Anti-EpCAM CAR T cells caused lethal cytotoxicity in mice, but caused on-target, off-tumor lung and liver injury. ICAM-1 and VCAM-1 were elevated in these tissues, and blockade of integrins LFA-1 and VLA-4 alleviated toxicity and off-tumor trafficking. Triple knockdown (TKD) of integrin subunits CD11a/CD49 plus PSGL1 (TKD) in the CAR vector mimicked this effect and preserved efficacy. TKD cells had decreased exhaustion/activation, increased memory/anti-apoptotic gene expression, and were more serially cytotoxic in vitro. In a model with hEpCAM, TKD cells exhibited similar tumor infiltration and efficacy to control cells, along with improved persistence and decreased exhaustion.
Contributed by Morgan Janes
ABSTRACT: Chimeric antigen receptor (CAR)-T cell therapies have revolutionized the landscape of cancer treatment, in particular in the context of hematologic malignancies. However, for solid tumors that lack tumor-specific antigens, CAR-T cells can infiltrate and attack nonmalignant tissues expressing the CAR target antigen, leading to on-target, off-tumor toxicity. Severe on-target, off-tumor toxicities have been observed in clinical trials of CAR-T therapy for solid tumors, highlighting the need to address this issue. Here, we demonstrated that targeting the cell adhesion and migration molecules lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18) and very late activation antigen 4 (VLA-4; CD49d/CD29) with blocking antibodies reduced the on-target, off-tumor toxicity of CAR-T cells in mice. To translate this observation into improved CAR-T cell therapy, we either knocked out both CD11a and CD49d or knocked down CD11a and CD49d along with PSGL1, another cell adhesion molecule, in CAR-T cells. We found that these modified CAR-T cells exhibited reduced on-target, off-tumor toxicity in vivo without affecting CAR-T cell efficacy. Furthermore, we showed that this approach promoted T cell memory formation and decreased tonic signaling. On the basis of these data, we engineered a human version of these low-toxicity CAR-T cells and further validated the feasibility of this approach in vitro and in vivo. Together, these results provide a potential solution to address the clinical challenge of on-target, off-tumor toxicity in CAR-T therapy.
Author Info: (1) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Shanghai Cancer Institute, State Key Laboratory
Author Info: (1) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (2) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (3) Mini-invasive Interventional Therapy Center, Shanghai East Hospital, Tongji University, Shanghai 200025, China. (4) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (5) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (6) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (7) Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (8) Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (9) Department of Liver Surgery and Liver Transplantation, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China. (10) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (11) Suzhou Immunofoco Biotechnology Co. Ltd, Suzhou, Jiangsu 215000, China. (12) Mini-invasive Interventional Therapy Center, Shanghai East Hospital, Tongji University, Shanghai 200025, China. (13) Suzhou Immunofoco Biotechnology Co. Ltd, Suzhou, Jiangsu 215000, China. (14) Department of Plastic Surgery, Zhongshan Hospital, Fudan University, Shanghai 200025, China. (15) Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai 200025, China. (16) Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (17) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (18) Suzhou Immunofoco Biotechnology Co. Ltd, Suzhou, Jiangsu 215000, China. (19) Suzhou Immunofoco Biotechnology Co. Ltd, Suzhou, Jiangsu 215000, China. (20) Suzhou Immunofoco Biotechnology Co. Ltd, Suzhou, Jiangsu 215000, China. (21) Department of Urology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China. (22) Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (23) Department of Interventional Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Shanghai Cancer Institute, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Mini-invasive Interventional Therapy Center, Shanghai East Hospital, Tongji University, Shanghai 200025, China.
