上海交通大学：《医学微生物》课程教学资源（PPT课件讲稿）英文版 Similar to Viruses Atypical Agents

Prion

Prion

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

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

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

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

▪ 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 CUD(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

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

PRION PROTEIN(PrP) PrP PrPRES or PrPSc alpha- helical beta-pleated sheet protease sensitive protease resistant Helical- Happy Beta-pleated sheet-Bad

Simplified model for prion disease PrP PrPSC

Simplified model for prion disease

How can this model explain the sporadic, acquired or inherited form of the disease spontaneous conversion SPORADIC acquired conversion ACQUIRED acquired PrP germline mutation, spontaneous conversion more likely < INHERITED matic mutation, spontaneous conversion more likely SPORADIC

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

hy are there differences in prion diseases? PrP PrPSC PrP PrPs

Why are there differences in prion diseases?

germline mutation 1 INHERITED germline mutation 2 INHERITED disease caused by germline mutation 1 may differ from that caused by germline mutation 2