Detection of Disease-Associated Prion Protein in the Posterior Portion of the Small Intestine Involving the Continuous Peyer’s Patch in Cattle Orally Infected with Bovine Spongiform Encephalopathy Agent

Abstract

Twenty-eight calves were exposed to 5 g of homogenized brainstems confirmed as bovine spongiform encephalopathy (BSE) agents. Two to five animals were sequentially killed for post-mortem analyses 20 months post-inoculation (MPI) at intervals of 6 or 12 months. Samples from animals challenged orally with BSE agents were examined by Western blot and immunohistochemical analyses. Immunolabelled, disease-associated prion protein (PrPsc) was detected in a small portion of follicles in the continuous Peyer's patch from the posterior portion of the small intestine involving the entire ileum and the posterior jejunum but not in the discrete Peyer's patches in the remaining jejunum in preclinical animals at 20, 36, and 48 MPI. The PrPsc-positive cells corresponded to tingible body macrophages on double immunofluorescence labelling. In addition, PrPsc accumulated in 7 of 14 animals in the central nervous system (CNS) after 34 MPI, and five of them developed clinical signs and were killed at 34, 46, 58, and 66 MPI. Two preclinical animals killed at 36 and 48 MPI presented the earliest detectable and smallest deposition of immunolabelled PrPsc in the dorsal motor nucleus of the vagus nerve, the spinal trigeminal nucleus of the medulla oblongata at the obex region, and/or the intermediolateral nucleus of the 13th thoracic segment of the spinal cord. Based on serial killing, no PrPsc was detectable in the CNS, including the medulla oblongata at the obex level, before 30 MPI, by Western blot and immunohistochemical analyses. These results are important for understanding the pathogenesis of BSE.

Prion in Saliva of Bovine Spongiform Encephalopathy–Infected Cattle

“…We then diluted the concentrated samples 1:10 with the normal isoform of prion protein substrate containing 0.5% potassium dextran sulfate. Using the sPMCA technique as described (1), we amplifi ed the samples in 3-8 tubes, and we used Western blot to analyze the proteinase K-treated sPMCA products (2).…”

“…infection represents a major public health problem in the United States; nearly 1.4 million human cases and 600 associated deaths are reported each year (1). Reptile and amphibian exposures might cause >70,000 of these cases annually (2). Furthermore, children are at increased risk of acquir-…”

Minimal Involvement of the Circumventricular Organs in the Pathogenesis of Spontaneously Arising and Experimentally Induced Classical Bovine Spongiform Encephalopathy

“…It is restricted to the Peyer's patches of the ileum (Terry et al, 2003;Hoffmann et al, 2011) and the jejunum of orally-dosed animals (Hoffmann et al, 2011;Okada et al, 2011;Stack et al, 2011), and to the ENS of a proportion of clinically-ill spontaneously infected BSE cases (Terry et al, 2003;Iwata et al, 2006). Bioassay in conventional or transgenic mice with peripheral tissues from orally-dosed cattle has resulted in infectivity being detected, in addition to the distal ileum and jejunum (Wells et al, 1994(Wells et al, , 1998Hoffmann et al, 2011), in the palatine tonsil at 10 (Wells et al, 2005) or 20 (Espinosa et al, 2007) months post challenge, still during the preclinical period.…”

“…The ability of the BSE agent to cross the species barrier has been documented by the natural occurrence of BSE-like conditions in felids (Wyatt et al, 1991;Kirkwood et al, 1995;Hilbe et al, 2009) and ungulates other than cattle (Jeffrey and Wells, 1988;Kirkwood et al, 1993;Eloit et al, 2005;Seuberlich et al, 2006), and also by successful experimental transmissions to a wide variety of mammals including amongst others, wild type mice (Bruce, 2003), sheep and goats (Foster et al, 1993), pigs (Dawson et al, 1990) and red deer (Dagleish et al, 2008;Martin et al, 2009). Despite the fact that BSE is considered to be caused by a single, stable agent, its pathogenesis differs significantly depending on the host species (Bruce, 2003).…”

Consideration of Risk Variations in Japan Derived from the Proposed Revisions of the Current Countermeasures against BSE

“…The average incubation period in the CPP-inoculated mice was 248.9 ± 14.4 days. On the other hand, mice inoculated with DPPs showed no infectivity and survived for 650 days 31) .…”