DNA vaccination with a plasmid containing the gp72 gene of Trypanosoma cruzi

PADILLA AM, RODRIGUES MM, BOSCARDIN SB, PÉREZ BRANDÁN CM, DIOSQUE P AND MA BASOMBRIO.

Caxambu, Brasil

Otro; Reunión Anual de la Sociedad Brasilera de Protozoología.; 2003

Sociedad Brasilera de Protozoologia

The gp72 is a glicoprotein of Trypanosoma cruzi involved in the adhesion of the flagellum to the parasite´s body. The deletion of the gp72 gene produces atypical forms of reduced infectivity in mice. Here we tested the immunogenicity of a gp72-containing plasmid as a DNA vaccine against the T. cruzi infection. Female Balb/c mice were immunized with four doses of 100 micrograms of plasmid. The control group received same doses with the empty vector plasmid pcDNA3. After the vaccination shedule, mice´s sera were taken in order to perform ELISA assays. The delay type hipersensibility (DTH) reaction was recorded and the mice were challenged with Tulahuen blood trypomastigotes. The DTH reaction of the immunized mice was increased compared with the control reactions, although the optical densities of the sera tested by ELISA were not different between the groups. After the challenge, the immunized mice displayed a slightly lower level of parasitemia than the control group. On the basis of the present results we will attempt to improve the vaccine´s immunogenicity employing the gp72-containing plasmid, testing different immunization schedules or multi-component vaccines.