title: Alarmin HMGB1 is released in the small intestine of gnotobiotic piglets infected with enteric pathogens and its level in plasma reflects severity of sepsis.
abstract: OBJECTIVE
  Alarmin high mobility group box 1 (HMGB1) is essential for correct DNA folding and transcription. It can be released from damaged cells or secreted by stimulated cells. HMGB1 has been detected in serum or plasma as a late marker of sepsis, but its suitability as a marker of sepsis has been disputed.
  
  
  METHODS
  One-week-old germ-free piglets were orally infected/colonized with enteric bacterial pathogens (Salmonella Typhimurium or Escherichia coli O55) or with probiotic bacteria (E. coli Nissle 1917) for 24 h. The transcriptions of HMGB1, interleukin (IL)-8, tumor necrosis factor (TNF)-α, and IL-10 (quantitative reverse transcription and polymerase chain reaction), their protein levels (ELISA), and clinical state of the piglets (somnolence, anorexia, diarrhea, tachycardia, tachypnea, and tremor) were estimated.
  
  
  RESULTS
  The piglets infected with enteric pathogens suffered from infections. HMGB1 was transcribed in the terminal ileum constitutively, regardless of any bacterial presence. In contrast, the transcription of cytokines was upregulated by virulent bacteria. HMGB1, IL-8, and TNF-α levels in the ileum were increased by both enteric pathogens, while IL-10 levels increased in E. coli O55-infected piglets only. HMGB1 significantly increased in the plasma of piglets infected with virulent E. coli only, but cytokine levels were in most cases increased by both virulent bacteria. HMGB1 and cytokine levels in ileum lavages and plasma of piglets colonized with probiotic E. coli remained comparable to those of the non-stimulated germ-free piglets.
  
  
  CONCLUSIONS
  The local and systemic expression of HMGB1, its relationship to the inflammatory cytokines, and clinical findings showed HMGB1 as a suitable marker of severity of sepsis in the gnotobiotic piglet infection model.
authors.affiliation: Department of Immunology and Gnotobiology, Institute of Microbiology of Academy of Sciences of Czech Republic, Doly 183, 549 22, Novy Hradek, Czech Republic.
authors.forename: Alla
authors.initials: A
authors.lastname: Splichalova
authors.forename: Igor
authors.initials: I
authors.lastname: Splichal
authors.forename: Petra
authors.initials: P
authors.lastname: Chmelarova
authors.forename: Ilja
authors.initials: I
authors.lastname: Trebichavsky
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood* / Q000276:immunology / Q000382:microbiology; D001424:Bacterial Infections / Q000097:blood* / Q000276:immunology / Q000382:microbiology; D015415:Biomarkers / Q000097:blood*; D003967:Diarrhea; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000254:growth & development; D005856:Germ-Free Life; D024243:HMGB1 Protein / Q000097:blood; D007082:Ileum / Q000378:metabolism* / Q000382:microbiology; D007249:Inflammation / Q000097:blood* / Q000276:immunology / Q000382:microbiology; D016753:Interleukin-10 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012486:Salmonella typhimurium / Q000254:growth & development; D018805:Sepsis / Q000097:blood* / Q000276:immunology / Q000382:microbiology; D012720:Severity of Illness Index; D013552:Swine; D013610:Tachycardia; D014202:Tremor; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D024243:HMGB1 Protein; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10