To engineer CAR T cells that allow control of dosing, especially in case of toxicity, Jan et al. developed ON or OFF switches using the non-immunosuppressive drug lenalidomide for chemical switch control. Screening of chimeric zinc finger domains revealed super-degrons with high sensitivity to lenalidomide. The super-degron ON-switch requires lenalidomide-induced dimerization and antigen binding for antitumor activity, allowing for deliberate titration of CAR T cell activity. The OFF switch CAR T cells demonstrated antitumor responses and T cell persistence while “ON”, but rapidly degraded the CARs upon lenalidomide treatment, resulting in reduced cytokine production.
Contributed by Maartje Wouters
ABSTRACT: Cell-based therapies are emerging as effective agents against cancer and other diseases. As autonomous "living drugs," these therapies lack precise control. Chimeric antigen receptor (CAR) T cells effectively target hematologic malignancies but can proliferate rapidly and cause toxicity. We developed ON and OFF switches for CAR T cells using the clinically approved drug lenalidomide, which mediates the proteasomal degradation of several target proteins by inducing interactions between the CRL4(CRBN) E3 ubiquitin ligase and a C2H2 zinc finger degron motif. We performed a systematic screen to identify "super-degron" tags with enhanced sensitivity to lenalidomide-induced degradation and used these degradable tags to generate OFF-switch degradable CARs. To create an ON switch, we engineered a lenalidomide-inducible dimerization system and developed split CARs that required both lenalidomide and target antigen for activation. Subtherapeutic lenalidomide concentrations controlled the effector functions of ON- and OFF-switch CAR T cells. In vivo, ON-switch split CARs demonstrated lenalidomide-dependent antitumor activity, and OFF-switch degradable CARs were depleted by drug treatment to limit inflammatory cytokine production while retaining antitumor efficacy. Together, the data showed that these lenalidomide-gated switches are rapid, reversible, and clinically suitable systems to control transgene function in diverse gene- and cell-based therapies.
Author Info: (1) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. Department of Pathology, Mass
Author Info: (1) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA. (2) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (3) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (4) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA. (5) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (6) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (7) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (8) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (9) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (10) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (11) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (12) Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (13) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (14) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (15) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (16) Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA. (17) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. (18) Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA. (19) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. mvmaus@mgh.harvard.edu benjamin_ebert@dfci.harvard.edu. Cellular Immunotherapy Program, Massachusetts General Hospital Cancer Center, Charlestown, MA 02114, USA. Harvard Medical School, Boston, MA 02115, USA. (20) Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. mvmaus@mgh.harvard.edu benjamin_ebert@dfci.harvard.edu. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
