Expression of Toll-like receptors in cultured nasal epithelial cells.
CONCLUSIONS
Nasal epithelial cells are constitutively equipped with all Toll-like receptors (TLRs) which are essential for innate immunity. Both mRNA and protein levels of TLR3 expression increased in more differentiated nasal epithelial cells. Considering that the ligand for TLR3 is viral dsRNA, this result is in good accordance with previous reports demonstrating that more differentiated airway epithelial cells have increased resistance to rhinovirus infection.


OBJECTIVE
Nasal epithelial cells use innate immune responses to combat inspired potential pathogens. TLRs are receptors that recognize pathogen-associated molecular patterns of microbes. Therefore, we investigated the expression of TLRs in cultured nasal epithelial cells obtained from nasal polyps.


METHODS
Submerged single layer (SSL) and air-liquid interface (ALI) nasal epithelial cell cultures with or without 10(-7) M retinoid acid (+/- RA) were created.


RESULTS
ALI + RA culture developed ciliary differentiation as observed by light and scanning electron microscopic examination in 3 weeks. It had higher interleukin (IL)-8 basal secretion (21.9 vs 0.82-1.45 ng/ml) and transepithelial potential (-20.4 mV). TLR1-10 mRNA expression in cultured nasal epithelial cells was determined by RT-PCR. Only TLR3 mRNA significantly increased at day 20 vs day 1 (n=5, p=0.02) in ALI + RA cell culture. Higher TLR3 protein was also expressed at day 20 in ALI + RA cell culture but not in SSL culture by western blotting.
Lin
Chih-Feng
CF
Department of Otolaryngology, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
Tsai
Ching-Hwa
CH
Cheng
Chiung-Hsiang
CH
Chen
Yuh-Shyan
YS
Tournier
Frédéric
F
Yeh
Te-Huei
TH
D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D016209:Interleukin-8 / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D009297:Nasal Mucosa / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051196:Toll-Like Receptor 3 / Q000235:genetics; D051193:Toll-Like Receptors / Q000235:genetics*; D014212:Tretinoin / Q000494:pharmacology
D016209:Interleukin-8; D012333:RNA, Messenger; D051196:Toll-Like Receptor 3; D051193:Toll-Like Receptors; D014212:Tretinoin