Hessel, E. | bioRxiv Science

bioRxiv2023

PI4KIII3β inhibition reduces rhinovirus associated cell shedding and ciliary dysfunction

BackgroundPatients with chronic obstructive pulmonary disease (COPD) experience respiratory exacerbations, many of which are associated with rhinoviruses. Current treatment strategies do not target the pathogenic rhinovirus trigger. Research questionWhat is the immediate effect of rhinovirus on the ciliated respiratory epithelium and can viral replication and epithelial toxicity be reduced by targeted PI4KIII{beta} inhibition. MethodsShort (24h) and longer (7 days) rhinovirus infection were explored in primary ciliated airway epithelial cultures from multiple healthy and COPD patients using high-speed video microscopy, viral titration assays and immunofluorescence studies. Ciliated epithelial cultures were pre-treated with a PI4KIII{beta} (GSK533) blocker prior to infection to assess efficacy against rhinovirus. Cytokine and chemokine production were assessed by multiplex immunoassays. ResultsWithin hours of infection rhinovirus co-localised with ciliated cells causing extensive apoptosis-associated shedding of predominantly ciliated cells within 24 hours. Viral replication that peaked at day 1 and cleared by day 7, was associated with dramatic loss of ciliated cells confirmed by reduced ciliary activity and ciliary DNAI2 protein expression. Ciliary beat frequency (CBF) of remaining cilia was significantly reduced by day 7 in cultures from COPD. Infection was partly dependent on PI4KIII{beta} with the GSK533 blocker reducing viral replication while preserving ciliary activity. High levels of pro-inflammatory mediators were secreted by infected cells. ConclusionDecreased ciliation due to rhinovirus infection is likely to impair mucociliary clearance in healthy individuals and COPD patients, contributing to the pathophysiology of COPD exacerbations. PI4KIII{beta} inhibition blocks viral replication, helping to preserve ciliary activity. Take home messageRhinovirus replication in the healthy and COPD respiratory epithelium is mediated by PI4KIII{beta} and intracellular PI4P platform formation. Inhibition of PI4KIII{beta} reduced viral replication and ciliated cell loss.

cell biology↗

bioRxiv2022

Quantitative imaging reveals PI3Kδ inhibition reduces rhinovirus-induced damage of small airway epithelia in ex vivo cultured human precision cut lung slices from COPD patients

Chronic obstructive pulmonary disease (COPD) is one of the major causes of disability and death worldwide and a significant risk factor for respiratory infections. Rhinoviral infections are the most common trigger of COPD exacerbations which lead to a worsening of disease symptoms, decline in lung function and increased mortality. The lack of suitable disease models to study the relevant cellular and molecular mechanism hinders the discovery of novel medicines that prevent disease progression in exacerbating COPD patients. We used quantitative multi-color imaging of COPD and control patient derived human precision-cut lung slices (hPCLS) to study the impact of rhinovirus infection on the structure and function of the small airway epithelium. Data analysis highlighted that COPD-derived hPCLS have a higher cellular density and basal cell hyperplasia, more unciliated airway surface areas with mucus overproduction, and shorter cilia length compared to control hPCLS. In response to rhinovirus 16 infection, COPD-derived hPCLS secreted higher amounts of pro-inflammatory cytokines and displayed decreased epithelial integrity and reduced airway ciliation. Finally, treatment with a selective PI3K{delta} inhibitor reduced secretion of rhinovirus-induced cytokines and ameliorated rhinovirus-induced damage to COPD small airway epithelia. Thus, these data demonstrate the potential of quantitative imaging to assess complex airway functions in a patient-derived lung tissue model system, and indicate that targeting PI3K{delta} might be a promising therapeutic opportunity to limit rhinovirus-induced airway damage in exacerbating COPD patients. SummaryPI3K{delta} inhibition reduces rhinovirus-mediated damage of small airway epithelia from chronic obstructive pulmonary disease (COPD) patients

pathology↗