Interaction of interleukin 7 (IL-7) with glycosaminoglycans and its biological relevance

Cytokine. 1995 May;7(4):325-30. doi: 10.1006/cyto.1995.0041.

Abstract

We have investigated the binding of interleukin 7 (IL-7) to sulfated glycosaminoglycans and evaluated its biological consequences. IL-7 binds to heparin and heparan sulfate, to a lesser extent to dermatan sulfate and does not bind to chondroitin sulfate. It was eluted from heparin by 0.3-0.6 M NaCl and from heparan sulfate by < 0.3 M NaCl. We also measured the affinity of IL-7 for heparin using an affinity co-electrophoresis method and found an affinity of 25 nM. In spite of these findings, IL-7 does not bind to the S17 cell line which supports lymphopoiesis. However, addition of heparin to cultures of an IL-7-dependent pre-B cell line (2E8) inhibited IL-7-stimulated proliferation and IL-7 complexed with heparin was more resistant than free IL-7 to protease treatment. Taken together, these results suggest that heparin may act as a carrier for IL-7, blocking its interaction with target cells and protecting it from degradation during transit.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / drug effects
  • Cattle
  • Cell Division / drug effects
  • Cell Line
  • Chondroitin Sulfates / metabolism
  • Chromatography, Affinity
  • Dermatan Sulfate / metabolism
  • Endopeptidases / metabolism
  • Glycosaminoglycans / metabolism*
  • Hematopoietic Stem Cells / drug effects
  • Heparin / metabolism
  • Heparin / pharmacology
  • Heparitin Sulfate / metabolism
  • Humans
  • Interleukin-7 / metabolism*
  • Interleukin-7 / pharmacology
  • Mice
  • Protein Binding

Substances

  • Glycosaminoglycans
  • Interleukin-7
  • Dermatan Sulfate
  • Heparin
  • Chondroitin Sulfates
  • Heparitin Sulfate
  • Endopeptidases