Authors : A. Daryani, A. Zavaran Hosseini , M. Sharif , A. Dalimi , M.H. Dehghan and H. Ziaei
Abstract: Toxoplasma gondii is an obligate intracellular parasite that infects all mammalian cells. Several antigens such as excreted/secreted antigens have been identified as potential vaccine candidates. The main goal of the present study was to determine how excreted/secreted antigens from peritoneal exudates of infected mice (mESA) stimulate cell-mediated immune responses and protective immunity against toxoplasmosis in the murine model. The supernatants produced from the peritoneal fluids were fractionated by precipitation with ammonium sulphate solution (30-80% saturated). For induction of cell-mediated immune responses, Delayed type hypersensitivity was measured in injected footpad measured in injected footpad. By adding [ H] thymidine to cell cultures, their radioactivities were measured. Nitric oxide was measured by Griess method. For immunization, Balb/c mice were immunized 2 times with mESA, mESA-40% and Toxoplasma Lysate Antigen (TLA). The virulent RH strain of Toxoplasma gondii was used for challenging. The pattern of lymphocyte responsiveness was dependent on the kind of antigen employed for induction of the blastogenesis. In sensitized mice, those received mESA-40% displayed higher counts per minute than mice that stimulated by mESA (p<0.05). The highest amounts of nitric oxide were observed in macrophages, which received mESA-40% and mESA (p<0.05). Mice immunized with mESA-40% survived longer than those immunized with mESA and other antigens (p<0.05). As fraction 40% (mESA-40%) showed a good result in induction of cell-mediated responses in the murine model, for getting better response, this antigen have to be purified further.
Daryani, A. , A. Zavaran Hosseini , M. Sharif , A. Dalimi , M.H. Dehghan and H. Ziaei , 2006. Protective Role of Antigens from Peritoneal Exudates of Infected Mice Against Toxoplasmosis. International Journal of Molecular Medicine and Advance Sciences, 2: 138-143.