Subscribe to the BioNews newsletter for free

Advanced Search

Search for

Like the Progress Educational Trust on Facebook



Gene, toxin and virus interact in Crohn's disease

05 July 2010

By Victoria Kay

Appeared in BioNews 565

US scientists have shown for the first time how a virus, a toxin and a genetic mutation interact to cause Crohn's disease. The study, in mice, may help explain why many people with disease risk genes don't develop the condition.

The study authors, led by Professors Thaddeus Stappenbeck and Herbert Virgin from the Washington University School of Medicine, made their discovery by accident. They had been studying how a gene mutation can lead to Crohn's-like symptoms in mice through the disruption of so-called 'Paneth cells' that line the small intestine. The normal function of these cells is to release anti-microbial agents that regulate the growth of natural bacterial in the gut.

However, when their study was moved to a new sterile facility, the mice grown there were completely healthy, despite having the genetic mutation. After further investigation, a mouse strain of the norovirus - a sickness virus commonly found in traditional animal houses but absent from the new sterile facility - was implicated. When the apparently healthy mice were fed the virus, the Paneth cells became abnormal and the intestinal symptoms re-emerged

The infected mice were then fed a toxic chemical known to perforate the gut and went on to develop a full blown inflammatory bowel disease similar to Crohn's disease.

Gene expression studies showed the genetic mutation causes the Paneth cells to respond differently to infection by the norovirus. Mice without the genetic mutation saw decreased expression of certain genes when they were infected by the virus. Expression of the same genes increased, however, in mice carrying the genetic mutation.

This affected their ability to release anti-microbial agents to control the bacteria in the gut meaning that, when the gut sustained an injury - as simulated by the toxin - the unregulated bacteria spread, leading to inflammatory bowel disease.

When the infected mice were treated with antibiotics (killing the bacteria), the symptoms went away.

'We've provided a very specific example of a virus triggering a complex disease - if the mice don't have the virus, they don't get the symptoms', said Professor Virgin. 'Many viruses infect nearly 100 percent of people, and when their genes interact with our genes, they may be contributing to such diseases'.

Professor Richard Blumberg, from Harvard Medical School, said that this study 'sort of opens a Pandora's box that makes interrogating the gene-environment interactions in this and other complex diseases much more complex'.

The study is published in Cell.

Gene + virus + injury = disease?
The Scientist (blog) | 24 June 2010
Scientific American | 24 June 2010
Science Magazine | 24 June 2010
Virus gene interaction triggers Crohn like pathology in mouse model
Medscape Today | 29 June 2010
EurekAlert | 24 June 2010


31 January 2011 - by Dr Jay Stone 
An international team of scientists has discovered that people with celiac disease and Crohn's disease share a number of common genetic loci. The researchers carried out a combined meta-analysis of genome-wide association study (GWAS) data from two large studies, one on each condition, and identified four 'risk loci' in common...
23 August 2010 - by Victoria Kay 
Researchers have come one step closer to being able to predict who will develop full-blown symptoms following infection with the tuberculosis (TB) bacterium...
12 July 2010 - by Victoria Kay 
A US study looking at the relationship between genes known to cause a rare genetic disease has shown that common and rare genetic variants interact to make symptoms more or less severe...

30 November 2009 - by Dr Marianne Kennedy 
New genetic studies have identified several key genetic regions which could play a role in ulcerative colitus, a common form of inflammatory bowel disease (IBD). All three studies were reported in Nature Genetics on 15 November....
05 November 2006 - by Dr Jess Buxton 
US and Canadian scientists have identified a gene involved in Crohn's disease, an inflammatory bowel condition. The team discovered that a version of a gene involved in the body's inflammation response is linked to a decreased risk of Crohn's disease. The researcher say that this means...
13 April 2004 - by BioNews 
Swedish scientists have identified two new genes linked to an increased risk of asthma and other breathing problems. Researchers at the Karolinska Institute say that alterations in the GPRA and AAA1 genes, located on chromosome seven, both make proteins involved in the disease. Their findings, published in the journal Science...

Be the first to have your say.

You need to or  to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions

- click here to enquire about using this story.

Published by the Progress Educational Trust


Public Conference
8 December 2017

Speakers include

Professor Azim Surani

Professor Magdalena Zernicka-Goetz

Professor Robin Lovell-Badge

Sally Cheshire

Professor Guido Pennings

Katherine Littler

Professor Allan Pacey

Dr Sue Avery

Professor Richard Anderson

Dr Elizabeth Garner

Dr Andy Greenfield

Dr Anna Smajdor

Dr Henry Malter

Vivienne Parry

Dr Helen O'Neill

Dr César Palacios-González

Philippa Taylor

Fiona Fox

Sarah Norcross

Sandy Starr


Good Fundraising Code

Become a Friend of PET HERE and give the Progress Educational Trust a regular donation