title: Specific humoral and cellular immunity induced by Trypanosoma cruzi DNA immunization in a canine model.
abstract: Chagas disease has a high incidence in Mexico and other Latin American countries. Because one of the most important known methods of prevention is vector control, which has been effective only in certain areas of South America, the development of a vaccine to protect people at risk has been proposed. In this study, we assessed the cellular and humoral immune response generated following immunization with pBCSP and pBCSSP4 plasmids containing the genes encoding a trans-sialidase protein (present in all three forms of T. cruzi) and an amastigote specific glycoprotein, respectively, in a canine model. Thirty-five beagle dogs were divided randomly into 5 groups (n=7) and were immunized twice intramuscularly with 500 μg of pBCSSP4, pBCSP, pBk-CMV (empty plasmid) or saline solution. Fifteen days after the last immunization the 4 groups were infected intraperitoneally with 500,000 metacyclic trypomastigotes. The fifth group was unimmunized/infected. The parasitaemia in the immunized/infected dogs was for a shorter period (14 vs. 29 days) and the parasite load was lower. The concentration of IgG1 (0.612±0.019 O.D.) and IgG2 (1.167±0.097 O.D.) subclasses was measured (absorbance) 15 days after the last immunization with both recombinant plasmids, the majority of which were IgG2. The treatment of parasites using the serum from dogs immunized with pBCSP and pBCSSP4 plasmids produced 54% (±11.8) and 68% (±21.4) complement-mediated lysis, respectively. At 12 h post immunization, an increase in cytokines was not observed; however, vaccination with pBCSSP4 significantly increased the levels of IFN-γ and IL-10 at 9 months post-infection. The recombinant plasmid immunization stimulated the spleen cell proliferation showing a positive stimulatory index above 2.0. In conclusion, immunization using both genes effectively induces a humoral and cellular immune response.
authors.affiliation: Department of Molecular Biology, Instituto Nacional de Cardiología "Ignacio Chávez", Juan Badiano No, 1, Col, Sección XVI, Tlalpan, Mexico City, CP 14080, Mexico. rm.olivia@gmail.com.
authors.forename: Minerva
authors.initials: M
authors.lastname: Arce-Fonseca
authors.forename: Martha A
authors.initials: MA
authors.lastname: Ballinas-Verdugo
authors.forename: Emma R Abreu
authors.initials: ER
authors.lastname: Zenteno
authors.forename: Davinia
authors.initials: D
authors.lastname: Suárez-Flores
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Carrillo-Sánchez
authors.forename: Ricardo
authors.initials: R
authors.lastname: Alejandre-Aguilar
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rosales-Encina
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Reyes
authors.forename: Olivia
authors.initials: O
authors.lastname: Rodríguez-Morales
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D049109:Cell Proliferation; D014355:Chagas Disease / Q000469:parasitology / Q000517:prevention & control*; D016207:Cytokines / Q000097:blood; D016054:DNA, Protozoan / Q000008:administration & dosage / Q000276:immunology*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D008297:Male; D009439:Neuraminidase / Q000235:genetics / Q000378:metabolism; D010586:Phagocytes / Q000276:immunology; D010957:Plasmids; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014349:Trypanosoma cruzi / Q000276:immunology*; D014556:Urine / Q000469:parasitology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D016207:Cytokines; D016054:DNA, Protozoan; D006023:Glycoproteins; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; C501457:SSP4 protein, Trypanosoma cruzi; D019444:Vaccines, DNA; C069715:trans-sialidase; D009439:Neuraminidase