title: Fully human CD19-specific chimeric antigen receptors for T-cell therapy.
abstract: Impressive results have been achieved by adoptively transferring T-cells expressing CD19-specific CARs with binding domains from murine mAbs to treat B-cell malignancies. T-cell mediated immune responses specific for peptides from the murine scFv antigen-binding domain of the CAR can develop in patients and result in premature elimination of CAR T-cells increasing the risk of tumor relapse. As fully human scFv might reduce immunogenicity, we generated CD19-specific human scFvs with similar binding characteristics as the murine FMC63-derived scFv using human Ab/DNA libraries. CARs were constructed in various formats from several scFvs and used to transduce primary human T-cells. The resulting CD19-CAR T-cells were specifically activated by CD19-positive tumor cell lines and primary chronic lymphocytic leukemia cells, and eliminated human lymphoma xenografts in immunodeficient mice. Certain fully human CAR constructs were superior to the FMC63-CAR, which is widely used in clinical trials. Imaging of cell surface distribution of the human CARs revealed no evidence of clustering without target cell engagement, and tonic signaling was not observed. To further reduce potential immunogenicity of the CARs, we also modified the fusion sites between different CAR components. The described fully human CARs for a validated clinical target may reduce immune rejection compared with murine-based CARs.
authors.affiliation: Fred Hutchinson Cancer Research Center, Clinical Research Division, Program in Immunology, Seattle, WA, USA.
authors.forename: D
authors.initials: D
authors.lastname: Sommermeyer
authors.affiliation: Fred Hutchinson Cancer Research Center, Clinical Research Division, Program in Immunology, Seattle, WA, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hill
authors.affiliation: Juno Therapeutics, Inc., Seattle, WA, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Shamah
authors.affiliation: Fred Hutchinson Cancer Research Center, Clinical Research Division, Program in Immunology, Seattle, WA, USA.
authors.forename: A I
authors.initials: AI
authors.lastname: Salter
authors.affiliation: Juno Therapeutics, Inc., Seattle, WA, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Juno Therapeutics, Inc., Seattle, WA, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Mohler
authors.affiliation: Fred Hutchinson Cancer Research Center, Clinical Research Division, Program in Immunology, Seattle, WA, USA.|Department of Medicine, University of Washington, Seattle, WA, USA.|Technical University of Munich, Institute for Advanced Study, Munich, Germany.
authors.forename: S R
authors.initials: SR
authors.lastname: Riddell
mesh_terms: D000818:Animals; D018941:Antigens, CD19 / Q000276:immunology*; D002051:Burkitt Lymphoma / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D005260:Female; D015723:Gene Library; D057809:HEK293 Cells; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D020014:K562 Cells; D051379:Mice; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D016513:Mice, SCID; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology*; D013045:Species Specificity; D013601:T-Lymphocytes / Q000637:transplantation*; D014161:Transduction, Genetic; D023041:Xenograft Model Antitumor Assays
chemical_list: D018941:Antigens, CD19; C000604811:CD19 molecule, human; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies