Background: Natural killer (NK) cells are known to mount a response against foreign target cells, where the absence of the dominant inhibitory killer Ig-like receptor (KIR)-human leukocyte antigen (HLA) interaction immensely lowers the threshold for NK cell activation. NK cells could thus constitute a vital part in the mucosal defense against cell-associated sexually transmitted diseases. Here, we performed a detailed analysis of hitherto unexplored KIR-HLA-incompatible NK cell interactions.

Methods and findings: In vitro, healthy NK cells were cocultured with CD4+ T cells derived from human immunodeficiency virus-1 patients, and the KIR-specific NK cell cytotoxicity was measured using flow cytometry. Genotyping of KIR and HLA predicted the KIR-HLA interactions occurring during these 124 allogeneic encounters. KIR2DL1+ NK cells were seen as the strongest intrinsic responders in the absence of their ligand with a 3.2-fold increase in KIR2DL1+ NK cells in the total NK cell response. An association between the size of the alloreactive NK cell population and the amount of CD4+ T cell death (p = 0.0023) and NK cell degranulation (p = 0.0036) was only present in NK cell donors with an activating KIR haplotype.

conclusion: We demonstrate differences in the activating effect of KIR-HLA incompatibility according to the KIR involved, with KIR2DL1 as the strongest responder. An activating KIR haplotype optimized the contribution of KIR-HLA-incompatible NK cells in the total NK cell response.

Original languageEnglish
Article number1588
JournalFrontiers in Immunology
Number of pages11
Publication statusPublished - 2018

Bibliographical note


    Research areas

  • allogeneic natural killer cell responses, killer Ig-like receptor-human leukocyte antigen ligand mismatch, in vitro natural killer-CD4 cocultures, human immunodeficiency virus-1 patients, HIV transmission, MHC CLASS-I, IMMUNOGLOBULIN-LIKE RECEPTORS, HUMAN NK CELLS, INHIBITORY RECEPTORS, SURFACE-MOLECULE, ACUTE-LEUKEMIA, COMPLEX, HLA, RECOGNITION, RESPONSIVENESS

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