Prion

Similar to Viruses Atypical Agents  Small  Filterable  Need host cells  No machinery for energy generation of protein synthesis

Different from viruses  No dectectable virions in infected tissues  No detectable virions in purified infectious material  If nucleic acid is present, very small  Very resistant

 Resistant to or only partially inactivated by 1. Formaldehyde 2. Ethanol 3. Glutaraldehyde 4. Ultraviolet and ionizing irradiation 5. Non-ionic detergents  Inactivated by 1. Autoclaving 2. 5%sodium hypochlorite 3. Sodium hydroxide 4. Proteases, urea, other protein denaturants

Pathogensis  Kuru  CJD(Creutzfeldt Jakob disease)  GSS(Gerstmann Straussler-Scheinker syndrome)  FFI(Fetal familial insomnia)  Scrapie(sheep and goats)  Bovine spongiform encephalopathy  Transmissible mink encephalopathy  Chronic wasting disease of mule deer

Simplified model for prion disease.

How can this model explain the sporadic, acquired or inherited form of the disease?

Why are there differences in prion diseases?