Peptide-binding assays and HLA II transgenic A[beta]° mice are consistent and complementary tools for identifying HLA II-restricted peptides

The identification of MHC class II-restricted peptides has become a priority for the development of peptide-based prophylactic and therapeutic vaccines. The aim of this study was to assess the correlations between peptide-binding assays on purified HLA II molecules and immunization of human HLA II transgenic mice deficient in murine class II molecules (Aβ°). We used as models two MHC class II-restricted peptides, one derived from the HIV Nef regulatory protein (Nef56-68) and the other from theSchistosoma mansoni28-kDa glutathione-S-transferase (Sm28GST190-211). High correlations were found between the two approaches, which showed that the Nef56-68and Sm28GST190-211peptides may represent promiscuous ligands for HLA-DQ and for HLA-DR molecules, respectively.We suggest a rational method based on the combination of peptide-binding assays and HLA II transgenic mice experiments as consistent and complementary tools for selecting T helper epitopes.