title: Performance of LBSap vaccine after intradermal challenge with L. infantum and saliva of Lu. longipalpis: immunogenicity and parasitological evaluation.
abstract: In the last decade, the search for new vaccines against canine visceral leishmaniasis has intensified. However, the pattern related to immune protection during long periods after experimental infection in vaccine trials is still not fully understood. Herein, we investigated the immunogenicity and parasitological levels after intradermal challenge with Leishmania infantum plus salivary gland extract in dogs immunized with a vaccine composed of L. braziliensis antigens plus saponin as an adjuvant (LBSap vaccine). The LBSap vaccine elicited higher levels of total anti-Leishmania IgG as well as both IgG1 and IgG2. Furthermore, dogs vaccinated had increased levels of lymphocytes, particularly circulating B cells (CD21(+)) and both CD4(+) and CD8(+) T lymphocytes. LBSap also elicited an intense in vitro cell proliferation associated with higher levels of CD4(+) T lymphocytes specific for vaccine soluble antigen and soluble lysate of L. infantum antigen even 885 days after experimental challenge. Furthermore, LBSap vaccinated dogs presented high IFN-γ and low IL-10 and TGF-β1 expression in spleen with significant reduction of parasite load in this tissue. Overall, our results validate the potential of LBSap vaccine to protect against L. infantum experimental infection and strongly support further evaluation of efficiency of LBSap against CVL in natural infection conditions.
authors.affiliation: Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
authors.forename: Bruno Mendes
authors.initials: BM
authors.lastname: Roatt
authors.forename: Rodrigo Dian de Oliveira
authors.initials: RD
authors.lastname: Aguiar-Soares
authors.forename: Juliana
authors.initials: J
authors.lastname: Vitoriano-Souza
authors.forename: Wendel
authors.initials: W
authors.lastname: Coura-Vital
authors.forename: Samuel Leôncio
authors.initials: SL
authors.lastname: Braga
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Corrêa-Oliveira
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
authors.forename: Andréa
authors.initials: A
authors.lastname: Teixeira-Carvalho
authors.forename: Marta
authors.initials: M
authors.lastname: de Lana
authors.forename: Nelder
authors.initials: N
authors.lastname: Figueiredo Gontijo
authors.forename: Marcos José
authors.initials: MJ
authors.lastname: Marques
authors.forename: Rodolfo Cordeiro
authors.initials: RC
authors.lastname: Giunchetti
authors.forename: Alexandre Barbosa
authors.initials: AB
authors.lastname: Reis
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism; D000953:Antigens, Protozoan / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D004283:Dog Diseases / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*; D004285:Dogs; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism; D056724:Immunity, Humoral; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D016130:Immunophenotyping; D018314:Leishmania infantum / Q000235:genetics / Q000276:immunology*; D054332:Leishmaniasis Vaccines / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000662:veterinary*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D059208:Parasite Load; D012503:Saponins / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D015703:Antigens, CD; D000953:Antigens, Protozoan; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D007074:Immunoglobulin G; D054332:Leishmaniasis Vaccines; D012503:Saponins