title: Protective immunity against challenge with Leishmania (Leishmania) chagasi in beagle dogs vaccinated with recombinant A2 protein.
abstract: In this study, we investigated in dogs the immunogenicity and protective immunity against Leishmania (Leishmania) chagasi infection induced by vaccination with a formulation containing the recombinant A2 protein, an amastigote specific antigen, and saponin. Vaccinated animals produced significantly increased levels of total IgG and IgG2, but not IgG1 anti-A2 antibodies, and remained negative in conventional leishmaniasis serodiagnostic methods. Significantly increased IFN-gamma and low IL-10 levels were detected in vaccinated animals before and after challenge, as compared to control animals. Importantly, while the symptoms onset appeared as early as three months after infection in most control dogs, 14 months after challenge, 5 out of 7 vaccinated dogs remained asymptomatic. Therefore, immunization with rA2 antigen was immunogenic and induced partial protection in dogs, and allowed the serological differentiation between vaccinated and infected animals, an important requirement for a canine visceral leishmaniasis (CVL) vaccine.
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. anav@uai.com.br
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Fernandes
authors.forename: Míriam Maria Silva
authors.initials: MM
authors.lastname: Costa
authors.forename: Eduardo Antônio Ferraz
authors.initials: EA
authors.lastname: Coelho
authors.forename: Marilene Suzan Marques
authors.initials: MS
authors.lastname: Michalick
authors.forename: Eloísa
authors.initials: E
authors.lastname: de Freitas
authors.forename: Maria Norma
authors.initials: MN
authors.lastname: Melo
authors.forename: Wagner
authors.initials: W
authors.lastname: Luiz Tafuri
authors.forename: Daniela de Melo
authors.initials: Dde M
authors.lastname: Resende
authors.forename: Vinícius
authors.initials: V
authors.lastname: Hermont
authors.forename: Christiane de Freitas
authors.initials: Cde F
authors.lastname: Abrantes
authors.forename: Ricardo Tostes
authors.initials: RT
authors.lastname: Gazzinelli
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology*; D001854:Bone Marrow Cells / Q000276:immunology; D002469:Cell Separation; D016207:Cytokines / Q000096:biosynthesis; D016054:DNA, Protozoan / Q000032:analysis / Q000302:isolation & purification; D004283:Dog Diseases / Q000276:immunology* / Q000517:prevention & control*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D007114:Immunization; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis; D007371:Interferon-gamma / Q000032:analysis / Q000096:biosynthesis; D016753:Interleukin-10 / Q000032:analysis / Q000096:biosynthesis; D018314:Leishmania infantum / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology* / Q000517:prevention & control / Q000662:veterinary*; D007958:Leukocyte Count; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology* / Q000627:therapeutic use*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014614:Vaccines, Synthetic / Q000276:immunology / Q000627:therapeutic use
chemical_list: C107645:A2 protein, Leishmania donovani; D000953:Antigens, Protozoan; D016207:Cytokines; D016054:DNA, Protozoan; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D014614:Vaccines, Synthetic; D016753:Interleukin-10; D007371:Interferon-gamma