Our intestine wall is made up of two types of cells – cells covered in finger-like villi which specialise in absorption, and smooth cells which shuttle microbes across the gut lining to be dealt with by our immune system. These smooth cells are a bit like security guards, keeping an eye out for any trouble. However, several pathogens are known to exploit them, hitching a ride for an easy way to infect and colonise tissues. Food-poisoning bacteria Salmonella typhimurium, (pictured in yellow) go one step further – they secrete a protein which changes villi-covered cells into transporter cells, making it even easier for them to infect the host. Here, just 120 minutes after infection, is a cell mid-way through the transition with just a few villi left. Understanding this interaction could help in developing oral vaccines which are taken up by the transporter cells.
Written by Sarah McLusky
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.