Asthma affects over 235 million people worldwide; its prevalence is continuously increasing, and patient numbers double every decade (WHO 2017). The EU-Symposium on the Awareness of Allergy 2016 declared that, chronic and allergic diseases are a major and growing health problem in Europe. Asthma presents as chronic airway inflammation and airway wall remodelling as the main pathologies. Anti-inflammatory drugs reduce inflammation, but do not affect airway wall remodelling. Our studies on asthma showed that epithelium derived heat shock protein (HSP) 60 activated the following mechanism in mesenchymal cells: HSP60 ? low C/EBP-a ? increased C/EBP-ß activity ? downregulated microRNA 19a ? increased Erk1/2 ? stimulated Stat3 ? increased PRMT1 ? high mitochondria and C/EBP-ß activity. Other asthma relevant cytokines including PDGF-BB, TNF-a, IL-1ß, and IL-4, also initiated this autologous self-sustaining mechanism in a cell type specific manner. Contrary to HSP60, epithelium derived HSP70 and HSP90 blocked airway remodelling. These data were generated from primary cell lines obtained from 6 hospitals: Basel (CH), Sydney (AU), Naples (IT), Liege (BE), Manitoba (CA), and Xi’an (CN).Overall objectives and specific aims: To understand the cause of asthma and airway wall remodelling with the aim to find new targets for therapy, and biomarkers to clearly diagnose asthma, to avoid misdiagnosis. The specific aims are to understand the following: (i) Does the ratio of C/EBP-a to C/EBP-ß in epithelial cells control the expression of HSP60, HSP70 and HSP90? (ii) Do secreted HSPs regulate C/EBP-isoforms in mesenchymal cells? According to the available literature, HSPs are controlled by C/EBPs. Hence, HSPs and C/EBPs may form an auto-regulative cycle, which we aim to explore. (iii) Which receptors mediate the effect of secreted HSPs on mesenchymal and epithelial cells? Others suggested that toll like receptors (TLRs) mediate the action of secreted HSPs, which was not confirmed in asthma. (iv) Which effect do HSP60, HSP70 and HSP90 have on remodelling and secretion of pro-inflammatory factors by epithelial and smooth muscle cells in asthma?Methods to be used: Using our available human primary cells, the cell type specific effects of recombinant human HSP60, HSP70 and HSP90 will be determined by 48-hour kinetic study using NGS, followed by KEGG analysis focusing on C/EBP regulating proteins. The effects of recombinant HSPs on the secretome of epithelial cells will be determined by mass spectrometry; the effect on mesenchymal cell secreted pro-inflammatory cytokines and extracellular matrix will be determined by ELISA. Mitochondria activity and structure will be determined by MitoTracker and immunofluorescence. C/EBPs will be upregulated by transfection with overexpression vectors, or downregulated by corresponding small inhibitory RNAs. Protein expression will be determined by Western-blotting and cell compartment distribution by immunofluorescence. The identified mechanism(s) will be verified in the rat in vivo model of asthma by our Chinese collaborator Prof Q. Sun (Xi’an), who has her own funding. Expected results and impact: The expected results will clarify the role of secreted HSPs and their regulation by C/EBPs in the pathogenesis of asthma. The results will provide new therapeutic targets for asthma, and may replace the use of inhaled corticosteroids, and thereby eliminating their side effects. Furthermore, the study will provide new asthma specific biomarkers, and thereby improve diagnosis. It can be envisaged that new inhalable drugs such as small peptides of HSPs or agonists to specific HSP receptors can be developed to achieve cell type specific, and asthma specific therapeutic effects, which could reduce both inflammation and remodelling.