HomeScience and ResearchScientific ResearchWe've Got Some New Insight On What Gets T Cells To The...

We’ve Got Some New Insight On What Gets T Cells To The Gut and What Keeps Them There

Published on

The gut sends immune system secret messages. We can finally see what they’re saying thanks to new study from experts at the La Jolla Institute for Immunology (LJI).

A new study published in the journal Science Immunology shows how the barrier cells that line the intestines tell the T cells that live there to do their job. These cells talk to one another by producing a protein called HVEM, which encourages T cells to live longer and spread out more to fend off possible infections.

The new study’s lead author, LJI Professor and Chief Scientific Officer Mitchell Kronenberg, Ph.D., says, the study “shows how barrier cells in the intestine, structural elements of the tissue, and resident immune cells communicate” to protect the host.

The gut is lined with barrier cells, also called “epithelial” cells. This layer is only one cell thick. One could imagine these cells lined up like people waiting to get into a nightclub. The epithelial cells adhere to one another. They bump into each other and converse. In the meantime, T cell security guards move around the line, scanning the entire block for any indications of disturbance. 

“These T cells,” according to Kronenberg, “move around the epithelial cells as if they are truly patrolling.”

But what prevents these T cells from continuing to function in the epithelium?

“We’ve got some insight on what gets T cells to the gut,” adds Kronenberg, “but we need to understand what keeps them there.”  In fact, many immune cells spend their whole lives in specific tissues. Kronenberg hopes that by understanding the signals that maintain T cells in specific tissues, he will be able to shed light on illnesses such as inflammatory bowel disease, in which much too many inflammatory T cells accumulate in the colon.

In the latest study, the researchers discovered that the basement membrane, a thin layer of proteins beneath the epithelium, transmits key signals in the gut. The basement membrane would be the walkway where everyone stands in our nightclub setting.

Their research demonstrates that signals from surface-bound HVEM proteins encourage the creation of proteins that make up the basement membrane in epithelial cells. They  discovered that the absence of HVEM rendered the epithelial cells incapable of performing their function because they produced less collagen and other structural elements required to preserve a healthy basement membrane.

T cells sense the basement membrane by expressing adhesion molecules called integrins on their surface. The T cell integrins’ contact with the proteins in the basement membrane promotes signals that enable the T cells to persist and patrol the epithelium. It’s as if the epithelial cells left notes on the sidewalk, such as “Stay here,” “Patrol here,” and “Do your job.” Without an adequate basement membrane, T cells could not survive or patrol as effectively.

Using a mouse model, the researchers demonstrated that eliminating HVEM expression in the gut epithelial cells alone had a devastating effect on gut health. Patrolling T cells were less able to survive and moved less. These T cells weren’t very good at keeping people safe.

When challenged with Salmonella typhimurium, an invasive bacterium that causes gastroenteritis, the T cells allowed the infection to take over the intestines and spread to the liver and spleen.

Therefore, HVEM from epithelial cells laid the groundwork for T cells to guard the gut—it was the very reason they survived in the epithelium—communicating with the T cells indirectly through the basement membrane.

Image Credit: Getty

You were reading: We’ve Got Some New Insight On What Gets T Cells To The Gut and What Keeps Them There

Latest articles

Here’s How and When Mount Everest-sized ‘Devil Comet’ Can Be Seen With Naked Eye

Mount Everest sized Comet 12P/Pons-Brooks, also known as "devil comet" which is making its...

Something Fascinating Happened When a Giant Quantum Vortex was Created in Superfluid Helium

Scientists created a giant swirling vortex within superfluid helium that is chilled to the...

The Science of Middle-aged Brain and the Best Thing You Can Do to Keep it Healthy, Revealed

Middle age: It is an important period in brain aging, characterized by unique biological...

Science Shock: Salmon’s Food Choices Better at Reducing Risk of Heart Disease and Stroke

Salmon: Rich in Health Benefits, Yet May Offer Less Nutritional Value - This is...

More like this

Here’s How and When Mount Everest-sized ‘Devil Comet’ Can Be Seen With Naked Eye

Mount Everest sized Comet 12P/Pons-Brooks, also known as "devil comet" which is making its...

Something Fascinating Happened When a Giant Quantum Vortex was Created in Superfluid Helium

Scientists created a giant swirling vortex within superfluid helium that is chilled to the...

The Science of Middle-aged Brain and the Best Thing You Can Do to Keep it Healthy, Revealed

Middle age: It is an important period in brain aging, characterized by unique biological...