P27 Exploring the effect of human rhinovirus-16 infection of expression of pannexin-1 in alveolar cells
Published on Dec 1, 2018in Thorax8.834
· DOI :10.1136/THORAX-2018-212555.185
Rational and hypothesis: Human rhinovirus (HRV) infections are a major causative agent of upper respiratory tract infection (URTI) and are associated with acute exacerbations of asthma and COPD. URTI is associated with excessive production of mucus within the airway, particularly in sufferers of chronic respiratory conditions. This mucus may lead to altered osmolality within the airway and contribute to hypotonic stimulus of the airway epithelium and airway hypersensitivity leading to cough. Hypotonic stimulus has previously been shown to activate transient receptor potential vanilloid 4 (TRPV4) ultimately leading to ATP release via pannexin-1. We hypothesised that HRV infection alters expression of proteins within this pathway leading to a hypersensitive cough reflex. Methods Immortalised alveolar epithelial (A549) cell line was first infected with HRV-16 for 1 hour at multiplicity of infection (MOI) 1 then allowed up to 72 hours to incubate. Following a time course of infection, the A549 cells were incubated with inhibitors for either TRPV4 (HC067047), RhoA (H-1152), myosin light chain kinase (ML-7) or pannexin-1 (carbenoxolone) then exposed to 33% hypoosmolality. Cells were lysed and subject to western blot analysis for pannexin-1 and TRPV4 expression. UV inactivated virus and isotonic buffer were included as negative controls. Findings No change was seen in TRPV4 whole cell expression over a 72 hour infection from any treatment group. No change was also seen in pannexin-1 whole cell expression over a 72 hour infection when treated with HC067047, H-1152 or ML-7. Interestingly, HRV-16 infection of A549 cell line caused a 9 fold upregulation of pannexin-1 whole cell protein expression significantly by 72 hours when treated with carbenoxolone and standardised to isotonic control p Conclusions HRV-16 at MOI 1 causes increased expression of pannexin-1 in alveolar cells. HRV-16 caused no effect to TRPV4 whole cell expression.