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Immunohistochemical localization of prion protein in spongiform encephalopathies and normal brain tissue
P Piccardo1, J Safar, M Ceroni
1Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Abstract:
We used polyclonal antibodies raised against hamster and mouse PrP27-30 as immunologic probes to study the localization of intracellular and extracellular deposits of prion protein in normal and scrapie-infected mouse and hamster brains and in Creutzfeldt-Jakob disease (CJD)-infected mouse brains. In addition, we examined normal human brain and brain tissues from patients with CJD, kuru, Alzheimer's disease, and idiopathic chronic encephalitis. There was positive staining in the cytoplasm of neurons of normal and scrapie- and CJD-infected mice, and in the neurons of normal and scrapie-infected hamsters. The staining pattern suggests the localization of PrP in an intracellular membrane compartment, most likely the rough endoplasmic reticulum or Golgi apparatus. Antibodies raised against a 15-amino-acid synthetic peptide of the N-terminal of hamster PrP27-30 displayed a similar pattern of staining in mouse brain sections. We observed no intracellular staining in human brain sections obtained at autopsy. Antibodies prepared against mouse and hamster PrP27-30 reacted with amyloid plaques in scrapie-infected mouse and kuru- and CJD-infected human brain sections but not with amyloid plaques in the brain of a patient with Alzheimer's disease.
Insights
Polyclonal antibodies revealed prion protein (PrP) intracellular deposits in normal and infected mouse and hamster neurons, likely in the endoplasmic reticulum or Golgi. Extracellular amyloid plaques were detected in scrapie, CJD, and kuru, but not Alzheimer's disease.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Prion diseases, including Creutzfeldt-Jakob disease (CJD), kuru, and scrapie, are characterized by the accumulation of misfolded prion protein (PrP).
- Understanding the cellular localization of PrP is crucial for elucidating disease mechanisms and developing therapeutic strategies.
Purpose of the Study:
- To investigate the intracellular and extracellular localization of prion protein (PrP) in various neurological conditions.
- To differentiate PrP deposition patterns in normal, scrapie-infected, and human prion disease brains.
Main Methods:
- Utilized polyclonal antibodies against hamster and mouse PrP27-30 for immunolocalization studies.
- Examined brain tissues from normal and infected mice, hamsters, and humans with CJD, kuru, Alzheimer's disease, and encephalitis.
- Employed antibodies against a synthetic N-terminal PrP peptide for comparative analysis.
Main Results:
- Intracellular PrP staining observed in neurons of normal and scrapie-infected mice and hamsters, suggesting localization within the rough endoplasmic reticulum or Golgi apparatus.
- No intracellular PrP staining detected in autopsied human brain sections.
- Antibodies recognized amyloid plaques in scrapie-infected mouse brains and human brains with kuru and CJD, but not in Alzheimer's disease brains.
Conclusions:
- Prion protein exhibits intracellular localization in neurons of rodents, potentially within the secretory pathway.
- Extracellular PrP amyloid plaques are characteristic of scrapie, CJD, and kuru, but distinct from Alzheimer's disease pathology.
- Immunohistochemical analysis with specific antibodies is valuable for differentiating prion protein deposition in various neurological disorders.