Highly efficient amplification of chronic wasting disease agent by protein misfolding cyclical amplification with beads (PMCAb)

PLoS ONE
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Abstract

Protein misfolding cyclic amplification (PMCA) has emerged as an important technique for detecting low levels of pathogenic prion protein in biological samples. The method exploits the ability of the pathogenic prion protein to convert the normal prion protein to a proteinase K-resistant conformation. Inclusion of Teflon® beads in the PMCA reaction (PMCAb) has been previously shown to increase the sensitivity and robustness of detection for the 263 K and SSLOW strains of hamster-adapted prions. Here, we demonstrate that PMCAb with saponin dramatically increases the sensitivity of detection for chronic wasting disease (CWD) agent without compromising the specificity of the assay (i.e., no false positive results). Addition of Teflon® beads increased the robustness of the PMCA reaction, resulting in a decrease in the variability of PMCA results. Three rounds of serial PMCAb allowed detection of CWD agent from a 6.7×10−13 dilution of 10% brain homogenate (1.3 fg of source brain). Titration of the same brain homogenate in transgenic mice expressing cervid prion protein (Tg(CerPrP)1536+/−mice) allowed detection of CWD agent from the 10−6 dilution of 10% brain homogenate. PMCAb is, thus, more sensitive than bioassay in transgenic mice by a factor exceeding 105. Additionally, we are able to amplify CWD agent from brain tissue and lymph nodes of CWD-positive white-tailed deer having Prnp alleles associated with reduced disease susceptibility.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Highly efficient amplification of chronic wasting disease agent by protein misfolding cyclical amplification with beads (PMCAb)
Series title PLoS ONE
DOI 10.1371/journal.pone.0035383
Volume 7
Issue 4
Year Published 2012
Language English
Publisher PLOS
Contributing office(s) Coop Res Unit Leetown
Description e35383; 7 p.
Online Only (Y/N) N
Additional Online Files (Y/N) N