Degradation of the Disease-Associated Prion Protein by a Serine Protease from Lichens
Christopher J. Johnson1,2*, James P. Bennett1,3, Steven M. Biro1,4, Juan Camilo Duque-Velasquez5¤, Cynthia M. Rodriguez1,4, Richard A. Bessen2, Tonie E. Rocke1 1 Prion Research Laboratory, United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, United States of America, 2 Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana, United States of America, 3 Institute for Environmental Studies, University of Wisconsin, Madison, Wisconsin, United States of America, 4 Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America, 5 Grupo de Investigacio´n CENTAURO, Facultad de Ciencias Agrarias, Universidad de Antioquia, Medellý´n, Antioquia, Colombia
The disease-associated prion protein (PrPTSE), the probable etiological agent of the transmissible spongiform encephalopathies (TSEs), is resistant to degradation and can persist in the environment. Lichens, mutualistic symbioses containing fungi, algae, bacteria and occasionally cyanobacteria, are ubiquitous in the environment and have evolved unique biological activities allowing their survival in challenging ecological niches. We investigated PrPTSE inactivation by lichens and found acetone extracts of three lichen species (Parmelia sulcata, Cladonia rangiferina and Lobaria pulmonaria) have the ability to degrade prion protein (PrP) from TSE-infected hamsters, mice and deer. Immunoblots measuring PrP levels and protein misfolding cyclic amplification indicated at least two logs of reductions in PrPTSE. Degradative activity was not found in closely related lichen species or in algae or a cyanobacterium that inhabit lichens. Degradation was blocked by Pefabloc SC, a serine protease inhibitor, but not inhibitors of other proteases or enzymes. Additionally, we found that PrP levels in PrPTSE-enriched preps or infected brain homogenates are also reduced following exposure to freshly-collected P. sulcata or an aqueous extract of the lichen. Our findings indicate that these lichen extracts efficiently degrade PrPTSE and suggest that some lichens could have potential to inactivate TSE infectivity on the landscape or be a source for agents to degrade prions. Further work to clone and characterize the protease, assess its effect on TSE infectivity and determine which organism or organisms present in lichens produce or influence the protease activity is warranted.
Citation: Johnson CJ, Bennett JP, Biro SM, Duque-Velasquez JC, Rodriguez CM, et al. (2011) Degradation of the Disease-Associated Prion Protein by a Serine Protease from Lichens. PLoS ONE 6(5): e19836. doi:10.1371/journal.pone.0019836 Editor: Jason C. Bartz, Creighton University, United States of America Received September 22, 2010; Accepted April 18, 2011; Published May , 2011 This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. Funding: This work was funded by the United States Geological Survey. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: firstname.lastname@example.org ¤ Current address: Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
Lichens May Aid in Combating Deadly Chronic Wasting Disease in Wildlife
Released: 5/17/2011 3:00:50 PM
Contact Information: U.S. Department of the Interior, U.S. Geological Survey Office of Communication 119 National Center Reston, VA 20192 Gail Moede Phone: 608-270-2438
Catherine Puckett Phone: 352-264-3532
Christopher Johnson Phone: 608-270-2400 x 2361
MADISON, Wis. – Certain lichens can break down the infectious proteins responsible for chronic wasting disease (CWD), a troubling neurological disease fatal to wild deer and elk and spreading throughout the United States and Canada, according to U.S. Geological Survey research published today in the journal PLoS ONE.
Like other "prion" diseases, CWD is caused by unusual, infectious proteins called prions. One of the best-known of these diseases is "mad cow" disease, a cattle disease that has infected humans. However, there is no evidence that CWD has infected humans. Disease-causing prions, responsible for some incurable neurological diseases of people and other diseases in animals, are notoriously difficult to decontaminate or kill. Prions are not killed by most detergents, cooking, freezing or by autoclaving, a method used to sterilize medical instruments.
"When prions are released into the environment by infected sheep or deer, they can stay infectious for many years, even decades," said Christopher Johnson, Ph.D., a scientist at the USGS National Wildlife Health Center and the lead author of the study. "To help limit the spread of these diseases in animals, we need to be able to remove prions from the environment."
The researchers found that lichens have great potential for safely reducing the number of prions because some lichen species contain a protease enzyme (a naturally produced chemical) capable of significantly breaking down prions in the lab.
"This work is exciting because there are so few agents that degrade prions and even fewer that could be used in the environment without causing harm," said Jim Bennett, Ph.D., a USGS lichenologist and a co-author of the study.
CWD and scrapie in sheep are different than other prion diseases because they can easily spread in sheep or deer by direct animal-to-animal contact or through contact with contaminated inanimate objects like soil. Chronic wasting disease was first diagnosed in the 1960s and has since been detected in 19 states and two Canadian provinces. CWD has been detected in wild elk, mule deer, white-tailed deer and moose in North America.
Lichens, said Johnson, produce unique and unusual organic compounds that aid their survival and can have antibiotic, antiviral and other chemotherapeutic activities. In fact, pharmaceutical companies have been examining the medicinal properties of lichens more closely in recent years.
Lichens - which are often mistaken for moss - are unusual plant-like organisms that are actually a symbioses of fungi, algae and bacteria living together. They usually live on soil, bark, leaves and wood and can live in barren and unwelcoming environments, including the Arctic and in deserts.
Future work will examine the effect of lichens on prions in the environment and determine if lichen consumption can protect animals from acquiring prion diseases.
The study, “Degradation of the disease-associated prion protein by a serine protease from lichens,” was published in PLoS ONE and is freely accessible to the public. The study was authored by USGS scientists Christopher Johnson, James Bennett and Tonie Rocke, as well as authors from Montana State University and the University of Wisconsin.
J Environ Qual. 2011 Mar-Apr;40(2):449-61.
Fate of prions in soil: a review.
Smith CB, Booth CJ, Pedersen JA.
Environmental Chemistry and Technology Program, Univ. of Wisconsin, 1525 Observatory Dr., Madison, WI 53706, USA.
Prions are the etiological agents of transmissible spongiform encephalopathies (TSSEs), a class of fatal neurodegenerative diseases affecting humans and other mammals. The pathogenic prion protein is a misfolded form of the host-encoded prion protein and represents the predominant, if not sole, component of the infectious agent. Environmental routes of TSE transmission areimplicated in epizootics of sheep scrapie and chronic wasting disease (CWD) of deer, elk, and moose. Soil represents a plausible environmental reservoir of scrapie and CWD agents, which can persist in the environment for years. Attachment to soil particles likely influences the persistence and infectivity of prions in the environment. Effective methods to inactivate TSE agents in soil are currently lacking, and the effects of natural degradation mechanisms on TSE infectivity are largely unknown. An improved understanding of the processes affecting the mobility, persistence, and bioaviailability of prions in soil is needed for the management of TSE-contaminated environments.
Thursday, February 17, 2011
Environmental Sources of Scrapie Prions
plenty of prions in North America to worry about too ;
Friday, May 13,
2011 EFSA Joint Scientific Opinion on any possible epidemiological or molecular association between TSEs in animals and humans
Sunday, May 01, 2011
STUDY OF ATYPICAL BSE 2010 Annual Report May 2011
Friday, March 4, 2011
Alberta dairy cow found with mad cow disease
Wednesday, August 11, 2010
REPORT ON THE INVESTIGATION OF THE SIXTEENTH CASE OF BOVINE SPONGIFORM ENCEPHALOPATHY (BSE) IN CANADA
Thursday, August 19, 2010
REPORT ON THE INVESTIGATION OF THE SEVENTEENTH CASE OF BOVINE SPONGIFORM ENCEPHALOPATHY (BSE) IN CANADA
Thursday, February 10, 2011
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY REPORT UPDATE CANADA FEBRUARY 2011 a nd how to hide mad cow disease in Canada Current as of: 2011-01-31
Wednesday, March 9, 2011
27 U.S. Senators want to force feed Japan Highly Potential North America Mad Cow Beef TSE PRION CJD
March 8, 2011
President Barack Obama The White House
1600 Pennsylvania Avenue, W Washington, DC 20500
Dear President Obama:
Monday, April 25, 2011
Experimental Oral Transmission of Atypical Scrapie to Sheep
Volume 17, Number 5–May 2011
Sunday, March 27, 2011
SCRAPIE USA UPDATE FEBRUARY 2011
Wednesday, February 16, 2011
SCRAPIE TRANSMISSION TO CHIMPANZEES
Increased Atypical Scrapie Detections
Press reports indicate that increased surveillance is catching what otherwise would have been unreported findings of atypical scrapie in sheep. In 2009, five new cases have been reported in Quebec, Ontario, Alberta, and Saskatchewan. With the exception of Quebec, all cases have been diagnosed as being the atypical form found in older animals. Canada encourages producers to join its voluntary surveillance program in order to gain scrapie-free status. The World Animal Health will not classify Canada as scrapie-free until no new cases are reported for seven years. The Canadian Sheep Federation is calling on the government to fund a wider surveillance program in order to establish the level of prevalence prior to setting an eradication date. Besides long-term testing, industry is calling for a compensation program for farmers who report unusual deaths in their flocks.
Tuesday, May 3, 2011
PRION, TSE, typical, atypical BSE, aka mad cow disease, spray dried blood, feed, and a recipe for disaster
Sunday, May 1, 2011
W.H.O. T.S.E. PRION Blood products and related biologicals May 2011
UPDATED DATA ON 2ND CWD STRAIN
Wednesday, September 08, 2010
CWD PRION CONGRESS SEPTEMBER 8-11 2010
NOW FOR RISK FACTORS FOR CWD TRANSMISSION TO CATTLE ;
----- Original Message -----
From: David Colby To: email@example.com Cc: stanley@XXXXXXXX
Sent: Tuesday, March 01, 2011 8:25 AM
Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations
Dear Terry Singeltary,
Thank you for your correspondence regarding the review article Stanley Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner asked that I reply to your message due to his busy schedule. We agree that the transmission of CWD prions to beef livestock would be a troubling development and assessing that risk is important. In our article, we cite a peer-reviewed publication reporting confirmed cases of laboratory transmission based on stringent criteria. The less stringent criteria for transmission described in the abstract you refer to lead to the discrepancy between your numbers and ours and thus the interpretation of the transmission rate. We stand by our assessment of the literature--namely that the transmission rate of CWD to bovines appears relatively low, but we recognize that even a low transmission rate could have important implications for public health and we thank you for bringing attention to this matter.
Warm Regards, David Colby
David Colby, PhDAssistant ProfessorDepartment of Chemical EngineeringUniversity of Delaware
PLEASE SEE FULL TEXT ;
Wednesday, January 5, 2011
ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011
David W. Colby1,* and Stanley B. Prusiner1,2
re-ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011 Prions
CWD to cattle figures CORRECTION
I believe the statement and quote below is incorrect ;
"CWD has been transmitted to cattle after intracerebral inoculation, although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding raised concerns that CWD prions might be transmitted to cattle grazing in contaminated pastures."
Please see ;
Within 26 months post inoculation, 12 inoculated animals had lost weight, revealed abnormal clinical signs, and were euthanatized. Laboratory tests revealed the presence of a unique pattern of the disease agent in tissues of these animals. These findings demonstrate that when CWD is directly inoculated into the brain of cattle, 86% of inoculated cattle develop clinical signs of the disease.
" although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). "
shouldn't this be corrected, 86% is NOT a low rate. ...
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Thanks so much for your updates/comments. We intend to publish as rapidly as possible all updates/comments that contribute substantially to the topic under discussion.
please see full text of my submission here ;
Wednesday, January 5, 2011
ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011
David W. Colby1,* and Stanley B. Prusiner1,2
SNIP...SEE FULL TEXT ;
Thursday, April 28, 2011
Chronic Wasting Disease Testing and Prevalence Wisconsin April 2011
CREUTZFELDT JAKOB DISEASE
Saturday, March 5, 2011
MAD COW ATYPICAL CJD PRION TSE CASES WITH CLASSIFICATIONS PENDING ON THE RISE IN NORTH AMERICA