Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Parasites break down mucous barrier in intestines to infect host

12.06.2006
The parasite that causes amoeba dysentery makes its way into the intestines by secreting an enzyme that dissolves the protective mucous layer of the intestines. This has been shown by researchers at the Sahlgrenska Academy at Göteborg University in Sweden.

This is the first time it has been elucidated how the pathogenic organism goes about penetrating a protective mucous layer. The findings are presented in the latest issue of the prestigious scientific journal Proceedings of the National Academy of Sciences in the U.S.

The parasite Entamoeba histolytica is extremely common, but many people live with the amoeba in their body without noticing it. Some 500 million people around the world carry the parasite, but only one tenth of them develop symptoms.

The amoeba can infect the large intestine and cause bloody diarrhea. If the parasite penetrates further into the body, it can form cysts in the liver, and the disease can be fatal.

The stomach and intestines are protected by a layer of mucous that is extra thick and dense in the large intestine. This mucous is made up of large carbohydrate-rich protein molecules called mucins. The mucous layer forms a barrier that is difficult to penetrate and normally cannot be broken down, but organisms that cause disease in the large intestine nevertheless managed to get through.

The article shows that the amoeba Entamoeba histolytica secrets specific protein-cleaving enzymes that can split the mucin, causing the network to collapse.

“The amoeba enzyme cleaves the mucin at a very particular and unusual protein sequence. This allows the amoeba to bore through the mucous layer like a projectile and infect the underlying epithelial cells of the intestine,” says research Martin Lidell.

In the Third World nearly 100,000 people die each year as a result of complications following amoeba infections.

“We now have a better understanding of amoeba infections, and this knowledge provides us with the possibility of designing drugs that can prevent the amoeba from breaking down the mucous barrier and thereby infect the person,” says Professor Gunnar C. Hansson, who directs mucin biological research at the Sahlgrenska Academy.

This research is being carried out in collaboration with amoeba experts in Canada.

Journal: Proceedings of the National Academy of Sciences, U.S.

Title of article: Entamoeba histolytica cysteine proteases cleave the MUC2 mucin in its C-terminal domain and dissolve the protective colonic mucus gel

Authors: Martin E. Lidell, Darcy M. Moncada, Kris Chadee, and Gunnar C. Hansson

Elin Lindström | alfa
Further information:
http://www.pnas.org
http://www.sahlgrenska.gu.se

More articles from Health and Medicine:

nachricht Fast-tracking T cell therapies with immune-mimicking biomaterials
16.01.2018 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht Dengue takes low and slow approach to replication
12.01.2018 | Duke University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Novel 3-D printing technique yields high-performance composites

16.01.2018 | Materials Sciences

New application for acoustics helps estimate marine life populations

16.01.2018 | Life Sciences

Fast-tracking T cell therapies with immune-mimicking biomaterials

16.01.2018 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>