Transmissible spongiform encephalopathy historical perspective

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rinky Agnes Botleroo, M.B.B.S.

Overview[edit | edit source]

Prion diseases are a group of neurodegenerative disorders which include Kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker (GSS) syndrome, and fatal familial insomnia in men, natural scrapie in sheep and goats, transmissible mink encephalopathy in ranch-reared mink, chronic wasting disease of mule deer, Bovine Spongiform Encephalopathy or "Mad Cow disease".Scarpie was fiirst described in 1732.Kuru is the first recognized prion disease in humans which was described in1957. Gajdusek, Gibbs and his colleagues demonstrated its transmissibility in 1965 .Later on, they also described the transmission of Creutzfeldt-Jakob disease (CJD) and Gerstmann-Sträussler-Scheinker. In 1982, Stanley B. Prusiner presented "prion hypothesis" which explains that a misfolded protein is responsible for the pathogenesis of prion diseases.

Historical Perspective[edit | edit source]

• Natural Scrapie^[1] is a infection that affects sheep and it is caused by an unknown infectious agent.
• It was first recognized in 1732.
• Kuru is the first prion disease in humans which was described in 1957.It is a fatal neurodegenerative disease that affected only people of a single language group in the remote mountainous interior of New Guinea.
• In 1959, veterinary pathologist W.J. Hadlow first described several similarities between Scrapie and Kuru.
• In 1959, I. Klatzo also recognized that Kuru's histopathology was similar to that of Creutzfeldt-Jakob disease (CJD).
• Creutzfeldt-Jakob disease (CJD) is another neurodegenerative progressive disease of unknown etiology that A.M. Jakob had first described in 1921.^[2]It is fatal.
• Gajdusek, C.J. Gibbs, Jr., and M.P. Alpers used the existing knowledge of Scrapie and started trials to transmit Kuru by inoculating Kuru brain tissue into non-human primates, It took them several years but finally they became successful in 1965.
• Later Gajdusek and his colleagues went on to demonstrate that not only the more common sporadic form of Creutzfeldt-Jakob disease (CJD) but also familial Creutzfeldt-Jakob disease (CJD) and a generally similar familial brain disease (Gerstmann-Sträussler-Scheinker syndrome) were also transmissible, first to non-human primates and later to other animals.^[2]
• In 1982, ^[1]Stanley B. Prusiner presented "prion hypothesis". Prusiner discovered that a misfolded form of a ubiquitous normal host protein usually but not all the time was detectable in tissues containing TSE agents.
• These misfolded proteins greatly helps in in understanding their pathogenesis and also in confirming the diagnosis.
• Prusiner also explained that the TSE agent was likely to be composed partially of an abnormal protein, for which he used the term "prion" protein.
• Expression of the prion protein by animals-while not essential for life-was later found to be compulsory to infect them with TSEs

References[edit | edit source]

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