title: A possible role of histone-like DNA-binding protein of Streptococcus intermedius in the pathogenesis of bile duct damage in primary biliary cirrhosis.
abstract: Bacterial infection has become a focus of attention in the pathogenesis of primary biliary cirrhosis (PBC). It was reported that anti-histone autoantibody was detected in PBC, suggesting that bacterial histone-like DNA-binding protein (HLP) may be involved in the pathogenesis of PBC. To identify bacterial species in PBC to confirm this possibility, serum reactivity to bacterial cells was studied by ELISA. The IgM class Streptococcus intermedius titers were significantly higher in PBC than chronic hepatitis due to hepatitis C virus (CH-C) and healthy subjects. Among the streptococci, S. intermedius was selected for further study. The antigenic peptide of S. intermedius of HLP was synthesized to examine the serum reactivity to Si-HLP. IgM class anti-Si-HLP peptide titers were significantly higher in PBC. Immunoreactivity to anti-Si-HLP was detected in the cytoplasm of biliary epithelial cells and inflammatory cells in the portal area in PBC patients' livers. Streptococci, especially S. intermedius, might play a key role in the pathogenesis of PBC, possibly involving HLP.
authors.affiliation: Department of Medicine and Gastroenterology, Tokyo Women's Medical University, Japan. haruta@research.twmu.ac.jp
authors.forename: Ikuko
authors.initials: I
authors.lastname: Haruta
authors.forename: Ken
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Etsuko
authors.initials: E
authors.lastname: Hashimoto
authors.forename: Hidehito
authors.initials: H
authors.lastname: Kato
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Hirota
authors.forename: Makio
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Miyake
authors.forename: Takehiko
authors.initials: T
authors.lastname: Uchiyama
authors.forename: Junji
authors.initials: J
authors.lastname: Yagi
authors.forename: Keiko
authors.initials: K
authors.lastname: Shiratori
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D001706:Biopsy; D004268:DNA-Binding Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008105:Liver Cirrhosis, Biliary / Q000097:blood / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D013290:Streptococcal Infections / Q000097:blood / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D034367:Streptococcus intermedius / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D004268:DNA-Binding Proteins