First published February 20, 2018 - More info
HLA-B*57 control of HIV involves enhanced CD8+ T cell responses against infected cells, but extensive heterogeneity exists in level of HIV control among B*57+ individuals. Using whole genome sequencing of untreated B*57+ HIV-1 infected controllers and non-controllers, we identified a single variant (rs643347A/G) encoding an isoleucine to valine substitution at position 47 (I47V) of the inhibitory killer cell immunoglobulin-like receptor, KIR3DL1, as the only significant modifier of B*57 protection. The association replicated in an independent cohort and across multiple outcomes. The modifying effect of I47V was confined to B*57:01, and was not observed for the closely related B*57:03. Positions 2, 47, and 54 track one another nearly perfectly, and two KIR3DL1 allotypes differing only at these three positions showed significant differences in binding B*57:01 tetramers, where the protective allotype showed lower binding. Thus, variation in an immune natural killer cell receptor that binds B*57:01 modifies its protection. These data speak to exquisite specificity of KIR-HLA interactions in human health and disease.