title: Immunization with the cysteine proteinase Ldccys1 gene from Leishmania (Leishmania) chagasi and the recombinant Ldccys1 protein elicits protective immune responses in a murine model of visceral leishmaniasis.
abstract: The gene Ldccys1 encoding a cysteine proteinase of 30 kDa from Leishmania (Leishmania) chagasi, as well as the recombinant cysteine proteinase rLdccys1, obtained by cloning and expression of the Ldccys1 gene in the pHIS vector, were used to evaluate their ability to induce immune protective responses in BALB/c mice against L. (L.) chagasi infection. Mice were immunized subcutaneously with rLdccys1 plus Bacille Calmette Guerin (BCG) or Propionibacterium acnes as adjuvants or intramuscularly with a plasmid carrying the Ldccys1 gene (Ldccys1/pcDNA3) and CpG ODN as the adjuvant, followed by a booster with rLdccys1 plus CpG ODN. Two weeks after immunization the animals were challenged with 1 x 10(7) amastigotes of L. (L.) chagasi. Both immunization protocols induced significant protection against L. (L.) chagasi infection as shown by a very low parasite load in the spleen of immunized mice compared to the non-immunized controls. However, DNA immunization was 10-fold more protective than immunization with the recombinant protein. Whereas rLdccys1 induced a significant secretion of IFN-gamma and nitric oxide (NO), animals immunized with the Ldccys1 gene increased the production of IgG2a antibodies, IFN-gamma and NO. These results indicated that protection triggered by the two immunization protocols was correlated to a predominant Th1 response.
authors.affiliation: Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
authors.forename: Josie Haydée L
authors.initials: JH
authors.lastname: Ferreira
authors.forename: Luciana Girotto
authors.initials: LG
authors.lastname: Gentil
authors.forename: Suzana Souza
authors.initials: SS
authors.lastname: Dias
authors.forename: Carlos Eduardo C
authors.initials: CE
authors.lastname: Fedeli
authors.forename: Simone
authors.initials: S
authors.lastname: Katz
authors.forename: Clara Lúcia
authors.initials: CL
authors.lastname: Barbiéri
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D005260:Female; D017125:Genes, Protozoan / Q000276:immunology*; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood; D007279:Injections, Subcutaneous; D007371:Interferon-gamma / Q000378:metabolism; D007891:Leishmania / Q000276:immunology*; D007896:Leishmaniasis / Q000097:blood / Q000517:prevention & control*; D054332:Leishmaniasis Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D051379:Mice; D009163:Mycobacterium bovis / Q000276:immunology; D009569:Nitric Oxide / Q000378:metabolism; D010957:Plasmids / Q000008:administration & dosage* / Q000276:immunology; D011425:Propionibacterium acnes / Q000276:immunology; D015800:Protozoan Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D013154:Spleen / Q000276:immunology / Q000469:parasitology; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D054332:Leishmaniasis Vaccines; D015800:Protozoan Proteins; D014614:Vaccines, Synthetic; D009569:Nitric Oxide; D007371:Interferon-gamma; D003546:Cysteine Endopeptidases