Dynamic analyses of PrP and PrP(Sc) in brain tissues of golden hamsters infected with scrapie strain 263K revealed various PrP forms.
OBJECTIVE
To expatiate dynamic changes in hamsters infected with scrapie strain 263K, to observe the presence and aggravation of various forms of PrP and PrP(Sc) during incubation period, and to probe primarily the relationship between the onset of clinic manifestations and the presence of different PrP(Sc) forms.


METHODS
Hamster-adapted scrapie strain 263K was intracerebrally inoculated into hamsters. Different forms of PrP and PrP(Sc) were monitored dynamically by Western blot and immuno-histochemical assays. The presence of scrapie-associated fibril (SAF) was assayed by electron microscopy analysis (EM) and immuno-golden EM.


RESULTS
PrP(Sc) was initially detected in the brain tissues of the animals in 20 days post-inoculation by immunohistochemistry and 40 days with Western blot. Quantitative evaluations revealed that the amounts of PrP and PrP(Sc) in brain tissues increased along with the incubation. Several high and low molecular masses of PrP were seen in the brains of the long-life span infected animals. Deglycosylation assays identified that the truncated PrP in the infected brains showed similar glycosylation patterns as the full-length PrP. The presence of short fragments was seemed to relate with the onset of clinical conditions.


CONCLUSIONS
These results indicate that infectious agents exist and accumulate in central nerve system prior to the onset of the illness. Various molecular patterns of PrP(Sc) may indwell in brain tissues during the infection.
Gao
Jian-Mei
JM
National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Yingxin Rd. 100, Beijing 100052, China.
Gao
Chen
C
Han
Jun
J
Zhou
Xiao-Bo
XB
Xiao
Xin-Li
XL
Zhang
Jin
J
Chen
Lan
L
Zhang
Bao-Yun
BY
Hong
Tao
T
Dong
Xiao-Ping
XP
D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D006031:Glycosylation; D007150:Immunohistochemistry; D008647:Mesocricetus; D008854:Microscopy, Electron; D018622:PrP 27-30 Protein / Q000032:analysis / Q000378:metabolism; D018621:PrPC Proteins / Q000032:analysis* / Q000378:metabolism; D018620:PrPSc Proteins / Q000032:analysis* / Q000378:metabolism; D012608:Scrapie / Q000378:metabolism* / Q000473:pathology
D018621:PrPC Proteins; D018620:PrPSc Proteins; D018622:PrP 27-30 Protein