A simple competitive assay to determine peptide affinity for HLA class II molecules: A useful tool for epitope prediction

► A new competition assay to assess peptide binding to recombinant HLA-DP4 molecules. ► Affinities of 13 peptides from human telomerase reverse transcriptase were measured. ► Ability of said peptides to activate CD4+ T lymphocytes was evaluated in vitro. ► Peptides with average (but not high) affinities were the best T cell epitopes. ► This new assay will be useful to predict HLA-class II restricted T cell epitopes.