LONDON (Dispatches) -- According to a joint study, lab models of the human brain show that activation or re-infection of VZV can trigger neuroinflammation and wake up HSV, leading to accumulation of Alzheimer’s linked proteins and neural decline.
Scientists at Tufts University and the University of Oxford , using a three-dimensional human tissue culture model mimicking the brain, have demonstrated that varicella zoster virus (VZV), which commonly causes chickenpox and shingles, may activate herpes simplex (HSV), another common virus, to set in motion the early stages of Alzheimer’s disease.
Normally HSV-1 -- one of the main variants of the virus -- lies dormant within the neurons of the brain, but when it is activated it leads to accumulation of tau and amyloid beta proteins, and loss of neuronal function -- signature features found in patients with Alzheimer’s.
Alzheimer’s disease can begin almost imperceptibly, often masquerading in the early months or years as forgetfulness that is common in older age. What causes the disease remains largely a mystery.