title: Cross-Protective Immunity to Leishmania amazonensis is Mediated by CD4+ and CD8+ Epitopes of Leishmania donovani Nucleoside Hydrolase Terminal Domains.
abstract: The nucleoside hydrolase (NH) of Leishmania donovani (NH36) is a phylogenetic marker of high homology among Leishmania parasites. In mice and dog vaccination, NH36 induces a CD4+ T cell-driven protective response against Leishmania chagasi infection directed against its C-terminal domain (F3). The C-terminal and N-terminal domain vaccines also decreased the footpad lesion caused by Leishmania amazonensis. We studied the basis of the crossed immune response using recombinant generated peptides covering the whole NH36 sequence and saponin for mice prophylaxis against L. amazonensis. The F1 (amino acids 1-103) and F3 peptide (amino acids 199-314) vaccines enhanced the IgG and IgG2a anti-NH36 antibodies to similar levels. The F3 vaccine induced the strongest DTH response, the highest proportions of NH36-specific CD4+ and CD8+ T cells after challenge and the highest expression of IFN-γ and TNF-α. The F1 vaccine, on the other hand, induced a weaker but significant DTH response and a mild enhancement of IFN-γ and TNF-α levels. The in vivo depletion with anti-CD4 or CD8 monoclonal antibodies disclosed that cross-protection against L. amazonensis infection was mediated by a CD4+ T cell response directed against the C-terminal domain (75% of reduction of the size of footpad lesion) followed by a CD8+ T cell response against the N-terminal domain of NH36 (57% of reduction of footpad lesions). Both vaccines were capable of inducing long-term cross-immunity. The amino acid sequence of NH36 showed 93% identity to the sequence of the NH A34480 of L. amazonensis, which also showed the presence of completely conserved predicted epitopes for CD4+ and CD8+ T cells in F1 domain, and of CD4+ epitopes differing by a single amino acid, in F1 and F3 domains. The identification of the C-terminal and N-terminal domains as the targets of the immune response to NH36 in the model of L. amazonensis infection represents a basis for the rationale development of a bivalent vaccine against leishmaniasis.
authors.affiliation: Laboratório de Biologia e Bioquímica de Leishmania, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Dirlei
authors.initials: D
authors.lastname: Nico
authors.affiliation: Laboratório de Biologia e Bioquímica de Leishmania, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Daniele Crespo
authors.initials: DC
authors.lastname: Gomes
authors.affiliation: Laboratório de Biologia e Bioquímica de Leishmania, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Marcus Vinícius
authors.initials: MV
authors.lastname: Alves-Silva
authors.affiliation: Laboratório de Biologia e Bioquímica de Leishmania, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Elisangela Oliveira
authors.initials: EO
authors.lastname: Freitas
authors.affiliation: Laboratório de Imunologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Morrot
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil ; Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais , Belo Horizonte , Brazil.
authors.forename: Diana
authors.initials: D
authors.lastname: Bahia
authors.affiliation: Programa de Pós Graduação em Clínica Médica Faculdade de Medicina, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Palatnik
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Centro de Terapia Celular e Molecular, Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil.
authors.forename: Mauricio M
authors.initials: MM
authors.lastname: Rodrigues
authors.affiliation: Laboratório de Biologia e Bioquímica de Leishmania, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.
authors.forename: Clarisa B
authors.initials: CB
authors.lastname: Palatnik-de-Sousa
keywords: cross-protection; cutaneous leishmaniasis; diffuse cutaneous leishmaniasis; nucleoside hydrolases; prophylaxis; recombinant vaccines; visceral leishmaniasis