title: CD28 costimulation provided through a CD19-specific chimeric antigen receptor enhances in vivo persistence and antitumor efficacy of adoptively transferred T cells.
abstract: Chimeric antigen receptors (CAR) combine an antigen-binding domain with a CD3-zeta signaling motif to redirect T-cell specificity to clinically important targets. First-generation CAR, such as the CD19-specific CAR (designated CD19R), may fail to fully engage genetically modified T cells because activation is initiated by antigen-dependent signaling through chimeric CD3-zeta, independent of costimulation through accessory molecules. We show that enforced expression of the full-length costimulatory molecule CD28 in CD8(+)CD19R(+)CD28(-) T cells can restore fully competent antigen-dependent T-cell activation upon binding CD19(+) targets expressing CD80/CD86. Thus, to provide costimulation to T cells through a CD19-specific CAR, independent of binding to CD80/CD86, we developed a second-generation CAR (designated CD19RCD28), which includes a modified chimeric CD28 signaling domain fused to chimeric CD3-zeta. CD19R(+) and CD19RCD28(+) CD8(+) T cells specifically lyse CD19(+) tumor cells. However, the CD19RCD28(+) CD8(+) T cells proliferate in absence of exogenous recombinant human interleukin-2, produce interleukin-2, propagate, and up-regulate antiapoptotic Bcl-X(L) after stimulation by CD19(+) tumor cells. For the first time, we show in vivo that adoptively transferred CD19RCD28(+) T cells show an improved persistence and antitumor effect compared with CD19R(+) T cells. These data imply that modifications to the CAR can result in improved therapeutic potential of CD19-specific T cells expressing this second-generation CAR.
authors.affiliation: Divisions of Molecular Medicine, Beckman Research Institute and City of Hope National Medical Center, Duarte, California, USA.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Kowolik
authors.forename: Max S
authors.initials: MS
authors.lastname: Topp
authors.forename: Sergio
authors.initials: S
authors.lastname: Gonzalez
authors.forename: Timothy
authors.initials: T
authors.lastname: Pfeiffer
authors.forename: Simon
authors.initials: S
authors.lastname: Olivares
authors.forename: Nancy
authors.initials: N
authors.lastname: Gonzalez
authors.forename: David D
authors.initials: DD
authors.lastname: Smith
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Forman
authors.forename: Michael C
authors.initials: MC
authors.lastname: Jensen
authors.forename: Laurence J N
authors.initials: LJ
authors.lastname: Cooper
mesh_terms: D000818:Animals; D018941:Antigens, CD19 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D018106:CD28 Antigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D000939:Epitopes; D005260:Female; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology; D008213:Lymphocyte Activation; D016393:Lymphoma, B-Cell / Q000276:immunology / Q000628:therapy; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D013601:T-Lymphocytes / Q000276:immunology*; D019076:Transgenes; D023041:Xenograft Model Antitumor Assays; D051020:bcl-X Protein / Q000096:biosynthesis / Q000276:immunology
chemical_list: D018941:Antigens, CD19; C494811:BCL2L1 protein, human; D018106:CD28 Antigens; D000939:Epitopes; D007376:Interleukin-2; D051020:bcl-X Protein; D007371:Interferon-gamma