|Knowles Jr, Donald|
Submitted to: Emerging Infectious Diseases
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2000
Publication Date: N/A
Technical Abstract: Scrapie is a fatal neurodegenerative disorder of sheep and goats and may be transmitted through reproduction. However, PrP in the reproductive tract is less well defined than Prp in brain. This study evaluated PrP in placental cotyledon(PC) and uterine caruncle(UC) of pregnant ewes with clinical scrapie. Homogenates(H) of PC or UC with or without centrifugations in 10% %sarkosyl were analyzed by Western blot using Mabs to N- (Mab 5B2) and C-termini (Mab 99) of Prp before and after treatments with PNGase F or PK. As expected, three PrP isoforms were detected in the brain. These isoforms corresponded to di-, mono- and un-glycosylated PrP with apparent MWs of ~37, ~33 and ~29 kDa and were resistant to PK. In contrast, two PrP isoforms with MWs of ~32 and ~28 kDa were detected by Mab 99 in PC and UC H of infected and uninfected ewes. The 28 kDa PrP was the predominant form detected in PC, whereas UC contained both. PC and UC PrP were glycosylated das shown by reduction of apparent MW to ~20 kDa when treated with PNGase F Glycosylated PC and UC PrP (32 and 28 kDa) were truncated at at N-terminus (N-T) as shown by lack of reactivity to Mab 5B2. Neither of these PrPs was resistant to PK. When PC and UC H were prepared by centrifugation with sarkosyl, a unglycosylated PK sensitive PrP of 27kDa was detected. This PrP was also truncated at N-T. These results show that PC and UC from infected and uninfected ewes contain high levels of glycosylated truncated PrP compared to unglycosylated truncated PrP, but no detectable glycosylated or unglycosylated full length PrP. This issue specific differential processing of PrP in brain, uterus and placenta may provide a useful model for other prion diseases in which extraneural accumulation of PrP occurs.