Can neurodegenerative disease be defined by four 'primary determinants': anatomy, cells, molecules, and morphology?
- R A Armstrong
- Folia neuropathologica
Intraneuronal prion protein (PrP) immunoreactivity (INIR), which might represent the non-pathological, cellular form of PrP, needs to be distinguished from disease-associated deposits specific for prion disease (PrD). In adjacent sections of PrD and control brains we applied pretreatments, one of which enhances the immunoreactivity of disease-associated PrP, and another that enhances INIR. We observed an inverse correlation between the proportion of neurons with INIR and the intensity of disease-associated PrP immunoreactivity and severity of lesions. Additionally, we found large intracytoplasmic inclusion-like bodies in ballooned neurons in PrD cases. We noted that the 3F4 (epitope: amino acids 109–112) anti-PrP antibody labels more INIR than antibodies directed against amino acids 23–85 (BG4) or 140–180 (KG9) in PrD cases, in contrast to controls, but all antibodies immunolabel more INIR in PrD brains. The up-regulation of PrP might represent an early loss of function of the non-pathological form of PrP, in parallel with a neurotoxic effect of accumulating disease-associated isoform, as part of the pathogenesis of prion diseases.