TGF-alpha regulates TLR expression and function on epidermal keratinocytes

J Immunol. 2005 May 15;174(10):6137-43. doi: 10.4049/jimmunol.174.10.6137.

Abstract

The expression of TLRs on epithelial cells provides a first line of defense against invading pathogens. We investigated the regulated expression and function of TLR5 and TLR9 on human keratinocytes, because we found by immunohistochemistry that these TLRs are expressed in distinct layers of the epidermis. We found that TGF-alpha, a growth and differentiation factor that is present during wound healing and in psoriasis, increased the expression of both TLR5 and TLR9 on keratinocytes. In addition, TGF-alpha regulated the function of TLR5 and TLR9, because activation with their respective ligands enhanced the production of IL-8 and human beta-defensins. These findings provide evidence that TGF-alpha up-regulates TLR expression and function, augmenting host defense mechanisms at epithelial surfaces.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adjuvants, Immunologic / physiology
  • Animals
  • DNA-Binding Proteins / biosynthesis
  • Diffusion Chambers, Culture
  • Epidermal Cells
  • Epidermis / immunology
  • Epidermis / metabolism
  • Humans
  • Interleukin-8 / biosynthesis
  • Keratinocytes / immunology*
  • Keratinocytes / metabolism*
  • Membrane Glycoproteins / biosynthesis*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / physiology*
  • Mice
  • Mice, Inbred BALB C
  • Organ Culture Techniques
  • RNA, Messenger / biosynthesis
  • Receptors, Cell Surface / biosynthesis*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / physiology*
  • Recombinant Proteins / pharmacology
  • Toll-Like Receptor 5
  • Toll-Like Receptor 9
  • Toll-Like Receptors
  • Transforming Growth Factor alpha / physiology*
  • Up-Regulation / genetics
  • Up-Regulation / immunology
  • beta-Defensins / biosynthesis

Substances

  • Adjuvants, Immunologic
  • DEFB103A protein, human
  • DEFB4A protein, human
  • DNA-Binding Proteins
  • Interleukin-8
  • Membrane Glycoproteins
  • RNA, Messenger
  • Receptors, Cell Surface
  • Recombinant Proteins
  • TLR5 protein, human
  • TLR9 protein, human
  • Tlr9 protein, mouse
  • Toll-Like Receptor 5
  • Toll-Like Receptor 9
  • Toll-Like Receptors
  • Transforming Growth Factor alpha
  • beta-Defensins