title: Helicobacter hepaticus induces an inflammatory response in primary human hepatocytes.
abstract: Helicobacter hepaticus can lead to chronic hepatitis and hepatocellular carcinoma in certain strains of mice. Until now the pathogenic role of Helicobacter species on human liver tissue is still not clarified though Helicobacter species identification in human liver cancer was successful in case controlled studies. Therefore we established an in vitro model to investigate the interaction of primary human hepatocytes (PHH) with Helicobacter hepaticus. Successful co-culturing of PHH with Helicobacter hepaticus was confirmed by visualization of motile bacteria by two-photon-microscopy. Isolated human monocytes were stimulated with PHH conditioned media. Changes in mRNA expression of acute phase cytokines and proteins in PHH and stimulated monocytes were determined by Real-time PCR. Furthermore, cytokines and proteins were analyzed in PHH culture supernatants by ELISA. Co-cultivation with Helicobacter hepaticus induced mRNA expression of Interleukin-1 beta (IL-1β), Tumor necrosis factor-alpha, Interleukin-8 (IL-8) and Monocyte chemotactic protein-1 (MCP-1) in PHH (p<0.05) resulting in a corresponding increase of IL-8 and MCP-1 concentrations in PHH supernatants (p<0.05). IL-8 and IL-1β mRNA expression was induced in monocytes stimulated with Helicobacter hepaticus infected PHH conditioned media (p<0.05). An increase of Cyclooxygenase-2 mRNA expression was observed, with a concomitant increase of prostaglandin E2 concentration in PHH supernatants at 24 and 48 h (p<0.05). In contrast, at day 7 of co-culture, no persistent elevation of cytokine mRNA could be detected. High expression of intercellular adhesion molecule-1 on PHH cell membranes after co-culture was shown by two-photon-microscopy and confirmed by flow-cytometry. Finally, expression of Cytochrome P450 3A4 and albumin mRNA were downregulated, indicating an impairment of hepatocyte synthesis function by Helicobacter hepaticus presence. This is the first in vitro model demonstrating a pathogenic effect of a Helicobacter spp. on human liver cells, resulting in an inflammatory response with increased synthesis of inflammatory mediators and consecutive monocyte activation.
authors.affiliation: Department of General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Kleine
authors.affiliation: Institute of Immunology, Hannover Medical School, Hannover, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Worbs
authors.affiliation: Department of General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Schrem
authors.affiliation: Department of General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Florian W R
authors.initials: FW
authors.lastname: Vondran
authors.affiliation: Department of General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany; Federal Armed Forces Medical Centre, Hannover, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kaltenborn
authors.affiliation: Department of General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Klempnauer
authors.affiliation: Institute of Immunology, Hannover Medical School, Hannover, Germany.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Förster
authors.affiliation: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Josenhans
authors.affiliation: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Suerbaum
authors.affiliation: Department of General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Bektas
mesh_terms: D001219:Aspartate Aminotransferases / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000494:pharmacology; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D016207:Cytokines / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D004790:Enzyme Induction / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D044923:Helicobacter hepaticus / Q000187:drug effects / Q000502:physiology*; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology / Q000382:microbiology* / Q000473:pathology*; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D036641:Microscopy, Fluorescence, Multiphoton; D008954:Models, Biological; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D016207:Cytokines; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D001219:Aspartate Aminotransferases; D015232:Dinoprostone