Partial protection against malaria by immunization with Leishmania enriettii expressing the Plasmodium yoelii circumsporozoite protein.
Mol Biochem Parasitol
; 69(2): 139-48, 1995 Feb.
Article
em En
| MEDLINE
| ID: mdl-7770079
ABSTRACT
Since infection with Leishmania species induces CD4+ and CD8+ anti-leishmania T cells, we assessed protection against malaria by immunization with Leishmania enriettii transfected with the gene encoding the Plasmodium yoelii circumsporozoite protein (PyCSP). The recombinant plasmid appeared to be a circular episome in the host cells. Reverse transcription PCR showed that the PyCSP was trans-spliced by the addition of the 39-bp spliced leader of L. enriettii at its 5' end. The transfectant expressed a protein in a pattern similar to that found in the sporozoite itself. Immunofluorescence and immunoelectron microscopy indicated that PyCSP was abundantly expressed on the surface of the parasite. Mice immunized with the transfectant produced antibodies to sporozoites, had a delay in onset of parasitemia after challenge, and 4 of 22 (18%) were completely protected. The protected mice had cytotoxic T lymphocytes against the PyCSP. Immunization with recombinant vaccinia, Salmonella typhimurium, and pseudorabies virus expressing the PyCSP induces excellent immune responses, but has not been shown to protect against challenge. Thus, the modest protection found in these initial studies represents a step forward. After further work Leishmania may prove to be an important live vector vaccine system for induction of protective immune responses.
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Base de dados:
MEDLINE
Assunto principal:
Plasmodium yoelii
/
Proteínas de Protozoários
/
Leishmania enriettii
/
Malária
Limite:
Animals
Idioma:
En
Ano de publicação:
1995
Tipo de documento:
Article