title: Diphtheria-toxin based anti-human CCR4 immunotoxin for targeting human CCR4(+) cells in vivo.
abstract: CC chemokine receptor 4 (CCR4) has attracted much attention as a promising therapeutic drug target for CCR4(+) tumor cells and Tregs. CCR4 is expressed on some tumor cells such as T-cell acute lymphoblastic leukemia (ALL), adult T-cell leukemia/lymphoma (ATLL), adult peripheral T cell lymphoma (PTCL) and cutaneous T cell lymphoma (CTCL). CCR4 is also expressed on majority of Tregs, mainly effector Tregs. In this study we have successfully developed three versions of diphtheria-toxin based anti-human CCR4 immunotoxins (monovalent, bivalent and single-chain fold-back diabody). Binding analysis by flow cytometry showed that all three versions of the anti-human CCR4 immunotoxins bound to the human CCR4(+) tumor cell line as well as CCR4(+) human PBMC. The bivalent isoform bound stronger than its monovalent counterpart and the single-chain foldback diabody isoform was the strongest among the three versions. In vitro efficacy analysis demonstrated that the bivalent isoform was 20 fold more potent in inhibiting cellular proliferation and protein synthesis in human CCR4(+) tumor cells compared to the monovalent anti-human CCR4 immunotoxin. The single-chain fold-back diabody isoform was 10 fold more potent than its bivalent counterpart and 200 fold more potent than its monovalent counterpart. The in vivo efficacy was assessed using a human CCR4(+) tumor-bearing mouse model. The immunotoxin significantly prolonged the survival of tumor-bearing NOD/SCID IL-2 receptor γ(-/-) (NSG) mice injected with human CCR4(+) acute lymphoblastic leukemia cells compared with the control group. This novel anti-human CCR4 immunotoxin is a promising drug candidate for targeting human CCR4(+) tumor cells and Tregs in vivo.
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Huiping
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Germana
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Christene A
authors.initials: CA
authors.lastname: Huang
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Division of Cardiac Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Joren C
authors.initials: JC
authors.lastname: Madsen
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; TBRC Laboratories, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Sachs
authors.affiliation: Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. Electronic address: zwang7@mgh.harvard.edu.
authors.forename: Zhirui
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA; D004167:Diphtheria Toxin / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D000922:Immunotoxins / Q000235:genetics / Q000494:pharmacology*; D051379:Mice; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics; D054398:Receptors, CCR4 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: C515354:CCR4 protein, human; D004167:Diphtheria Toxin; D000922:Immunotoxins; D054398:Receptors, CCR4; D004247:DNA
keywords: CCR4; CCR4(+) tumor; Diphtheria toxin; Immunotoxin; Pichia Pastoris expression; Treg