Type

Other / n/a

Authors

Shane J O'Neill
Noel G McElvaney
Clifford C Taggart
Catherine M Greene
Ruth E MacRedmond

Subjects

Microbiology

Topics
beta defensins lung medicine and health sciences respiratory mucosa epithelial cells toll like receptor 4 lipopolysaccharides humans

Respiratory epithelial cells require Toll-like receptor 4 for induction of human beta-defensin 2 by lipopolysaccharide. (2005)

Abstract BACKGROUND: The respiratory epithelium is a major portal of entry for pathogens and employs innate defense mechanisms to prevent colonization and infection. Induced expression of human beta-defensin 2 (HBD2) represents a direct response by the epithelium to potential infection. Here we provide evidence for the critical role of Toll-like receptor 4 (TLR4) in lipopolysaccharide (LPS)-induced HBD2 expression by human A549 epithelial cells. METHODS: Using RTPCR, fluorescence microscopy, ELISA and luciferase reporter gene assays we quantified interleukin-8, TLR4 and HBD2 expression in unstimulated or agonist-treated A549 and/or HEK293 cells. We also assessed the effect of over expressing wild type and/or mutant TLR4, MyD88 and/or Mal transgenes on LPS-induced HBD2 expression in these cells. RESULTS: We demonstrate that A549 cells express TLR4 on their surface and respond directly to Pseudomonas LPS with increased HBD2 gene and protein expression. These effects are blocked by a TLR4 neutralizing antibody or functionally inactive TLR4, MyD88 and/or Mal transgenes. We further implicate TLR4 in LPS-induced HBD2 production by demonstrating HBD2 expression in LPS non-responsive HEK293 cells transfected with a TLR4 expression plasmid. CONCLUSION: This data defines an additional role for TLR4 in the host defense in the lung.
Collections Ireland -> Royal College of Surgeons in Ireland -> Medicine Articles
Ireland -> Royal College of Surgeons in Ireland -> Department of Medicine

Full list of authors on original publication

Shane J O'Neill, Noel G McElvaney, Clifford C Taggart, Catherine M Greene, Ruth E MacRedmond

Experts in our system

1
Shane J O'Neill
Royal College of Surgeons in Ireland
Total Publications: 84
 
2
Noel G McElvaney
Royal College of Surgeons in Ireland
Total Publications: 194
 
3
Clifford C Taggart
Royal College of Surgeons in Ireland
Total Publications: 54
 
4
Catherine M Greene
Royal College of Surgeons in Ireland
Total Publications: 150