De Novo Generation of Infectious Prions In Vitro Produces a New Disease Phenotype

PLoS Pathogens

Rodrigo Morales¹  Abhisek Mukherjee¹  Marcelo A. Barria²  Claudio Soto²  Dennisse Gonzalez-Romero² 

[1] Department of Neurology, University of Texas Houston Medical School, Houston, Texas, United States of America;George and Cynthia Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America

关键词: Prions;    Hamsters;    Prion diseases;    Animal prion diseases;    Brain damage;    Mouse models;    Animal behavior;    Equipment;   

DOI  :  10.1371/journal.ppat.1000421

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Prions are the proteinaceous infectious agents responsible for Transmissible Spongiform Encephalopathies. Compelling evidence supports the hypothesis that prions are composed exclusively of a misfolded version of the prion protein (PrPSc) that replicates in the body in the absence of nucleic acids by inducing the misfolding of the cellular prion protein (PrPC). The most common form of human prion disease is sporadic, which appears to have its origin in a low frequency event of spontaneous misfolding to generate the first PrPSc particle that then propagates as in the infectious form of the disease. The main goal of this study was to mimic an early event in the etiology of sporadic disease by attempting de novo generation of infectious PrPSc in vitro. For this purpose we analyzed in detail the possibility of spontaneous generation of PrPSc by the protein misfolding cyclic amplification (PMCA) procedure. Under standard PMCA conditions, and taking precautions to avoid cross-contamination, de novo generation of PrPSc was never observed, supporting the use of the technology for diagnostic applications. However, we report that PMCA can be modified to generate PrPSc in the absence of pre-existing PrPSc in different animal species at a low and variable rate. De novo generated PrPSc was infectious when inoculated into wild type hamsters, producing a new disease phenotype with unique clinical, neuropathological and biochemical features. Our results represent additional evidence in support of the prion hypothesis and provide a simple model to study the mechanism of sporadic prion disease. The findings also suggest that prion diversity is not restricted to those currently known, and that likely new forms of infectious protein foldings may be produced, resulting in novel disease phenotypes.

【 授权许可】

CC BY