Introduction
Asthma is a chronic inflammatory disease of the airways affecting hundreds of millions of individuals worldwide. Acute exacerbations, most frequently triggered by respiratory viral infections such as rhinovirus (RV), represent a major source of morbidity and healthcare burden. While RV infection generally causes mild upper respiratory symptoms in healthy individuals, patients with asthma often develop exaggerated inflammatory responses, impaired antiviral immunity and prolonged disease severity. Increasing evidence suggests that these altered responses are closely linked to changes in cellular metabolism, yet the underlying mechanisms remain insufficiently understood.
The airway epithelium forms the first physical and immunological barrier against inhaled pathogens and actively regulates antiviral defence, inflammatory signalling and tissue homeostasis. Metabolic pathways such as glycolysis and mitochondrial oxidative phosphorylation influence how cells respond to infection. We hypothesised that metabolic dysfunction within the asthmatic airway epithelium contributes to defective antiviral responses and enhanced inflammation following RV infection.
Materials and Methods
We combined ex vivo analyses of clinical airway samples from patients with asthma (n = 26) and healthy controls (n = 11) with in vitro studies using primary human bronchial epithelial cells from healthy and asthmatic donors. Bronchial brushings and bronchoalveolar lavage fluid collected following experimental in vivo RV infection were analysed using transcriptomic and targeted metabolomic approaches. In parallel, differentiated epithelial cultures infected with RV-A16 underwent integrated multi-omic profiling, including transcriptomics and LC–MS-based proteomics and metabolomics. Mitochondrial function and metabolic dependencies were assessed using extracellular flux analysis (Seahorse) and single-cell SCENITH metabolic profiling, while mitochondrial morphology was quantified by confocal imaging. Complementary single-cell transcriptomic datasets were analysed to examine epithelial subset-specific responses to viral infection and type 2 inflammatory stimuli.
Results
In healthy bronchial epithelium, RV infection induced sustained mitochondrial stress and metabolic remodelling, while single-cell transcriptomic analyses showed acquisition of asthma-associated features across epithelial subsets. At baseline, asthmatic epithelial cells already displayed a related phenotype, characterised by altered mitochondrial structure, reduced mitochondria-derived ATP, increased glycolytic contribution and changes in mitochondrial, redox and lipid metabolic pathways. These alterations persisted after prolonged culture and epithelial differentiation, supporting an intrinsic epithelial metabolic phenotype in asthma. Functional SCENITH profiling further indicated reduced mitochondrial flexibility in asthma, with greater functional codependence between respiratory Complexes I and II. Following RV infection, healthy cells shifted towards this metabolically stressed, asthma-like state, whereas asthmatic cells showed comparatively limited further metabolic adaptation. Despite this convergence, infected asthmatic epithelium remained distinct, with persistent mitochondrial dysfunction, enhanced inflammatory responses and impaired antiviral immunity.
Discussion
Our findings identify epithelial immunometabolic dysfunction as a central feature of asthma and virus-induced exacerbation. They support a model in which the asthmatic airway epithelium exists in a metabolically stressed state with impaired mitochondrial function and increased reliance on glycolysis, limiting its capacity to adapt to the additional demands imposed by viral infection. The convergence of healthy cells towards a similar metabolic state following RV infection further links mitochondrial dysfunction to altered antiviral and inflammatory responses. Together, these findings highlight cellular metabolism as an important regulator of airway host defence and suggest that targeting epithelial metabolic pathways may offer new approaches to improve antiviral immunity and reduce exacerbation severity in asthma.