title: Augmentation of CAR T-cell Trafficking and Antitumor Efficacy by Blocking Protein Kinase A Localization.
abstract: Antitumor treatments based on the infusion of T cells expressing chimeric antigen receptors (CAR T cells) are still relatively ineffective for solid tumors, due to the presence of immunosuppressive mediators [such as prostaglandin E2 (PGE2) and adenosine] and poor T-cell trafficking. PGE2 and adenosine activate protein kinase A (PKA), which then inhibits T-cell receptor (TCR) activation. This inhibition process requires PKA to localize to the immune synapse via binding to the membrane protein ezrin. We generated CAR T cells that expressed a small peptide called the "regulatory subunit I anchoring disruptor" (RIAD) that inhibits the association of PKA with ezrin, thus blunting the negative effects of PKA on TCR activation. After exposure to PGE2 or adenosine in vitro, CAR-RIAD T cells showed increased TCR signaling, released more cytokines, and showed enhanced killing of tumor cells compared with CAR T cells. When injected into tumor-bearing mice, the antitumor efficacy of murine and human CAR-RIAD T cells was enhanced compared with that of CAR T cells, due to resistance to tumor-induced hypofunction and increased T-cell infiltration of established tumors. Subsequent in vitro assays showed that both mouse and human CAR-RIAD cells migrated more efficiently than CAR cells did in response to the chemokine CXCL10 and also had better adhesion to various matrices. Thus, the intracellular addition of the RIAD peptide to adoptively transferred CAR T cells augments their efficacy by increasing their effector function and by improving trafficking into tumor sites. This treatment strategy, therefore, shows potential clinical application for treating solid tumors. Cancer Immunol Res; 4(6); 541-51. ©2016 AACR.
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Kheng
authors.initials: K
authors.lastname: Newick
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Shaun
authors.initials: S
authors.lastname: O'Brien
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Veena
authors.initials: V
authors.lastname: Kapoor
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Steven
authors.initials: S
authors.lastname: Maceyko
authors.affiliation: Department of Biomedical Sciences, School of Veterinary Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Albert
authors.initials: A
authors.lastname: Lo
authors.affiliation: Department of Biomedical Sciences, School of Veterinary Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Ellen
authors.initials: E
authors.lastname: Puré
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Edmund
authors.initials: E
authors.lastname: Moon
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. albelda@mail.med.upenn.edu.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Albelda
mesh_terms: D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000096:biosynthesis; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D008654:Mesothelioma / Q000201:enzymology / Q000276:immunology / Q000628:therapy*; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D011948:Receptors, Antigen, T-Cell; D007371:Interferon-gamma; D017868:Cyclic AMP-Dependent Protein Kinases