Fig. 3.

Minimized DNA fusion vaccines to induce tumor-specific CTLs. Incorporating full-length FrC (Upper) as an immunoenhancing sequence can induce antibody and CD4⁺ T cell responses against fused tumor antigens. To induce CTLs, competitive peptides located in DOM2 and able to bind to human and mouse MHC class I molecules have been removed (Lower), leaving the Th-inducing sequences in DOM1. This minimized DOM1 sequence can enhance CD8⁺ responses against intracellular tumor-derived peptides.