Human T-Cell Clones as Tools to Identify Protective Antigens of Toxoplasma Gondii
Many in vitro and in vivo observations indicate that cell-mediated immunity plays an essential role in protection of the host against toxoplasmosis. In the mouse experimental model, it has recently been shown that both CD4+ and CD8+ lymphocytes are important in controlling acute infection and preventing reactivation of chronic toxoplasmosis [Suzuki and Remington, 1988; Araujo, 1991; Gassinelli et al, 1991; Gazzinelli et al 1992]. The exact mechanism by which these T-cell subsets confer protection has not yet been fully elucidated, but two lymphokines (IL-2 and IFN-γ) produced by these T-cells have been demonstrated to have a protective activity [Sharma et al., 1985]; Suzuki et al., 1988; Suzuki and Remington, 1990; Suzuki et al. 1990; Gazzinelli et al., 1991]. Parasite-specific T-cell clones (TCC) derived from naturally infected and immune individuals offer an ingenious way to dissect the cell-mediated immune response and to identify the parasite antigens which induce protective effector mechanisms. Such antigens should thus be considered as subunit vaccine candidates.
KeywordsProtective Antigen Recombinant Form Toxoplasma Gondii Host Cell Invasion Rhoptry Protein
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