Around 30 years ago, researchers in the United Kingdom discovered DNA of human herpes simplex virus 1 (HSV1) in postmortem brain samples of AD patients at much higher levels than in healthy brains, hinting that viral infection could be somehow involved in the disease [1]. Furthermore, the authors show that infection with herpesvirus seems to rapidly seed amyloid plaque deposition in a transgenic mouse model (5XFAD) and in a three-dimensional human neuronal cell-culture system [3]. The relevance of HSV1 brain infection for the development of AD is supported by studies on Apolipoprotein E (APOE)-ε4 transgenic mice, which show marked behavioral and pathological changes in HSV1-infected animals [6]. AD, Alzheimer's disease; APOE, Apolipoprotein E; HHV, human herpesvirus; KIR2DL2, killer immunoglobulin-like receptor 2. https://doi.org/10.1371/journal.ppat.1008575.g001 Interestingly, among the neurotropic herpesviruses, HSV1 and HHV6A have been reported to infect several cell types present in the central nervous system and dysregulate autophagy, a process required for homeostasis of cells, especially neurons [10]....

Controversial role of herpesviruses in Alzheimer’s disease

10.1371/journal.ppat.1008575