Correlation between Direct Binding Ability of SyntheticT. gondiiSAG1 Peptides to HLA-A2 Measured by a Sensor for Surface Plasmon Resonance and Antigenicity of the Peptides forT. gondii-Infected Cell-Specific CTL

Toxoplasma gondii(T. gondii) -infected B lymphoma cells presentT. gondiiantigens in the context of major histocompatibility complex molecules toT. gondii-specific CD8⁺cytotoxic T cells (CTL). HLA-A2 molecules ofT. gondii-infected human cells have been shown to be used in presenting T. gondiiantigens to CD8⁺CTL. SAG1, one of the major antigenic molecules ofT. gondii,is an antigen forT. gondii-specific CTL, and represents a possible basis for vaccines. The direct binding of nonamer SAG1 peptides to HLA-A2 was assayed here using an automated biosensor system with a sensor for surface plasmon resonance detection. The antigenicity of synthetic SAG1 peptides toT. gondii-specific CD8⁺CTL also was assayed. The present study found a high correlation between the binding ability of synthetic SAG1 peptides to HLA-A2 and the antigenicity of peptides toT. gondii-infected cell-specific CD8⁺CTL.