Virus-like structure calls into question origin of diseases such as 'mad cow'

Dec 13, 2010

(PhysOrg.com) -- A Yale University researcher has found virus-like genetic material within samples of Creutzfeldt-Jakob disease (CJD) and scrapie, a finding that challenges scientific consensus on the nature of these deadly brain-wasting diseases.

Many scientists say that transmissible spongiform encephalopathies (TSEs) — including CJD, scrapie and epidemic “mad cow” — are caused by a misfolded normal protein that spontaneously becomes infectious. This infectious prion form is transmitted without nucleic acid used by infectious agents such as viruses, they say.

But other scientists, such as Laura Manuelidis, professor of surgery at Yale School of Medicine, say a slow-acting may be the cause of TSEs.

In the study, published this week in the online edition of the Journal of Neurovirology, Manuelidis reports extracting new circular virus-like DNA sequences from infectious particles of three samples of CJD and scrapie. These viral signatures would not be expected to be found in CJD or scrapie samples if infected prions were the sole culprits in the disease, she said.

“These findings won’t end the TSE debate, but hopefully it will open the door to more discussions about the nature of the causal infectious agent in TSEs and other late onset neurological diseases” Manuelidis said.

While these sequences, called Sphinx elements, were only visible in preparations of the infectious particles, ultimately they were found at very low amounts in uninfected cells, the study reports. Manuelidis believes that more of these sequences may be discovered in preparations of other infectious particles.

“They are intriguing, not only for their function in TSEs, but also because they may have once been incorporated from distant bacterial viruses,” Manuelidis says.

Explore further: Better living through mitochondrial derived vesicles

Related Stories

Recommended for you

Student seeks to improve pneumonia vaccines

2 hours ago

Almost a million Americans fall ill with pneumonia each year. Nearly half of these cases require hospitalization, and 5-7 percent are fatal. Current vaccines provide protection against some strains of the ...

Seabed solution for cold sores

4 hours ago

The blue blood of abalone, a seabed delicacy could be used to combat common cold sores and related herpes virus following breakthrough research at the University of Sydney.

Better living through mitochondrial derived vesicles

Aug 19, 2014

(Medical Xpress)—As principal transformers of bacteria, organelles, synapses, and cells, vesicles might be said to be the stuff of life. One need look no further than the rapid rise to prominence of The ...

Zebrafish help to unravel Alzheimer's disease

Aug 19, 2014

New fundamental knowledge about the regulation of stem cells in the nerve tissue of zebrafish embryos results in surprising insights into neurodegenerative disease processes in the human brain. A new study by scientists at ...

Engineering new bone growth

Aug 19, 2014

MIT chemical engineers have devised a new implantable tissue scaffold coated with bone growth factors that are released slowly over a few weeks. When applied to bone injuries or defects, this coated scaffold ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Caliban
5 / 5 (1) Dec 13, 2010
Just because these viral frabments are present in a few diseased brains or other organs is neither evidence for nor against a viral genesis for TSEs, and to make the claim that it is affirmative evidence is straight-up insupportable. Mere presence does not equal causation. This needs further study to make any claim of fact.