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06:39
Isolation and Purification of Bacterial Extracellular Vesicles from Human Feces Using Density Gradient Centrifugation
Published on: September 1, 2023
Enterocyte microvillus-derived vesicles detoxify bacterial products and regulate epithelial-microbial interactions
David A Shifrin1, Russell E McConnell, Rajalakshmi Nambiar
1Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Current Biology : CB
|March 6, 2012
Summary
Intestinal epithelial cells release lumenal vesicles (LVs) containing active intestinal alkaline phosphatase (IAP). These LVs prevent pathogen adherence and limit bacterial growth, representing a novel host defense mechanism.
Area of Science:
- Gastroenterology
- Microbiology
- Cell Biology
Background:
- Intestinal epithelial cells (IECs) form a barrier and express host defense proteins like intestinal alkaline phosphatase (IAP).
- IAP detoxifies bacterial products and prevents inflammation.
- Previous work identified IAP-enriched vesicles shed from IEC microvilli into the lumen.
Purpose of the Study:
- To investigate the function of microvillus-derived lumenal vesicles (LVs) in host-microbial interactions.
- To determine if LVs possess antimicrobial properties.
- To understand how IECs respond to bacterial pathogens regarding LV production.
Main Methods:
- Characterization of native lumenal vesicles (LVs) for IAP activity.
- Assessing LV interaction with lumenal bacteria.
- Testing LV efficacy in preventing enteropathogenic E. coli (EPEC) adherence to epithelial monolayers.
- Quantifying the effect of LVs on bacterial population growth.
- Evaluating IEC response to Gram-negative pathogens concerning LV production.
Main Results:
- LVs contain catalytically active IAP capable of dephosphorylating lipopolysaccharide (LPS).
- LVs cluster on native lumenal bacteria.
- LVs inhibit EPEC adherence to epithelial monolayers and limit bacterial growth.
- IECs increase LV production in response to EPEC and other Gram-negative pathogens.
Conclusions:
- Microvillar vesicle shedding is a novel mechanism for delivering host defense proteins to the intestinal lumen.
- Microvillus-derived LVs play a role in modulating host-microbial interactions.
- LVs contribute to the innate immune defense of the intestinal epithelium.
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