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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #369550

Research Project: Immunodiagnostics to Detect Prions and Other Important Animal Pathogens

Location: Produce Safety and Microbiology Research

Title: Quantitating prion polymorphisms from heterozygous CWD-infected white-tailed deer

item Silva, Christopher - Chris
item Erickson-Beltran, Melissa
item DUQUE VELÁSQUEZ, CAMILO - University Of Alberta
item AIKEN, JUDD - University Of Alberta
item MCKENZIE, DEBBIE - University Of Alberta

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/23/2019
Publication Date: 10/25/2019
Citation: Silva, C.J., Erickson-Beltran, M.L., Duque Velásquez, C., Aiken, J.M., Mckenzie, D. 2019.Quantitating prion polymorphisms from heterozygous CWD-infected white-tailed deer [abstract]. 8th Iberian Congress on Prions. 8:33-33. ISBN: 978-972-579-050-2. October, 2019.

Interpretive Summary: N/A

Technical Abstract: Chronic wasting disease (CWD) is the only prion disease naturally transmitted among farmed and free-ranging cervids. By 2019, CWD-infected cervids had been detected in 26 states, three Canadian provinces, South Korea, Norway, Finland, and Sweden. Cervid PrPC contains at least 20 different polymorphic sites. Since the prion templated conformational conversion is influenced by PrPC, quantitating these polymorphisms is important. Two signal sequence polymorphisms are linked to PrPC polymorphisms, so they can also be quantitated. Chymotrypsin, trypsin, or trypsin/chymotrypsin was used to digest cervid PrP, resulting in a set of 18 peptides spanning the 20 polymorphic sites. These peptides are suitable for a mass spectrometry-based multiple reaction monitoring (MRM) analysis. Seven of the 18 peptides do not contain polymorphisms, so they can be used as internal standards to quantitate the relative amounts of the other, polymorphism-containing, peptides. The calibration curves relating the area ratios of the MRM signals from polymorphism-containing peptides to the internal standard peptides were linear and had excellent correlation coefficients. Samples from heterozygous (G96/S96 and Q95/H95) white-tailed deer orally dosed with homozygous (G96/G96) CWD were analyzed. The G96 polymorphism comprised 75 ± 5% of the total PrPSc from the G96/S96 heterozygotes. The same polymorphism comprised only 26 ± 5% of the Q95/H95 heterozygote’s PrPSc. Heterozygous deer facilitate conversion of different PrPC polymorphisms into PrPSc. This is significant for managing the spread of CWD. The relative amounts of the polymorphisms present in other heterozygous animal species and even humans can be quantitated using this approach.