Prions

Prions

1. History

   • 1730s
     • 1950s
       • 1960s
         • 1980s
           • 1982
             • 1985
               • 1986
                 • 1996
                   • A new variant of CJD is linked to exposure to BSE from British beef. By April 2005, 155 U.K. residents are dead. Because of the long incubation period, cases of CJD due to this incident will likely surface well into the future. The mad cow story isn't over yet.
                 • By the year 2000, nearly 180,000 cattle will become infected. To stop the spread, thousands of cattle are killed.
               • Scientists identify the PrP gene and discover that uninfected people produce a normal form of the PrP protein.
             • Dr. Stanley Prusiner coins the term "prion" (PROteinaceous INfectious particle). Highly purified PrP-res is shown to be infectious. He goes on to win the Nobel Prize in Medicine in 1997.
           • 60 people die from CJD after being infected by contaminated surgical instruments. 85 people die after receiving prion-infected growth hormone injections.
         • Scientists experimentally transmit Kuru and CJD to chimpanzees, demonstrating the transmissible nature of these diseases.
       • High levels of kuru appear among the Fore people of New Guinea.
     • Earliest written record of Scrapie in English sheep; already prevalent in central Europe.

2. Nature

   • Prions are PrP-sen into PrP-res.
     • scientists at the University of Texas performed this experiment successfully showing that PrP-res is indeed infectious
       • Questions still remain about what exactly triggers the folding of this protein.

3. Diseases

   • Classic CJD or Creutzfeldt-Jakob disease (human)
   • Fatal Familial Insomnia (human)
   • Scrapie (goats, sheep)
   • BSE or Bovine Spongiform Encephalopathy (cattle)
   • Chronic Wasting Disease (deer, elk)
   • Kuru (human)