Featured Research

from universities, journals, and other organizations

Stomach bacteria switch off human immune defenses to cause disease

Date:
September 2, 2013
Source:
Society for General Microbiology
Summary:
Helicobacter pylori is a bacterium that establishes a life-long stomach infection in humans, which in some cases can lead to duodenal ulcers or stomach cancer. New research gives us a clearer understanding of how these bacteria can manipulate the human immune system to survive in the mucosal lining of the stomach.

Helicobacter pylori is a bacterium that establishes a life-long stomach infection in humans, which in some cases can lead to duodenal ulcers or stomach cancer. New research, presented at this week’s Society for General Microbiology Autumn Conference, gives us a clearer understanding of how these bacteria can manipulate the human immune system to survive in the mucosal lining of the stomach.

Researchers from the University of Nottingham have shown that H. pylori is able to supress the body’s normal production of ‘human beta defensin 1’ (hβD1), an antimicrobial factor present in the stomach lining that helps prevent bacterial infection. By collecting stomach tissue biopsies from 54 patients at the Queens Medical Centre, Nottingham, the team showed that patients infected with H. pylori had ten times less hβD1 than uninfected patients. Those with the lowest amount of hβD1 had the most bacteria present in their stomach lining.

The most damaging strains of H. pylori make a molecular syringe called the cagT4SS, through which bacterial products are injected into cells of the stomach lining. In vitro work using human gastric epithelial cell lines showed that this activates chemical pathways to suppress hβD1 production. These activated pathways are also involved in the stimulation of an inflammatory response, meaning that these H. pylori strains are able to survive and colonise more abundantly, while continuing to cause tissue damage over many decades. Previous research suggests that chronic inflammation of the stomach lining is strongly linked to gastric cancer.

It is estimated that half of the world’s population have H. pylori in the mucosal lining of their stomach. For most people the infection is asymptomatic, although 1-2 per cent of those infected will develop gastric cancer. Survival rates for this disease remain low, as diagnosis is often very late, when the cancer is at an advanced stage.

Katie Cook, who is presenting this work says, “To identify people who are likely to suffer from stomach cancer we need to understand how H. pylori interacts with the cells of the stomach lining. Because our research is patient-focused we know that our findings are directly relevant.

“We hope to combine this work with that being carried out by our colleagues in order to develop a diagnostic test to predict the future risk of gastric cancer development.”


Story Source:

The above story is based on materials provided by Society for General Microbiology. Note: Materials may be edited for content and length.


Cite This Page:

Society for General Microbiology. "Stomach bacteria switch off human immune defenses to cause disease." ScienceDaily. ScienceDaily, 2 September 2013. <www.sciencedaily.com/releases/2013/09/130902101712.htm>.
Society for General Microbiology. (2013, September 2). Stomach bacteria switch off human immune defenses to cause disease. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2013/09/130902101712.htm
Society for General Microbiology. "Stomach bacteria switch off human immune defenses to cause disease." ScienceDaily. www.sciencedaily.com/releases/2013/09/130902101712.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins