Immunogenic and protective efficacy of recombinant ROP2 and ROP4 rhoptry proteins in murine experimental toxoplasmosis

Exp Parasitol. 2009 Jun 6. [Epub ahead of print]

Toxoplasma gondii: the immunogenic and protective efficacy of recombinant ROP2 and ROP4 rhoptry proteins in murine experimental toxoplasmosis

Dziadek B, Gatkowska J, Brzostek A, Dziadek J, Dzitko K, Dlugonska H.

Department of Immunoparasitology, University of Lodz, Lodz, Poland.

Toxoplasmosis is a one of the most world-wide spread zoonosis representing a very serious clinical and veterinary problem. In the presented study we evaluated the protective efficacy of a combined recombinant ROP2 and ROP4 subunit vaccine in a chronic Toxoplasma gondii infection in mice. The recombinant ROP2 (rROP2) and ROP4 (rROP4) proteins were cloned and expressed in Escherichia coli and then used for the immunization of C3H/HeJ mice. Both antigens generated a strong systemic mixed Th1/Th2 response polarized towards IgG1 antibody isotype. In contrast to rROP2 stimulating only the specific IL-2 release, rROP4 and crude TLA (Toxoplasma Lysate Antigen) used as a source of native forms of the parasite proteins induced significant proliferation of splenocytes and specific production of IFN-gamma as well as IL-2, the Th1 type cytokines. Challenge of rROP2 and rROP4-vaccinated mice with cysts of low virulent T. gondii DX strain resulted in a partial protection effect with a significantly lower brain parasites load when compared with control animals. In the immunized group of mice the brain cysts number was reduced by nearly 46% as was determined in two independent experiments. These results suggest that, similar to ROP2, rhoptry protein ROP4 could be a very good candidate for future anti-T. gondii multicomponent vaccine based on the recombinant forms of different parasite proteins.

PMID: 19508869 [PubMed - as supplied by publisher]