From: TSS (216-119-132-53.ipset12.wt.net)
Subject: Update on Creutzfeldt-Jakob disease
Date: December 13, 2004 at 8:20 am PST
Update on Creutzfeldt-Jakob disease.
Current Opinion in Neurology. 17(6):641-647, December 2004.
Mallucci, Giovanna; Collinge, John
Purpose of review: Prion diseases are transmissible fatal
neurodegenerative disorders in which infectivity is associated with
the accumulation of PrPSc, a disease-related isoform of normal
cellular prion protein. The recent emergence of variant
Creutzfeldt-Jakob disease has led to major public health concerns,
and the need for the development of effective treatments. As PrPSc
is associated both with pathology and infectivity, therapeutic
approaches to date have largely aimed at preventing its
accumulation, but this strategy has produced only modest results in
animal models. The link between PrPSc and neurotoxicity is unclear,
and alternative pathological processes need to be considered. Here
we focus on the latest progress in therapeutic strategies and
potential mechanisms of prion neurotoxicity.
Recent findings: Passive immunisation with anti-prion protein
antibodies prevents peripheral prion replication and blocks
progression to clinical disease in peripherally infected mice. A new
approach, in which neuronal cellular prion protein is depleted in
mice with established neuroinvasive prion infection, prevents the
onset of clinical disease, blocks neuronal cell loss and reverses
early spongiform pathology. This dramatic protective effect occurs
despite the continued build-up of extraneuronal PrPSc and continued
replication of prion infectivity, effectively producing a
Summary: New insights into the mechanisms of neurotoxicity in prion
diseases support the concept that PrPSc itself is not directly
neurotoxic. They suggest that neuronal prion propagation results in
the production of a toxic intermediate or depletion of a key
constituent. Prevention of the formation of such a species rather
than PrPSc accumulation itself is a clear target for prion therapeutics.
(C) 2004 Lippincott Williams & Wilkins, Inc.