Prion strain interactions are highly selective.

Area of Science:

• Neuroscience
• Biochemistry
• Protein Misfolding Diseases

Background:

• Misfolded and aggregated neuronal proteins often coexist in neurodegenerative diseases.
• The interactions and coaggregation of these proteins and their impact on disease pathogenesis remain largely unclear.

Purpose of the Study:

• To investigate whether distinct prion strains, differing in conformation, interact and alter disease progression in vivo.
• To test the hypothesis of cross-seeding and interference between different prion protein aggregates.

Main Methods:

• Tracking two distinct prion strains in mice using histopathology and biochemical analysis.
• Utilizing spectral analysis of plaque-bound polythiophene acetic acid (PTAA), a conformation-sensitive fluorescent amyloid ligand.

Main Results:

• Demonstrated highly selective and strain-specific interactions between prion strains.
• Observed three interaction outcomes: no interaction, hybrid plaque formation, or interference (blockage).
• Hybrid plaques were stable upon further passage, with strains retaining original conformational properties, suggesting a scaffold-like role.

Conclusions:

• Prion strain interactions are specific and can lead to novel aggregate structures or interference.
• Findings provide direct evidence for interactions between different protein aggregates, relevant to various neurodegenerative diseases.
• This study advances the understanding of prion biology and protein aggregation in disease contexts.