Immunization with a plasmid DNA containing the gene of trans-sialidase reduces Trypanosoma cruzi infection in mice.
Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, does not synthesize sialic acid, but expresses a trans-sialidase that catalyses the transfer of sialic acid from host glycoconjugates to the parasite surface. Several lines of evidence suggest that this enzyme is a virulence factor implicated in the establishment of infection. Here we studied whether immunization with a plasmid DNA containing a gene encoding for the catalytic domain of the enzyme could elicit protective immunity against T. cruzi infection in mice. We observed that immunization with this plasmid DNA generated antibody and T-cell mediated immune responses. Antibodies recognized the native enzyme and inhibited its activity in vitro. Upon challenge with bloodstream trypomastigotes, immunized animals displayed reduced parasitemia and mortality.
Costa
F
F
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Brazil.
Franchin
G
G
Pereira-Chioccola
V L
VL
Ribeirão
M
M
Schenkman
S
S
Rodrigues
M M
MM
D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis; D000953:Antigens, Protozoan / Q000276:immunology*; D014355:Chagas Disease / Q000517:prevention & control*; D016054:DNA, Protozoan / Q000008:administration & dosage; D005260:Female; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology*; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D009439:Neuraminidase / Q000235:genetics / Q000276:immunology*; D010957:Plasmids; D016052:Protozoan Vaccines; D013601:T-Lymphocytes / Q000276:immunology; D014349:Trypanosoma cruzi / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D006023:Glycoproteins; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; C069715:trans-sialidase; D009439:Neuraminidase