Naked Science Forum
Life Sciences => Cells, Microbes & Viruses => Topic started by: diegostation on 08/05/2005 18:57:26
-
Could stem cells be used for the cure of herpes? Maybe replacing the infected ganglions with new, healthy, stem cell produced ones?
-
An interesting idea, but certainly too radical to be practical !
Herpes simplex viruses, which cause cold sores and genital herpes, establish a lifelong latent (persistent) infection in sensory nerve cells supplying the affected part of the body.
Within the nerve cell the virus persists solely as a tiny circularised piece of DNA which sits in the nerve cell nucleus alongside the human DNA. Periodically, and usually in response to certain stimuli such as UV light (sunburn), skin trauma, immunosuppression or menstruation, something kickstarts one of the viral genes which then leads to 'reactivation' and the production of new viral particles. These are exported back down the nerve fibre to the skin where they produce a localised infectious lesion (the cold sore).
Because the latent virus exists solely as a piece of DNA, identical in most ways to human DNA, it's very difficult to selectively target the viral DNA with a drug. Bacteria are an easy target because the structure of their cells is grossly different to that of an animal (eukaryotic) cell, making drugs that can home in on specific bacterial components easier to find.
For this reason researchers are looking for drugs that might be able to stop the virus reactivating by interrupting the signals that trigger the process. In the future it may also be possible to produce agents which will selectively switch off the viral DNA so that it becomes 'unreactivatable'.
However, the idea of using stem cells to replace infected nerve cells is very unlikely to become a useful therapy. It would involve removing the infected neurones, and then replacing them with stem cells capable of becoming the correct types of nerve cells, which were then able to wire themselves into the spinal cord, and into the skin, in the correct way to restore normall sensation. I think a successful drug is more likely to turn up first !
I wrote a recent review of herpes simplex infections including cold sores and genital herpes (http://www.thenakedscientists.com/HTML/articles/article/chrissmithcolumn4.htm), which you might find useful.
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
-
If you see no cure in sight for herpes using stem cells, why not treat with radiation to kill the virus then follow-up with stem cells to regenerate nerve cells killed by the radiation?
ps- what institution is doing the herpes research you refer to?
-
If you see no cure in sight for herpes using stem cells, why not treat with radiation to kill the virus then follow-up with stem cells to regenerate nerve cells killed by the radiation?
ps- what institution is doing the herpes research you refer to?
As has been hinted at by Chris, nerve cells are extremely difficult to replace. The problem is not that it is difficult to grow a nerve cell, but that we do not know how to wire up the nerve cell correctly (a single cell can stretch many feet long, and need to find exactly the right targets at each end to make sure it conducts the right signal from the correct place to the correct place).
Maybe a bit too radical, but I would have thought that maybe the best way to attack a dormant virus is to use a GM virus (or other intracellular parasite) to hunt and destroy the herpes virus.
-
I have been doing some research on using medical grade DMSO and Acyclovir to make the herpes virus "unreactivatable". Does this sound somewhat promising?
The person would apply Acyclovir cream to the lower back (for genital herpes) and then apply DMSO (the easiest method would be to use a prediluted DMSO spray). Acyclovir is meant to disrupt the viral DNA so that it cannot replicate. But antiviral medications can only treat a herpes outbreak, not the virus itself. So, if DMSO could carry the antiviral to cells, in theory, it would be able to disrupt the viral DNA within the cell...right?
Does this sound too crazy to work? The person may still have the virus in their cells, but it would be "unreactivatable".