A possible role of histone-like DNA-binding protein of Streptococcus intermedius in the pathogenesis of bile duct damage in primary biliary cirrhosis.
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.
Haruta
Ikuko
I
Department of Medicine and Gastroenterology, Tokyo Women's Medical University, Japan. haruta@research.twmu.ac.jp
Kikuchi
Ken
K
Hashimoto
Etsuko
E
Kato
Hidehito
H
Hirota
Katsuhiko
K
Kobayashi
Makio
M
Miyake
Yoichiro
Y
Uchiyama
Takehiko
T
Yagi
Junji
J
Shiratori
Keiko
K
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*
D000907:Antibodies, Bacterial; D004268:DNA-Binding Proteins