LunX-CAR T Cells as a Targeted Therapy for Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) carries a high mortality, and efficacious therapy is lacking. Therapy using chimeric antigen receptor (CAR) T cells has been used efficaciously against hematologic malignancies, but the curative effect against solid tumors is not satisfactory. A lack of antigen targets is one of the main reasons for this limited efficacy. Previously, we showed that lung-specific X (LUNX; also known as BPIFA1, PLUNC, and SPLUNC1) is overexpressed in lung cancer cells. Here, we constructed a CAR-T-cell-based strategy to target LunX (CAR(LunX) T cells). CAR T cells were developed so that, upon specific recognition of LunX, they secreted cytokines and killed LunX-positive NSCLC cells. In vitro, CAR(LunX) T cells displayed enhanced toxicity toward NSCLC lines and production of cytokines and showed specific LunX-dependent recognition of NSCLC cells. Adoptive transfer of CAR(LunX) T cells induced regression of established metastatic lung cancer xenografts and prolonged survival. CAR(LunX) T cells could infiltrate into the tumor. Also, we constructed a patient-derived xenograft model of lung cancer. After therapy with CAR(LunX) T cells, tumor growth was suppressed, and survival was prolonged significantly. Together, our findings offer preclinical evidence of the immunotherapeutic targeting of LunX as a strategy to treat NSCLC.