title: Chimeric antigen receptor T Cells with dissociated signaling domains exhibit focused antitumor activity with reduced potential for toxicity in vivo.
abstract: Adoptive immunotherapy using T lymphocytes genetically modified to express a chimeric antigen receptor (CAR-T) holds considerable promise for the treatment of cancer. However, CAR-based therapies may involve on-target toxicity against normal tissues expressing low amounts of the targeted tumor-associated antigen (TAA). To specify T cells for robust effector function that is selective for tumor but not normal tissue, we developed a trans-signaling CAR strategy, whereby T-cell activation signal 1 (CD3z) is physically dissociated from costimulatory signal 2 (CD28) in two CARs of differing antigen specificity: mesothelin and a-folate receptor (FRa). Human T cells were genetically modified to coexpress signal 1 (anti-Meso scFv-CD3z) and signal 2 (anti-FRa scFv-CD28) CARs in trans. Trans-signaling CAR-T cells showed weak cytokine secretion against target cells expressing only one TAA in vitro, similar to first-generation CAR-T cells bearing CD3z only, but showed enhanced cytokine secretion upon encountering natural or engineered tumor cells coexpressing both antigens, equivalent to that of second-generation CAR-T cells with dual signaling in cis. CAR-T cells with dual specificity also showed potent anticancer activity and persistence in vivo, which was superior to first-generation CAR-T cells and equivalent to second-generation CARs. Importantly, second-generation CAR-T cells exhibited potent activity against cells expressing mesothelin alone, recapitulating normal tissue, whereas trans-signaling CAR-T cells did not. Thus, a dual specificity, trans-signaling CAR approach can potentiate the therapeutic efficacy of CAR-T cells against cancer while minimizing parallel reactivity against normal tissues bearing single antigen.
authors.forename: Evripidis
authors.initials: E
authors.lastname: Lanitis
authors.forename: Mathilde
authors.initials: M
authors.lastname: Poussin
authors.forename: Alex W
authors.initials: AW
authors.lastname: Klattenhoff
authors.forename: Degang
authors.initials: D
authors.lastname: Song
authors.forename: Raphael
authors.initials: R
authors.lastname: Sandaltzopoulos
authors.forename: Carl H
authors.initials: CH
authors.lastname: June
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Powell
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D046528:Chimerism; D005260:Female; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D000090204:Mesothelin; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010051:Ovarian Neoplasms / Q000276:immunology / Q000628:therapy*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D023041:Xenograft Model Antitumor Assays
chemical_list: C000715528:Msln protein, mouse; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D000090204:Mesothelin