Effect of Nitrogen Gas Plasma Generated by a Fast-Pulsed Power Supply Using a Static Induction Thyristor on Scrapie Prion.

Akikazu Sakudo,Yuichiro Imanishi,Azumi Hirata,Yuichi Koga,Hideharu Shintani

doi:10.3390/pathogens9100819

Abstract

Previous studies show that nitrogen gas plasma generated by a fast-pulsed power supply using a static induction thyristor has both virucidal and bactericidal effects. In this study, nitrogen gas plasma was further evaluated for its potential effects on prions, which are well known to be the most resistant pathogen to both chemical and physical inactivation. Aliquots (10 μL) of mouse brain homogenate infected with Chandler scrapie prion were spotted onto cover glasses and subjected to nitrogen gas plasma. Treated samples were recovered and subjected to further analyses. Control prion samples were prepared in exactly the same way but without plasma treatment. Protein misfolding cyclic amplification (PMCA) showed that nitrogen gas plasma treatment at 1.5 kilo pulse per second for 15 or 30 min caused a reduction in the in vitro propagation level of PrPres (proteinase K-resistant prion protein), which was used as an index of abnormal prion protein (PrPSc). Moreover, mice injected with prion treated with plasma for 30 min showed longer survival than mice injected with control prion, indicating that nitrogen gas plasma treatment decreased prion infectivity. Altogether, these results suggest that nitrogen gas plasma treatment can inactivate scrapie prions by decreasing the propagation activity and infectivity of PrPSc.

Highlights

Proteinaceous infectious particles or “prions” cause transmissible spongiform encephalopathies (TSEs) or prion diseases (PDs), including scrapie in small ruminants, bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeldt–Jakob disease (CJD) in humans [1,2,3]
We applied the BLP–TES device to the nitrogen gas plasma treatment of prion derived from Chandler scrapie prion-infected mouse brain homogenate
We analyzed the effect of nitrogen gas plasma as a potential disinfection method for the scrapie prion agent

Summary

Introduction

Proteinaceous infectious particles or “prions” cause transmissible spongiform encephalopathies (TSEs) or prion diseases (PDs), including scrapie in small ruminants, bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeldt–Jakob disease (CJD) in humans [1,2,3]. The major component of prions is an abnormal isoform of prion protein (PrPSc ). Conversion of the cellular isoform of prion protein (PrPC ). To the conformationally refolded, β-sheet-rich isoform PrPSc is a critical event in the pathogenesis of all prion diseases [3,4,5]. The interaction between PrPSc and PrPC starts a chain reaction, in which each newly converted PrPSc molecule interacts with further PrPC molecules, leading to an accumulation of PrPSc [2,6]. The reaction and propagation of PrPSc can be mimicked in vitro by protein misfolding cyclic amplification (PMCA) [7,8,9].

Methods

Results

Conclusion