PrPCWD in the myenteric plexus, vagosympathetic trunk and endocrine glands of deer with chronic wasting disease

Accumulated evidence in experimental and natural prion disease systems supports a neural route of infectious prion spread from peripheral sites of entry to the central nervous system. However, little is known about prion trafficking routes in cervids with a naturally occurring prion disease known as chronic wasting disease (CWD). In the brain, the pathogenic isoform of the prion protein (PrPCWD) accumulates initially in the dorsal motor nucleus of the vagus nerve. To assess whether alimentary-associated neural pathways may play a role in prion trafficking, neural and endocrine tissues from mule deer naturally infected with CWD (n = 6) were examined by immunohistochemistry. PrPCWD was detected in the myenteric plexus, vagosympathetic trunk, nodose ganglion, pituitary, adrenal medulla and pancreatic islets. No to scant Prp(CWD) staining was detected in other nerves or ganglia (brachial plexus, sciatic nerve, gasserian ganglion, coeliac ganglion, cranial cervical ganglion, spinal nerve roots) of CWD-positive deer and no PrPCWD was detected in nerves or endocrine tissues from I I control deer. These findings suggest that: (i) transit of PrPCWD in nerves, either centrifugally or centripetally, is one route of prion trafficking and organ invasion and (ii) endocrine organs may also be targets for cervid pathogenic prion accumulation.