THE ROLE OF PLANTS AS AN ENVIRONMENTAL RESERVOIR OF CHRONIC WASTING DISEASE PRIONS

Ortega, Aimee

ABSTRACT:THE ROLE OF PLANTS AS AN ENVIRONMENTAL RESERVOIR OF CHRONIC WASTING DISEASE PRIONS Transmissible Spongiform Encephalopathies (TSEs) are a group of diseases caused by an abnormal version, PrPRES, of the normal cellular host protein prion protein (Prnp) termed PrPC. Disease is fatal resulIng in amyloid deposits and spongiform degeneraIon in the brain in most but not all cases. Clinical signs can include wasIng, increases in salivaIon, and general motor impairment but many other clinical signs exist and can vary between TSEs. PrPRES is incredibly resistant to degradaIon and can withstand radiaIon, formalin treatment, and autoclaving to name a few tried decontaminaIon methods whereas PrPC is degraded normally. This diﬀerence in degradaIon allows for diﬀerenIaIon between the two protein forms as PrPRES is resistant to degradaIon by Proteinase K. In the early 1980s this abnormal protein was discovered to be the sole causaIve agent of the various TSEs which at the Ime was a novel ﬁnding and a novel method of disease transmission. It is thought that slightly misfolded forms of PrPC occur which can then misfold further eventually forming PrPRES. PrPRES then has the ability to act as a template for conversion, converIng PrPC. Numerous TSEs exist that aﬀect both humans and a variety of animals. One of the animal TSEs is Chronic wasIng disease (CWD) which aﬀects cervids such as elk, deer, and moose (Cervus candensis, Odocoileus hemionus, Alces alces) and has become endemic in both free-‐ ranging and capIve herds. The exact mechanisms behind spread of CWD are unknown but research has shown that environmental reservoirs play a role in transmission dynamics. We chose to explore whether PrPRES can be detected on or inside grasses and plants naturally exposed to prions in CWD endemic areas by use of Protein Misfolding Cyclic AmpliﬁcaIon (PMCA). Here we present novel environmental evidence showing that PrPRES can be found on the surface of mulIple plants from Rocky Mountain NaIonal Park and mice inoculated with these samples are showing clinical signs of disease.