title: [Unconventional transmissible agents or prions].
abstract: NEUROGENERATIVE DISEASES: Unconventional transmissible agents or prions cause subacute transmissible spongiform encephalopathies (TSE) in man and animals. These rare neurological diseases have a long incubation period. The only clinical manifestations are signs of central nervous system deficits.
  
  
  RESULTS
  There are three characteristics features vacuolization of the cerebral cortex, neuronal loss and astrogliosis. A host protein, the PrP (prion protein) accumulates in the central nervous system of infected individuals in quantities proportional to the titer of the infectious agent. The gene coding for the PrP is the main factor determining genetic susceptibility to unconventional transmissible agents. THE TRANSMISSIBLE AGENT: The exact nature of these unconventional transmissible agents remains a question of debate. For certain authors, prions are proteins totally devoid of nucleic genomes, being composed entirely by a particular pathogenic form of the protease-resistant PrP protein. For others, the structure is more conventional, containing an independent genome, the PrP being the recepto and virulence factor.
authors.affiliation: Service de Neurovirologie, Commissariat à l'Energie atomique, Centre de recherches du Service de Santé des Armées, Fontenay-aux-Roses.
authors.forename: D
authors.initials: D
authors.lastname: Dormont
mesh_terms: D000818:Animals; D006801:Humans; D017096:Prion Diseases / Q000235:genetics / Q000378:metabolism / Q000635:transmission*; D011328:Prions / Q000737:chemistry
chemical_list: D011328:Prions