title: The transmembrane CXC-chemokine ligand 16 is induced by IFN-gamma and TNF-alpha and shed by the activity of the disintegrin-like metalloproteinase ADAM10.
abstract: The novel CXC-chemokine ligand 16 (CXCL16) functions as transmembrane adhesion molecule on the surface of APCs and as a soluble chemoattractant for activated T cells. In this study, we elucidate the mechanism responsible for the conversion of the transmembrane molecule into a soluble chemokine and provide evidence for the expression and shedding of CXCL16 by fibroblasts and vascular cells. By transfection of human and murine CXCL16 in different cell lines, we show that soluble CXCL16 is constitutively generated by proteolytic cleavage of transmembrane CXCL16 resulting in reduced surface expression of the transmembrane molecule. Inhibition experiments with selective hydroxamate inhibitors against the disintegrin-like metalloproteinases a disintegrin and metalloproteinase domain (ADAM)10 and ADAM17 suggest that ADAM10, but not ADAM17, is involved in constitutive CXCL16 cleavage. In addition, the constitutive cleavage of transfected human CXCL16 was markedly reduced in embryonic fibroblasts generated from ADAM10-deficient mice. By induction of murine CXCL16 in ADAM10-deficient fibroblasts with IFN-gamma and TNF-alpha, we show that endogenous ADAM10 is indeed involved in the release of endogenous CXCL16. Finally, the shedding of endogenous CXCL16 could be reconstituted by retransfection of ADAM10-deficient cells with ADAM10. Analyzing the expression and release of CXCXL16 by cultured vascular cells, we found that IFN-gamma and TNF-alpha synergize to induce CXCL16 mRNA. The constitutive shedding of CXCL16 from the endothelial cell surface is blocked by inhibitors of ADAM10 and is independent of additional inhibition of ADAM17. Hence, during inflammation in the vasculature, ADAM10 may act as a CXCL16 sheddase and thereby finely control the expression and function of CXCL16 in the inflamed tissue.
authors.affiliation: Institute for Biochemistry, Christian-Albrechts-University, Kiel, Germany.
authors.forename: Soeren
authors.initials: S
authors.lastname: Abel
authors.forename: Christian
authors.initials: C
authors.lastname: Hundhausen
authors.forename: Rolf
authors.initials: R
authors.lastname: Mentlein
authors.forename: Alexander
authors.initials: A
authors.lastname: Schulte
authors.forename: Theo A
authors.initials: TA
authors.lastname: Berkhout
authors.forename: Neil
authors.initials: N
authors.lastname: Broadway
authors.forename: Dieter
authors.initials: D
authors.lastname: Hartmann
authors.forename: Radek
authors.initials: R
authors.lastname: Sedlacek
authors.forename: Sebastian
authors.initials: S
authors.lastname: Dietrich
authors.forename: Barbara
authors.initials: B
authors.lastname: Muetze
authors.forename: Bjoern
authors.initials: B
authors.lastname: Schuster
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Kallen
authors.forename: Paul
authors.initials: P
authors.lastname: Saftig
authors.forename: Stefan
authors.initials: S
authors.lastname: Rose-John
authors.forename: Andreas
authors.initials: A
authors.lastname: Ludwig
mesh_terms: D051722:ADAM Proteins; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D019556:COS Cells; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D000075743:Chemokine CXCL16; D054427:Chemokine CXCL6; D019743:Chemokines, CXC / Q000096:biosynthesis* / Q000378:metabolism*; D016207:Cytokines / Q000494:pharmacology; D019483:Disintegrins / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007371:Interferon-gamma / Q000502:physiology*; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008666:Metalloendopeptidases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D011498:Protein Precursors / Q000096:biosynthesis / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000378:metabolism*; D051116:Receptors, Scavenger; D012995:Solubility; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
chemical_list: C423727:CXCL16 protein, human; D000075743:Chemokine CXCL16; D054427:Chemokine CXCL6; D019743:Chemokines, CXC; C498926:Cxcl16 protein, mouse; D016207:Cytokines; D019483:Disintegrins; D008565:Membrane Proteins; D011498:Protein Precursors; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human; C491234:Adam10 protein, mouse; D013755:Tetradecanoylphorbol Acetate