Background: There is limited understanding of the impact of anti-IL5 treatment on nasal polyp tissue biology in chronic rhinosinusitis with nasal polyps (CRSwNP). The aim of this study was to determine the effect of the nasal polyp tissue cellular proteome and transcriptome in response to six months of anti-IL5 treatment with mepolizumab in CRSwNP utilising high-plex spatial profiling. Methods: GeoMx™ Digital Spatial Profiling (DSP) of 80 proteins and 1,833 mRNA targets in the polyp stroma and of the whole transcriptome (18,815 mRNA targets) in polyp epithelia was undertaken on formalin-fixed paraffin embedded slides of sinonasal biopsies collected before and after 16 and 24 weeks of treatment with mepolizumab. Results: Anti-IL5 therapy with mepolizumab in patients with eosinophilic CRSwNP had significant tissue biological impact. Treatment-related changes in proteins within immune checkpoint inhibition, neutrophil degranulation and the innate immune system were key biological mechanisms identified in a protein interaction network. Transcriptionally, there were significant reductions in gene sets associated with the reactome terms innate and adaptive immune system, neutrophil degranulation and TGFβ receptor signalling in epithelial to mesenchymal transition within polyp stroma, as well as enhancing antioxidant pathways. In polyp epithelia, increases in gene sets associated with the reactome-terms cilium assembly and keratinisation and a reduction in the regulation of KIT signalling were observed with treatment. Conclusions: Spatial profiling technology demonstrates that the effects of anti-IL5 treatment within nasal polyp tissue extend well beyond simple eosinophil reduction to broader regulation of innate and adaptive immune cells and in improving the epithelial barrier biology.

Background. Patients with severe asthma may have a greater risk of dying from COVID-19 disease. Angiotensin converting enzyme-2 (ACE2) and the enzyme proteases, transmembrane protease serine 2 (TMPRSS2) and FURIN, are needed for viral attachment and invasion into host cells. Methods. We examined microarray mRNA expression of ACE2, TMPRSS2 and FURIN in sputum, bronchial brushing and bronchial biopsies of the European U-BIOPRED cohort. Clinical parameters and molecular phenotypes, including asthma severity, sputum inflammatory cells, lung functions, oral corticosteroid (OCS) use, and transcriptomic-associated clusters, were examined in relation to gene expression levels. Results. ACE2 levels were significantly increased in sputum of severe asthma compared to mild-moderate asthma. In multivariate analyses, sputum ACE2 levels were positively associated with OCS use and male gender. Sputum FURIN levels were significantly related to neutrophils (%) and the presence of severe asthma. In bronchial brushing samples, TMPRSS2 levels were positively associated with male gender and body mass index, whereas FURIN levels with male gender and blood neutrophils. In bronchial biopsies, TMPRSS2 levels were positively related to blood neutrophils. The neutrophilic molecular phenotype characterised by high inflammasome activation expressed significantly higher FURIN levels in sputum than the eosinophilic Type 2-high or the pauci-granulocytic oxidative phosphorylation phenotypes. Conclusion. Levels of ACE2 and FURIN may differ by clinical or molecular phenotypes of asthma. Sputum FURIN expression levels were strongly associated with neutrophilic inflammation and with inflammasome activation. This might indicate the potential for a greater morbidity and mortality outcome from SARS-CoV-2 infection in neutrophilic severe asthma.