Li, Han, and Zhu et al. observed that T cell activation increased NKG2D ligand (NKG2DL) expression, enabling T cell depletion by NK cells. Overexpressing (OE) full-length NKG2D in CAR T cells led to its colocalization with NKG2DL on the cell surface, reducing NKG2DL detection (by cis masking) and NK killing. NKG2D-OE also improved CAR T cell cytotoxicity by binding NKG2DL on tumor cells (in trans) and increasing CAR-T activation, memory phenotype, CAR-proximal signaling, and proliferative capacity, without affecting exhaustion. NKG2D-OE improved CAR-T efficacy in heme and solid tumor models, and boosted tumor infiltration.
Contributed by Alex Najibi
(1) Li J (2) Han L (3) Zhu Q (4) Liu N (5) Ma H (6) Wu Z (7) Wang Y (8) Lin X (9) Wei J (10) Han W
Li, Han, and Zhu et al. observed that T cell activation increased NKG2D ligand (NKG2DL) expression, enabling T cell depletion by NK cells. Overexpressing (OE) full-length NKG2D in CAR T cells led to its colocalization with NKG2DL on the cell surface, reducing NKG2DL detection (by cis masking) and NK killing. NKG2D-OE also improved CAR T cell cytotoxicity by binding NKG2DL on tumor cells (in trans) and increasing CAR-T activation, memory phenotype, CAR-proximal signaling, and proliferative capacity, without affecting exhaustion. NKG2D-OE improved CAR-T efficacy in heme and solid tumor models, and boosted tumor infiltration.
Contributed by Alex Najibi
ABSTRACT: Chimeric antigen receptor (CAR)-T cell therapy has achieved remarkable success in hematologic malignancies, but durable efficacy remains limited by insufficient CAR-T cell persistence. Here, we show that activated CAR-T cells upregulate multiple NKG2D ligands (NKG2DLs), increasing their susceptibility to natural killer (NK) cell-mediated CAR-T cell cytotoxicity. To address this vulnerability, we engineer CAR-T cells to overexpress full-length NKG2D (CAR-NG). NKG2D overexpression reduces the surface accessibility of endogenous NKG2DLs without decreasing their total protein abundance. In parallel, engagement of tumor-expressed NKG2DLs in trans provides additional costimulatory signals, enhancing CAR-T cell activation and proliferation while attenuating exhaustion-associated phenotypes. In hematologic and solid tumor models, CAR-NG cells exhibit reduced susceptibility to NK-cell-mediated cytotoxicity, improved tumor control, increased in vivo expansion, deeper tumor infiltration, and no evident additional toxicity compared with conventional CAR-T cells. These findings identify NKG2D overexpression as an engineering strategy that enhances CAR-T antitumor activity primarily through tumor NKG2DL-dependent trans costimulation.
Author Info:
(1) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. (2) Department of Biotherapy, the First Medical Center, Chinese PLA General Ho
spital, Beijing, China. (3) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. (4) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. (5) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. (6) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. (7) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. (8) Beijing Changping Laboratory, Beijing, China; School of Basic Medical Sciences, Tsinghua University School of Medicine, Beijing, China; Tsinghua-Peking Center for Life Sciences, Beijing, China. Electronic address: linxin307@tsinghua.edu.cn. (9) Beijing Changping Laboratory, Beijing, China. Electronic address: woshiwjs@hotmail.com. (10) Department of Biotherapy, the First Medical Center, Chinese PLA General Hospital, Beijing, China. Electronic address: hanwdrsw@163.com.
Citation: Cell Rep Med 2026 Oct 16 103116 Epub10/16/2026
