ENPP3 CAR T cells combined with CD206 modulation suppress adrenocortical carcinoma
Reona Okada, Arnulfo Mendoza, Darryl Nousome, Samarth Mathur, Constanza Rodriguez, Jangsuk Oh, Katie Pendo, Ira Phadke, Haiying Qin, Sitanshu S Singh, Rosie Kaplan, Jaydira del Rivero, Mary F Wedekind, Elijah F Edmondson, Markku Miettinen, Kelli M Wilson, Shinjen Lin, Glenn Y Gomba, David O Holland, Sudipto Das, Udo Rudloff, Thorkell Andresson, Ken Chih-Chien Cheng, Xiyuan Zhang, Karlyne M Reilly, Brigitte Widemann, Rosa NguyenBackground
Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with poor prognosis and limited curative treatment options. While chimeric antigen receptor (CAR) T cells have shown some promise in solid tumors, ACC remains largely unexplored in this context. Here, we used patient-derived xenograft (PDX) models of ACC to identify immunotherapeutic targets and develop novel CAR T-cell strategies.
Methods
Target identification and tumor microenvironment (TME) profiling were conducted using publicly available bulk and single-cell RNA sequencing data from patients with ACC samples. Surface proteomic analysis and flow cytometry of PDXs were conducted to validate antigen candidates. CAR T cells were engineered and tested for cytotoxicity in vitro and in vivo and profiled using flow cytometry and cytokine analysis.
Results
We identified ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP3) as a shared immunotherapy target in 4/7 (57%) ACC PDXs. ENPP3-targeted CAR T-cells eradicated >85% of ENPP3 + ACC cells in vitro but showed attenuated efficacy in PDX mouse models. Restrained ENPP3 CAR T-cell activity correlated with immunosuppressive features of the TME, particularly the presence of CD206 + tumor-associated macrophages (TAMs). Co-treatment with an agent modulating CD206 + TAMs restored CAR T-cell function and improved antitumor responses in ENPP3 high and ENPP3 low PDX models (difference between mean tumor weights −270.1 mg±117.4; p < 0.05).
Conclusion
ENPP3 is a novel target for CAR T-cell therapy in ACC. ENPP3 CAR T cells, when combined with CD206 modulation to overcome immune suppression within the TME, have therapeutic efficacy in ACC by mediating robust tumor growth suppression. This combinatorial strategy, which includes CAR T cells alongside therapies that recalibrate immunosuppressive CD206 + TAMs, may be a novel approach for improved immunotherapy of solid cancers beyond ACC.