title: Alveolar epithelial cell-macrophage interactions affect oxygen-stimulated interleukin-8 release.
abstract: Interactions of alveolar macrophages with respiratory epithelium may play a key role in hyperoxia-induced lung inflammation. We studied the effect of cell-cell contact with epithelial cells in hyperoxia on macrophages' secretion of interleukin-8 (IL-8). A549 pulmonary epithelial cells and THP-1 monocyte/macrophage cells were cultured either singly, in contact coculture, or prevented from contact by a porous membrane, and exposed to oxygen or room air. Phorbol-12-myristate-13-acetate-(PMA)-treated THP-1 cells were exposed to the same conditions. Neither cell line cultured alone produced appreciable amounts of IL-8 in hyperoxia. Contact cocultures exposed to hyperoxia produced increased IL-8, while in the noncontact coculture it was attenuated. Both cell-cell contact and PMA increased THP-1 cell CD54 expression. Intracellular IL-8 production was increased in contact cocultured, hyperoxia exposed THP-1 cells, while the A549 sample showed no change. Increased IL-8 mRNA expression was not demonstrated in cocultured, hyperoxic exposed THP-1 cells, suggesting nontranscriptional regulation of IL-8 protein levels. Contact with epithelial cells appears to potentiate macrophage responses to hyperoxia.
authors.affiliation: Division of Neonatology, Strong Children's Research Center, University of Rochester, Rochester, New York, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Hjort
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Brenyo
authors.forename: Jacob N
authors.initials: JN
authors.lastname: Finkelstein
authors.forename: Mark W
authors.initials: MW
authors.lastname: Frampton
authors.forename: Michael B
authors.initials: MB
authors.lastname: LoMonaco
authors.forename: Judith C
authors.initials: JC
authors.lastname: Stewart
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Johnston
authors.forename: Carl T
authors.initials: CT
authors.lastname: D'Angio
mesh_terms: D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D009000:Monocytes / Q000276:immunology / Q000473:pathology; D010100:Oxygen / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020545:Respiratory Mucosa / Q000166:cytology* / Q000378:metabolism; D015854:Up-Regulation / Q000276:immunology
chemical_list: D016209:Interleukin-8; D012333:RNA, Messenger; D010100:Oxygen