Annihilation of Non-small Cell Lung Cancer by NKG2D CAR-T Cells Produced from T Cells from Peripheral Blood of Healthy Donors

Some progress has been made in immunotherapy with chimeric antigen receptor (CAR)-T cells targeting NKG2D-NKG2DL with the purpose of eradicating solid tumors. Non-small cell lung cancer (NSCLC) has been shown to express NKG2DL. This study hence evaluated the therapeutic effect of NKG2D CAR-T cells on NSCLC. Accordingly, NKG2D CAR-T cells were obtained from diverse human autologous T cell sources. T cells from peripheral blood T lymphocytes of healthy volunteers (without NKG2D CAR insertion) were used as NT-T cells. Coculture of effector cells (CAR-T cells or NT-T cells) with target cells (NSCLC cells such as PC-9 or NCL-H460 cells) was performed at different ratios. The cytotoxicity of CAR-T cells was examined using lactate dehydrogenase assay kits. Murine xenograft assay was conducted to investigate the in vivo antitumor effect of CAR-T cells. Cytokines secreted from CAR-T cells were assessed by enzyme-linked immunosorbent assay. CAR-T cell infiltration into xenografts was observed through immunochemical assay. Based on the results, NKG2DL was highly expressed in NSCLC cells. Compared with NT-T cells, NKG2D CAR-T cells from different sources of T cells delivered stronger toxicity, and secreted more effector and memory function-related cytokines to NSCLC cells, and those from the peripheral blood of healthy donors (H-T cells) exhibited the strongest effect. Furthermore, compared with NT-T cells, H-T cells and NKG2D CAR-T cells from NSCLC patients' peripheral blood diminished tumor, improved survival, increased body weight and tumor-infiltrating capacity, and upregulated serum IFN-γ level in NOG mice. Collectively speaking, NKG2D CAR-T cells exhibit a robust effect on eradicating NSCLC in a NKG2DL-dependent manner, thus making themselves a promising therapeutic candidate for NSCLC patients.