The virus flu

Content

  • Virus-thief
  • A moving target
  • Alternative vaccination
  • live vaccine
  • One against all


    The virus fluVirus-thief

    Common virus - is nothing more than a clever piecethe genetic material in a protein shell, which, like the smuggler, the cell carries its genes and uses its molecular mechanism for its own reproduction. But when the scientists studied the process flow of viral infections, they found a gap in the life cycle of viruses.

    When viruses multiply, the majority of themI do not care about the accuracy of the genetic code - the genome - and it often lacks a vital part of the "code." These defective viruses interfere with reproduction of their normal counterparts and have thus a protective effect. In particular, scientists have observed a similar effect in the study of viral plant diseases - broad beans and turnip.

    The mechanisms of this phenomenon is still not fully understood. According to one theory, defective viruses interfere with others simply to kill his "master". Biologists have also suggested that these viruses play a role similar nature which assigned in human society, for example, thief fraudsters and swindlers who live off the toil of others - just live virus protection at the expense of foreign proteins.

    Whatever it was, a few decades agoScientists hoped to "disperse" the reaction to the incredible speed and overcome viral infection. It seemed that this discovery will finally create a cure for the common cold, which is caused by numerous viruses that get into the respiratory tract. But when the expected result has not turned out, the enthusiasm quickly faded. Now, however, this hypothesis is reborn.


    A moving target

    Animal experiments have shown that usingdefective viruses can provide instant protection against flu symptoms, slow the progression of infection to such an extent that the body gets time to strengthen immunity against the disease.

    Injection of the protective virus through the nose canprotect from any kind of flu - even the Spanish flu, which in 1918 claimed the lives of 50 million people. According to the chief apologist for similar studies in the UK, Professor Nigel Dimmock of Warwick University, is all set to test new vaccines on patients.

    Dimmock work will create an alternativetraditional vaccine, based on stimulating the immune system. When vaccination white blood cells produce antibodies, which attach to the surface of the virus and begin to kill him. This method has worked well in the fight against diseases such as smallpox, polio and measles, but it is less effective against the flu. Because the genetic code of the virus of influenza recorded in 13.6 thousand nucleotides, constantly changing, and for the vaccine, these modifications are like a moving target for the arrow. The vaccine is designed for one type of flu, for example, H3N2, is powerless against another - for example, against the H5N1 avian influenza virus.

    The study, published in the British MedicalJournal, showed that there is very little evidence of the effectiveness of seasonal influenza vaccines. Recently, a group of scientists from the University of Hong Kong, led by Professor Guan Yi announced the opening of a new deadly strain of H5N1. This information increased the fear of the appearance of mutant virus that is transmitted to humans and against which current vaccines will be powerless.


    Alternative vaccination

    The time is a new form of protection based on thethe resurrection of the idea of ​​virus-defender. "As a result of errors during replication of all viruses produce incomplete version of its genome. At the same time, these small defective viruses can interfere with the normal viral RNA replication process. Therefore, we call them the RNA interferential or protecting ", - explains Professor Dimmock.

    The genetic material of bird flu virusIt consists of eight RNA segments. As normal, "Protective viruses", in which only 400 "letters" of the genetic code, has a protein shell, which helps them to penetrate into the cells. They affect the same organs as usual viruses - the lungs and respiratory system. But they can only proliferate via normal viruses and defective RNA as less, it is played faster and soon protective viruses is greater than normal. "That's why interferential RNA can protect us - explains Professor Dimmock. - But while these properties easily see very few examples in the cell culture example, in the literature of such therapy. "


    live vaccine

    A big step forward has been in research and developmentIt made when scientists realized that although nature creates various types of interferential RNA, the best effect is achieved by using one type of virus. This can be achieved by cloning a laboratory or RNA by selection of virus that has one dominant type interferential RNA. "The latter method has allowed us to get our most active virus protection," - says Professor Dimmock.

    In a naturally occurring virus protection,which intends to use Professor Dimmock, missing 80% of one of the parts of the genetic code. This specificity makes the virus harmless and prevents it from multiplying on their own - as the normal influenza virus. However, if the cell where the virus was protective, there is another influenza virus, it can use its proteins for reproduction, and much faster than their "owner".

    Thus, conventional breeding virusesInfluenza virus crowded out protection. This slows down the development of infection and eliminates the symptoms and gives the body time to mobilize the immune system so that it can repel invaders.

    Security virus as it makes its"Full brother" in a live vaccine. Research shows that it will only work against influenza A, but not against the common cold or other respiratory diseases. But it need not be adapted to the specific mutations or strains of influenza virus. "As interferential RNA affects the replication process itself, it has to be active against all varieties of influenza A," - said Professor Dimmock.


    One against all

    This gives a significant advantage when the epidemic,because they do not have to spend time figuring out the virus strain before deploying anti-flu campaign. Conventional vaccines are effective only against certain strains of the virus known, and the launch of mass production of vaccines against newly emerging subtypes takes more than one month.

    In addition, the protective virus - a natural byproductInfection product - provides real-time protection, while the effect of conventional influenza vaccination may not be immediately apparent, but within three weeks. Tests on animals have shown that a single dose is effective protection against virus infection even after 6 weeks. This is its main advantage over antiviral drugs, which are not protected on the day. Although many bacteria develop resistance to drugs, an influenza virus does not become resistant to the protective virus.

    "Protective virus works even whenIll get it within 24 hours after infection, "- says Professor Dimmock. He and his colleagues have applied for a patent for virus protection and hope to conduct clinical trials on patients in a specially created for this purpose at the University of Warwick company ViraBiotech.

    Virologist from the London School of Medicine QueenMary's School of Medicine, Professor John Oxford said: "This discovery is at the peak of science, but its development takes a lot of time. Of course, to have something that guarantees protection against surprises that presents us with a virus, very tempting. I am surprised that none of us engaged in this earlier - because this discovery lay under our feet. "

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