Prediction of CD4(+) T cell epitopes restricted to HLA-DP4 molecules.

We have set up a method to predict peptide binding to HLA-DP4 molecules. These HLA II molecules are the most frequent worldwide and hence are an interesting target for epitope-based vaccines. The prediction is based on quantitative matrices built with binding data for peptides substituted at anchoring positions for HLA-DP4. A set of 98 peptides of various origins was used to compare the prediction with binding activity. At different prediction thresholds, the positive predictive value and the sensitivity of the prediction ranged from 50% to 80%, demonstrating its efficiency. This prediction method can be applied to the entire genomes of pathogens and large peptide sequences derived from tumor antigens.