title: T cell contact-mediated activation of respiratory burst in human polymorphonuclear leukocytes is inhibited by high-density lipoproteins and involves CD18.
abstract: Polymorphonuclear neutrophils (PMN) are recruited to sites of inflammation, where they are in close vicinity with other immune cell types. The present study demonstrates that direct cell-cell contact with stimulated T cells activates PMN respiratory burst. To discard interferences with soluble products, membranes isolated from human T lymphocytes (msT) or the monocytic cell line HUT-78 (msHUT) were used to mimic cellular contact. msT and msHUT induced a dose-dependent production of radical oxygen species (ROS) in PMN, as detected by chemiluminescence. Similar results were obtained with fixed, stimulated T cells, confirming that ROS production was a result of cell-surface molecules and not to soluble products of T cells. ROS production was mainly intracellular, suggesting that ROS may take part in intracellular processes. High-density lipoproteins (HDL), which had previously been shown to inhibit T cell contact-induced cytokine production in monocyte-macrophages, potently reduced ROS production induced in PMN upon contact with stimulated T cells. This supports the emerging role of HDL as immunomodulators in inflammatory diseases. Furthermore, monoclonal antibodies to CD18 inhibited 60% of the PMN respiratory burst induced by msT, suggesting that CD18 contributed to PMN activation. The present results emphasize the importance of direct cell-cell contact with stimulated T cells in inflammatory processes.
authors.affiliation: Division of Immunology and Allergy, Department of Internal Medicine, University Hospital, 24 rue Micheli-du-Crest, 1211 Geneva 14, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Cettour-Rose
authors.forename: Thi Xuan Khanh
authors.initials: TX
authors.lastname: Nguyen
authors.forename: Lena
authors.initials: L
authors.lastname: Serrander
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Kaufmann
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Dayer
authors.forename: Danielle
authors.initials: D
authors.lastname: Burger
authors.forename: Pascale
authors.initials: P
authors.lastname: Roux-Lombard
mesh_terms: D018821:CD18 Antigens / Q000378:metabolism*; D002448:Cell Adhesion; D002450:Cell Communication / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D017382:Reactive Oxygen Species; D016897:Respiratory Burst; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D018821:CD18 Antigens; D008075:Lipoproteins, HDL; D017382:Reactive Oxygen Species