Allele diversity of the killer cell immunoglobulin-like receptors KIR3DL1/S1 and the combination with their HLA ligands in Mexican Mestizos from Mexico City

Killer cell immunoglobulin-like receptors (Kills), expressed on Natural Killer (NK) cells, activate/inhibit NK cell function through interactions with their HLA A, B and C ligands. KIR3DL1 is one of the most polymorphic genes and its effect varies depending on the interaction of the specific allotype with its Bw4 ligand. We investigated the allelic diversity of KIR3DL1/S1 using sequence based typing and we typed as well, their Bw4 ligands in Mexican Mestizos of Mexico City. The results showed that this population has a great KIR3DL1 allelic diversity with *01502 (19.9%), *00101 (13.2%) and *00501 (12.8%) being the most common alleles, while KIR3DS1 showed predominance of '01301 (86%); these data agree with the diversity found in most populations studied. At least one KIR3DLI-HIGH surface expression allele was present in 67.5% of the subjects. Phylogenetic comparisons between Mestizos and 28 different populations showed that allelic diversity of KIR3DL1/S1 was similar in Mexican Mestizos from Mexico and in Hispanics from USA. Knowledge of KIR and MHC diversity worldwide is fundamental for understanding the impact of MR and KIR-ligand polymorphism on NK cell effector functions and is relevant in genetic anthropology, disease association and transplantation.