Cytotoxic T cell induction with ratchet peptide libraries.

Overview

Immunization with synthetic peptides are used to induce cytotoxic T cell (CTL) responses in vivo. However, CTL peptide vaccines require the use of multiple peptides to overcome genetic diversity associated with MHC restriction, and prior epitope identification from the chosen protein template. We describe here a method whereby all nonamer sequences from a longer template can be synthesized simultaneously in a ratchet peptide library (RPL) covering all potential epitopes within a protein. We synthesized an RPL based on a template sequence from the Plasmodium berghei circumsporozoite (CS) protein (CSRPL). Using a lipopeptide formulation we immunized mice i.p. with the CSRPL and elicited CS specific CTL, which recognized the CS252-260 H-2Kd restricted CTL epitope.