title: CTLA-4Ig suppresses liver injury by inhibiting acquired immune responses in a mouse model of fulminant hepatitis.
abstract: Expression of costimulatory molecules is significantly upregulated in various organs in an animal model of severe hepatitis induced by injection of Propionibacterium acnes (P. acnes) and lipopolysaccharide (LPS). In the present study, we examined whether blockade of costimulatory signals by CTLA-4Ig can suppress the liver injury in this model. We injected an adenovirus encoding CTLA-4Ig (AdCTLA-4Ig) into mice 7 days before, on the same day, or 3 days after P. acnes priming. The virus was found to infect the liver preferentially, and CTLA-4Ig was detected in the serum as early as 2 days after viral injection. After injection of LPS, liver injury and survival rates were examined. Most of the mice not injected with AdCTLA-4Ig died within 12 hours after injection of LPS. In contrast, all the AdCTLA-4Ig-injected mice survived when the virus was injected 7 days before or on the same day as P. acnes priming. Importantly, hemorrhagic liver injury and serum alanine aminotransferase levels were significantly reduced after LPS injection even when AdCTLA-4Ig was injected 3 days after P. acnes priming. Immunological analyses showed that CTLA-4Ig inhibited the activation and expansion of P. acnes-specific CD4+ T cells in the hepatic lymph nodes, leading to a reduction in the recruitment of the cells to the liver. The total amounts of interferon-gamma, interleukin-12, and various chemokines in the liver were then decreased, resulting in inhibition of the secondary recruitment of not only T cells but also macrophages. In conclusion, CTLA-4Ig could be useful for treatment of severe liver injury.
authors.affiliation: The Third Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Toyama, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Katsuharu
authors.initials: K
authors.lastname: Hirano
authors.forename: Kazumi
authors.initials: K
authors.lastname: Ebata
authors.forename: Masami
authors.initials: M
authors.lastname: Minemura
authors.forename: Akiharu
authors.initials: A
authors.lastname: Watanabe
authors.forename: Toshiro
authors.initials: T
authors.lastname: Sugiyama
mesh_terms: D000069594:Abatacept; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D018122:B7-1 Antigen / Q000378:metabolism; D051940:B7-2 Antigen; D039481:CD11b Antigen / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D002452:Cell Count; D002455:Cell Division / Q000276:immunology; D003713:Dendritic Cells / Q000502:physiology; D004195:Disease Models, Animal; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D018796:Immunoconjugates / Q000097:blood / Q000235:genetics*; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D018950:Lipopolysaccharide Receptors / Q000235:genetics; D008070:Lipopolysaccharides; D008099:Liver / Q000473:pathology / Q000502:physiology; D017114:Liver Failure, Acute / Q000276:immunology* / Q000401:mortality / Q000628:therapy*; D008264:Macrophages / Q000473:pathology; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011425:Propionibacterium acnes; D014366:Tryptophan Oxygenase / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D039481:CD11b Antigen; C497965:Cd86 protein, mouse; D018796:Immunoconjugates; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D014409:Tumor Necrosis Factor-alpha; D000069594:Abatacept; D007371:Interferon-gamma; D014366:Tryptophan Oxygenase