Klebsiella pneumoniaeIncreases the Levels of Toll-Like Receptors 2 and 4 in Human Airway Epithelial Cells

• DOI: 10.1128/iai.00852-08
• Publication Date: 2008-11-18T01:55:54Z
• Authors: Verónica Regueiro; David Moranta; Miguel A. Campos; Javier Margareto; Junkal Garmendia; José A. Bengoechea
• Keywords: 0301 basic medicine; Mitogen-Activated Protein Kinase 3; Polysaccharides, Bacterial; Respiratory System; NF-kappa B; 610; 500; Epithelial Cells; p38 Mitogen-Activated Protein Kinases; Toll-Like Receptor 2; I-kappa B Kinase; Up-Regulation; 3. Good health; Toll-Like Receptor 4; Klebsiella pneumoniae; 03 medical and health sciences; Cell Line, Tumor; Humans; Bacterial Capsules; Signal Transduction

ABSTRACT Airway epithelial cells act as the first barrier against pathogens. These recognize conserved structural motifs expressed by microbial pathogens via Toll-like receptors (TLRs) on surface. In contrast to level of expression in lymphoid cells, TLR2 and TLR4 airway is low under physiological conditions. Here we explored whether Klebsiella pneumoniae upregulates TLRs human cells. We found that A549 primary was upregulated upon infection with K. . The increased resulted enhancement cellular response stimulation Pam3CSK4 lipopolysaccharide, which are agonists, respectively. -dependent upregulation TLR occurred a positive IκBα-dependent NF-κΒ pathway negative p38 p44/42 mitogen-activated protein kinase-dependent pathways. showed -induced dependent activation. An isogenic capsule polysaccharide (CPS) mutant did not increase expression. Purified CPS expression, polymyxin B abrogate CPS-induced upregulation. Although no proteins were detected preparation sodium dodecyl sulfate-polyacrylamide gel electrophoresis colloidal gold staining, could rule out possibility traces our have been responsible, at least part, for