can not remember each viral infection that you have ever had? Do not worry, your blood box. A new test identifies antibodies in the blood of a person to reveal a history of virus they were infected throughout their lives. The method could be useful not only for diagnosis of current and past illnesses, but for the development of vaccines and study the links between the virus and chronic diseases.
"This really is a technical tour de force," says Hidde Ploegh immunologist at the Massachusetts Institute of Technology in Cambridge, who was not involved in the new work. But others point out that it is difficult to know how past infections new technological accidents.
Now researchers are wondering if a patient has a particular virus infection herpes and influenza virus-testing blood samples for AIDS pathogen at a time. Many tests look for antibodies, immune system proteins produced to recognize the invaders, while others hunt for their own genetic material of the virus. Some tests can measure the presence or absence of more lasting antibodies that can persist for decades after infection.
Researchers led by Stephen Elledge biologist from Brigham and Women's Hospital in Boston and Harvard Medical School wanted to develop a test that could watch every current or past infection with one shot. They first assembled a library of nearly a hundred thousand fragments of protein synthesis, each of which represents a part of a virus which can recognize an antibody. When proteins are added to a drop of blood, the antibodies bind to fragments thereof; researchers can isolate antibodies and, from the fragments they matched with, identify someone virus was infected and that antibodies generated in response body.
The new test, called virscan, "allowing scientists to ask questions that could not simply be asked before," says Elledge. "You can compare groups of people, young and old, or those with a disease and those without and see if there is a difference in their viral stories. "for example, virscan could help determine if viral infections can trigger diabetes or chronic fatigue syndrome.
Elledge and colleagues used virscan over 500 people in the United States, Thailand, South Africa and Peru, some of them infected with HIV. on average, they report online today in Science , most people had antibodies to approximately 10 previous viral infections, although those with HIV and living outside averaging over the United States. throughout all populations, viruses common, including virus and rhinovirus herpes (that cause colds) topped the list. Surprisingly, many people had the same exact antibodies generated to infection; researchers thought the immune responses of people to be more diversified, says Elledge. This observation could inform the future development of the vaccine, he said.
That test really draws everything is up for debate, however, says microbiologist Vincent Racaniello of Columbia University. "Before we consider this a definitive definition of what people have been infected, we need to be sure there is a complete picture," he said. "Right now, I do not think it is." Racaniello stresses that virscan did not identify as many people as expected with antibodies to norovirus and rotavirus, which cause a large number of intestinal infections. This could be because antibodies to these viruses do not stick around for as long as the other-although researchers have shown that, in general, most antibodies last a lifetime or due to put in technical custody of test .
Elledge admits that, for now, virscan could miss some viruses, because they are too small or contain certain modifications that the fragment library can not understand. "We know that we will probably miss a little," he said. "But we're still detect many."
"The work is distinguished by its size and technological innovation," says Ploegh. "But if you ask an immunologist how many viruses or pathogens that you fought in your life and that the signatures of these infections remain, the results of this study would not be a surprise." actual technology value lies in the new scientific questions be answered, he said. "sketch for the natural history of the human species in interaction with viruses, I think this is a very important tool."
virscan has not yet been scaled for commercial use, but Elledge hope it does not cost much more than existing tests that look a pathogen at a time. If so, it could even be used for routine screening for annual medical examinations, he said. "You could give a drop of blood every few years and they can run to see if you have new infections," he said. This could help to diagnose viruses such as hepatitis C, which people often do not know they have.
0 Komentar