Sialylated keratan sulfate proteoglycans are Siglec-8 ligands in human airways

Anabel Gonzalez-Gil, Ryan N. Porell, Steve M. Fernandes, Yadong Wei, Huifeng Yu, Daniela J. Carroll, Ryan McBride, James C. Paulson, Michael Tiemeyer, Kazuhiro Aoki, Bruce Scott Bochner, Ronald L. Schnaar

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Human siglecs are a family of 14 sialic acid-binding proteins, most of which are expressed on subsets of immune cells where they regulate immune responses. Siglec-8 is expressed selectively on human allergic inflammatory cells-primarily eosinophils and mast cells-where engagement causes eosinophil apoptosis and inhibits mast cell mediator release. Evidence supports a model in which human eosinophils and mast cells bind to Siglec-8 sialoglycan ligands on inflammatory target tissues to resolve allergic inflammation and limit tissue damage. To identify Siglec-8-binding sialoglycans from human airways, proteins extracted from postmortem human trachea were resolved by size-exclusion chromatography and composite agarose-acrylamide gel electrophoresis, blotted and probed by Siglec-8-Fc blot overlay. Three size classes of Siglec-8 ligands were identified: 250 kDa, 600 kDa and 1 MDa, each of which was purified by affinity chromatography using a recombinant pentameric form of Siglec-8. Proteomic mass spectrometry identified all size classes as the proteoglycan aggrecan, a finding validated by immunoblotting. Glycan array studies demonstrated Siglec-8 binding to synthetic glycans with a terminal Neu5Acα2-3(6-sulfo)-Gal determinant, a quantitatively minor terminus on keratan sulfate (KS) chains of aggrecan. Treating human tracheal extracts with sialidase or keratanase eliminated Siglec-8 binding, indicating sialylated KS chains as Siglec-8-binding determinants. Treating human tracheal histological sections with keratanase also completely eliminated the binding of Siglec-8-Fc. Finally, Siglec-8 ligand purified from human trachea extracts induced increased apoptosis of freshly isolated human eosinophils in vitro. We conclude that sialylated KS proteoglycans are endogenous human airway ligands that bind Siglec-8 and may regulate allergic inflammation.

Original languageEnglish (US)
Pages (from-to)786-801
Number of pages16
JournalGlycobiology
Volume28
Issue number10
DOIs
StatePublished - Jan 1 2018

Fingerprint

Sialic Acid Binding Immunoglobulin-like Lectins
Keratan Sulfate
Proteoglycans
Ligands
keratan-sulfate endo-1,4-beta-galactosidase
Eosinophils
Mast Cells
Aggrecans
Trachea
Polysaccharides
Tissue
Apoptosis
Inflammation
Affinity chromatography
Size exclusion chromatography
Agar Gel Electrophoresis
Acrylamide
Neuraminidase
N-Acetylneuraminic Acid

Keywords

  • Apoptosis
  • Eosinophil
  • Sialic acid
  • Siglec
  • Trachea

ASJC Scopus subject areas

  • Biochemistry

Cite this

Gonzalez-Gil, A., Porell, R. N., Fernandes, S. M., Wei, Y., Yu, H., Carroll, D. J., ... Schnaar, R. L. (2018). Sialylated keratan sulfate proteoglycans are Siglec-8 ligands in human airways. Glycobiology, 28(10), 786-801. https://doi.org/10.1093/glycob/cwy057
Gonzalez-Gil, Anabel ; Porell, Ryan N. ; Fernandes, Steve M. ; Wei, Yadong ; Yu, Huifeng ; Carroll, Daniela J. ; McBride, Ryan ; Paulson, James C. ; Tiemeyer, Michael ; Aoki, Kazuhiro ; Bochner, Bruce Scott ; Schnaar, Ronald L. / Sialylated keratan sulfate proteoglycans are Siglec-8 ligands in human airways. In: Glycobiology. 2018 ; Vol. 28, No. 10. pp. 786-801.
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Gonzalez-Gil, A, Porell, RN, Fernandes, SM, Wei, Y, Yu, H, Carroll, DJ, McBride, R, Paulson, JC, Tiemeyer, M, Aoki, K, Bochner, BS & Schnaar, RL 2018, 'Sialylated keratan sulfate proteoglycans are Siglec-8 ligands in human airways' Glycobiology, vol. 28, no. 10, pp. 786-801. https://doi.org/10.1093/glycob/cwy057

Sialylated keratan sulfate proteoglycans are Siglec-8 ligands in human airways. / Gonzalez-Gil, Anabel; Porell, Ryan N.; Fernandes, Steve M.; Wei, Yadong; Yu, Huifeng; Carroll, Daniela J.; McBride, Ryan; Paulson, James C.; Tiemeyer, Michael; Aoki, Kazuhiro; Bochner, Bruce Scott; Schnaar, Ronald L.

In: Glycobiology, Vol. 28, No. 10, 01.01.2018, p. 786-801.

Research output: Contribution to journalArticle

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AU - Gonzalez-Gil, Anabel

AU - Porell, Ryan N.

AU - Fernandes, Steve M.

AU - Wei, Yadong

AU - Yu, Huifeng

AU - Carroll, Daniela J.

AU - McBride, Ryan

AU - Paulson, James C.

AU - Tiemeyer, Michael

AU - Aoki, Kazuhiro

AU - Bochner, Bruce Scott

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Gonzalez-Gil A, Porell RN, Fernandes SM, Wei Y, Yu H, Carroll DJ et al. Sialylated keratan sulfate proteoglycans are Siglec-8 ligands in human airways. Glycobiology. 2018 Jan 1;28(10):786-801. https://doi.org/10.1093/glycob/cwy057