Fig 4.
87V mouse scrapie does not induce persistent PrPSc formation in CF10+Mo3F4 cells but can efficiently convert Mo3F4 PrPC to protease resistance. (A) CF10+Mo3F4 cells (15) were exposed to 1% normal mouse brain homogenate (NBH) or 1% brain homogenates from mice infected with scrapie strains 22L and 87V. After 12 passages (22L and 87V) or 13 passages (normal mouse brain homogenate), the cells were analyzed by immunoblotting for PrPSc using anti-PrP mouse monoclonal antibody 3F4. Only cells exposed to the 22L mouse scrapie brain homogenate were positive for PrPSc. Molecular mass markers in kilodaltons are shown on the left. (B) Brain homogenates from mice infected with 22L or 87V scrapie as well as normal brain homogenate were mixed with homogenates from CF10+Mo3F4 cells (Mo3F4) or CF10 cells (Vector). After 4 days, the reaction mixtures were treated with PK and analyzed for total PrPSc by using mouse monoclonal antibody 6D11 (top) and for newly formed PrPSc by using mouse monoclonal antibody 3F4 (bottom). Molecular mass markers in kilodaltons are shown on the right.