Abstract

Scrapie is a transmissible spongiform encephalopathy with a wide PrPres dissemination in many non-neural tissues and with high levels of transmissibility within susceptible populations. Mechanisms of transmission are incompletely understood. It is generally assumed that it is horizontally transmitted by direct contact between animals or indirectly through the environment, where scrapie can remain infectious for years. In contrast, in utero vertical transmission has never been demonstrated and has rarely been studied. Recently, the use of the protein misfolding cyclic amplification technique (PMCA) has allowed prion detection in various tissues and excretions in which PrPres levels have been undetectable by traditional assays. The main goal of this study was to detect PrPres in fetal tissues and the amniotic fluid from natural scrapie infected ewes using the PMCA technique. Six fetuses from three infected pregnant ewes in an advanced clinical stage of the disease were included in the study. From each fetus, amniotic fluid, brain, spleen, ileo-cecal valve and retropharyngeal lymph node samples were collected and analyzed using Western blotting and PMCA. Although all samples were negative using Western blotting, PrPres was detected after in vitro amplification. Our results represent the first time the biochemical detection of prions in fetal tissues, suggesting that the in utero transmission of scrapie in natural infected sheep might be possible.

Highlights

  • Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases that affect both humans and animals

  • Most TSE diagnostic techniques are based on the immunodetection of PrPres in extracts or tissue sections of the central nervous system (CNS), mainly by Western blotting (WB), immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA)

  • Scrapie is associated with high levels of transmissibility within susceptible populations

Read more

Summary

Introduction

Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases that affect both humans and animals. TSEs are characterized by long incubation periods, brain vacuolation and the accumulation of an abnormal isoform (PrPres) of a normal cellular protein (PrPc), mainly in nervous tissues. This abnormal protein is considered the only reliable biochemical disease marker [1]. Scrapie is a TSE that affects sheep and goats This disease is associated with a wide PrPres dissemination in many non-neural tissues, including the lymphoreticular system and the placenta [2,3], and with high levels of transmissibility within susceptible populations, the mechanisms of transmission are not completely understood. Placentas from susceptible infected animals may harbor a high amount of PrPres and high levels of infectivity [6] when the fetus presents a susceptible PrP genotype [7,8,9]

Objectives
Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call