Exploratory project PRIONDIFF (2021 - 2023)

Prion diseases: modelling the process of dissemination and neuroinvasion

The prion paradigm unifies a number of age-related, devastating neurodegenerative pathologies. The PrionDif project seeks to develop a multi-scale mechanistic model accounting for the spatiotemporal dynamic of prion spreading within the brain. This approach will allow the identification of key processes to enable therapeutic advances and promote early diagnosis.

Background and challenges

In the prion paradigm framework, host-encoded monomeric proteins are converted into misfolded aggregated assemblies, which serve as a template for further autocatalytic recruitment and conversion in the brain. Since the late 2000s, the prion paradigm has been extended to other neurodegenerative diseases due to protein misfolding such as Alzheimer's and Parkinson's disease.

In mammalian prion diseases, also known as Transmissible Spongiform Encephalopathies (TSE), prion assemblies (PrPSc), formed from the cellular prion protein (PrPC), contain all the structural information necessary to their replication and their specific stereotyped disease phenotype in the infected host. In TSE, multiple PrPSc conformational variants exist. They define the prion strains and dictate specific physiopathological patterns such as region-specific PrPSc deposits in the same host species. Although self-replicative processes provide a mechanistic framework for the prion paradigm, to date there is no mechanistic link between prion replication, the neuroinvasion process and the strain-specific neuropathological pattern

Goals

The PrionDif project seeks to develop a multi-scale mechanistic model accounting for the spatiotemporal dynamic of prion spreading within the brain by integrating experimental observations with an effective model of prion replication which takes into account the dynamicity of PrPSc assemblies. By integrating the spatio-temporal mapping of the spread of prion replicative centres with the prion replication/dissemination model, we aim to build a synthetic multi-scale model of prion structural diversification and lesional propagation. This open-access model will allow us to investigate which parameters of the prion replication process specific to each strain dictate the progression of the disease and the apparition of strain specific PrPSc deposition patterns.

Ultimately, this synthetic approach will allow the identification of key processes to enable therapeutic advances and promote early diagnosis

Contact - coordination :

Partnerships

INRAE participants

Animal health division

Expertise

UMR VIM Molecular Virology and Immunology

Macro-Assembly Pathology and Prion Diseases (MAP²) team

Expertise:

- molecular biophysics & biochemistry

- non-equilibrium kinetics and modelling

- stochastic process, Gillespie-type approach

- retro-synthetic approach

- characterisation of prion assemblies

- patterning and prion strains

- spatial-temporal evolution of different prion assembly subspecies

UMR IHAP (Interactions between hosts and pathogens)

Pathogenesis of transmissible spongiform encephalopathies team

Expertise :

- Physiopathology of prions

- Tractography, systemic and tissue dissemination of prions

- Typing of prion strains

Partners

INRIA

Expertise

Dracula team (Institut Camille Jordan/INRIA/ université de Lyon 2)

Mathematical modelling of reactions under diffusion controls; data integration; synthetic biology; control theory; optimisation; predictive approach