Description and molecular modeling of two novel HLA alleles: HLA-A*0343 and A*0345

We report the identification of two novel human leucocyte antigen (HLA) in two Caucasian individuals. HLA-A*0343 differs from A*03010101 by four changes at nucleotides 411–414 (CCGG→TGAA) and by a point mutation at position 418 (G→C). These differences lead to two amino acid substitutions at codon 114, where arginine has changed into negatively charged glutamic acid, and at codon 116, where aspartic acid has changed into positively charged histidine. Molecular modeling showed that these changes have a profound influence on the overall charge of the F pocket of the groove, resulting in potentially important changes in the peptide repertoire. HLA-A*0345 was found in a hematological female patient candidate to bone marrow transplantation. This new variant differs from HLA-A*03010101 at position 845 (C→A) encoding an amino acid change of threonine to asparagine at codon 258 located in the α3 domain. Molecular modeling does not suggest a substantial role of this substitutions on the interaction with β2-microglobulin or CD8.