title: Short-term protection conferred by Leishvacin® against experimental Leishmania amazonensis infection in C57BL/6 mice.
abstract: To date, there is no vaccine available against human leishmaniasis. Although some vaccination protocols can induce immunity in murine models, they fail to induce protection in humans. The reasons for that remain unclear. The aim of the present study was to characterize the changes in the pattern of the immune response during subcutaneous vaccination with Leishvacin® in mice. We also investigated whether IFN-γ and nitric oxide synthase are indispensable for the protection elicited by the vaccine. C57BL/6 WT vaccinated mice showed smaller lesions and fewer numbers of parasites in footpads until 8 weeks post-infection. Up to this time, they produced higher levels of IFN-γ, IL-2, IL-4, IL-17A and IL-10 and higher specific antibody response than control non-vaccinated mice. Moreover, we showed that IFN-γ, most likely by induction of iNOS expression, is essential for immunity. However, after 12 weeks of infection, we observed loss of difference in lesion size and parasite burden between the groups. Loss of resistance was associated with the disappearance of differences in cytokine patterns between vaccinated and control mice, but not of antibody response, which remained different until a later time of infection. The reversal of resistance to L. amazonensis could not be explained by upregulation of regulatory cytokines. Our data point to a subversion of the host immune response by L. amazonensis even when a protective response was previously induced.
authors.affiliation: Laboratório de Gnotobiologia e Imunologia, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Matheus Batista Heitor
authors.initials: MB
authors.lastname: Carneiro
authors.affiliation: Laboratório de Gnotobiologia e Imunologia, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Louisa Maria
authors.initials: LM
authors.lastname: de Andrade e Sousa
authors.affiliation: Laboratório de Gnotobiologia e Imunologia, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Leonardo Gomes
authors.initials: LG
authors.lastname: Vaz
authors.affiliation: Laboratório de Gnotobiologia e Imunologia, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Liliane Martins
authors.initials: LM
authors.lastname: Dos Santos
authors.affiliation: Centro de Pesquisas, Biomm S/A, Montes Claros, MG 39400-307, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Vilela
authors.affiliation: Departamento de Patologia Geral, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minhas Gerais, Brazil.
authors.forename: Carolina Carvalho
authors.initials: CC
authors.lastname: de Souza
authors.affiliation: Departamento de Patologia Geral, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minhas Gerais, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gonçalves
authors.affiliation: Departamento de Patologia Geral, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minhas Gerais, Brazil.
authors.forename: Wagner Luis
authors.initials: WL
authors.lastname: Tafuri
authors.affiliation: Departamento de Ciências Biológicas, ICEB/NUPEB, Universidade Federal de Ouro Preto, Brazil.
authors.forename: Luís Carlos Crocco
authors.initials: LC
authors.lastname: Afonso
authors.affiliation: Laboratório de Gnotobiologia e Imunologia, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Departamento de Ciências Biológicas, ICEB/NUPEB, Universidade Federal de Ouro Preto, Brazil.
authors.forename: Denise Fonseca
authors.initials: DF
authors.lastname: Côrtes
authors.affiliation: Laboratório de Gnotobiologia e Imunologia, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Departamento de Ciências Biológicas, ICEB/NUPEB, Universidade Federal de Ouro Preto, Brazil. Electronic address: lqvieira@icb.ufmg.br.
authors.forename: Leda Quercia
authors.initials: LQ
authors.lastname: Vieira
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D016207:Cytokines / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007074:Immunoglobulin G / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D020381:Interleukin-17 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D007894:Leishmania mexicana / Q000276:immunology*; D054332:Leishmaniasis Vaccines / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology / Q000469:parasitology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D011425:Propionibacterium acnes / Q000276:immunology; D014611:Vaccination
chemical_list: D000913:Antibodies, Protozoan; D016207:Cytokines; C556062:IL10 protein, mouse; D007074:Immunoglobulin G; D020381:Interleukin-17; D054332:Leishmaniasis Vaccines; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse
keywords: IL-10; Leishmania amazonensis; Leishvacin® IFN-γ iNOS; vaccine