Surveillance of chronic wasting disease (CWD) in Japan
Kimi Shimada^Yoshifumi Iwamaru^ Hiroko Hayashi^ Morikazu Ima- mura^ Masuhiro Takata\ Yuko K. Ushiki\ Kumiko M. Kimura\ Yuichi Tagawa^ Motohiro Horiuchi^, Morikazu Shinagawa^ and Takashi Yoko- yama^
^Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba 305-0856 Japan ^Hokkaido University
<e-mail> [email protected]
Abstract
Chronic wasting disease (CWD) in cervids including elk, mule deer, and white-tailed deer, is a member of the transmissible spongiform encephalo- pathies (TSEs). CWD is a serious problem in North America. The de- tection of abnormal isoforms of prion protein (PrP^^) is a key factor for the diagnosis of CWD, similar to other TSEs. The surveillance program for TSEs in animals is conducted by the Ministry of Agriculture, Forestry, and Fishery (MAFF) and is targeted to sheep, goats, and deer. In Japan, sev- eral different anti-prion protein (PrP) monoclonal antibodies (mAbs) are utilized for bovine spongiform encephalopathy (BSE) confirmation.
Since CWD does not occur naturally in Japan, the immunoreactivity of the antibodies against PrP^^ found in deer was not known. In this study, we examined the immunoreactivities of these antibodies against PrP^^ found in CWD. The protocols that are used in Japan for confirmation of BSE cases are Western blot (WB) and immunohistochemistry (IHC). We used these same protocols to examine CWD positive brain samples which were provided by Dr. A. Davis of the National Veterinary Service Laboratory, USA. Mabs. Tl, T2, 44B1, and 72-5, were used successfully to detect PrP^' in CWD affected mule deer brains by WB. In IHC, PrP^' was de- tected with mAbs T2, 44B1, and polyclonal antibody B103. These re- sults determined that the antibodies used for BSE confirmation are also applicable to CWD, as for scrapie. These same antibodies could detect PrP^ from Japanese deer by WB without proteinase digestion. The amino acid sequence of PrP of Japanese deer was found to be the same as se- quence as the one reported for mule deer. These antibodies were then
171
172
