VirScan – "time machine" for virologists
A gadget has been created that reveals the history of infection with viruses by a drop of blood
Harvard bioengineers have developed a VirScan test system that reveals the history of human infection with various viruses in the past by one drop of blood, and one such test will cost only $ 25, according to an article published in the journal Science (Xu et al., Comprehensive serological profiling of human populations using a synthetic human virome).
"VirScan is a kind of time machine – using this technique, we can take a small drop of blood and find out what a person has been sick with over the past years of his life. What makes this technology unique is its scalability. Now doctors have to guess which virus has infected the body. With our technology, they will be able to search for almost every conceivable kind of virus, even the rarest, in one sitting," Stephen Elledge from Harvard University said (in a press release from Howard Hughes Medical Institute Your Viral Infection History from a Single Drop of Blood – VM).
The invention of Elledge and his colleagues is a set of short fragments of protein molecules covering the shells of various viruses, long enough to be recognized by the human immune system.
These fragments of pathogen shells were obtained in a not entirely trivial way: scientists grew them using a bacteriophage, another virus specializing in infecting bacteria, by embedding about 93 short fragments encoding viral proteins in its DNA. Thus, VirScan is a set of several thousand varieties of the same bacteriophage, in the surface of the shell of which a fragment of the "armor" of another virus is embedded.
If our body has previously encountered this or that virus, then antibodies will usually be present in the blood that "remember" its identification marks, including these proteins, and begin to cling to them and make them visible to other components of the immune system that are directly engaged in the destruction of "aggressors".
The scheme of VirScan's work from an article in Science – VM.
VirScan's work is based on this reaction – when the "cocktail" gets into the blood sample, the antibodies stick to the protein particles familiar to them. After this reaction is over, virologists wash out all other protein particles and blood residues, and determine the strain and type of virus by decoding the DNA of the bacteriophage.
Since our body continues to produce antibodies 20-40 years after infection, VirScan allows doctors to look into the past and find out what their patient was sick with in past seasons. The whole procedure takes about 2-3 days, and its price does not exceed $ 25. According to Elledge and his colleagues, their brainchild recognizes not only the flu and other harmless viruses, but also particles of HIV, hepatitis virus and other deadly retroviruses.
To test VirScan's performance, biologists traveled to Peru, South Africa and some other countries of the world, where they tested the detector with the assistance of almost six hundred volunteers. The system has proven itself well, recognizing from 95 to 100% of viruses.
In addition, she helped scientists uncover a curious fact from our lives – as it turned out, a middle-aged adult suffers about 10 viral infections over the years of his life. In addition, they managed to uncover many interesting details in the interaction of viruses and antibodies, which, as Elledge and his colleagues hope, will help virologists improve methods of combating many diseases.
Portal "Eternal youth" http://vechnayamolodost.ru05.06.2015