Thursday, August 15, 2013
AD.56: The emergence of novel BSE prions by serial passages of H-type BSE in bovinized mice
Kentaro Masujin, Naoko Tabeta, Ritsuko Miwa, Kohtaro Miyazawa, Hiroyuki Okada, Shirou Mohri and Takashi Yokoyama
National Institute of Animal Health; Tsukuba, Japan
H-type bovine spongiform encephalopathy (BSE) is an atypical form of BSE, and has been detected in several European countries, and North America. Transmission studies of H-type BSE led to the emergence of the classical BSE (C-BSE) phenotypes during passages in inbred wild type and bovinized PrP-overexpressing transgenic mice. In this study, we conducted serial passages of Canadian H-type BSE isolate in bovinized PrP-overexpressing transgenic mice (TgBoPrP). H-type BSE isolate was transmitted to TgBoPrP with incubation periods of 320 ± 12.2 d at primary passage. The incubation period of 2nd and 3rd passage were constant (~= 220 d), no clear differences were observed in their biological and biochemical properties. However, at the forth passage, 2 different BSE phenotypes were confirmed; one is shorter survival times (109 ± 4 d) and the other is longer survival times. TgBoPrP mice with longer incubation period showed the H-type phenotype of PrPsc profile and pathology. However, those of shorter incubation period were different phenotypes from previously existed BSE prions (C-BSE, L-type BSE, and H-type BSE). *** This study imply the possibility that the novel BSE prions with high virulence in cattle will be emerged during intraspecies transmission.
Saturday, July 6, 2013
Small Ruminant Nor98 Prions Share Biochemical Features with Human Gerstmann-Sträussler-Scheinker Disease and Variably Protease-Sensitive Prionopathy