Levels of prion protein in brain may not be reliable marker for disease

Nov 30, 2007

Rapid diagnostic testing used to check for the presence of prion diseases such as “mad cow disease” might fail to identify some highly infectious samples, researchers have found. Currently, scanning beef or other meat products for possible prion infection involves sampling brain tissue from the animal for abnormally folded prion protein, also called PrP; this form of PrP, which is sticky and hard to degrade, is believed to be the infectious agent behind prion diseases.

Rona Barron and colleagues tested whether abnormal PrP and infectivity was an absolute association. They injected mice with two different strains of prion-infected tissue and quantified the degree of infection in these mice. Next, they examined the amount of abnormally folded PrP in brains of the sick mice and found that it did not correlate in any way with how infectious the disease strain was; in fact, some highly infectious tissue samples had nearly undetectable levels of abnormal PrP.

These data suggest that not all abnormal PrP found in diseased tissues is infectious, and may instead be a pathologic by-product of disease. Some other agent, or a specific conformation of abnormally folded PrP, may therefore be responsible for prion disease, and current assays relying solely on abnormal PrP detection could therefore underestimate the frequency of infection. Barron and colleagues note that it’s vital to find additional disease markers to help ensure no future prion outbreaks occur.

Source: American Society for Biochemistry and Molecular Biology

Explore further: Controlling Ebola in West Africa most effective way to decrease international risk

add to favorites email to friend print save as pdf

Related Stories

Unravelling the mystery of misfolding prions

May 30, 2012

(Phys.org) -- Researchers at the University of Alberta's physics department and the National Institute for Nanotechnology (NINT) are the first to map out the folding pathways of prions, malformed ...

Scientists show prions mutate and adapt to host environment

Dec 17, 2010

Scientists from the Florida campus of The Scripps Research Institute have shown that prions, bits of infectious protein that can cause fatal neurodegenerative disease such as bovine spongiform encephalopathy (BSE) or "mad ...

Iron is involved in prion disease-associated neuronal demise

Mar 13, 2009

Imbalance of iron homeostasis is a common feature of prion disease-affected human, mouse, and hamster brains, according to a new study by Dr. Neena Singh and colleagues at Case Western Reserve University School of Medicine, ...

Recommended for you

Ebola: Why virus kills some, other people survive

11 minutes ago

People who shared an apartment with the country's first Ebola patient are emerging from quarantine healthy. And while Thomas Eric Duncan died and two U.S. nurses were infected caring for him, there are successes, ...

Sleep duration affects risk for ulcerative colitis

2 hours ago

If you are not getting the recommended seven-to-eight hours of sleep each night, you may be at increased risk of developing ulcerative colitis, according to a new study1 in Clinical Gastroenterology and Hepatolog ...

User comments : 0