title: Inflammatory activation of neutrophils by Helicobacter pylori; a mechanism insensitive to pertussis toxin.
abstract: Chronic active gastritis of the antral mucosa is a characteristic feature of infection with Helicobacter pylori and interactions between bacterial components and inflammatory cells are believed to play an important pathogenic role. Neutrophils stimulated with H. pylori sonicate were demonstrated to release L-selectin (CD62L) expressed on the cellular surface, with a subsequent up-regulation of the beta2-integrins CD11b and CD11c, both in a dose- and time-dependent manner, reaching maximum levels after 45-60 min of stimulation. No changes were observed for the CD11a receptor upon stimulation. The activating properties of H. pylori sonicates on neutrophils were heat-labile and susceptible to protease attack, indicating the protein nature of the activating factor. After size fractionation, the major neutrophil-inducing activity was detected in the high molecular weight fraction exhibiting urease activity. Pertussis toxin was unable to inhibit neutrophil activation by the H. pylori protein(s). We conclude that proteins from H. pylori have a potent inflammatory effect on the surface membrane molecules CD62L, CD11b and CD11c essential for transendothelial migration of neutrophils to areas of inflammation. The neutrophil-activating protein(s) act via a pertussis toxin-insensitive mechanism.
authors.affiliation: Department of Clinical Immunology, Aalborg Hospital, and Institute of Biotechnology, Aalborg University, Aalborg, Denmark.
authors.forename: P S
authors.initials: PS
authors.lastname: Hansen
authors.forename: P H
authors.initials: PH
authors.lastname: Madsen
authors.forename: S B
authors.initials: SB
authors.lastname: Petersen
authors.forename: H
authors.initials: H
authors.lastname: Nielsen
mesh_terms: D018821:CD18 Antigens / Q000096:biosynthesis; D020013:Calcium Signaling / Q000276:immunology; D002458:Cell Fractionation; D004352:Drug Resistance, Microbial; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005756:Gastritis / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000276:immunology / Q000473:pathology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D016167:Integrin alphaXbeta2 / Q000096:biosynthesis; D019041:L-Selectin / Q000096:biosynthesis; D016177:Macrophage-1 Antigen / Q000096:biosynthesis; D018375:Neutrophil Activation / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D037342:Pertussis Toxin; D013010:Sonication; D010566:Virulence Factors, Bordetella / Q000633:toxicity*
chemical_list: D018821:CD18 Antigens; D016167:Integrin alphaXbeta2; D016177:Macrophage-1 Antigen; D010566:Virulence Factors, Bordetella; D019041:L-Selectin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins