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TLR3 activation increases chemokine expression in human fetal airway smooth muscle cells.

Authors :
Faksh A
Britt RD Jr
Vogel ER
Thompson MA
Pandya HC
Martin RJ
Pabelick CM
Prakash YS
Source :
American journal of physiology. Lung cellular and molecular physiology [Am J Physiol Lung Cell Mol Physiol] 2016 Jan 15; Vol. 310 (2), pp. L202-11. Date of Electronic Publication: 2015 Nov 20.
Publication Year :
2016

Abstract

Viral infections, such as respiratory syncytial virus and rhinovirus, adversely affect neonatal and pediatric populations, resulting in significant lung morbidity, including acute asthma exacerbation. Studies in adults have demonstrated that human airway smooth muscle (ASM) cells modulate inflammation through their ability to secrete inflammatory cytokines and chemokines. The role of ASM in the developing airway during infection remains undefined. In our study, we used human fetal ASM cells as an in vitro model to examine the effect of Toll-like receptor (TLR) agonists on chemokine secretion. We found that fetal ASM express multiple TLRs, including TLR3 and TLR4, which are implicated in the pathogenesis of respiratory syncytial virus and rhinovirus infection. Cells were treated with TLR agonists, polyinosinic-polycytidylic acid [poly(I:C)] (TLR3 agonist), lipopolysaccharide (TLR4 agonist), or R848 (TLR7/8 agonist), and IL-8 and chemokine (C-C motif) ligand 5 (CCL5) secretion were evaluated. Interestingly, poly(I:C), but neither lipopolysaccharide nor R848, increased IL-8 and chemokine (C-C motif) ligand 5 secretion. Examination of signaling pathways suggested that the poly(I:C) effects in fetal ASM involve TLR and ERK signaling, in addition to another major inflammatory pathway, NF-κB. Moreover, there are variations between fetal and adult ASM with respect to poly(I:C) effects on signaling pathways. Pharmacological inhibition suggested that ERK pathways mediate poly(I:C) effects. Overall, our data show that poly(I:C) initiates activation of proinflammatory pathways in developing ASM, which may contribute to immune responses to infection and exacerbation of asthma.<br /> (Copyright © 2016 the American Physiological Society.)

Details

Language :
English
ISSN :
1522-1504
Volume :
310
Issue :
2
Database :
MEDLINE
Journal :
American journal of physiology. Lung cellular and molecular physiology
Publication Type :
Academic Journal
Accession number :
26589477
Full Text :
https://doi.org/10.1152/ajplung.00151.2015