DEC 27, 2017 06:48 AM PST

Interaction Between T Cells and Bile Tells the Story of Crohn's Disease

WRITTEN BY: Kara Marker

The interaction between effector T cells and bile acid is little understood, yet the details behind the relationship could reveal a major mechanism of how Crohn’s disease develops. From Osaka University, scientists conducted a brand new study to unravel the extent to which effector T cells and bile acid contribute toward Crohn’s disease.

 Fixed stenosis of the small intestine in Crohn's disease. Credit: Wikimedia user Hellerhoff

Crohn’s disease (CD) is a chronic inflammatory bowel disease (IBD) in the gastrointestinal (GI) tract that usually impacts the end of the small intestine and the beginning of the large intestine. More than half a million people in the United States are estimated to have Crohn’s disease.

Osaka University scientists began their study with bile acid, a “detergent-like metabolite” produced in the liver as a result of cholesterol catabolism, a metabolic process completed to release energy. Then, bile acid is transported to the small intestine to help with digestion. However, sometimes bile acid is not associated with being helpful; sometimes it can cause cell death in the liver and in epithelial cells.

Effector T cells are active cells of the immune system that, in the context of the GI tract, boost activity of a protein called Mdr1 “to maintain homeostasis in the presence of bile acids,” explained study author Hisako Kayama. "Notably, those lacking Mdr1 display mucosal dysfunction and induce Crohn's disease-like [inflammation of the small intestine]."

Kayama’s study also led to the identification of a group of people with Crohn’s disease focused in the third part of the small intestine, called the ileum, who lack sufficient Mdr1 activity in response to bile acids.

What does Mdr1 do exactly? It delivers toxins and drugs, called xenobiotics, out of the cell and supports effector T cells during bile acid exposure, dampening the effect of cell damage, boosting cell survival, and suppressing inflammatory cytokine expression, Kayama described.

His study shows that Mdr1 is an important player in regulating the balance of bile acids in the GI tract: just enough to facilitate healthy digestion, not too much that IBD flares up.

“Future validation studies of larger IBD patient cohorts is important to test whether an Mdr1 loss-of-function is associated with a unique clinical course of ileal CD,” Kayama said. “Such knowledge may present opportunities for non-traditional, bile acids-directed therapy."

The present study was published in the journal Immunity.

Sources: Journal of Lipids, National Institute of Diabetes and Digestive and Kidney Diseases, Osaka University

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog:
You May Also Like
JUN 22, 2018
Health & Medicine
JUN 22, 2018
A New Test for Peanut Allergy: Better, Faster, Cheaper.
Scientists from the Medical Research Council (MRC) in the UK have come up with a test to detect peanut allergies and it’s safer, quicker and more acc...
JUN 27, 2018
JUN 27, 2018
Immune Cells Responsible for Chemo-induced Diarrhea
While studying specific immune cells in the context of chronic itching in the skin, two Washington University School of Medicine scientists discovered that...
JUL 04, 2018
JUL 04, 2018
Can Herpes Raise Your Risk for Alzheimer's?
Alzheimer's disease has no cure and no well-understood cause. Experts know that tangles of tau protein that develop in the brain impact memory and func...
JUL 06, 2018
Cell & Molecular Biology
JUL 06, 2018
Small Molecules Found to Dial Down Autoimmunity
Scientists have now identified two combinations of small molecules that tamp down a protein called STING....
AUG 28, 2018
Drug Discovery
AUG 28, 2018
Combination Therapy for Advanced Melonoma
According to a research study led by UCLA, a bacteria-like agent used in combination with an immunotherapeutic drug may help patients survive longer with a...
SEP 03, 2018
SEP 03, 2018
Insulin Boosts the Immune System
Insulin boosts T cells to better fight infection and bolster the immune response....
Loading Comments...