title: A novel high mobility group box 1 neutralizing chimeric antibody attenuates drug-induced liver injury and postinjury inflammation in mice.
abstract: Acetaminophen (APAP) overdoses are of major clinical concern. Growing evidence underlines a pathogenic contribution of sterile postinjury inflammation in APAP-induced acute liver injury (APAP-ALI) and justifies development of anti-inflammatory therapies with therapeutic efficacy beyond the therapeutic window of the only current treatment option, N-acetylcysteine (NAC). The inflammatory mediator, high mobility group box 1 (HMGB1), is a key regulator of a range of liver injury conditions and is elevated in clinical and preclinical APAP-ALI. The anti-HMGB1 antibody (m2G7) is therapeutically beneficial in multiple inflammatory conditions, and anti-HMGB1 polyclonal antibody treatment improves survival in a model of APAP-ALI. Herein, we developed and investigated the therapeutic efficacy of a partly humanized anti-HMGB1 monoclonal antibody (mAb; h2G7) and identified its mechanism of action in preclinical APAP-ALI. The mouse anti-HMGB1 mAb (m2G7) was partly humanized (h2G7) by merging variable domains of m2G7 with human antibody-Fc backbones. Effector function-deficient variants of h2G7 were assessed in comparison with h2G7 in vitro and in preclinical APAP-ALI. h2G7 retained identical antigen specificity and comparable affinity as m2G7. 2G7 treatments significantly attenuated APAP-induced serum elevations of alanine aminotransferase and microRNA-122 and completely abrogated markers of APAP-induced inflammation (tumor necrosis factor, monocyte chemoattractant protein 1, and chemokine [C-X-C motif] ligand 1) with prolonged therapeutic efficacy as compared to NAC. Removal of complement and/or Fc receptor binding did not affect h2G7 efficacy.
  
  
  
  This is the first report describing the generation of a partly humanized HMGB1-neutralizing antibody with validated therapeutic efficacy and with a prolonged therapeutic window, as compared to NAC, in APAP-ALI. The therapeutic effect was mediated by HMGB1 neutralization and attenuation of postinjury inflammation. These results represent important progress toward clinical implementation of HMGB1-specific therapy as a means to treat APAP-ALI and other inflammatory conditions. (Hepatology 2016;64:1699-1710).
authors.affiliation: Department of Medicine, Rheumatology Unit, Karolinska Institute, Stockholm, Sweden. peter.lundback@medisin.uio.no.
authors.forename: Peter
authors.initials: P
authors.lastname: Lundbäck
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, Liverpool University, Liverpool, United Kingdom.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Lea
authors.affiliation: Department of Medicine, Rheumatology Unit, Karolinska Institute, Stockholm, Sweden.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Sowinska
authors.affiliation: Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Ottosson
authors.affiliation: Section of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden.
authors.forename: Camilla Melin
authors.initials: CM
authors.lastname: Fürst
authors.affiliation: Department of Medicine, Rheumatology Unit, Karolinska Institute, Stockholm, Sweden.
authors.forename: Johanna
authors.initials: J
authors.lastname: Steen
authors.affiliation: Department of Medicine, Rheumatology Unit, Karolinska Institute, Stockholm, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Aulin
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, Liverpool University, Liverpool, United Kingdom.
authors.forename: Joanna I
authors.initials: JI
authors.lastname: Clarke
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, Liverpool University, Liverpool, United Kingdom.
authors.forename: Anja
authors.initials: A
authors.lastname: Kipar
authors.affiliation: Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Klevenvall
authors.affiliation: Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Huan
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Palmblad
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, Liverpool University, Liverpool, United Kingdom.
authors.forename: B Kevin
authors.initials: BK
authors.lastname: Park
authors.affiliation: Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Tracey
authors.affiliation: Section of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Blom
authors.affiliation: Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Andersson
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular & Clinical Pharmacology, Liverpool University, Liverpool, United Kingdom. D.Antoine@liverpool.ac.uk.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Antoine
authors.affiliation: Department of Medicine, Rheumatology Unit, Karolinska Institute, Stockholm, Sweden. helena.harris@ki.se.
authors.forename: Helena
authors.initials: H
authors.lastname: Erlandsson Harris
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects; D000818:Animals; D057134:Antibodies, Neutralizing / Q000627:therapeutic use*; D058633:Antipyretics / Q000009:adverse effects; D056486:Chemical and Drug Induced Liver Injury / Q000188:drug therapy* / Q000209:etiology; D024243:HMGB1 Protein / Q000627:therapeutic use*; D007249:Inflammation / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D018712:Analgesics, Non-Narcotic; D057134:Antibodies, Neutralizing; D058633:Antipyretics; D024243:HMGB1 Protein; D000082:Acetaminophen