title: Toward immunotherapy with redirected T cells in a large animal model: ex vivo activation, expansion, and genetic modification of canine T cells.
abstract: Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) has shown promising antitumor activity in early phase clinical studies, especially for hematological malignancies. However, most preclinical models do not reliably mimic human disease. We reasoned that developing an adoptive T-cell therapy approach for spontaneous osteosarcoma (OS) occurring in dogs would more closely reproduce the condition in human cancer. To generate CAR-expressing canine T cells, we developed expansion and transduction protocols that allow for the generation of sufficient numbers of CAR-expressing canine T cells for future clinical studies in dogs within 2 weeks of ex vivo culture. To evaluate the functionality of CAR-expressing canine T cells, we targeted HER2(+) OS. We demonstrate that canine OS is positive for HER2, and that canine T cells expressing a HER2-specific CAR with human-derived transmembrane and CD28.ζ signaling domains recognize and kill HER2(+) canine OS cell lines in an antigen-dependent manner. To reduce the potential immunogenicity of the CAR, we evaluated a CAR with canine-derived transmembrane and signaling domains, and found no functional difference between human and canine CARs. Hence, we have successfully developed a strategy to generate CAR-expressing canine T cells for future preclinical studies in dogs. Testing T-cell therapies in an immunocompetent, outbred animal model may improve our ability to predict their safety and efficacy before conducting studies in humans.
authors.affiliation: *Center for Cell and Gene Therapy, Texas Children's Hospital, Houston Methodist Hospital, Baylor College of Medicine †Texas Children's Cancer Center, Texas Children's Hospital, Baylor College of Medicine Departments of ‡Pathology and Immunology §Pediatrics ∥Molecular Virology and Microbiology, Baylor College of Medicine, Houston ¶Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Texas A&M University, College Station, TX.
authors.forename: Melinda
authors.initials: M
authors.lastname: Mata
authors.forename: Juan F
authors.initials: JF
authors.lastname: Vera
authors.forename: Claudia
authors.initials: C
authors.lastname: Gerken
authors.forename: Cliona M
authors.initials: CM
authors.lastname: Rooney
authors.forename: Tasha
authors.initials: T
authors.lastname: Miller
authors.forename: Catherine
authors.initials: C
authors.lastname: Pfent
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Wang
authors.forename: Heather M
authors.initials: HM
authors.lastname: Wilson-Robles
authors.forename: Stephen
authors.initials: S
authors.lastname: Gottschalk
mesh_terms: D000818:Animals; D018106:CD28 Antigens / Q000235:genetics / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004195:Disease Models, Animal; D004285:Dogs; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D020014:K562 Cells; D008213:Lymphocyte Activation; D012516:Osteosarcoma / Q000628:therapy*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism*; D037182:T-Cell Antigen Receptor Specificity; D013601:T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D019076:Transgenes / Q000235:genetics
chemical_list: D018106:CD28 Antigens; D018719:Erb-b2 Receptor Tyrosine Kinases; D011948:Receptors, Antigen, T-Cell; C508053:ERBB2 protein, human