Common herpes virus causes signs of Alzheimer’s disease in brain cells
HEALTH 6 May 2020
By Alice Klein

A cell infected with herpes virus

Mini-brains grown in a dish rapidly develop signs of Alzheimer’s disease when infected with the common herpes virus that causes cold sores. The finding adds to growing evidence that some cases of Alzheimer’s are triggered by viruses and could potentially be treated with antiviral drugs.

A major hallmark of Alzheimer’s disease is the build-up in the brain of protein clumps called beta-amyloid plaques. An emerging school of thought is that these plaques function as defences against viruses and bacteria that sometimes manage to get into the brain.

Herpes simplex virus-1 (HSV-1), which causes cold sores and stays in the body for life, is one virus that has been linked to Alzheimer’s disease. People with HSV-1 are more likely to get Alzheimer’s, and high levels of herpes viruses have been found in the brains of people who died with the condition.

To understand how HSV-1 might cause Alzheimer’s disease, Dana Cairns at Tufts University in Massachusetts and her colleagues added the virus to clumps of brain tissue grown in dishes. They made the mini-brains by filling doughnut-shaped scaffolds with human stem cells that were then coaxed into forming brain cells.

Rapid damage
Within three days of being infected with HSV-1, the mini-brains developed large beta-amyloid plaques reminiscent of those found in the brains of people with Alzheimer’s disease. The mini-brains also showed other signs of the condition, such as inflammation and loss of brain cells.

In contrast, when the mini-brains were treated with valacyclovir, a commonly used herpes drug, they seemed to be protected against HSV-1 damage. This finding lends support to a clinical trial currently under way in the US that is testing whether valacyclovir helps to treat Alzheimer’s disease in people who also have HSV-1, says Cairns.

Read more: We may finally know what causes Alzheimer’s – and how to stop it
One unresolved question is why HSV-1, which is found in about two-thirds of people under 50, seems to invade the brains of some people but not others. Those with weaker blood-brain barriers due to age or genetic factors may be more at risk, says Cairns.

Cairns and her colleagues now hope to test whether other microbes, such as Porphyromonas gingivalis, a bacterium that has been linked with Alzheimer’s and gum disease, also cause plaque formation in their brain models.

Journal reference: Science Advances, DOI: 10.1126/sciadv.aay8828

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Read more: https://www.newscientist.com/article/2242749-common-herpes-virus-causes-signs-of-alzheimers-disease-in-brain-cells/#ixzz6PRI3kIOT

So would it be the case that all those teenagers spreading their cold sores around are giving each other dementia ¿

SCIENCE said:

So would it be the case that all those teenagers spreading their cold sores around are giving each other dementia ¿

I don’t know but herpes viruses have been capable of surviving in humans for a very long time now. It is interesting the suggestion of what the plaque is attempting to do in the way of combating the affects of herpes entering the brain or managing this phase of the infection.

monkey skipper said:

SCIENCE said:

So would it be the case that all those teenagers spreading their cold sores around are giving each other dementia ¿

I don’t know but herpes viruses have been capable of surviving in humans for a very long time now. It is interesting the suggestion of what the plaque is attempting to do in the way of combating the affects of herpes entering the brain or managing this phase of the infection.

Yeah apparently this is what happens otherwise https://www.nhs.uk/conditions/encephalitis/causes/ and it sounds bad so we wonder maybe cold sores should be considered more than just a minor inconvenience…

Just like coronaviruses should be considered more than “just a little cold” and so forth.

We heard the herpes were also implicated in some leukaemias, imagine preventing all these nasty diseases by not spreading what are thought to be mild ones!

cheers for that, interesting

transition said:

cheers for that, interesting

It is interesting as they suggested anti-virals may prevent the secondary conditons suspected in this research.

It seems to be the immune system is the key to cancer switches and my understanding that is a point of focus of cancer research now ie to find the immune switches for the cancers cells and treating cancer that way going forward. I believe this is the direction of breast cancer treatment research in Australia , for example. It makes sense to me , given that the human body naturally will produce mutant cells that immune system regularily identifies and destroys it is when this system fails that a person develops cancer.

I was also led to believe that is why smoking links to cancer because it can block the body’s capacity to detect the mutant cancer causing cells.

There are many images of the herpes virus on the web, but one can almost say that no two images look alike. Somewhat coronavirus-like but not quite.

mollwollfumble said:

There are many images of the herpes virus on the web, but one can almost say that no two images look alike. Somewhat coronavirus-like but not quite.

There is more than one type of herpes virus

https://www.ncbi.nlm.nih.gov/books/NBK8157/