title: Switch-mediated activation and retargeting of CAR-T cells for B-cell malignancies.
abstract: Chimeric antigen receptor T (CAR-T) cell therapy has produced impressive results in clinical trials for B-cell malignancies. However, safety concerns related to the inability to control CAR-T cells once infused into the patient remain a significant challenge. Here we report the engineering of recombinant antibody-based bifunctional switches that consist of a tumor antigen-specific Fab molecule engrafted with a peptide neo-epitope, which is bound exclusively by a peptide-specific switchable CAR-T cell (sCAR-T). The switch redirects the activity of the bio-orthogonal sCAR-T cells through the selective formation of immunological synapses, in which the sCAR-T cell, switch, and target cell interact in a structurally defined and temporally controlled manner. Optimized switches specific for CD19 controlled the activity, tissue-homing, cytokine release, and phenotype of sCAR-T cells in a dose-titratable manner in a Nalm-6 xenograft rodent model of B-cell leukemia. The sCAR-T-cell dosing regimen could be tuned to provide efficacy comparable to the corresponding conventional CART-19, but with lower cytokine levels, thereby offering a method of mitigating cytokine release syndrome in clinical translation. Furthermore, we demonstrate that this methodology is readily adaptable to targeting CD20 on cancer cells using the same sCAR-T cell, suggesting that this approach may be broadly applicable to heterogeneous and resistant tumor populations, as well as other liquid and solid tumor antigens.
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: David T
authors.initials: DT
authors.lastname: Rodgers
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Magdalena
authors.initials: M
authors.lastname: Mazagova
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Eric N
authors.initials: EN
authors.lastname: Hampton
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Nitya S
authors.initials: NS
authors.lastname: Ramadoss
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Ian R
authors.initials: IR
authors.lastname: Hardy
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Andrew
authors.initials: A
authors.lastname: Schulman
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Du
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Oded
authors.initials: O
authors.lastname: Singer
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Vanessa
authors.initials: V
authors.lastname: Nunez
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Jiayin
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Ashley K
authors.initials: AK
authors.lastname: Woods
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019;
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Wright
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019; Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037 schultz@scripps.edu chkim@calibr.org tyoung@calibr.org.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Schultz
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019; schultz@scripps.edu chkim@calibr.org tyoung@calibr.org.
authors.forename: Chan Hyuk
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92019; schultz@scripps.edu chkim@calibr.org tyoung@calibr.org.
authors.forename: Travis S
authors.initials: TS
authors.lastname: Young
mesh_terms: D000818:Animals; D018941:Antigens, CD19 / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D001386:Azides; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology; D050976:Basic-Leucine Zipper Transcription Factors / Q000276:immunology; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000009:adverse effects / Q000379:methods*; D015448:Leukemia, B-Cell / Q000628:therapy*; D008213:Lymphocyte Activation; D008231:Lymphopenia / Q000209:etiology / Q000517:prevention & control; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010649:Phenylalanine / Q000031:analogs & derivatives; D015202:Protein Engineering / Q000379:methods; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D029701:Saccharomyces cerevisiae Proteins / Q000276:immunology; D051918:Sialic Acid Binding Ig-like Lectin 2 / Q000276:immunology*; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology; D013329:Structure-Activity Relationship; D037182:T-Cell Antigen Receptor Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000637:transplantation; D023041:Xenograft Model Antitumor Assays
chemical_list: D018941:Antigens, CD19; D000951:Antigens, Neoplasm; D001386:Azides; D050976:Basic-Leucine Zipper Transcription Factors; C497867:CD22 protein, human; D016207:Cytokines; C501391:GCN4 protein, S cerevisiae; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D051918:Sialic Acid Binding Ig-like Lectin 2; D057127:Single-Chain Antibodies; C027162:4-azidophenylalanine; D010649:Phenylalanine
keywords: antibody engineering; autologous cell therapy; cancer; chimeric antigen receptor T cell; leukemia