Bacillus subtilis extracellular vesicles can be transported through an in vitro intestinal epithelial cell model

ANA PAULA DOMINGUEZ RUBIO; JIMENA HEBE MARTÍNEZ; CARLA SOLER; MARIANA PIURI; OSCAR E PÉREZ; ANTONIO MARCILLA

Lisboa

Conferencia; 3rd International Conference on Material Science & Nanotechnology? (ICMSN 2021).; 2021

INNOVINC International. Website: https://materials-science.org/

Bacterial Extracellular Vesicles (EVs) have been related to inter-kingdom communication between probiotic/pathogenic bacteria and their hosts. The gastrointestinal tract (GIT) mucosal surface is the primary interface between gut bacteria and internal host tissues. A vital communication between kingdoms in the mammalian GIT is supposed to occur through an exchange of EVs that may interact in a triangular way between gut bacteria and the host. Our aim was to investigate the transcytosis process of B. subtilis EVs using an 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-2 cells are time-dependent. To study the transcytosis process we used a transwell system and EVs were quantified 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 after 240 min with an estimated average uptake efficiency of 30% and this process is dose-dependent. EVs movement into intestinal epithelial cells was mainly through Z axis and scarcely on X and Y axis. This work demonstrates that bacterial EVs could be transported across the gastrointestinal epithelium. Our findings suggest that this mechanism could be the first step allowing EVs to reach the bloodstream for further delivery up to extraintestinal tissues and organs. The expression and further encapsulation of bioactive molecules into these natural nanoparticles produced by probiotic bacteria EVs of GRAS (Generally Recognized as Safe) bacteria could have practical implications in food, nutraceuticals and clinical therapies.