NKG2D-based Chimeric Antigen Receptor (NKG2D CAR)

The Engineered NKG2D Chimeric Antigen Receptor (NKG2D CAR) is a synthetic fusion protein designed to redirect immune effector cells, such as T cells or Natural Killer (NK) cells, to recognize and destroy malignant cells (Baumeister et al., 2019, PMID: 30305270). Unlike conventional CARs that typically utilize a single-chain variable fragment (scFv) derived from an antibody, the NKG2D CAR employs the extracellular domain of the natural NKG2D receptor (KLRK1) to bind its targets (Leung, 2014, PMID: 24923441). This design allows the CAR to recognize up to eight different ligands, including MICA, MICB, and ULBP1-6, which are frequently overexpressed on the surface of stressed, infected, or transformed cells but are largely absent from healthy tissues (Dembic et al., 2023, PMID: 36835421). Upon ligand binding, the NKG2D CAR triggers intracellular signaling through fused domains such as CD3-zeta, often supplemented by costimulatory domains like 4-1BB or DAP10, to induce potent cytotoxic activity and cytokine secretion (Van Seggelen et al., 2015, PMID: 25810491). This multi-ligand targeting strategy is particularly effective at addressing tumor heterogeneity and preventing antigen escape, a common mechanism of resistance in single-antigen targeted therapies (Sallman et al., 2023, PMID: 36638467). Therapeutic candidates like CYAD-01 and NKX101 have been evaluated in clinical trials for hematological malignancies like acute myeloid leukemia and various solid tumors (Celyad Oncology, 2024; Nkarta Therapeutics, 2024). Despite its promise, safety monitoring is critical due to the potential for on-target off-tumor toxicity if ligands are expressed at low levels on healthy cells, as well as standard CAR-T associated risks like cytokine release syndrome (Leivas et al., 2021, PMID: 33804334).

Other names

NKG2D-CARNKG2D-CD3z CARKLRK1-based Chimeric Antigen ReceptorChimeric NKG2D ReceptorNKG2D-BBz CAR

The NKG2D CAR utilizes the extracellular domain of the human NKG2D receptor to bind multiple stress-induced ligands (MICA, MICB, ULBP1-6) on tumor cells, triggering intracellular signaling cascades via CD3-zeta and costimulatory domains (e.g., 4-1BB or DAP10) that lead to targeted cell lysis and pro-inflammatory cytokine release (PMID: 29632024).