Increased diversity within the HLA-B*07 group: Identification of the two novel alleles B*0709 and B*0710

The identification of the two novel alleles, HLA-B*0709 and B*0710, is desc ribed. B*0709 differs from B*07021 by a nucleotide exchange at position 419 (A>C) which is located in exon 3. At the protein level the nucleotide exch ange results in an amino acid residue difference (Tyr116Ser). The other new ly detected allele, B*0710, differs from B*07021 by a nucleotide exchange a t position 272 (A>G) which is located in exon 2. This nucleotide exchange a lso leads to an amino acid substitution (Tyr67Cys). The allogeneic potentia l in case of mismatch with other alleles of the B*07 group at bone marrow t ransplantation was assessed. The peptide motifs between B*0709 and B*0711 m ay be very similar and thus the alloreactive potential in case of mismatch may be low In contrast, mismatches of B*0709 and B*0710 with other B*07 all eles are likely to stimulate alloreactive T cells.