Petitdidier Elodie auteur aut IRD Pagniez Julie auteur aut IRD Pissarra J. auteur aut IRD Holzmuller P. auteur aut IRD Papierok G. auteur aut IRD Vincendeau P. auteur aut IRD Lemesre Jean-Loup auteur aut IRD Bras Goncalves Rachel auteur aut IRD text journalArticle eng text/pdf reformatted digital access Dogs are the main reservoir of zoonotic visceral leishmaniasis. Vaccination is a promising approach to help control leishmaniasis and to interrupt transmission of the Leishmania parasite. The promastigote surface antigen (PSA) is a highly immunogenic component of Leishmania excretory/secretory products. A vaccine based on three peptides derived from the carboxy-terminal part of Leishmania amazonensis PSA and conserved among Leishmania species, formulated with QA-21 as adjuvant, was tested on naive Beagle dogs in a preclinical trial. Four months after the full course of vaccination, dogs were experimentally infected with Leishmania infantum promastigotes. Immunization of dogs with peptide-based vaccine conferred immunity against experimental infection with L. infantum. Evidence for macrophage nitric oxide production and anti-leishmanial activity associated with IFN-y production by lymphocytes was only found in the vaccinated group. An increase in specific IgG2 antibodies was also measured in vaccinated dogs from 2 months after immunization. Additionally, after challenge with L. infantum, the parasite burden was significantly lower in vaccinated dogs than in the control group. These data strongly suggest that this peptide-based vaccine candidate generated cross-protection against zoonotic leishmaniasis by inducing a Th1-type immune response associated with production of specific IgG2 antibodies. This preclinical trial including a peptide-based vaccine against leishmaniasis clearly demonstrates effective protection in a natural host. This approach deserves further investigation to enhance the immunogenicity of the peptides and to consider the possible engineering of a vaccine targeting several Leishmania species. specialized 052 080 050 4 art. 49 [9 ] 2019 https://www.documentation.ird.fr/hor/fdi:010077468 10.1038/s41541-019-0144-2 [F B010077468] https://www.documentation.ird.fr/hor/fdi:010077468 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers20-01/010077468.pdf IRD - Base Horizon / Pleins textes 2020-02-05 2025-02-24 fdi:010077468 fre