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.
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.
Ferreira
Josie Haydée L
JH
Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
Gentil
Luciana Girotto
LG
Dias
Suzana Souza
SS
Fedeli
Carlos Eduardo C
CE
Katz
Simone
S
Barbiéri
Clara Lúcia
CL
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
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