Identification of a new variant, HLA-Cw*1507, differing from Cw*1502 only at the KIR-related dimorphism of codons 77 and 80

We describe here a novel allele, HLA-Cw*1507, identified by polymerase chai n reaction using sequence-specific primers (PCR-SSP) and sequence-based typ ing (SBT). Cw*1507 is similar to Cw*1502 with differences at nucleotide pos itions 302 (A to G) and 312 (A to C) in exon 2. The substitutions observed in Cw*1507, change codon 77 from AAC (asparagine) to AGC (serine) and codon 80 from AAA (lysine) to AAC (asparagine), compared to Cw*1502. Residues 77 and 80 of HLA-C alleles are located in the alpha 1 domain, where they can influence interaction between antigenic peptides and the T-cell receptor. A lso, the dimorphism at these residues from asparagine and lysine to serine and asparagine, respectively, are known to modulate interaction with the na tural killer (MK) cell killer inhibitory receptor (KIR). The new HLA-Cw*150 7, together with Cw*1502, represents the fourth pair of HLA-C alleles diffe ring only at the KIR-related dimorphic codons 77 and 80.