Lung transplantation (LT) is a life-saving treatment for patients (pt) with advanced, progressive and end-stage lung diseases. However, despite improvements in surgical techniques and therapies, the median survival after LT is 5.7 years, according to the International Society for Heart and Lung Transplantation. In the first year, the most common complication is acute cellular rejection, which, together with infections, promotes the onset of chronic lung allograft dysfunction (CLAD), for which no specific therapy currently exists. Extracellular vesicles (EVs) mediate cell-to-cell communication by transferring proteins, lipids, and RNA molecules to recipient cells, thereby influencing their physiological or pathological state.
In this project, we aim to study the role of EVs in inflammation during LT chronic rejection. Since specific biomarkers for CLAD have not yet been identified, it would be useful to investigate the CLAD lung microenvironment of LT pt through EVs. We will co-culture human bronchial epithelial cells (HBEpC) and human pulmonary microvascular endothelial cells (HPMEC) with EVs isolated from the bronchoalveolar lavage fluid (BAL) of patients with CLAD (EVs-CLAD) and without rejection (EVs- CTRL). After co-culture, HBEpC will be collected, RNA will be extracted, and we will perform a gene expression analysis focusing on inflammation-related pathways. Cell supernatants will be collected for proteomic analysis. Endothelial dysfunction and permeability in HPMEC will be evaluated after co-culture by measuring nitric oxide (NO) release and performing a Transwell Permeability Assay, respectively. In all experiments, we will compare the effects of EVs-CLAD and EVs-CTRL. These data could provide further insights into the inflammatory mechanisms underlying graft rejection. We plan to use the budget from the “Early Career Development 2025 (Linea 8 del Piano di Sostegno alla Ricerca – PSR)” to purchase reagents for cell biology experiments (cell lines and culture)