Foreign PrP expression and scrapie infection in tissue culture cell lines

PrP expression and scrapie infectivity was studied in a group of tissue culture cell lines from mice, hamsters, rats and humans. Cell surface PrP protein was detected in seven of ten cell lines from a variety of tissues and showed both cell surface and cytoplasmic perinuclear distributions. Mouse N2a neuroblastoma cells could be persistently infected with scrapie in vitro, but OBL-21 mouse neuroma cells were never successfully infected. Foreign PrP molecules including hamster PrP, mutant hamster PrP with leucine at amino acid 102, and mutant mouse PrP expressing a hamster-encoded PrP antigen epitope were expressed in mouse N2a cells. However, none of these cell lines could be successfully infected with the 263K hamster scrapie agent. Furthermore, expression of these foreign PrP molecules did not lead to spontaneous generation of protease-resistant PrP or a transmissible scrapie-like agent in vitro.