Chemotactic agents induce IL-6Ralpha shedding from polymorphonuclear cells: involvement of a metalloproteinase of the TNF-alpha-converting enzyme (TACE) type

Eur J Immunol. 2002 Oct;32(10):2965-70. doi: 10.1002/1521-4141(2002010)32:10<2965::AID-IMMU2965>3.0.CO;2-V.

Abstract

Interleukin (IL)-6 transsignaling plays a pivotal role in the shift from neutrophil to monocyte recruitment at the inflammatory site. Release of neutrophil IL-6 receptor-alpha (IL-6Ralpha, CD126) in its soluble form is a key step of IL-6 transsignaling, however, its physiological inducers are poorly known. Here, we observed that the neutrophil chemoattractants IL-8, C5a complement fraction, platelet activating factor, leukotriene B4 and N-formyl-methionyl-leucyl-phenylalanine rapidly decreased IL-6Ralpha membrane expression and increased soluble IL-6Ralpha concentrations in the neutrophil supernatants, consistent with a shedding process. IL-6Ralpha shedding involved a TNF-alpha-converting enzyme-type metalloproteinase since it was partly decreased in the presence of a specific inhibitor, but not cathepsin G since PMSF or alpha1 antichymotrypsin had no effect. Neutrophil IL-6Ralpha shedding may be a common feature of neutrophilic infiltrates in various inflammatory situations, allowing IL-6 transsignaling, decreasing neutrophil infiltration and in the meantime favoring monocyte recruitment, thus the initiation of an immune response and subsequently the resolution of inflammation.

MeSH terms

  • ADAM Proteins
  • ADAM17 Protein
  • Cathepsin G
  • Cathepsins / physiology
  • Chemotactic Factors / pharmacology*
  • Dipeptides / pharmacology
  • Humans
  • Hydroxamic Acids / pharmacology
  • Interleukin-8 / pharmacology
  • Metalloendopeptidases / physiology*
  • Neutrophils / physiology*
  • Platelet Activating Factor / pharmacology
  • Receptors, Interleukin-6 / metabolism*
  • Serine Endopeptidases

Substances

  • Chemotactic Factors
  • Dipeptides
  • Hydroxamic Acids
  • Interleukin-8
  • N-((2-(hydroxyaminocarbonyl)methyl)-4-methylpentanoyl)-3-(2'-naphthyl)alanylalanine, 2-aminoethylamide
  • Platelet Activating Factor
  • Receptors, Interleukin-6
  • Cathepsins
  • Serine Endopeptidases
  • CTSG protein, human
  • Cathepsin G
  • ADAM Proteins
  • Metalloendopeptidases
  • ADAM17 Protein
  • ADAM17 protein, human