Mind the Gap: Lack of Association between KIR3DL1*004/HLA-Bw4-Induced Natural Killer Cell Function and Protection from HIV Infection

Several combinations of genes encoding KIR3DL1 alleles and their HLA-Bw4 ligands have been linked with favorable outcomes upon exposure to or infection with human immunodeficiency virus (HIV). Some protective KIR3DL1/HLA-Bw4 combinations confer elevated natural killer (NK) cell functional potential. The K562-stimulated functionality of NK cells from KIR3DL1*004/HLA-Bw4 and control genotype carriers was assessed by flow cytometry and found to be higher in KIR3DL1*004/HLA-Bw4 carriers. However, a comparison of the frequency of this combined genotype among HIV-exposed uninfected and HIV-infected subjects revealed no between-group differences. Thus, despite its ability to license NK cells, KIR3DL1*004/HLA-Bw4 is not associated with a reduced risk of infection.