Prp-c and Prp-Sc at the fetal-maternal interface

Area of Science:

• Veterinary Pathology
• Neurodegenerative Diseases
• Prion Biology

Background:

• Scrapie is a fatal, naturally occurring prion disease affecting sheep and goats.
• Transmission is suspected via exposure to the scrapie agent in placental tissues of infected ewes.
• Understanding prion distribution is crucial for disease control and prevention strategies.

Purpose of the Study:

• To determine the distribution and biochemical characteristics of PrP cellular (PrP-C) in ovine reproductive and placental tissues.
• To map the distribution of the infectious PrP scrapie (PrP-Sc) form within these tissues during pregnancy.
• To assess the potential for in utero scrapie transmission to the ovine embryo/fetus.

Main Methods:

• Immunohistochemical analysis to detect PrP-C and PrP-Sc.
• Biochemical characterization including proteinase K digestion and molecular mass determination.
• Examination of reproductive organs, placental tissues, fetal tissues, and fetal fluids from pregnant and non-pregnant sheep.

Main Results:

• PrP-C was detected in various reproductive, placental, and fetal tissues, with higher concentrations in cotyledonary chorioallantois, allantoic fluid, and caruncular endometrium of pregnant ewes.
• Caruncular endometrial PrP-C levels increased during pregnancy.
• PrP-Sc was exclusively found in the caruncular endometrium and cotyledonary chorioallantois of infected pregnant ewes.

Conclusions:

• PrP-Sc is localized to specific maternal reproductive tissues, not widely distributed throughout the reproductive tract or fetal fluids.
• The amnion, which physically separates the fetus from the placenta, tested negative for PrP-Sc.
• These findings suggest that the ovine fetus is likely protected from scrapie exposure in utero.