A brother and sister with an extremely rare genetic condition have a stunning ability to fight off viruses — an ability that could lead to a new family of antiviral drugs.
Their bodies stop viruses from building a protective shell, which leaves viruses "naked" and vulnerable, researchers report in the New England Journal of Medicine.
The siblings, an 11-year-old boy and a 6-year-old girl, are severely disabled, suffering seizures, developmental delays, fragile bones and hearing loss, among other conditions.
But the same mutation that’s caused their health troubles also manages to cripple viruses, preventing them from setting up an infection. The children are practically immune to many viral infections.
“They are teaching us that we can manipulate the immune system,” said Dr. Sergio Rosenzweig, an immune deficiency expert at NIH’s National Institute of Allergy and Infectious Diseases.
Tests using cells from the children, who are being studies as part of NIH’s research into rare diseases, shows their cells also resist herpes, dengue and hepatitis C viruses. They don’t resist all viruses — cold viruses such as adenoviruses don’t use a sugar-protein shell.
“We can use the lessons used from these patients to apply to the general population to learn how to modulate the immune system,” Rosenzweig, who led the research team, told NBC News.
The mutation prevents the children’s bodies from finishing a very basic biological function called glycosylation, which is the process of attaching sugars to proteins. “It affects almost every organ, every function of the body,” Rosenzweig said.
It also blocks viruses, because viruses are not complete organisms. They can’t do anything without first hijacking a cell. In the children, they are hijacking faulty cells that are useless to the virus. Viruses like influenza and the AIDS virus use their victim’s glycosylation to build a protective shield.
“They need us to build that shell,” says Rosenzweig.
“Without that shell, the virus is going to be naked. When the virus is naked, it dies and it cannot infect other cells.”
Rosenzweig thinks it’s possible to block this function temporarily — not long enough to damage a person’s cells, but long enough to make a virus naked. In fact, he says, scientists have been working on a compound that will do this — sometimes called a MOG inhibitor — for 20 years or so.
One, called miglustat, is already on the market to treat Gaucher disease, a genetic disease that affects fat storage and liver function.
One study testing miglustat in patients with HIV found only mild side-effects.
“The worst side-effect was flatulence,” Rosenzweig said. “So I don’t think that would be a problem unless you were in the same room as that person.”