title: Unstable B7-H4 cell surface expression and T-cell redirection as a means of cancer therapy.
abstract: Tumor immune regulation has been demonstrated in clinical studies using antibodies targeted to the B7/CD28 family. B7 homolog 4 (B7-H4) negatively regulates immune responses and is overexpressed in many types of human cancer, indicating that B7-H4 may be a potential target of cancer therapy. B7-H4 expression is affected by the microenvironment, and its presence has been reported in cancer tissues and immune cells. We found an upregulation of B7-H4 expression using comprehensive whole exome sequencing and gene expression profiling (project HOPE) launched by the Shizuoka Cancer Center based on tumor tissue samples from 1,058 cancer patients. We were successful in producing monoclonal antibodies for B7-H4 and demonstrated B7-H4 dimerization and rapid cell surface disappearance by antibody cross-linking in breast cancer cells, even under typical conditions. These observations may explain why antibody-dependent cellular cytotoxicity (ADCC) did not function in vivo on the B7-H4-expressing tumor cells. Unstable cell surface antigens are not suitable as targets for ADCC, and we therefore performed an indirect ADCC-redirecting T-cell cytotoxicity assay to study B7-H4 using polyclonal anti-mouse IgG antibody-mediated linking. Our results showed the possibility of targeting the B7-H4 molecule as a means of treating cancer.
authors.affiliation: Division of Immunotherapy, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Iizuka
authors.affiliation: Division of Immunotherapy, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Kondou
authors.affiliation: Division of Immunotherapy, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Chizu
authors.initials: C
authors.lastname: Nonomura
authors.affiliation: Division of Immunotherapy, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ashizawa
authors.affiliation: Division of Medical Genetics, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ohshima
authors.affiliation: Division of Regional Resources, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kusuhara
authors.affiliation: Division of Thoracic Surgery, Shizuoka Cancer Center Hospital, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Isaka
authors.affiliation: Division of Thoracic Surgery, Shizuoka Cancer Center Hospital, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Ohde
authors.affiliation: Office of the President, Shizuoka Cancer Center Hospital, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Yamaguchi
authors.affiliation: Division of Immunotherapy, Shizuoka Cancer Center Research Institute, Shizuoka 411-8777, Japan.
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Akiyama
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000096:biosynthesis* / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology; D059016:Tumor Microenvironment / Q000235:genetics / Q000276:immunology; D060907:V-Set Domain-Containing T-Cell Activation Inhibitor 1 / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007074:Immunoglobulin G; D060907:V-Set Domain-Containing T-Cell Activation Inhibitor 1; C475826:VTCN1 protein, human