title: Enhanced effector responses in activated CD8+ T cells deficient in diacylglycerol kinases.
abstract: Recent clinical trials have shown promise in the use of chimeric antigen receptor (CAR)-transduced T cells; however, augmentation of their activity may broaden their clinical use and improve their efficacy. We hypothesized that because CAR action requires proteins essential for T-cell receptor (TCR) signal transduction, deletion of negative regulators of these signaling pathways would enhance CAR signaling and effector T-cell function. We tested CAR activity and function in T cells that lacked one or both isoforms of diacylglycerol kinase (dgk) expressed highly in T cells, dgkα and dgkζ, enzymes that metabolize the second messenger diacylglycerol (DAG) and limit Ras/ERK activation. We found that primary murine T cells transduced with CARs specific for the human tumor antigen mesothelin showed greatly enhanced cytokine production and cytotoxicity when cocultured with a murine mesothelioma line that stably expresses mesothelin. In addition, we found that dgk-deficient CAR-transduced T cells were more effective in limiting the growth of implanted tumors, both concurrent with and after establishment of tumor. Consistent with our studies in mice, pharmacologic inhibition of dgks also augments function of primary human T cells transduced with CARs. These results suggest that deletion of negative regulators of TCR signaling enhances the activity and function of CAR-expressing T cells and identify dgks as potential targets for improving the clinical potential of CARs.
authors.affiliation: Divisions of Hematology/Oncology, Pulmonology, and Rheumatology, Departments of Medicine, and Path and Lab Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Riese
authors.forename: Liang-Chuan S
authors.initials: LC
authors.lastname: Wang
authors.forename: Edmund K
authors.initials: EK
authors.lastname: Moon
authors.forename: Rohan P
authors.initials: RP
authors.lastname: Joshi
authors.forename: Anjana
authors.initials: A
authors.lastname: Ranganathan
authors.forename: Carl H
authors.initials: CH
authors.lastname: June
authors.forename: Gary A
authors.initials: GA
authors.lastname: Koretzky
authors.forename: Steven M
authors.initials: SM
authors.lastname: Albelda
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D019852:Diacylglycerol Kinase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004075:Diglycerides / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D058851:GPI-Linked Proteins / Q000276:immunology; D057809:HEK293 Cells; D006801:Humans; D016219:Immunotherapy, Adoptive; D007527:Isoenzymes / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D000090204:Mesothelin; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009374:Neoplasms, Experimental / Q000276:immunology / Q000473:pathology / Q000628:therapy; D011948:Receptors, Antigen, T-Cell / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology
chemical_list: C011439:1,2-diacylglycerol; D004075:Diglycerides; D058851:GPI-Linked Proteins; D007527:Isoenzymes; C000715528:Msln protein, mouse; D011948:Receptors, Antigen, T-Cell; D019852:Diacylglycerol Kinase; D000090204:Mesothelin