New therapeutic HIV vaccine
Scientists from the University of Antwerp and the Antwerp Institute of Tropical Medicine have tested a new therapeutic HIV vaccine on volunteers. The study participants were injected with dendritic cells previously isolated from their own blood and provided with genetic instructions for the synthesis of HIV proteins. This did not lead to the cure of the disease, but increased the effectiveness of the fight of the immune system of patients with the virus.
Currently, complex antiretroviral therapy makes it possible to effectively control HIV infection, which provides HIV-positive patients with a relatively high quality of life. However, upon discontinuation of therapy, the virus is immediately activated.
The reason for this lies in the fact that when infected with the immunodeficiency virus, human dendritic cells are unable to perform their main function – to present (provide information in the form of foreign proteins) to cytotoxic CD8 T-lymphocytes, which, in turn, cannot develop a full-fledged immune response.
Belgian researchers followed the path of "if you can't, we'll teach you, if you don't want to, we'll make you." They have developed a method of introducing genetic instructions in the form of informational RNA (mRNA) of HIV proteins into the dendritic cells of HIV-positive patients. As a result, cells begin to synthesize and bring to the surface of their membrane proteins typical of viral particles. Subsequent experiments in laboratory conditions demonstrated the ability of such modified dendritic cells to selectively stimulate the activity of cytotoxic T-lymphocytes against HIV.
As part of a subsequent clinical study, scientists isolated dendritic cells from a large volume of blood from six HIV-positive patients who had been using cocktails of antiretroviral drugs for a long time. The cells were cultured under special conditions and subjected to a developed procedure for the introduction of appropriate genetic instructions, after which they were frozen.
The participants were given four injections of a small number of their own upgraded dendritic cells. 4-week intervals were maintained between injections. The efficiency of recognition of CD8 virus particles by T-lymphocytes of patients increased after each vaccination, while the procedure had practically no side effects. The most important result is that laboratory testing has demonstrated that each subsequent stage of vaccination increases the ability of cytotoxic cells isolated from patients to suppress HIV activity.
Unfortunately, HIV is an unsurpassed master of disguise. It changes the proteins that make up its particles extremely quickly, which, in most cases, allows a small number of virions to escape from persecution. Therefore, the developed vaccine does not completely get rid of HIV, but it is safe and has a pronounced, albeit limited, therapeutic effect.
The article by Van Gulck E et al. mRNA-based dendritic cell vaccination induces potent antiviral T-cell responses in HIV-1-infected patients is published in the journal AIDS.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the Institute of Tropical Medicine Antwerp: New HIV-vaccine tested on people.
Portal "Eternal youth" http://vechnayamolodost.ru
15.02.2012