Th2-type cytokines modulate IL-6 release by human bronchial epithelial cells

Immunol Lett. 1999 Nov 1;70(2):83-8. doi: 10.1016/s0165-2478(99)00138-8.

Abstract

The multifunctional cytokine IL-6, which can be locally produced by human bronchial epithelial cells (HBECs), has been found to play a role in IL-4 dependent IgE synthesis. Since the allergic reaction in bronchial asthma is associated with the upregulation of IL-4 and Th2 type of immune response, the purpose of our study was to assess whether IL-4 and related cytokines IL-10 and IL-13 regulate IL-6 release by HBEC s. HBECs were obtained by bronchial brushing, cultured in LHC-9/RPMI 1640. At the third passage the cells were stimulated with cytokines (0.1-20 ng/ml) diluted in unsupplemented media for 24 h. The supernatants were tested for IL-6 content by sandwich ELISA. Unstimulated HBECs produced detectable amounts of IL-6 (368+/-25 pg/ml). Exposure to IL-10 (368+/-22 pg/ml) and IL-13 (395+/-6 pg/ml) resulted in little changes. IL-4 caused a slight but significant increase in IL-6 release (530+/-45 pg/ml), P<0.05, TNFalpha (1657+/-85 pg/ml) and IFNgamma (1953+/-37 pg/ml) showed strong induction of IL-6 release in HBECs (P<0.005 and P<0.001, respectively). Both IL-4 and IL-13 significantly inhibited TNF induced IL-6 release (P<0.01 for both) while augmenting the effect of IFNgamma (P<0.005 and P<0.01, respectively.). IL-10 was without a significant effect. We conclude that Th2-type cytokines IL-4 and IL-13 affect the release of IL-6 by HBECs in response to TNFalpha (inhibition) and IFgamma (augmentation). IL-10 had no effect on the regulation of IL-6 release. Modulation of IL-6 levels by Th2-type cytokines may play a role in allergic reactions through the IL-6 promoting effect on IL-4 mediated IgE production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchi / drug effects*
  • Bronchi / metabolism
  • Cells, Cultured
  • Culture Media, Serum-Free
  • Enzyme-Linked Immunosorbent Assay
  • Epithelial Cells / drug effects*
  • Epithelial Cells / metabolism
  • Humans
  • Interleukin-13 / pharmacology*
  • Interleukin-4 / pharmacology*
  • Interleukin-6 / biosynthesis*
  • Th2 Cells / immunology*

Substances

  • Culture Media, Serum-Free
  • Interleukin-13
  • Interleukin-6
  • Interleukin-4