Compelling transgenetic evidence for transmission of bovine spongiform encephalopathy prions to humans

There is growing concern that bovine spongiform encephalopathy (BSE) may ha ve passed from cattle to humans. We report here that transgenic (Tg) mice e xpressing bovine (Bo) prion protein (PrP) serially propagate BSE prions and that there is no species barrier for transmission from cattle to Tg(BoPrP) mice. These same mice were also highly susceptible to a new variant of Cre utzfeldt-Jakob disease (nvCJD) and natural sheep scrapie, The incubation ti mes (approximate to 250 days), neuropathology, and disease-causing PrP isof orms in Tg(BoPrP)Prnp(0/0) mice inoculated with nvCJD and BSE brain extract s were indistinguishable and differed dramatically from those seen in these mice injected with natural scrapie prions, Our findings provide the most c ompelling evidence to date that prions from cattle with BSE have infected h umans and caused fatal neurodegeneration.