Antemortem Detection and Conformational Switches of Prion Proteins

摘要

Blood from animals with prion disease contain low levels of prion infectivity, which primarily resides in the white blood cells (WBCs). We have developed a method that combines isolation of WBCs and cell blotting of PrPsc to detect individual cells that contain PrPsc. Sensitivity studies suggest that it can detect as low as 10 prion-infected cells in 5 x 105 WBCs. The assay is able to detect the prion-infected cells in the blood of some, but not all, prion-infected animals at the clinical stage. We believe that the combination of this method with a recently published successful cyclic amplification of protein misfolding (PMCA) procedure may give the required sensitivity for antemortem detection of prion in blood. In addition, a structure-activity relationship study of the fungal HET-s prion shows that a unique amyloid fibrillar structure is the infectious entity of the HET-s prion, and glycoform stoichiometry of host protein was found to regulate prion strain specificity.