Prion Strain Diversity and Selective Vulnerability in CJD

SUMMARY

# Prion Strain Diversity and Selective Vulnerability in CJD ## Background and Rationale The heterogeneity observed in sporadic Creutzfeldt-Jakob Disease (sCJD) represents one of the most compelling puzzles in contemporary neurodegenerative disease research, with patients presenting dramatically different clinical courses despite sharing a common underlying pathological mechanism involving the misfolding of the prion protein (PrPᶜ) into its pathogenic scrapie form (PrPˢᶜ). This comprehensive inve

METHODOLOGY NOTES

**Phase 1: Patient Recruitment and Clinical Characterization (Months 1-12)** • Recruit 150 sporadic CJD patients from multiple clinical centers with confirmed diagnoses • Obtain detailed clinical histories, neurological assessments, and MRI imaging • Collect CSF samples for RT-QuIC analysis and 14-3-3 protein levels • Document disease duration, presenting symptoms, and progression patterns • Perform PRNP genotyping for codon 129 polymorphism status **Phase 2: Neuropathological Analysis (Months 6-18)** • Obtain brain tissue samples from 100 autopsy cases with confirmed sCJD • Perform immunohistochemistry for PrP^Sc using 3F4, 12B2, and 1E4 antibodies • Conduct Western blot analysis using proteinase K digestion to determine PrP^Sc type (1 vs 2) • Map regional distribution of spongiform changes and PrP^Sc deposition • Quantify neuronal loss and astrocytic gliosis in affected brain regions **Phase 3: Prion Strain Characterization (Months 12-24)** • Extract PrP^Sc from brain homogenates u