DNA Vaccination with Genes EncodingToxoplasma gondiiAntigens GRA1, GRA7, and ROP2 Induces Partially Protective Immunity against Lethal Challenge in Mice

• DOI: 10.1128/iai.68.1.38-45.2000
• Publication Date: 2009-05-01T17:57:25Z
• Authors: M. Vercammen; T. Scorza; K. Huygen; J. De Braekeleer; R. Diet; D. Jacobs; E. Saman; H. Verschueren
• Keywords: Splenocyte; Isotype

ABSTRACT C57BL/6, C3H, and BALB/c mice were vaccinated with plasmids encoding Toxoplasma gondii antigens GRA1, GRA7, ROP2, previously described as strong inducers of immunity. Seroconversion for the relevant antigen was obtained in majority animals. T. lysate stimulated specific T-cell proliferation secretion gamma interferon (IFN-γ) spleen cell cultures from C3H but not those control mice. Although proliferating, splenocytes DNA-vaccinated C57BL/6 also produced IFN-γ. No interleukin-4 detected supernatants lysate-stimulated any mouse strains evaluated. As infected animals, a high ratio immunoglobulin G2a (IgG2a) to IgG1 antibodies found mice, suggesting that Th1-type response had been induced. For isotype antibody DNA vaccination less polarized. The protective potential demonstrated plasmid or ROP2 partially protected against lethal oral challenge cysts two different strains: survival rates increased 10% controls at least 70% after one case 50% 90% other. In challenged nonlethal dose, number brain significantly lower than controls. did protect Our results demonstrate first time an animal model effect .