The negative-feedback regulation of the IL-13 signal by the IL-13 receptor alpha2 chain in bronchial epithelial cells

Cytokine. 2003 Dec 21;24(6):293-303. doi: 10.1016/j.cyto.2003.08.006.

Abstract

Bronchial asthma is a complex disease characterized by airway inflammation involving Th2 cytokines. Among Th2 cytokines, the significance of IL-13 in the pathogenesis of bronchial asthma has recently emerged. Particularly, the direct action of IL-13 on bronchial epithelial cells (BECs) is critical for generation of airway hyperresponsiveness. IL-13 has two binding units; the IL-13 receptor alpha1 chain transduces the IL-13 signal comprising a heterodimer with the IL-4R alpha chain, whereas the IL-13 receptor alpha2 chain (IL-13Ralpha2) is thought to act as a decoy receptor. However, it remains obscure how expression of these molecules is regulated in each cell. In this article, we analyzed the expression of these components in BECs. Either IL-4 or IL-13 induced intracellular expression of IL-13Ralpha2 in BECs, which was STAT6-dependent and required de novo protein synthesis. IL-13Ralpha2 expressed on the cell surface as a monomer inhibited the STAT6-dependent IL-13 signal. Furthermore, expression of IL-13Ralpha2 was induced in lung tissues of ovalbumin-induced asthma model mice. Taken together, our results suggested the possibility that IL-13Ralpha2 induced by its ligand is transferred to the cell surface by an unknown mechanism, and it down-regulates the IL-13 signal in BECs, which functions as a unique negative-feedback system for the cytokine signal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asthma / metabolism
  • Bronchi / metabolism*
  • Disease Models, Animal
  • Epithelial Cells / metabolism*
  • Feedback, Physiological / physiology*
  • Humans
  • Interleukin-13 / metabolism*
  • Interleukin-13 Receptor alpha1 Subunit
  • Interleukin-4 / metabolism
  • Mice
  • RNA, Messenger / metabolism
  • Receptors, Interleukin / biosynthesis*
  • Receptors, Interleukin / genetics
  • Receptors, Interleukin-13

Substances

  • IL13RA1 protein, human
  • Il13ra1 protein, mouse
  • Interleukin-13
  • Interleukin-13 Receptor alpha1 Subunit
  • RNA, Messenger
  • Receptors, Interleukin
  • Receptors, Interleukin-13
  • Interleukin-4