Secretion of miRNA-containing extracellular vesicles (EV) by bronchial epithelial cells in allergic airway inflammation

Background: miRNAs (miR) are critical regulators of the immune system. Recently they have been shown to be secreted into EVs for inter-cell communication (Valadi et al., Nat Cell Biol, 2007). We previously identified an up-regulation of miR-17 and -21 in murine lung homogenate in Ovalbumin (OVA) induced allergic airway inflammation (AAI). Objective: We now asked if mir-17 and miR-21 are produced by the human bronchial epithelium and released into EVs in AAI. Methods: Primary normal human bronchial epithelial (NHBE) cells were cultured at the air-liquid interface and treated with Interleukin (IL) 13 to model a T-…