Extracellular vesicles produced by Bacillus subtilis release RNA and cross in human intestinal Caco-2 cells

SOLER C; PIURI MARIANA; D'ANTON CL; PEREZ OSCAR; DOMINGUEZ RUBIO ANA PAULA; PALAVECINO M

Workshop; Workshop EVs in Immunology; 2020

Bacterial EVs have been related to inter-kingdom communication between probiotic/pathogenicbacteria and their hosts. Our aim was to investigate the transcytosis process of B. subtilis EVs usingan in vitro intestinal epithelial cell model. In this study, using Confocal Laser Scanning Microscopy,we report that uptake and internalization of CFSE-labeled B. subtilis EVs (115 nm ± 27 nm) by Caco-2cells are time-dependent. To study the transcytosis process we used a transwell system and EVs werequantified in the lower chamber by Fluorescence and Nanoparticle Tracking Analysis measurements.Intact EVs are transported across a polarized cell monolayer at 60?120 min and increased after240 min with an estimated average uptake efficiency of 30% and this process is dose-dependent. EVsmovement into intestinal epithelial cells was mainly through Z axis and scarcely on X and Y axis. Thiswork demonstrates that EVs could be transported across the gastrointestinal epithelium. We speculatethis mechanism could be the first step allowing EVs to reach the bloodstream for further delivery upto extraintestinal tissues and organs. The expression and further encapsulation of bioactive moleculesinto natural nanoparticles produced by probiotic bacteria could have practical implications in food,nutraceuticals and clinical therapies