Natural Killer Group 2 Member D (NKG2D) and CD16 (FcγRIIIa) (NKG2D/CD16)

The target system comprising stress-induced ligands for NK-like receptors (specifically NKG2D) and the Fc regions of tumor-targeting antibodies (which engage CD16) represents a critical axis in innate cancer immunotherapy. NKG2D (KLRK1) is a potent activating receptor on Natural Killer (NK) cells and T cells that recognizes 'stress' ligands such as MICA, MICB, and ULBPs, which are frequently upregulated on the surface of malignant or infected cells. CD16 (FcγRIIIa) is the primary receptor responsible for antibody-dependent cellular cytotoxicity (ADCC), binding to the Fc portion of IgG antibodies. Therapeutic strategies, such as multispecific NK cell engagers (NKCEs), are designed to co-engage these two receptors to maximize NK cell activation against tumors. By bridging the tumor cell to the NK cell through these specific pathways, these drugs can overcome the immunosuppressive tumor microenvironment and promote robust anti-tumor immunity. This approach is currently being explored in various clinical trials for both hematological malignancies and solid tumors, aiming to provide a more targeted and potent alternative to traditional monoclonal antibodies.

Other names

KLRK1Natural killer cell lectin-like receptor subfamily K member 1CD314Fc gamma receptor IIIaFCGR3ACD16aNK cell activating receptors

Drugs targeting this dual system typically act as multispecific NK cell engagers (NKCEs). They bind to a tumor-associated antigen (TAA) while simultaneously engaging the activating receptors NKG2D and CD16 on Natural Killer (NK) cells. This dual engagement bypasses inhibitory signals and triggers potent NK cell-mediated lysis of the tumor cell through the release of perforin and granzymes, as well as the secretion of pro-inflammatory cytokines like IFN-gamma.