Extracellular Vesicle Biology in the Pathogenesis of Lung Disease

Abstract As our understanding of diseases of the lung continues to evolve, we recognize that the mechanisms that drive cell/environment communication leading to disease development and progression are complex. In 2008, investigators first identified intact cell free microRNAs in circulation with some localized within lipid-encapsulated microvesicles termed extracellular vesicles (EVs). Prior to and following this discovery, investigators have determined that EVs may drive biological processes fundamental to human disease and homeostasis. The cargo in EVs which includes, proteins, miRNAs and mRNAs is protected from degradation, often reflects the pathogenesis of the cell of origin and may serve as a conduit for communication between cells subsequently reprogramming recipient cell function. Furthermore, EVs have been detected in bodily fluids including blood urine, sputum and bronchoalveolar lavage. The release and shuttling of EVs between cells following both environmental exposure and during disease development and progression has added a new layer of complexity to cell-cell communication in lung disease. While the majority of studies implicating EVs in human biology have been conducted in cancer, we have witnessed an emergence of EV based studies in other physiopathological conditions. EV mediated transfer of genetic content may link environmental stressors to the lung immune response through intercellular communication within the lung and development of disease. This perspective will focus on the growing field of EV biology in human lung diseases and its application to both the development and progression of lung disease and in biomarker discovery.