Impact Of Hla Allele-Kir Pairs On Hiv Clinical Outcome In South Africa

Background. HLA class I contributes to HIV immune control through antigen presentation to cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. In contrast to investigations of CTL, studies of NK cells in HIV control through HLA-killer immuno-globulin-like receptor (KIR) interactions remain sparse in African cohorts.Methods. Treatment-naive, chronically HIV-infected adults (N = 312) were recruited from South Africa, and the effects of HLA-KIR pairs on clinical outcome were analyzed.Results. There was no significant difference in viral load among all subjects with HLA alleles from the HLA-C1 group (P = .1). However, differences in HLA-C type significantly influenced viremia among 247 KIR2DL3 positives (P = .04), suggesting that specific HLA-KIR interactions contribute to immune control. Higher viral load (P = .02) and lower CD4(+) T-cell counts (P = .008) were observed in subjects with HLA-C*16:01(+)KIR2DL3(+). Longitudinal analysis showed more rapid progression to AIDS among HLAC*16:01(+)KIR2DL3(+) subjects (adjusted hazard ratio 1.9, P = .03) than those without this genotype, independent of CD4+ T-cell count and viral load.Conclusions. These results highlight the existence of unique anti-HIV innate immunity within distinct populations and the contribution of KIR on NK cells and some CTLs to the well-described HLA-mediated impact on HIV disease progression.