Transcytosis of Bacillus subtilis extracellular vesicles through an in vitro intestinal epithelial cell model

Abstract

Bacterial eVs have been related to inter-kingdom communication between probiotic/pathogenic bacteria and their hosts. 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 eVs could be transported across the gastrointestinal epithelium. We speculate 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 natural nanoparticles produced by probiotic bacteria could have practical implications in food, nutraceuticals and clinical therapies.

Biological functions of Lacticaseibacillus rhamnosus JB-1 membrane vesicles: lipoteichoic acid, immune activity, and gut epithelial endocytosis

“…While the current paper was in preparation, two recent reports found similar results in gram-positive non-pathogenic bacteria. Rubio and colleagues found that Bacillus subtilis MV were internalized and apparently transcytosed by Caco-2 cells in vitro 30 , while Bajic and colleagues demonstrated that MV from Lactiplantibacillus plantarum BGAN8 are endocytosed by HT-29 cells in a clathrin-dependent manner 31 .…”

Therapeutic Potential of Mesenchymal Stem Cells and Their Products in Lung Diseases—Intravenous Administration versus Inhalation

“…EVs injected intravenously into mice first reached spleen and liver and subsequently distributed to gastrointestinal tract and lungs [105]. Permeation for exosomes across epithelial barriers (e.g., blood-brain barrier, gastrointestinal barrier) has been shown for endogenous and exogenous (Bacillus subtilis-derived) exosomes [106]. The transport is assumed to be better when parental cells and barrier forming cells are similar.…”

Bacterial Membrane Vesicles in Pneumonia: From Mediators of Virulence to Innovative Vaccine Candidates

“…In this context it is worth to speculate whether (O)MVs could actually be transcytosed through the alveolar barrier allowing for infectious dissemination throughout the body. While such mechanisms were not described in the lung yet, it was already shown in the gut that (O)MVs are indeed able to cross epithelial barriers and enter the vascular system [ 77 , 78 ]. On the functional level, OMVs from a variety of lung pathogens including P. aeruginosa , L. pneumophila, A. baumannii , K. pneumoniae , M. catarrhalis, and S. maltophilia can induce the release of proinflammatory mediators from the epithelium.…”