Discrimination between the main activating and inhibitory killer cell immunoglobulin‐like receptor positive natural killer cell subsets using newly characterized monoclonal antibodies

Abstract

Summary Natural killer (NK) cells are key components of the innate anti‐viral and anti‐tumour immune responses. NK cell function is regulated by the interaction of killer cell immunoglobulin‐like receptors (KIR) with human leucocyte antigen (HLA) class I molecules. In this study, we report on the generation of KIR‐specific antibodies allowing for discrimination between activating and inhibitory KIR. For this purpose, BALB/c mice were immunized with human KIR2DS2 recombinant protein. The precise specificity of KIR2DS2‐specific clones was determined on KIR‐transfected BW cells and KIR‐genotyped NK cells. When used in combination with EB6 (KIR2DL1/2DS1) or GL183 (KIR2DL2/2DL3/2DS2), two KIR‐specific monoclonal antibodies (mAbs), 8C11 (specific for KIR2DL1/2DL2/2DL3/2DS2) and 1F12 (specific for KIR2DL3/2DS2), discriminated activating KIR2DS1 (8C11− EB6+) from inhibitory KIR2DL1 (8C11+ GL183−) and KIR2DL2 (1F12− GL183+), while excluding the main HLA‐Cw‐specific KIR. Using these mAbs, KIR2DS1 was shown to be expressed on the surface of NK cells from all individuals genotyped as KIR2DS1+ (n = 23). Moreover, KIR2DS1 and KIR2DL1 were independently expressed on NK cells. We also determined the amino acid position recognized by the 8C11 and 1F12 mAbs, which revealed that some KIR2DL1 allele‐encoded proteins are not recognized by 8C11. Because most available anti‐KIR mAbs recognize both inhibitory and activating forms of KIR, these newly characterized antibodies should help assess the expression of activating and inhibitory KIR and their functional relevance to NK biology.

Maternal activating KIRs protect against human reproductive failure mediated by fetal HLA-C2

“…Furthermore, a fundamental distinction between the 2 KIR haplotypes with respect to HLA-C is the presence in the B haplotype of the 2DS1 gene ( Figure 1). It was therefore important to determine whether uNK cells are the same as PBNK cells in expressing 2DS1 when the gene is present (23). By using a combination of mAbs, we were able to show that uNK subsets express both 2DL1 and 2DS1 proteins (Supplemental Figure 2).…”

Deciphering the killer‐cell immunoglobulin‐like receptor system at super‐resolution for natural killer and T‐cell biology

“…Although antibody combinations can help to decipher these activating KIRs,187, 192, 201 they do not allow analysis at single KIR level because of antibody cross‐reactivity. Aptamers, short single‐stranded nucleic acid oligomers that bind to a specific target molecule, with their unique features of high binding affinity and specificity, could offer a useful alternative to antibodies in discriminating subtly different forms of KIR 209.…”

NK cell responses to cytomegalovirus infection lead to stable imprints in the human KIR repertoire and involve activating KIRs

“…To discriminate between KIR2DL2 and KIR2DS2, we combined the mABs GL183 and 180701 (KIR2DL3) with the recently described 1F12 antibody (KIR2DL3/S2) ( Figure 6C). 33 In all 3 donors (#033, #154, and #198), the expanded cells exclusively expressed KIR2DS2 ( Figure 6C and supplementary Table 3). The 3 remaining undefined expanded populations were all KIR3DS1 1 at the genetic level.…”