Prion hypothesis proven?

Protein aggregates generated in a test tube infected wildtype hamsters with a disease much like scrapie, according to an article appearing this week in Cell. Such a demonstration has, in the past, been called the gold standard of proof for the prion hypothesis, Stanley Prusiner's Nobel-winning assertion that infectious, self-replicating protein isoforms are the culprit in transmissible spongiform encephalopathies (TSEs) like scrapie, Creutzfeldt-Jakob disease, and mad cow disease.

Study coauthor Claudio Soto, said that this demonstration, together with a paper published by Prusiner's group last summer, should allay most doubts. "There is really little room for skepticism," he told The Scientist.

But the study has done little to quiet prion hypothesis skeptics. "I'm not going to abandon alternative hypotheses for the time being," said Robert A. Somerville of the Institute for Animal Health, Edinburgh.

While Prusiner's group had successfully infected a mouse with a recombinant protein derived from bacteria, some ...