Hope for Preventing Shingles
In a study published in PLOS Pathogens in June 2015, scientists at Bar-Ilan University in Israel report on a novel experimental model that, for the first time, successfully mimics the “sleeping” and “waking” of the varicella-zoster virus. The red, itchy rash caused by varicella-zoster, chickenpox virus usually disappears within a week or two. Yet once infection occurs, the varicella-zoster virus, or VZV, remains dormant in the nervous system awaiting a signal that re-activates this “sleeper” virus in the form of an extremely unpleasant but common disease: herpes zoster, or shingles.
A release from the university explains that based on neurons generated from human embryonic stem cells, and not requiring the use of experimental animals, the model allows scientists to test drugs and develop therapies to prevent shingles. The treatments may also contribute to the fight against other viruses such as herpes and polio that target the human nervous system.
A Painful Awakening
The release quotes Prof. Ronald Goldstein, a member of BIU’s Mina and Everard Goodman Faculty of Life Sciences, as saying, “Most adults harbor latent VZV in their nervous system – a ‘souvenir’ from a bout with childhood chickenpox. In one-third of people over 50, or in those with weakened immune systems, VZV re-activation triggers the localized rash, itchiness and pain of shingles. In one-third of these cases, however, shingles symptoms are far more serious, causing debilitating pain that can last for months or even years.”
Goldstein explains that, while an anti-shingles vaccine exists, it provides effective protection in only 50% of cases and cannot be given to immune-compromised patients – such as transplant recipients – who are at particularly high risk for shingles onset.
The new model, which makes it possible to establish stable, latent-state VZV in neurons derived from human embryonic stem cells (hESCs), was created by Amos Markus, a PhD student in Goldstein’s lab. A major contributor to the model is Prof. Paul “Kip” Kinchington of the Departments of Ophthalmology and of Microbiology and Molecular Genetics at the University of Pittsburgh, with whom Goldstein has been collaborating closely for the past five years. An authority on the genetic modification of VZV, Kinchington made key discoveries about proteins involved in VZV activity.
The significance of this advance is in its potential impact on biomedical research; the model makes it possible to experimentally trigger re-activation of the dormant virus, to characterize the molecular processes involved, and to identify potential targets for shingles-prevention therapies.