Tumor-expressed Natural Killer cell receptor ligand (NKRL)

Tumor-expressed Natural Killer (NK) receptor ligands are a diverse group of cell-surface proteins, such as MICA, MICB, and ULBPs, that are upregulated by malignant cells in response to cellular stress, DNA damage, or oncogenic transformation (PMID: 31101619). These ligands primarily interact with activating receptors like NKG2D or inhibitory receptors like NKG2A on NK cells and certain T cell subsets to modulate immune surveillance (PMID: 29463791). In many cancers, tumors evade immune detection by proteolytically shedding these ligands from the cell surface, creating soluble decoys that impair NK cell function and promote immune tolerance (PMID: 29593297). Therapeutic strategies targeting these ligands include monoclonal antibodies designed to prevent shedding or stabilize surface expression, as well as CAR-NK and CAR-T cells engineered to recognize these stress-induced markers (PMID: 33614536). Additionally, the overexpression of inhibitory ligands like HLA-E allows tumors to suppress NK cell activity, making the HLA-E/NKG2A axis a significant target for checkpoint inhibition (PMID: 30531905). Overall, these ligands serve as critical molecular switches that determine the efficacy of the innate immune response against cancer.

Other names

NKG2D ligandNKG2DLStress-induced ligandMHC class I polypeptide-related sequence A/BMICA/BUL16-binding proteinULBPNK cell activating ligandNK cell inhibitory ligandHLA-ECD155CD112

Enhancement of NK cell-mediated cytotoxicity by stabilizing surface ligand expression, preventing proteolytic shedding of decoys, or direct engagement via chimeric antigen receptors and bispecific engagers (PMID: 29593297, 33614536).