14 Jun 2001

Abnormal forms of the prion protein are thought to be the infective agent responsible for bovine spongiform encephalopathy (BSE, or "mad cow disease") and its human form, variant Creutzfeldt-Jakob disease (vCJD). The pathogenic prion can spread disease through contaminated beef products as well as though human blood and tissue. The protein is expressed highly only in the brain, and the lack of methods to detect the low amounts in blood and other tissues has fueled public alarm over the potential spread of vCJD. In this week's Nature Claudio Soto and colleagues at the Serono Pharmaceutical Research Institute in Geneva, Switzerland, describe a method by which the abnormal, pathogenic form of the prion protein can convert large amounts of normal prion into the abnormal state. The method could form the basis for a test to detect trace amounts of infective prion in the blood of infected animals or humans. The technique could also be used to produce large quantities of abnormal prion protein in the test tube, enabling the prion to be studies with greater ease.—June Kinoshita