Natural killer cell activating receptors (NK cell activating receptors) (NKARs)

Natural killer (NK) cell activating receptors are a diverse group of germline-encoded surface proteins that trigger the cytotoxic activity and cytokine production of NK cells upon binding to ligands on stressed, infected, or malignant cells (Vivier et al., 2011, Science). Key members include the natural cytotoxicity receptors (NKp30, NKp44, NKp46), C-type lectin-like receptors (NKG2D), and the low-affinity Fc receptor CD16 (FCGR3A) (Shimasaki et al., 2020, Nature Reviews Drug Discovery). These receptors signal through adapter molecules containing immunoreceptor tyrosine-based activation motifs (ITAMs), such as DAP12 or CD3-zeta, to initiate the release of perforin and granzymes (Long et al., 2013, Annual Review of Immunology). In oncology, these pathways are exploited through the development of NK cell engagers (NKCEs) and chimeric antigen receptor (CAR)-NK cells designed to enhance anti-tumor immunity (Gauthier et al., 2019, Cell). Therapeutic strategies often involve multi-specific antibodies that bridge NK cell activating receptors to tumor-associated antigens, thereby bypassing inhibitory signals and promoting targeted cell lysis (Demaria et al., 2019, Nature Reviews Cancer).

Other names

Activating NK receptorsNatural cytotoxicity receptorsNCRsNK cell activation pathwaysNK cell engager targets

Agonism of activating receptors (such as CD16A, NKp46, or NKG2D) to trigger NK cell-mediated lysis of target cells and cytokine release, often via bispecific or trispecific engagers that bridge the NK cell to a tumor-associated antigen.