title: Immuno-targeting the multifunctional CD38 using nanobody.
abstract: CD38, as a cell surface antigen is highly expressed in several hematologic malignancies including multiple myeloma (MM) and has been proven to be a good target for immunotherapy of the disease. CD38 is also a signaling enzyme responsible for the metabolism of two novel calcium messenger molecules. To be able to target this multifunctional protein, we generated a series of nanobodies against CD38 with high affinities. Crystal structures of the complexes of CD38 with the nanobodies were solved, identifying three separate epitopes on the carboxyl domain. Chromobodies, engineered by tagging the nanobody with fluorescence proteins, provide fast, simple and versatile tools for quantifying CD38 expression. Results confirmed that CD38 was highly expressed in malignant MM cells compared with normal white blood cells. The immunotoxin constructed by splicing the nanobody with a bacterial toxin, PE38 shows highly selective cytotoxicity against patient-derived MM cells as well as the cell lines, with half maximal effective concentration reaching as low as 10(-11) molar. The effectiveness of the immunotoxin can be further increased by stimulating CD38 expression using retinoid acid. These results set the stage for the development of clinical therapeutics as well as diagnostic screening for myeloma.
authors.affiliation: School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: School of Biomedical Sciences, Li Ka Shing School of Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Shali
authors.initials: S
authors.lastname: Qi
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Mandy
authors.initials: M
authors.lastname: Unger
authors.affiliation: School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Yun Nan
authors.initials: YN
authors.lastname: Hou
authors.affiliation: School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Qi Wen
authors.initials: QW
authors.lastname: Deng
authors.affiliation: School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Biomedical Sciences, Li Ka Shing School of Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Connie M C
authors.initials: CMC
authors.lastname: Lam
authors.affiliation: Functional Laboratory, School of Medicine, Yangtze University, 1 Nanhuan Road, Jingzhou, Hubei 434023, China.
authors.forename: Xian Wang
authors.initials: XW
authors.lastname: Wang
authors.affiliation: Department of Hematology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518029, China.
authors.forename: Du
authors.initials: D
authors.lastname: Xin
authors.affiliation: Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Koch-Nolte
authors.affiliation: School of Biomedical Sciences, Li Ka Shing School of Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Hao
authors.affiliation: Department of Biology, and Shenzhen Key Laboratory of Cell Microenvironment, South University of Science and Technology of China, Shenzhen 518055, China.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Hon Cheung
authors.initials: HC
authors.lastname: Lee
authors.affiliation: School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Yong Juan
authors.initials: YJ
authors.lastname: Zhao
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000276:immunology* / Q000378:metabolism; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D000074322:Antineoplastic Agents, Immunological / Q000737:chemistry* / Q000494:pharmacology; D002460:Cell Line; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008562:Membrane Glycoproteins / Q000276:immunology* / Q000378:metabolism; D008958:Models, Molecular; D009101:Multiple Myeloma / Q000188:drug therapy; D011485:Protein Binding; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D061905:Single-Domain Antibodies / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000074322:Antineoplastic Agents, Immunological; D008562:Membrane Glycoproteins; D061905:Single-Domain Antibodies; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1