title: Expression of the chemokine receptors CXCR1 and CXCR2 on granulocytes in human endotoxemia and tuberculosis: involvement of the p38 mitogen-activated protein kinase pathway.
abstract: The chemokine receptors CXCR1 and CXCR2 critically determine the functional properties of granulocytes. To obtain insight in the regulation of these receptors during infection, CXCR expression was determined on blood granulocytes by fluorescence-activated cell sorter analysis in healthy subjects intravenously injected with lipopolysaccharide (LPS) and in patients with active tuberculosis. In healthy subjects, LPS induced a transient decrease in granulocyte CXCR1 and CXCR2 expression, whereas in tuberculosis patients, only CXCR2 showed reduced levels. In whole blood in vitro, LPS, lipoarabinomannan from Mycobacterium tuberculosis, and lipoteichoic acid from Staphylococcus aureus reduced expression of CXCR2 but not of CXCR1. CXCR2 down-regulation induced by LPS or tumor necrosis factor-alpha in vitro was abrogated by a p38 mitogen-activated protein kinase (MAPK) inhibitor. Granulocytes may down-regulate CXCR2 and, to a lesser extent, CXCR1 at their surface upon their first interaction with mycobacterial or bacterial pathogens by a mechanism that involves activation of p38 MAPK.
authors.affiliation: Laboratory of Experimental Internal Medicine and Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine, and AIDS, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: N P
authors.initials: NP
authors.lastname: Juffermans
authors.forename: P E
authors.initials: PE
authors.lastname: Dekkers
authors.forename: M P
authors.initials: MP
authors.lastname: Peppelenbosch
authors.forename: P
authors.initials: P
authors.lastname: Speelman
authors.forename: S J
authors.initials: SJ
authors.lastname: van Deventer
authors.forename: T
authors.initials: T
authors.lastname: van Der Poll
mesh_terms: D000328:Adult; D015536:Down-Regulation; D019446:Endotoxemia / Q000201:enzymology / Q000378:metabolism*; D005260:Female; D006098:Granulocytes / Q000378:metabolism*; D006801:Humans; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009169:Mycobacterium tuberculosis; D023062:Receptors, Interleukin-8A / Q000096:biosynthesis*; D023063:Receptors, Interleukin-8B / Q000096:biosynthesis*; D013211:Staphylococcus aureus; D014376:Tuberculosis / Q000201:enzymology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D008070:Lipopolysaccharides; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; D014409:Tumor Necrosis Factor-alpha; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases