PrPSc formation and clearance as determinants of prion tropism

PLoS Pathogens

Jonathan Trinh¹  Ronald A. Shikiya¹  Thomas E. Eckland¹  Sara A. M. Holec¹  Anthony E. Kincaid¹  Katie A. Langenfeld¹  Candace K. Mathiason²  Jason C. Bartz³ 

[1] Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America;Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America;Department of Pharmacy Science, Creighton University, Omaha, Nebraska, United States of America

关键词: Hamsters;    Spleen;    Animal prion diseases;    Prion diseases;    Tropism;    Respiratory infections;    Lymph nodes;    Cofactors (biochemistry);   

DOI  :  10.1371/journal.ppat.1006298

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Prion strains are characterized by strain-specific differences in neuropathology but can also differ in incubation period, clinical disease, host-range and tissue tropism. The hyper (HY) and drowsy (DY) strains of hamster-adapted transmissible mink encephalopathy (TME) differ in tissue tropism and susceptibility to infection by extraneural routes of infection. Notably, DY TME is not detected in the secondary lymphoreticular system (LRS) tissues of infected hosts regardless of the route of inoculation. We found that similar to the lymphotropic strain HY TME, DY TME crosses mucosal epithelia, enters draining lymphatic vessels in underlying laminae propriae, and is transported to LRS tissues. Since DY TME causes disease once it enters the peripheral nervous system, the restriction in DY TME pathogenesis is due to its inability to establish infection in LRS tissues, not a failure of transport. To determine if LRS tissues can support DY TME formation, we performed protein misfolding cyclic amplification using DY PrPSc as the seed and spleen homogenate as the source of PrPC. We found that the spleen environment can support DY PrPSc formation, although at lower rates compared to lymphotropic strains, suggesting that the failure of DY TME to establish infection in the spleen is not due to the absence of a strain-specific conversion cofactor. Finally, we provide evidence that DY PrPSc is more susceptible to degradation when compared to PrPSc from other lymphotrophic strains. We hypothesize that the relative rates of PrPSc formation and clearance can influence prion tropism.

【 授权许可】

CC BY