EFFICACY OF SYNTHETIC VACCINES IN THE INDUCTION OF CYTOTOXIC T-LYMPHOCYTES - COMPARISON OF THE COSTIMULATING SUPPORT PROVIDED BY HELPER T-CELLS AND LIPOAMINO ACID

Synthetic vaccines that specifically induce active immunity mediated b y cytotoxic T lymphocytes (CTL) are of great interest considering the central role of these cells in immune responses against intracellular antigens. The influence of specific T helper (Th) cell recruitment and of the potent immunostimulating lipoamino acid tripalmitoyl-S-glycery lcysteine (P3C) on CTL mediated immunity induced by CTL epitopes was a nalysed and compared. Synthetic peptides that represent CTL epitopes w ere found to be inefficient for CTL priming. However, when combined wi th peptides that contain Th cell epitopes, with proteins that carry mu ltiple Th cell epitopes or with P3C, efficient priming of CTL was obta ined. The costimulating support by P3C and proteins resulted in high c ytolytic activities already after 9 days whereas, in the case of singl e helper epitopes, incubation periods of about 4 weeks were required. The effects of P3C and helper epitopes were additive.