Extracellular Vesicles, a Key Mediator to Link Environmental Microbiota to Airway Immunity.

Asthma is considered the hallmark of chronic airway inflammation, in which several inflammatory cells of the innate and adaptive immune system act together. The disease is thought to be caused by a combination of genetic and environmental factors; however, precise mechanisms for airway inflammation remain unclear. The human microbiota provides an increasingly favored explanation for inflammatory diseases; an altered microbiota composition has been shown to regulate immune responses. However, given the complexity of the microbiota, additional research is needed to elucidate its role in the development of disease. One of the candidate molecules that link microbiota to disease is the extracellular vesicles (EVs). EVs are secreted by diverse cell types and they possess the pathophysiological function of delivering signals between bacteria and host. We discuss the role of the microbiota in the development of asthma through releasing EVs.