Understanding the key features of the spontaneous formation of bona fde prions through a novel methodology that enables their swift and consistent generation

Among transmissible spongiform encephalopathies or prion diseases afecting humans, sporadic forms such as spo‑ radic Creutzfeldt–Jakob disease are the vast majority. Unlike genetic or acquired forms of the disease, these idiopathic forms occur seemingly due to a random event of spontaneous misfolding of the cellular PrP (PrPC) into the patho‑ genic isoform (PrPSc). Currently, the molecular mechanisms that trigger and drive this event, which occurs in approximately one individual per million each year, remain completely unknown. Modelling this phenomenon in experimental settings is highly challenging due to its sporadic and rare occurrence. Previous attempts to model spontaneous prion misfolding in vitro have not been fully successful, as the spontaneous formation of prions is infre‑ quent and stochastic, hindering the systematic study of the phenomenon. In this study, we present the frst method that consistently induces spontaneous misfolding of recombinant PrP into bona fde prions within hours, providing unprecedented possibilities to investigate the mechanisms underlying sporadic prionopathies. By fne‑tuning the Pro‑ tein Misfolding Shaking Amplifcation method, which was initially developed to propagate recombinant prions, we have created a methodology that consistently produces spontaneously misfolded recombinant prions in 100% of the cases. Furthermore, this method gives rise to distinct strains and reveals the critical infuence of charged sur‑ faces in this process.The present work was partially funded by three different grants awarded by “Ministerio de Economía y Competitividad” (Spanish Government), grant numbers PID2021-122201OB-C21, PID2021-1222010B-C22 and PID2020-117465GB-I00, funded by MCIN/AEI/10.13039/501100011033 and co-financed by the European Regional Development Fund (ERDF), and by the Instituto de Salud Carlos III (ISCIII), grant number AC21_2/00024. Additionally, CIC bioGUNE currently holds a Severo Ochoa Excellence accreditation, CEX2021-001136-S, also funded by MCIN/AEI/10.13039/501100011033. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

A Protein Misfolding Shaking Amplificationbased method for the spontaneous generation of hundreds of bona fide prions

Prion diseases are a group of rapidly progressing neurodegenerative disorders caused by the misfolding of the endogenous prion protein (PrPC) into a pathogenic form (PrPSc). This process, despite being the central event underlying these disorders, remains largely unknown at a molecular level, precluding the prediction of new potential outbreaks or interspecies transmission incidents. In this work, we present a method to generate bona fide recombinant prions de novo, allowing a comprehensive analysis of protein misfolding across a wide range of prion proteins from mammalian species. We study more than 380 different prion proteins from mammals and classify them according to their spontaneous misfolding propensity and their conformational variability. This study aims to address fundamental questions in the prion research field such as defining infectivity determinants, interspecies transmission barriers or the structural influence of specific amino acids and provide invaluable information for future diagnosis and therapy applications.The authors would like to thank the following for their support: IKERBasque foundation, personnel from vivarium, IT service (in particular to Sara Gómez Ramos for her assistance with the PrPdex webpage), maintenance departments of CIC bioGUNE, Neiker and IRTA-CReSA. The authors would also like to acknowledge the work from past laboratory members of the Prion Research Lab from CIC bioGUNE, that despite not directly involved in the manuscript have contributed along the years to the development of all the methods and techniques currently used in the laboratory (specially to Tomás Barrio and Leire Hervá for their efforts at the initial and end stages of the work, respectively). Finally, we would like to thank Jesús R. Requena for always useful scientific discussions and advice. The present work was partially funded by different grants awarded by “Ministerio de Economía y Competitividad” (Spanish Government), grant numbers PID2021-122201OB-C21, PID2021-1222010BC22, PID2021-125946OB-I00 and IJC2020-045506-I, funded by MCIN/ AEI /10.13039/501100011033 and co-financed by the European Regional Development Fund (ERDF), and by the Instituto de Salud Carlos III (ISCIII), grant number AC21_2/00024, to J.C. Additionally, CIC bioGUNE currently holds a Severo Ochoa Excellence accreditation, CEX2021- 001136-S, also funded by MCIN/AEI /10.13039/501100011033. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

Understanding the key features of the spontaneous formation of bona fide prions through a novel methodology that enables their swift and consistent generation

Abstract Among transmissible spongiform encephalopathies or prion diseases affecting humans, sporadic forms such as sporadic Creutzfeldt–Jakob disease are the vast majority. Unlike genetic or acquired forms of the disease, these idiopathic forms occur seemingly due to a random event of spontaneous misfolding of the cellular PrP (PrPC) into the pathogenic isoform (PrPSc). Currently, the molecular mechanisms that trigger and drive this event, which occurs in approximately one individual per million each year, remain completely unknown. Modelling this phenomenon in experimental settings is highly challenging due to its sporadic and rare occurrence. Previous attempts to model spontaneous prion misfolding in vitro have not been fully successful, as the spontaneous formation of prions is infrequent and stochastic, hindering the systematic study of the phenomenon. In this study, we present the first method that consistently induces spontaneous misfolding of recombinant PrP into bona fide prions within hours, providing unprecedented possibilities to investigate the mechanisms underlying sporadic prionopathies. By fine-tuning the Protein Misfolding Shaking Amplification method, which was initially developed to propagate recombinant prions, we have created a methodology that consistently produces spontaneously misfolded recombinant prions in 100% of the cases. Furthermore, this method gives rise to distinct strains and reveals the critical influence of charged surfaces in this process

A Protein Misfolding Shaking Amplification-based method for the spontaneous generation of hundreds of bona fide prions

Abstract Prion diseases are a group of rapidly progressing neurodegenerative disorders caused by the misfolding of the endogenous prion protein (PrPC) into a pathogenic form (PrPSc). This process, despite being the central event underlying these disorders, remains largely unknown at a molecular level, precluding the prediction of new potential outbreaks or interspecies transmission incidents. In this work, we present a method to generate bona fide recombinant prions de novo, allowing a comprehensive analysis of protein misfolding across a wide range of prion proteins from mammalian species. We study more than 380 different prion proteins from mammals and classify them according to their spontaneous misfolding propensity and their conformational variability. This study aims to address fundamental questions in the prion research field such as defining infectivity determinants, interspecies transmission barriers or the structural influence of specific amino acids and provide invaluable information for future diagnosis and therapy applications

A Protein Misfolding Shaking Amplification-based method for the spontaneous generation of hundreds of bona fide prions

Prion diseases are a group of rapidly progressing neurodegenerative disorders caused by the misfolding of the endogenous prion protein (PrP C) into a pathogenic form (PrP Sc). This process, despite being the central event underlying these disorders, remains largely unknown at a molecular level, precluding the prediction of new potential outbreaks or interspecies transmission incidents. In this work, we present a method to generate bona fide recombinant prions de novo, allowing a comprehensive analysis of protein misfolding across a wide range of prion proteins from mammalian species. We study more than 380 different prion proteins from mammals and classify them according to their spontaneous misfolding propensity and their conformational variability. This study aims to address fundamental questions in the prion research field such as defining infectivity determinants, interspecies transmission barriers or the structural influence of specific amino acids and provide invaluable information for future diagnosis and therapy applications. To study neurodegenerative prion diseases, a method (PMSA) for generating prions spontaneously is presented. Applied to 380+ different prion proteins, their tendency to become pathogenic was ranked, illuminating their formation process