Genetic profiles of killer-cell immunoglobulin-like receptors and HLA ligands in Thai blood donors

Killer-cell immunoglobulin-like receptors (KIRs) play an important role in natural killer (NK) cell regulation. Interaction of KIRs with human leukocyte antigen (HLA) class I molecules can transmit signals to regulate the function of NK cells. In this study, the diversities of KIR genes and their ligands in 500 Thai blood donors were investigated. The coexistence of inhibitory KIRs (iKIR), activating KIRs (aKIR) and their ligands in the same individuals were also analyzed. Overall, 36 KIR genotypes were identified. The most common genotype was genotype AA1 (40.8%). All individuals carried at least one iKIR-HLA pair whereas 18% of the individuals lacked aKIR-HLA pair. The most common compound KIR-HLA profile was the presence of 3 iKIR-HLA pairs with 1 aKIR-HLA pair (21.4%). The most common compound gene profile of KIR-HLA pairs was the combined presence of KIR2DL3-C1, 3DL1-Bw4, 3DL2-A3/A11 and the full length KIR2DS4-its ligands (8%). This study provided a comprehensive analysis of the KIR-HLA profiles in Thai blood donors in regards to KIR genotypes, HLA ligands, KIR-HLA ligand pairs and compound gene profiles of both iKIRs and aKIRs and their ligands. These findings will be useful as baseline information for further studies in the associations of KIR genes and various diseases.