ALLELE-SPECIFIC PEPTIDE LIGAND MOTIFS OF HLA-C MOLECULES

The consensus motifs of HLA-Cw3, -Cw4, -Cw6, and -Cw7 ligands were det ermined by pool sequencing. Together with information obtained by sequ encing of some prominent individual peptides, the results indicate the following: (i) all four HLA-C molecules are associated with peptides. (ii) These peptides adhere to allele-specific motifs that are similar to those of to HLA-A or -B molecules; they have a preferred length of nine amino acids and an anchor residue at the C terminus. (iii) AH fo ur HLA-C molecules analyzed exhibit related peptide motifs, although e ach allelic product shows individual characteristics in fine specifici ty. (iv) Processing and origin of peptides appear not to be different from that of other class I molecules. (v) No obvious difference at C-t erminal position 9 was present in the peptides isolated from the two d imorphic variants of HLA-C that determine dominant resistance to natur al killer NK1-specific cells (HLA-Cw4, -Cw6) or to NK2-specific cells (HLA-Cw3, -Cw7) and that differ in two residues in or near the pocket at position 9.