Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New study shows how mad cow prions hitch a ride into intestine

15.12.2004


They piggyback on iron-storing proteins after surviving digestive juices



A new study from the Department of Pathology at Case Western Reserve University School of Medicine shows that the infectious version of prion proteins, the main culprits behind the human form of mad cow disease or variant Creutzfeldt-Jakob Disease (vCJD), are not destroyed by digestive enzymes found in the stomach. Furthermore, the study finds that the infectious prion proteins, also known as prions, cross the normally stringent intestinal barrier by riding piggyback on ferritin, a protein normally absorbed by the intestine and abundantly present in a typical meat dish. The study appears in the Dec. 15 issue of the Journal of Neuroscience.

Prions are a modified form of normal proteins, the prion proteins, which become infectious and accumulate in the nervous system causing fatal neurodegenerative disease. Variant CJD results from eating contaminated beef products from cattle infected with mad cow disease. To date, 155 cases of confirmed and probable vCJD in the world have been reported, and it is unclear how many others are carrying the infection.


According to the study’s senior author Neena Singh, M.D., Ph.D., associate professor of pathology, little is known about the mechanism by which prions cross the human intestinal barrier, which can be a particularly difficult obstacle to cross. "The mad cow epidemic is far from over, and the continuous spread of a similar prion disease in the deer and elk population in the U.S. raises serious public health concerns," said Singh. "It is therefore essential to understand how this disease is transmitted from one species to another, especially in the case of humans where the infectious prions survive through stages of cooking and digestion."

Using brain tissues infected with the spontaneously occurring version of CJD which is also caused by prions, the researchers simulated the human digestive process by subjecting the tissue to sequential treatment with digestive fluids as found in the human intestinal tract. They then studied how the surviving prions are absorbed by the intestine using a cell model. The prions were linked with ferritin, a cellular protein that normally binds excess cellular iron to store it in a soluble, non-toxic form within the cell. "Since ferritin shares considerable similarity between species, it may facilitate the uptake of prions from distant species by the human intestine,"said Singh."This important finding provides insight into the cellular mechanisms by which infectious prions ingested with contaminated food cross the species barrier, and provides the possibility of devising practical methods for blocking its uptake," she said. "If we can develop a method of blocking the binding of prions to ferritin, we may be able to prevent animals from getting this disease through feed, and stop the transmission to humans."

Currently, Singh’s group is checking whether prions from distant species such as deer and elk can cross the human intestinal barrier.

George Stamatis | EurekAlert!
Further information:
http://www.case.edu

More articles from Studies and Analyses:

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

nachricht Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>