Natural Killer cell ligands (NK ligands)

Tumor cell ligands recognized by NK cells encompass a diverse group of surface proteins that regulate Natural Killer (NK) cell activity through activating and inhibitory receptors (Shimasaki et al., 2020). Activating ligands, such as MICA, MICB, and the ULBP family, are typically upregulated under conditions of cellular stress or malignancy and are recognized by the NKG2D receptor to trigger immune-mediated lysis (Lanier, 2015). Conversely, tumor cells often exploit inhibitory ligands, such as HLA-E (recognized by NKG2A) or classical MHC class I molecules (recognized by KIRs), to evade immune surveillance (André et al., 2018). Therapeutic interventions targeting these interactions include monoclonal antibodies that block inhibitory checkpoints, bispecific NK-cell engagers (BiKEs), and CAR-NK cells designed to recognize stress-induced ligands (Duan et al., 2021). The expression of these ligands is often dynamic, with tumor cells employing mechanisms like proteolytic shedding to release soluble forms that act as decoys, further dampening the immune response (Shimasaki et al., 2020). Clinical development in this area focuses on stabilizing ligand expression or preventing shedding to enhance the efficacy of NK cell-based therapies. Overall, these ligands represent a pivotal interface in cancer immunology, offering multiple avenues for precision medicine and combination therapies.

Other names

Tumor cell ligands recognized by NK cellsNKG2D ligandsStress-induced ligandsNK cell activating ligandsNK cell inhibitory ligandsNK ligands

Modulation of NK cell activity through the blockade of inhibitory ligand-receptor interactions or the enhancement of activating ligand-receptor signaling.