Prion diseases are characterized by the prominent accumulation of the misfolded form (PrPSc) of a normal cellular protein referred to as cellular prion protein (PrPC) in the central nervous system. The pathological features attributable to and biochemical properties of PrPSc in macaque monkeys infected with bovine spongiform encephalopathy (BSE) prions have been found to be similar to those of human subjects with variant Creutzfeldt-Jakob disease (vCJD). In the current study, we developed a highly efficient method for in vitro amplification of cynomolgus macaque BSE PrPSc. This method involves amplifying PrPSc by protein misfolding cyclic amplification (PMCA) using mouse brain homogenate as a PrPC substrate in the presence of sulphated dextran compounds. This method can be used to amplify very small amounts of PrPSc present in the cerebrospinal fluid (CSF) and white blood cells (WBCs), as well as in the peripheral tissues of macaques that have been intracerebrally inoculated with BSE prions. After clinical signs of the disease appeared in three macaques, we detected PrPSc in the CSF by serial PMCA, and the PrPSc levels in CSF tended to increase with disease progression. In addition, PrPSc was detectable in WBCs during the clinical phases of the disease in two of the three macaques. Thus, our highly sensitive, novel method may be useful for furthering the understanding of the tissue distribution of PrPSc in nonhuman primate models of CJD.
(Influenza and Prion Disease Research Center)
Murayama Y. et al (2014) J. Gen. Virol. 95(11):2576-2588