Gene therapy against HIV/AIDS success inspires
Scientists from Virxsys (Gaithersburg, Maryland) and the University of Pennsylvania have developed a fundamentally new method of gene therapy that prevents the reproduction of HIV in the body.
The principle of operation of the method under the working code VRX496 is based on the fact that viral particles themselves are not dangerous and begin to act only inside the cell. Once inside the T-lymphocytes, HIV embeds its DNA into the chromosome of an infected cell and uses its molecular mechanisms to replicate its genetic material.
To deceive the virus, scientists used a complex technique. First, they isolate T-lymphocytes from the patient's blood and embed in them a gene encoding an altered version of one of the envelope proteins of the immunodeficiency virus. After that, using a culture method patented by the university, the number of cells is increased hundreds of times and injected back into the patient.
The virus penetrating the treated cell uses a "defective" gene for its replication, as a result of which newly formed viral particles have defective capsids and lose the ability to infect healthy cells.
If, at the same time, the virus resorts to its favorite tactic of developing resistance to treatment – removing the "bad" gene – it also loses the ability to reproduce fully.
VRX496 is currently at an early stage of clinical trials, the purpose of which is to assess safety and select optimal dosages. Of the 54 trial participants, none developed serious side effects, while the majority showed clinical signs of treatment effectiveness: a decrease in viral load and an increase in the number of normal T-lymphocytes.
One of the first test participants, who had the most severe form of the disease at the time of the start of treatment, has been feeling satisfactory for more than 4 years, despite the developed tolerance to traditional drugs.
Analysis of 9 blood samples of randomly selected participants in clinical trials of the method showed that most of the detected viral particles are harmless mutated forms of the virus.
Currently, HIV-infected patients are forced to take cocktails of expensive and very toxic drugs. Experts believe that the proposed method of gene therapy, which does not rid a person of the disease, but allows controlling its course, is an acceptable alternative.
According to Virxsys Executive director Riku Rautsola, if the HIV gene therapy method proposed by the company receives official approval (which will happen no earlier than in a few years), the approximate cost of the procedure will be $ 130,000. This is a large sum, but it should be borne in mind that the lifetime provision of HIV-infected people with a complex of modern antiretroviral drugs costs about 700,000 dollars.
Portal "Eternal youth" www.vechnayamolodost.ru based on Philly materials14.02.2008