Gut neurons help our immune system control inflammation

Neurons present in our gut play a key role in protecting intestinal tissue from over-inflammation, says a new research from the Rockefeller University.

The immune system exercises constant vigilance to protect the body from external threats -- including what we eat and drink.

"Our work identifies a mechanism by which neurons work with immune cells to help intestinal tissue respond to perturbations without going too far," said assistant professor Daniel Mucida who led the research.

Different populations of macrophages are among the many types of immune cells present in intestinal tissue.

Using a 3D imaging technique, the researchers looked in depth at the differences between the two key macrophage populations.

In addition to variations in how the cells look and move, they noticed that intestinal neurons are surrounded by macrophages.

When Mucida and colleagues analysed the genes that are expressed in the two macrophage populations, they found that lamina propria macrophages preferentially express pro-inflammatory genes.

In contrast, the muscularis macrophages preferentially express anti-inflammatory genes and these are boosted when intestinal infections occur.

"We came to the conclusion that one of the main signals to control infection seems to come from neurons," Mucida noted.

The researchers also observed that the muscularis macrophages are activated within one to two hours following an infection.

"We now have a much better picture of how the communication between neurons and macrophages in the intestine helps to prevent potential damage from inflammation," Mucida added.

The findings, published in the journal Cell, can have treatment implications for gastrointestinal diseases such as irritable bowel syndrome (IBS).