Where is the immunodeficiency virus hiding?
Innovative scanning technique made it possible to see clusters of HIV
In such cases, the disease returns after the patient stops taking antiviral drugs.
With this knowledge, scientists began to develop various methods for determining the dislocation of HIV foci in the body. Previously, researchers assumed that the immunodeficiency virus can hide in the immune cells of the body, slowly multiplying or being there in a "dormant" state. This hypothesis was confirmed after biopsy of immune tissue sites in the intestines of HIV-positive patients in remission.
It is obvious that for the final victory over the disease, it is necessary to activate the focus of "sleeping" HIV for subsequent destruction. In modern medicine, such techniques are often used, but until now, doctors did not have an accurate way to determine the places of accumulation of viruses and their numbers.
The lead author of the new study, Francois Villinger from Emory University in Atlanta, USA, suggested that positron emission tomography (PET) technique can be used to identify the foci of the disease. This method is quite effective when it comes to the search for cancerous tumors, and therefore scientists wondered if it was possible to set up a tomograph in such a way that it also detected foci of HIV accumulation.
Villinger and his colleagues note that this idea was born after antibodies binding to the African monkey immunodeficiency virus (SIV) were discovered.
To test their hypothesis, the researchers injected radioactively labeled antibodies to three SIV-positive monkeys who were treated with antiviral drugs. "Radioactive" antibodies bind to antigens on the surface of viruses and emit radiation, and during PET scanning, scientists detect radiation sources in the body.
A snapshot from the article A live look at the AIDS virus (Jon Cohen, News from Science) – VM.
PET scan helped to determine the location
active accumulations of the immunodeficiency virus in monkeys.
They are indicated in yellow
(photo by Philip J. Santangelo).
Thus, the study revealed the viral protein gp120 in various parts of the animal's body, including the nose, lungs, intestines, genitals and lymph nodes in the armpits and inguinal region. There were no antibodies in the brain, but scientists believe that there may be a focus of the disease.
The resolution of the tomograph was not enough to determine which cells contained the protein of the desired virus (and, accordingly, the virus itself). But the autopsy that followed after the death of the monkeys showed that the virus was indeed present in the immune cells of the organs indicated by the PET scan.
Scientists consider the disadvantage of the technique to be the fact that PET will not be able to identify foci where the virus is completely inactive. Only those clusters will be visible to the tomograph, where the replication of infectious agents, albeit slow, is observed.
In the future, Villinger and his colleagues plan to develop antibodies that can recognize the gp120 protein produced by the human strain of the virus. An article with the results of this study was published in the journal Nature Methods (Santangelo et al., Whole-body immunoPET reveals active SIV dynamics in viremic and anti–retroviral therapy-treated macaques).
Portal "Eternal youth" http://vechnayamolodost.ru11.03.2015