Characterization of KIR + NK cell subsets with a monoclonal antibody selectively recognizing KIR2DL1 and blocking the specific interaction with HLA-C

Meazza, Raffaella; Falco, Michela; Canevali, Paolo; Loiacono, Fabrizio; Colomar-Carando, Natalia; Muntasell i Castellví, Aura, 1972-; Rea, Anna; Mingari, Maria Cristina; Locatelli, Franco; Moretta, Lorenzo; López-Botet, M. (Miguel); Pende, Daniela

doi:http://dx.doi.org/10.1111/tan.14640

Characterization of KIR + NK cell subsets with a monoclonal antibody selectively recognizing KIR2DL1 and blocking the specific interaction with HLA-C

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Meazza R, Falco M, Canevali P, Loiacono F, Colomar-Carando N, Muntasell A, Rea A, Mingari MC, Locatelli F, Moretta L, Lopez-Botet M, Pende D. Characterization of KIR + NK cell subsets with a monoclonal antibody selectively recognizing KIR2DL1 and blocking the specific interaction with HLA-C. HLA. 2022 Aug;100(2):119-32. DOI: 10.1111/tan.14640

Abstract

The phenotypic identification of different NK cell subsets allows more in-depth characterization of KIR repertoire and function, which are of potential interest in KIR and disease association studies. KIR genes are highly polymorphic, but a great homology exists among the various sequences and few monoclonal antibodies (mAbs) specifically recognize a single KIR. This is the case of HP-DM1 which was demonstrated by analysis of cell transfectants and epitope mapping to be exclusively KIR2DL1-specific, covering all allotypes identified to date, except for KIR2DL1*022 and *020, and also to react with KIR2DS1*013. Here, we compared in immunofluorescence analyses the staining of HP-DM1 with other available mAbs to precisely identify KIR2DL1+ NK cells in potential donors for αβT/B-depleted haplo-HSCT, with known KIR genotype. HP-DM1 mAb was used in combination with EB6 or 11PB6 (anti-KIR2DL1/S1 and anti-KIR2DL3*005), 143211 (anti-KIR2DL1/S5), and HP-MA4 (anti-KIR2DL1/S1/S3/S5) mAbs, allowing the accurate identification of different KIR+ NK cell subsets. These phenotypic evaluations appeared useful to dissect the expression pattern of various KIR2D in NK cells from KIR2DL3*005+ individuals, particularly if KIR2DS1 is present. HP-DM1 mAb remarkably refined NK cell phenotyping of donors carrying KIR2DS5, either in the centromeric or telomeric region. Functional assays with KIR2DL1+ /S1+ /S5+ NK cells confirmed that only HP-DM1 exclusively reacts with KIR2DL1. Finally, we demonstrated that HP-DM1 mAb blocked KIR2DL1 recognition of C2+ HLA-C. Altogether, the data support that HP-DM1 is a unique reagent valuable for characterizing KIR+ NK cell subsets.