TY - JOUR
T1 - Toll-Like Receptor Expression in Human Keratinocytes
T2 - Nuclear Factor κB Controlled Gene Activation by Staphylococcus aureus is Toll-Like Receptor 2 but Not Toll-Like Receptor 4 or Platelet Activating Factor Receptor Dependent
AU - Mempel, Martin
AU - Voelcker, Verena
AU - Köllisch, Gabriele
AU - Plank, Christian
AU - Rad, Roland
AU - Gerhard, Markus
AU - Schnopp, Christina
AU - Fraunberger, Peter
AU - Walli, Autar K.
AU - Ring, Johannes
AU - Abeck, Dietrich
AU - Ollert, Markus
N1 - Funding Information:
We gratefully acknowledge the skillful technical assistance of S. Bogner, B. Heuser, and G. Roth. Bacterial strains were kindly provided by T. Foster, University of Dublin. We also thank M. Braun-Falco (TU Munich) for providing the GFP-expressing plasmid, C. Kirschning (TU Munich) for providing TLR2 and TLR4 expression plasmids, and S. Bauer (TU Munich) for help with the TLR expression data. This work was funded in part by grant 01GC0104 from the German Federal Ministery of Science and Education (BMBF), grant UW-S15T03 (Project 3b) from the National Genome Research Network (NGFN), and grant KKF 8760160 from the Technical University Munich.
PY - 2003/12
Y1 - 2003/12
N2 - Cultured primary human keratinocytes were screened for their expression of various members of the toll-like receptor (TLR) family. Keratinocytes were found to constitutively express TLR1, TLR2, TLR3, TLR5, and TLR9 but not TLR4, TLR6, TLR7, TLR8, or TLR10 as shown by polymerase chain reaction analysis. The expression of the crucial receptor for signaling of staphylococcal compounds TLR2 was also confirmed by immunohistochemistry, in contrast to TLR4, which showed a negative staining pattern. Next, we analyzed the activation of the proinflammatory nuclear transcription factor κB by Staphylococcus aureus strain 8325-4. Using nuclear extract gel shifts, RelA staining, and luciferase reporter transfection plasmids we found a clear induction of nuclear factor κB translocation by the bacteria. This translocation induced the transcription of nuclear factor κB controlled genes such as inducible nitric oxide synthetase, COX2, and interleukin-8. Transcription of these genes was followed by production of increased amounts of interleukin-8 protein and NO. Inhibition experiments using monoclonal antibodies and the specific platelet activating factor receptor inhibitor CV3988 showed that nuclear factor κB activation by S. aureus was TLR2 but not TLR4 or platelet activating factor receptor dependent. In line, the purified staphylococcal cell wall components lipoteichoic acid and peptidoglycan, known to signal through TLR2, also showed nuclear factor KB translocation in human keratinocytes, indicating a crucial role of the staphylococcal cell wall in the innate immune stimulation of human keratinocytes. These results help to explain the complex activation of human keratinocytes by S. aureus and its cell wall components in various inflammatory disorders of the skin.
AB - Cultured primary human keratinocytes were screened for their expression of various members of the toll-like receptor (TLR) family. Keratinocytes were found to constitutively express TLR1, TLR2, TLR3, TLR5, and TLR9 but not TLR4, TLR6, TLR7, TLR8, or TLR10 as shown by polymerase chain reaction analysis. The expression of the crucial receptor for signaling of staphylococcal compounds TLR2 was also confirmed by immunohistochemistry, in contrast to TLR4, which showed a negative staining pattern. Next, we analyzed the activation of the proinflammatory nuclear transcription factor κB by Staphylococcus aureus strain 8325-4. Using nuclear extract gel shifts, RelA staining, and luciferase reporter transfection plasmids we found a clear induction of nuclear factor κB translocation by the bacteria. This translocation induced the transcription of nuclear factor κB controlled genes such as inducible nitric oxide synthetase, COX2, and interleukin-8. Transcription of these genes was followed by production of increased amounts of interleukin-8 protein and NO. Inhibition experiments using monoclonal antibodies and the specific platelet activating factor receptor inhibitor CV3988 showed that nuclear factor κB activation by S. aureus was TLR2 but not TLR4 or platelet activating factor receptor dependent. In line, the purified staphylococcal cell wall components lipoteichoic acid and peptidoglycan, known to signal through TLR2, also showed nuclear factor KB translocation in human keratinocytes, indicating a crucial role of the staphylococcal cell wall in the innate immune stimulation of human keratinocytes. These results help to explain the complex activation of human keratinocytes by S. aureus and its cell wall components in various inflammatory disorders of the skin.
KW - Bacterial cell wall
KW - Infection
KW - Proinflammatory activation
UR - http://www.scopus.com/inward/record.url?scp=10744222928&partnerID=8YFLogxK
U2 - 10.1111/j.1523-1747.2003.12630.x
DO - 10.1111/j.1523-1747.2003.12630.x
M3 - Article
C2 - 14675188
AN - SCOPUS:10744222928
SN - 0022-202X
VL - 121
SP - 1389
EP - 1396
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
IS - 6
ER -