Probing the Interplay Between Viruses and the Immune System
Scientists have developed a new test that can identify almost every viral exposure a person has ever had using only one drop of blood.
The research has potential for new discoveries on the interplay between the human immune system and the vast array of viruses that can infect humans. The test is expected to become an important research tool for epidemiologists seeking to track patterns of diseases in various populations, and may shed light on whether viruses or the body’s immune responses to them contribute to chronic diseases and cancer.
Researchers from Harvard Medical School and Brigham and Women’s Hospital tested blood samples from 600 people from the U.S., Peru, South Africa and Thailand. A Harvard Medical School release explains the researchers developed a library of peptides—the short protein fragments derived from viruses—representing 1,000 viral strains. That’s pretty much the whole human virome, or all the viruses to which humans are susceptible. Using a test called VirScan on a single drop of blood, the scientists were able to detect evidence of past and present viral exposure. The study is published in the journal Science.
“VirScan is a little like looking back in time,“ senior author Stephen J. Elledge, a Harvard professor of genetics said in the release, because the test shows viruses a person has had over many years. “A viral infection can leave behind an indelible footprint on the immune system,” he said. “Having a simple reproducible test like VirScan may help us generate new hypotheses and understand the interplay between the virome and the host’s immune system, with implications for a variety of diseases.”
For instance, researchers may be able to identify correlations between an early exposure and a disease later in life. A connection is already known between the Epstein-Barr virus, one of the most common viruses observed in this study, and certain cancers. Dr. Elledge also notes that a unique feature of the new research is scale: now, doctors have to test individually for any viruses they suspect whereas VirScan tests for almost every virus known in one test.
A New York Times story by Denise Grady quoted several scientists on the vast potential for the work. Dr. William Schaffner, an infectious disease expert at Vanderbilt University, likened the research to the introduction of the electron microscope. He also suggested that tests in large populations could identify the ages at which children are most exposed to various illnesses, which could help find the best timing for vaccinations. Others hailed the possibility for new discoveries through big data on viral exposure. The Times story notes researchers have long suspected that such autoimmune disorders as Type 1 diabetes and multiple sclerosis may be related to viral exposure that provoke the immune system to produce antibodies, which then mistake the body’s own cells for viruses and attack them. Further, the technology may help researchers learn why cancers progress faster in some patients than others, and why responses to treatment differ.
“I am sure there will be lots of applications we haven’t even dreamed of,” Dr. Elledge told the Times. “That’s what happens when you invent technology. You can’t imagine what people will do with it.”