[USCC] Fwd: Prion Research - A letter, titled "Production of cattle lacking prion protein" was published in the December 31, 2006 issue of Nature Biotechnology.

[Jim McNelly]

>
>*   Prion Research - A letter, titled 
>"Production of cattle lacking prion protein" was 
>published in the December 31, 2006 issue of 
>Nature Biotechnology by researchers with the 
>National Animal Disease Center, USDA Agriculture 
>Research Service in Ames, Iowa; Hematech, Inc. 
>of Sioux Falls, South Dakota; Department of 
>Neurology, University of Texas Medical Branch in 
>Galveston, Texas; Pharmaceutical Division, Kirin 
>Brewery Co. of Tokyo, Japan; and Gemini Science 
>Inc. of La Jolla, California - The abstract of 
>the letter states " ... Prion diseases are 
>caused by propagation of misfolded forms of the 
>normal cellular prion protein PrPC, such as 
>PrPBSE in bovine spongiform encephalopathy (BSE) 
>in cattle and PrPCJD in Creutzfeldt-Jakob 
>disease (CJD) in humans ... Disruption of PrPC 
>expression in mice, a species that does not 
>naturally contract prion diseases, results in no 
>apparent developmental abnormalities ... 
>However, the impact of ablating PrPC function in 
>natural host species of prion diseases is 
>unknown. Here we report the generation and 
>characterization of PrPC-deficient cattle 
>produced by a sequential gene-targeting system 
>... At over 20 months of age, the cattle are 
>clinically, physiologically, 
>histopathologically, immunologically and 
>reproductively normal. Brain tissue homogenates 
>are resistant to prion propagation in vitro as 
>assessed by protein misfolding cyclic 
>amplification ... PrPC-deficient cattle may be a 
>useful model for prion research and could 
>provide industrial bovine products free of prion 
>proteins ..." - The abstract of the paper is 
>posted at 
><http://www.nature.com/nbt/journal/vaop/ncurrent/abs/nbt1271.html>http://www.nature.com/nbt/journal/vaop/ncurrent/abs/nbt1271.html 
>from which the complete text is available to 
>those who subscribe to the journal and to others 
>who pay a fee - Reprint requests may be directed 
>to Yoshimi Kuroiwa by e-mail at 
><mailto:YKuroiwa at Hematech.com>YKuroiwa at Hematech.com 
>or James Robl at 
><mailto:JRrobl at Hematech.com>JRRobl at Hematech.com 
>or Jürgen Richt at <mailto:JRicht at NADC.ARS.USDA.gov>JRicht at NADC.ARS.USDA.gov
>      *   On December 31, the USDA Agricultural 
> Research Service issued a News Release on the 
> letter, titled “USDA Researchers Evaluate 
> Prion-Free Cattle” which is posted at 
> <http://www.ars.usda.gov/is/pr/2006/061231.htm>http://www.ars.usda.gov/is/pr/2006/061231.htm 
>
>
>http://www.nature.com/nbt/journal/vaop/ncurrent/abs/nbt1271.html
>
>Letters
>
>Published online: 31 December 2006; | doi:10.1038/nbt1271
>
>Production of cattle lacking prion protein
>
>Jürgen A Richt1, 6, Poothappillai Kasinathan2, 
>Amir N Hamir1, Joaquin Castilla3, Thillai 
>Sathiyaseelan2, Francisco Vargas1, Janaki 
>Sathiyaseelan2, Hua Wu2, Hiroaki Matsushita2, 
>Julie Koster2, Shinichiro Kato4, 5, Isao 
>Ishida4, Claudio Soto3, James M Robl2 & Yoshimi Kuroiwa4, 5, 6
>
>1  National Animal Disease Center, Agriculture 
>Research Services, United States Department of 
>Agriculture, 2300 Dayton Avenue, Ames, Iowa 50010, USA.
>
>2  Hematech, Inc., 4401 S. Technology Drive, 
>Sioux Falls, South Dakota 57106, USA.
>
>3  Department of Neurology, University of Texas 
>Medical Branch, 301 University Boulevard, Galveston, Texas, 77555-0646, USA.
>
>4  Pharmaceutical Division, Kirin Brewery Co., 
>Ltd., 26-1, Jingumae 6-chome, Shibuya-ku, Tokyo, Japan.
>
>5  Gemini Science Inc., 9420 Athena Circle, La Jolla, California 92109, USA.
>
>6  These authors contributed equally to this work.
>
>Correspondence should be addressed to Yoshimi 
>Kuroiwa ykuroiwa at hematech.com or James M Robl 
>jrobl at hematech.com or Jürgen A Richt jricht at nadc.ars.usda.gov
>
>Prion diseases are caused by propagation of 
>misfolded forms of the normal cellular prion 
>protein PrPC, such as PrPBSE in bovine 
>spongiform encephalopathy (BSE) in cattle and 
>PrPCJD in Creutzfeldt-Jakob disease (CJD) in 
>humans1. Disruption of PrPC expression in mice, 
>a species that does not naturally contract prion 
>diseases, results in no apparent developmental 
>abnormalities2, 3, 4, 5. However, the impact of 
>ablating PrPC function in natural host species 
>of prion diseases is unknown. Here we report the 
>generation and characterization of 
>PrPC-deficient cattle produced by a sequential 
>gene-targeting system6. At over 20 months of 
>age, the cattle are clinically, physiologically, 
>histopathologically, immunologically and 
>reproductively normal. Brain tissue homogenates 
>are resistant to prion propagation in vitro as 
>assessed by protein misfolding cyclic 
>amplification7. PrPC-deficient cattle may be a 
>useful model for prion research and could 
>provide industrial bovine products free of prion proteins.
>
>end
>
>*****************
>
>http://www.ars.usda.gov/is/pr/2006/061231.htm
>
>USDA Researchers Evaluate Prion-Free Cattle
>
>By Sean Adams
>
>December 31, 2006
>
>WASHINGTON, Dec. 31—The U.S. Department of 
>Agriculture's Agricultural Research Service 
>(ARS) announced today that initial results of a 
>research project involving prion-free cattle are 
>now available online at www.nature.com/nbt/. ARS 
>scientists evaluated cattle that have been 
>genetically modified so they do not produce 
>prions, and determined that there were no 
>observable adverse effects on the animals' health.
>
>"These cattle can help in the exploration and 
>improved understanding of how prions function 
>and cause disease, especially with relation to 
>bovine spongiform encephalopathy, or BSE," said 
>Edward B. Knipling, administrator of ARS. "In 
>particular, cattle lacking the gene that 
>produces prions can help scientists test the 
>resistance to prion propagation, not only in the 
>laboratory, but in live animals as well."
>
>Prions are proteins that are naturally produced 
>in animals. An abnormal form of prion is 
>believed to cause devastating illnesses called 
>transmissible spongiform encephalopathies 
>(TSEs), the best known of which is BSE.
>
>ARS studied eight Holstein males that were 
>developed by Hematech Inc., a pharmaceutical 
>research company based in Sioux Falls, S.D. The 
>evaluation of the prion-free cattle was led by 
>veterinary medical officer Juergen Richt of ARS' 
>National Animal Disease Center (NADC) in Ames, 
>Iowa. The evaluation revealed no apparent 
>developmental abnormalities in the prion-free cattle.
>
>Richt said, "The cattle were monitored for 
>growth and general health status from birth up 
>to 19 months of age. Mean birth and daily gain 
>were both within the normal range for Holsteins. 
>General physical examinations, done at monthly 
>intervals by licensed veterinarians, revealed no unusual health problems."
>
>ARS, with assistance from researchers at 
>Hematech and the University of Texas, evaluated 
>the cattle using careful observation, 
>post-mortem examination of two of the animals, 
>and a technology that amplifies abnormal 
>proteins to make them easier to detect. Further 
>testing will take at least three years to complete.
>
>The evaluation was reported today in the online 
>version of the scientific journal Nature 
>Biotechnology. ARS is USDA's chief intramural scientific research agency.
>
>Last Modified: 12/31/2006
>
>
>
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