Could a Drug Engineered from Bananas Fight Deadly Viruses?
A banana a day may not keep the doctor away, but a substance originally found in bananas and carefully edited by scientists could someday fight off a wide range of viruses, according to a study done by an international team of researchers and published in October 2015 in the journal Cell.
Beyond that, a release from the University of Michigan Life Sciences Institute notes that the process used to create the virus-fighting form may help scientists develop even more drugs by harnessing the “sugar code” that our cells use to communicate. That code gets hijacked by viruses and other invaders.
The new research focuses on a protein called banana lectin, or BanLec, that “reads” the sugars on the outside of both viruses and cells. Five years ago, scientists showed it could keep the virus that causes AIDS from getting into cells – but it also caused side effects that limited its potential use.
In the published paper, the scientists report how they created a new form of BanLec that still fights viruses in mice, but doesn’t have a property that causes irritation and unwanted inflammation.
They succeeded in peeling apart these two functions by carefully studying the molecule in many ways, and pinpointing the tiny part that triggered side effects. Then, they engineered a new version of BanLec, called H84T, by slightly changing the gene that acts as the instruction manual for building it.
The result: a form of BanLec that worked against the viruses that cause AIDS, hepatitis C and influenza in tests in tissue and blood samples – without causing inflammation. The researchers also showed that H84T BanLec protected mice from getting infected by flu virus.
The release quotes David Markovitz, M.D., co-senior author of the new paper and a professor of internal medicine at the University of Michigan Medical School, as saying, “What we’ve done is exciting because there is potential for BanLec to develop into a broad spectrum antiviral agent, something that is not clinically available to physicians and patients right now. But it’s also exciting to have created it by engineering a lectin molecule for the first time, by understanding and then targeting the structure.”
A global project tackles a global problem
The 26 scientists on the team – from Germany, Ireland, Canada, Belgium and the United States – worked together over several years to figure out exactly how BanLec worked against viruses, and then to build a better version. They were funded by the U.S. and European governments, and by foundations.
They used a wide range of scientific tools – including X-ray techniques used by the U-M Center for Structural Biology that let them figure out the location of every atom in the original and new forms of BanLec.
Their efforts helped them understand how BanLec connects to both viruses and to sugar molecules on the outside of cells, and how it leads to irritation and other side effects by triggering signals that call in the “first responders” of the body’s immune system.