Infection route-independent accumulation of splenic abnormal prion protein

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• Prion diseases, like scrapie, are characterized by the accumulation of abnormal prion protein (PrPSc).
• Understanding the kinetics of PrPSc accumulation is crucial for disease progression and potential therapeutic interventions.

Purpose of the Study:

• To investigate the accumulation kinetics of PrPSc in spleens and brains of mice infected with scrapie (Obihiro-1 strain).
• To compare PrPSc accumulation patterns following different inoculation routes: intracerebral (i.c.), intraperitoneal (i.p.), and oral.

Main Methods:

• Mice were inoculated with scrapie via i.c., i.p., or oral routes.
• PrPSc accumulation was monitored over time using Western blotting with anti-prion protein antibodies.
• Detection of PrPSc in spleen and brain tissues at various post-inoculation time points.

Main Results:

• PrPSc was first detected in spleens by day 70 and in brains by day 116 after i.c. inoculation.
• Splenic PrPSc peaked earlier (day 116) than cerebral PrPSc (day 152) following i.c. infection.
• Detectable PrPSc levels in spleen appeared earlier (days 93-94) than in brain (days 231-259) after i.p. and oral inoculation.

Conclusions:

• Splenic PrPSc accumulation precedes detectable cerebral PrPSc accumulation.
• The observed splenic PrPSc increase occurs independently of the inoculation route.
• These findings highlight the spleen as an early site for PrPSc propagation in scrapie infection.