title: Nanobodies that block gating of the P2X7 ion channel ameliorate inflammation.
abstract: Ion channels are desirable therapeutic targets, yet ion channel-directed drugs with high selectivity and few side effects are still needed. Unlike small-molecule inhibitors, antibodies are highly selective for target antigens but mostly fail to antagonize ion channel functions. Nanobodies-small, single-domain antibody fragments-may overcome these problems. P2X7 is a ligand-gated ion channel that, upon sensing adenosine 5'-triphosphate released by damaged cells, initiates a proinflammatory signaling cascade, including release of cytokines, such as interleukin-1β (IL-1β). To further explore its function, we generated and characterized nanobodies against mouse P2X7 that effectively blocked (13A7) or potentiated (14D5) gating of the channel. Systemic injection of nanobody 13A7 in mice blocked P2X7 on T cells and macrophages in vivo and ameliorated experimental glomerulonephritis and allergic contact dermatitis. We also generated nanobody Dano1, which specifically inhibited human P2X7. In endotoxin-treated human blood, Dano1 was 1000 times more potent in preventing IL-1β release than small-molecule P2X7 antagonists currently in clinical development. Our results show that nanobody technology can generate potent, specific therapeutics against ion channels, confirm P2X7 as a therapeutic target for inflammatory disorders, and characterize a potent new drug candidate that targets P2X7.
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Welbeck
authors.initials: W
authors.lastname: Danquah
authors.affiliation: Department of Nephrology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Catherine
authors.initials: C
authors.lastname: Meyer-Schwesinger
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.|Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Rissiek
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Carolina
authors.initials: C
authors.lastname: Pinto
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Arnau
authors.initials: A
authors.lastname: Serracant-Prat
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Amadi
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.|Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Domenica
authors.initials: D
authors.lastname: Iacenda
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.|Department of Nephrology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Jan-Hendrik
authors.initials: JH
authors.lastname: Knop
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.|Department of Nephrology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Hammel
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.|Université de Bordeaux, Institut des Maladies Neurodégénératives, CNRS UMR 5293, Bordeaux 33076, France.
authors.forename: Philine
authors.initials: P
authors.lastname: Bergmann
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Schwarz
authors.affiliation: Ablynx NV, Technologiepark 21, B-9052 Zwijnaarde, Belgium.
authors.forename: Joana
authors.initials: J
authors.lastname: Assunção
authors.affiliation: Ablynx NV, Technologiepark 21, B-9052 Zwijnaarde, Belgium.
authors.forename: Wendy
authors.initials: W
authors.lastname: Rotthier
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Haag
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Tolosa
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.|Department of Radiology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bannas
authors.affiliation: Université de Bordeaux, Institut des Maladies Neurodégénératives, CNRS UMR 5293, Bordeaux 33076, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Boué-Grabot
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Magnus
authors.affiliation: Ablynx NV, Technologiepark 21, B-9052 Zwijnaarde, Belgium.
authors.forename: Toon
authors.initials: T
authors.lastname: Laeremans
authors.affiliation: Ablynx NV, Technologiepark 21, B-9052 Zwijnaarde, Belgium.
authors.forename: Catelijne
authors.initials: C
authors.lastname: Stortelers
authors.affiliation: Institute of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany. nolte@uke.de.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Koch-Nolte
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry; D016923:Cell Death; D002460:Cell Line; D049109:Cell Proliferation; D017449:Dermatitis, Allergic Contact / Q000628:therapy; D005260:Female; D005921:Glomerulonephritis / Q000628:therapy; D057809:HEK293 Cells; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D053583:Interleukin-1beta / Q000737:chemistry; D008024:Ligands; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000166:cytology; D058920:Purinergic P2X Receptor Antagonists / Q000737:chemistry*; D058486:Receptors, Purinergic P2X7 / Q000737:chemistry*; D061905:Single-Domain Antibodies / Q000737:chemistry*; D013601:T-Lymphocytes / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D053583:Interleukin-1beta; D008024:Ligands; C546468:P2RX7 protein, human; D058920:Purinergic P2X Receptor Antagonists; D058486:Receptors, Purinergic P2X7; D061905:Single-Domain Antibodies; D000255:Adenosine Triphosphate