1. Vaccination with a Leishmania infantum HSP70-II null mutant confers long-term protective immunity against Leishmania major infection in two mice models.
- Author
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Solana, José Carlos, Ramírez, Laura, Corvo, Laura, de Oliveira, Camila Indiani, Barral-Netto, Manoel, Requena, José María, Iborra, Salvador, and Soto, Manuel
- Subjects
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LEISHMANIA infantum , *PARASITIC vaccines , *IMMUNITY , *DRUG development , *T cells , *MICROBIAL virulence , *THERAPEUTICS - Abstract
Background: The immunization with genetically attenuated Leishmania cell lines has been associated to the induction of memory and effector T cell responses against Leishmania able to control subsequent challenges. A Leishmania infantum null mutant for the HSP70-II genes has been described, possessing a non-virulent phenotype. Methodology/Principal findings: The L. infantum attenuated parasites (LiΔHSP70-II) were inoculated in BALB/c (intravenously and subcutaneously) and C57BL/6 (subcutaneously) mice. An asymptomatic infection was generated and parasites diminished progressively to become undetectable in most of the analyzed organs. However, inoculation resulted in the long-term induction of parasite specific IFN-γ responses able to control the disease caused by a challenge of L. major infective promastigotes. BALB/c susceptible mice showed very low lesion development and a drastic decrease in parasite burdens in the lymph nodes draining the site of infection and internal organs. C57BL/6 mice did not show clinical manifestation of disease, correlated to the rapid migration of Leishmania specific IFN-γ producing T cells to the site of infection. Conclusion/Significance: Inoculation of the LiΔHSP70-II attenuated line activates mammalian immune system for inducing moderate pro-inflammatory responses. These responses are able to confer long-term protection in mice against the infection of L. major virulent parasites. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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