title: A Tet-On Inducible System for Controlling CD19-Chimeric Antigen Receptor Expression upon Drug Administration.
abstract: T cells genetically modified with a CD19 chimeric antigen receptor (CD19CAR) are remarkably effective against B-cell malignancies in clinical trials. However, major concerns remain regarding toxicities, such as hypogammaglobulinemia, due to B-cell aplasia or severe cytokine release syndrome after overactivation of CAR T cells. To resolve these adverse events, we aimed to develop an inducible CAR system by using a tetracycline regulation system that would be activated only in the presence of doxycycline (Dox). In this study, the second-generation CD19CAR was fused into the third-generation Tet-On vector (Tet-CD19CAR) and was retrovirally transduced into primary CD8(+) T cells. Tet-CD19CAR T cells were successfully generated and had minimal background CD19CAR expression without Dox. Tet-CD19CAR T cells in the presence of Dox were equivalently cytotoxic against CD19(+) cell lines and had equivalent cytokine production and proliferation upon CD19 stimulation, compared with conventional CD19CAR T cells. The Dox(+) Tet-CD19CAR T cells also had significant antitumor activity in a xenograft model. However, without Dox, Tet-CD19CAR T cells lost CAR expression and CAR T-cell functions in vitro and in vivo, clearly segregating the "On" and "Off" status of Tet-CD19CAR cells by Dox administration. In addition to suicide-gene technology, controlling the expression and the functions of CAR with an inducible vector is a potential solution for CAR T-cell therapy-related toxicities, and may improve the safety profile of CAR T-cell therapy. This strategy might also open the way to treat other malignancies in combination with other CAR or TCR gene-modified T cells. Cancer Immunol Res; 4(8); 658-68. ©2016 AACRSee related Spotlight by June, p. 643.
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Reona
authors.initials: R
authors.lastname: Sakemura
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan. tseit@med.nagoya-u.ac.jp.
authors.forename: Seitaro
authors.initials: S
authors.lastname: Terakura
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan. Division of Clinical Hematology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
authors.forename: Jakrawadee
authors.initials: J
authors.lastname: Julamanee
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Erina
authors.initials: E
authors.lastname: Takagi
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Miyao
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Koyama
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Goto
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Hanajiri
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Murata
authors.affiliation: Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kiyoi
mesh_terms: D000818:Animals; D018941:Antigens, CD19 / Q000276:immunology* / Q000378:metabolism*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D004195:Disease Models, Animal; D004318:Doxycycline / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D023061:Gene Order; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D016219:Immunotherapy, Adoptive; D020014:K562 Cells; D018345:Mice, Knockout; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism*; D012190:Retroviridae / Q000235:genetics; D057127:Single-Chain Antibodies / Q000235:genetics / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D014161:Transduction, Genetic; D023041:Xenograft Model Antitumor Assays
chemical_list: D018941:Antigens, CD19; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D004318:Doxycycline