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uproot the scab from the stem

Israeli development may lead to an effective vaccine

fall asleep and wake up. VZV viruses (painted green) inside fibers of nerve cells. Photo courtesy of Prof. Ron Goldstein, Bar-Ilan University
fall asleep and wake up. VZV viruses (painted green) inside fibers of nerve cells. Photo courtesy of Prof. Ron Goldstein, Bar-Ilan University

Most of us get chicken pox as children, a skin disease manifested by an itchy rash, which goes away after a few days. We continue our routine, but the virus that causes the disease does not leave us. It penetrates into the nerve cells in the body and remains in the nervous system in a hidden or dormant state. The virus that causes chicken pox, known as VZV (Varicella Zoster Virus) is a relative of the herpes virus, which also hides in the nervous system, and from time to time emerges and causes severe sores on the lips. However, unlike its relative, VZV does not often come out of hiding. When it comes out, it does so in a big way, causing a serious disease called shingles (also known by the English name shingles). The disease is characterized by rashes on the skin, as well as severe pain in different parts of the body, which may last for many months. The outbreak of shingles may be the result of a decrease in the function of the immune system, or of mental stress. However, the biological mechanism leading to the awakening of the virus to the outbreak of the disease is unknown, because the virus only attacks human nerve cells, and it is impossible to study the disease in animals. The research breakthrough may be provided by the development of scientists from Bar Ilan University. The researchers from the Department of Life Sciences, led by research student Amos Marcus and Prof. Ron Goldstein, used a technique developed by Goldstein to cause embryonic stem cells to develop in vitro into an active culture of human nerve cells. This system makes it possible to do experiments that there is no other way to do them, and in recent years Goldstein decided to harness it for the study of various diseases.

wake up call

In the first step - a few years ago, Goldstein and his colleagues were able to infect the nerve cells in their culture with the VZV virus. Now they report in an article in the journal PLoS Pathogens that they have succeeded in creating a model of the hidden infection. The researchers proved through DNA tests that the genetic material of the virus is inside the cells, even when it is inactive, and does not cause the nerve cells to produce the viral proteins. In addition, they found a way to stimulate the activity of the hidden virus, through the elimination of growth factors, which are used as a permanent component in the growth medium of the cells in culture. Another way to make the virus come out of the hidden state, was to add to the culture substances that inhibit the activity of the enzymes responsible for the normal growth and development processes in the cells. This is the first time in more than 50 years of studying the virus that it can be awakened from its slumber experimentally," says Goldstein. "Until now, when researchers quietly infected nerve cells with the virus, it was impossible to know whether it was indeed a hidden infection or a partial infection that did not succeed at all." In the first experiments, Goldstein and his colleagues received a relatively low success rate in their attempts to reactivate the virus. The cultures usually grow at a temperature of 37°, like the body temperature of humans. However, the researchers decided to try to lower the temperature by 3-4°, in order to simulate what is happening in the nerve cells close to the skin. When they did this, the success rates did soar, and they had a system that controls the infection of the virus and its awakening from a dormant state to an active state.

Partial but promising

Researchers still know very little about the biology of the VZV virus's emergence process. It is not clear, for example, if it is constantly trying to erupt, but is normally blocked by the immune system, or if the outbreak is the result of an external chemical signal, indicating for example the weakness of the immune system. Therefore it is also clear that the experimental system developed by Goldstein and his colleagues is very partial. In the culture of the nerve cells, there are no cells of the immune system, so the information that can be obtained from it about the natural mechanism of killing the virus is limited. Another drawback of the experimental system is that so far the researchers have only kept the virus dormant for about two months, while in humans it can easily remain dormant for 60 years or more. However, the researchers hope that even in this partial system, it will be possible to identify proteins involved in the processes of awakening the virus and no less - in the processes of keeping it dormant. "The next step in our research is deciphering the molecular mechanisms that the virus uses to remain hidden in cells, and those that enable its awakening," explains Goldstein. "Deciphering these mechanisms should allow the development of a better vaccine than those currently available for shingles, whose effectiveness percentages are relatively low. "In the next step, we hope to develop new genetic treatments that will make it possible to neutralize the virus while it is hiding in the nervous system, and prevent it from breaking out." Such a success could improve the lives of millions of people who have had chicken pox in the past, and now may develop shingles.

5 תגובות

  1. Liowash - you are right if there are many who are not vaccinated and pass the disease on to the vaccinated. If a large majority is immune the risk is low. In any case, if there is a weak infection, it is likely that there will be few viruses hiding in the nervous system and there will be a mild case of shingles, if any. But it is clear that we have to wait for data collection that will take decades to verify what is happening.
    For miracles - true, but since Obamacare the number of insured people has increased and in fact anyone who is not insured is a criminal against the new law. Those who have no money get free insurance. It will take some time before all the insurance refusers are caught in the net.
    In addition - I have bad memories of the disease - I got infected from the children at the age of over 30, and I was very sick. My whole body was like exploding nylon, including in my mouth, luckily not in my eyes. After I recovered, I donated two doses of blood in one day because the Ministry of Health was specifically looking for me and they told me that there are people with immune system problems or during chemotherapy treatment, and if they contract the disease it is certain death, unless they receive antibodies from a person who has recently become ill.

  2. Herzl
    Everything is true except for what you said about medical insurance in the US. There are many who do not have any insurance.

  3. Vaccination causes the children to become infected in a weak way and instead of hundreds of blisters they have a few and many times it looks like a bite here and there that goes away after a week.
    From here to the assumption that there is no infection in nerve cells is a dangerous logical leap.

  4. There is already a vaccine. In the US, every doctor prescribes the shingles vaccine for every person over the age of 60. Insurance covers the vaccine, and there is an economic consideration here - the vaccine is much cheaper than treating the disease. In Israel, the vaccine is still not in the basket for budget reasons, and this causes budgetary waste! (Well, also a lot of suffering for the patients, but that doesn't interest the budget calculators).
    In addition, in about 20-30 years the subject of shingles will disappear except for people whose parents denied them a chicken pox vaccine when they were children.

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