Medical Research Council - London Institute of Medical Sciences

Now in our 8th year of bringing you beautiful imagery from biomedical science every day

On the Hook

A way that harmless and harmful bacteria in the gut are distinguished by our immune system

09 May 2019

On the Hook

Our gut plays host to a whole community of microbes, including many harmless commensals, that may even be beneficial. To avoid destruction by our immune system, they need to communicate with their host’s cells, and recent research may have uncovered a way for some bacteria to do this. Segmented filamentous bacteria closely associate with the intestinal epithelial cells lining the gut, latching onto them with a hook-like protrusion (pictured, as a computer reconstruction, overlaid onto a microscopy image). Electron microscopy revealed that membrane spheres, known as vesicles, are formed where bacterium and host meet, and carry antigens, protein markers of bacterial identity, back into the host cell. Antigens are typically used by the immune system to recognise and target foreign cells, but delivering them this way may alter the immune system’s reaction, protecting the bacteria. Nicknamed MATE, this ingenious process is revealing previously-unknown mechanisms for determining friend from foe.

Written by Emmanuelle Briolat

Search The Archive

Submit An Image

What is BPoD?

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.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.