Transmission electron micrograph of the 2009 H1N1 influenza virus
Scientists at MIT are developing a new drug that may fight viruses as effectively as antibiotics like penicillin dispatch bacteria. The broad-spectrum treatment is designed to trigger cell suicide in cells that have been invaded by a virus, thereby halting infection, while leaving healthy cells alone.
In lab tests using animal and human cells, the new therapy was effective against 15 viruses, including the common cold, H1N1 influenza, dengue fever, a polio virus, a stomach virus and several types of hemorrhagic fever. “In theory, it should work against all viruses,” said Todd Rider, a senior staff scientist in Lincoln Laboratory’s Chemical, Biological, and Nanoscale Technologies Group at MIT, who invented the new technology.
Microscope images show that DRACO successfully treats viral infections. In the right-hand set of four photos, dengue virus kills untreated monkey cells (lower left), while DRACO shows no toxicity in uninfected cells (upper right) and cures an infected cell population (lower right). (Photo: Courtesy MIT)
The drug works by using human cells’ natural defense systems against viral infection. When a virus infects a healthy cell, it takes over the cell’s machinery for its own purposes: to replicate. In the process, the virus produces long strands of double-stranded RNA, or dsRNA — the telltale mark of an infected cell.
Eventually, once the virus has finished replicating, it will kill off its host cell and move on.
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To fight infection, human cells have proteins that attach to dsRNA and trigger a cascade of reactions that stop viruses from copying themselves. Rider had the idea to combine one of these proteins with yet another protein that induces cells to commit suicide, a process known as apoptosis.
The end result is a drug called DRACO (for double-stranded RNA activated caspase oligomerizers). When one end of DRACO binds to dsRNA, it signals the other end of DRACO to initiate apoptosis, killing cells before the virus has a chance to replicate.
“Viruses are pretty good at developing resistance to things we try against them, but in this case, it’s hard to think of a simple pathway to drug resistance,” said Karla Kirkegaard, a professor of microbiology and immunology at Stanford University.
In lab experiments, DRACO cured mice that had been infected with the H1N1 flu virus. The researchers think the treatment could potentially be used to thwart outbreaks of new viruses like the one that causes SARS.
The scientists are currently testing DRACO against more viruses in mice and said they hope to license the technology for trials in larger animals someday in humans.
The results were published in the online medical journal PLOS One.
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Meredith Melnick is a reporter at TIME. Find her on Twitter at @MeredithCM. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.