunology*; D029968:Escherichia coli Proteins / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D007921:Leptospira interrogans / Q000276:immunology; D007922:Leptospirosis / Q000276:immunology / Q000401:mortality / Q000517:prevention & control*; D008074:Lipoproteins / Q000008:administration & dosage / Q000276:immunology*; D016019:Survival Analysis; D014611:Vaccination / Q000379:methods; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C406589:LipL32 protein, Leptospira; D008074:Lipoproteins; D022223:Vaccines, Subunit; D014614:Vaccines, Synthetic; C027538:heat-labile enterotoxin, E coli