Scrapie and bovine spongiform encephalopathy: immunological properties and diagnosis for food products

Abstract

While spongiform encephalopathies do not cross, in principle, the species barrier in natural conditions, experimental transmission has been shown to be dependent of the host gene expressing the prion protein (PrPC). Cerebral and peritoneal routes are the most successful for experimental transmission, ie, from sheep to cow, but the oral route is the most probable for the natural transmission. In natural conditions there is no immune response in the infected but tolerant animal, whatever the species. It is possible to obtain specific polyclonal and monoclonal antibodies, which, however, do not distinguish PrPC from the disease-specific prion protein (PrPSC). Transmission of scrapie (SC) or bovine spongiform encephalopathy (BSE) to humans, either by meat or by milk, has not been demonstrated.