Genomic diversity of natural killer cell receptor genes in three populations

We report the distribution of genes encoding 11 killer cell immunoglobulin- like receptors (KIR) and 2 CD94:NKG2 receptors, in 32 Caucasians, 67 Austra lian Aborigines and 59 Vietnamese, The inhibitory and the activating KIR ge nes were found at different frequency in the three populations. No correlat ion was found between the polymorphism of the KIR genes and the HLA specifi cities oi the tested samples, The most significant KIR associations were 2D L2 with 2DS2; 2DL2 with 2DS3 and 3DL1 with 2DS4 in all three study groups. In Caucasians and Vietnamese 2DS2 was associated with 2DS3 and 2DS1 with 3D S1. KIR 2DL1 was strongly associated with three other KIRs: 2DL3, 3DL1 and 2DS4 in Aborigines. The distribution of the KIR phenotypes was different in the three populations. The AA1 phenotype was frequent in Vietnamese (42.4% ) and Caucasians (31.2%), but very rare in Aborigines (1.5%). In contrast, the BB7 phenotype was very common for Aborigines (22.4%) and was absent in the two other groups, Our data demonstrate that different associations and putative KIR haplotypes could be distinguished in different populations.