A Comparative Analysis of Amyloid Precursor Protein Processing in Neuronal Cells Infected with HSV-1 and PRV

Abstract

Recent epidemiological and experimental findings suggest that HSV-1, in particular, might contribute to the pathogenesis of Alzheimer’s disease (AD), although no causal relation has been demonstrated yet. This neurodegenerative disorder is often associated with intracellular and extracellular accumulation of amyloid beta (Aβ), a hallmark of amyloid plaque deposits, from the processing of amyloid precursor protein (APP). However, little if any research has been done on examining the effects of PRV infection on the processing of APP. The aim of this study was to identify and compare the effects of HSV-1 and PRV infection on APP processing in mouse neuroblastoma cells. We found that HSV-1 infection yielded an important C-terminal fragment cleavage product of APP and also induced elevated levels of Aβ intracellularly and extracellularly. Immunofluorescence imaging also showed that HSV induced aggregation of APP to the endomembrane system. These phenomena were not seen with PRV infection. We hypothesize that HSV-1 ICP34.5 may be critical for disruption of this processing pathway and that repeated HSV-1 reactivation could be a risk factor for AD.