Zika virus has infected hundreds of thousands of people around the
world, mostly in the Americas. In the United States and its territories,
more than 38,000 Zika cases have been reported so far, most of them in
Puerto Rico. There are no vaccines or treatments to prevent or treat the
symptoms of Zika infection.
Until it burst onto the scene in 2016, Zika was an obscure,
little-known virus. As a result, scientists know little about how it
‘Seven key proteins in the Zika virus that may be the culprits behind the birth defects and neurological problems have been identified by researchers.’
Over the past year, scientists have learned that the Zika virus can cause a range
of dangerous health problems, including birth defects such as
microcephaly and neurological problems such as Guillain-Barré syndrome.
But they don't know which Zika protein or proteins are causing harm, or
exactly how these proteins cause damage.
Now, a new study by scientists at the University of Maryland School
of Medicine (UM SOM) has for the first time identified seven key
proteins in the virus that may be the culprits behind this damage. The
study is the first comprehensive description of the Zika virus genome.
The study was published today in the journal Proceedings of the National Academy of Sciences
"The mechanism of this virus has been a real mystery," said the lead
researcher on the study, Richard Zhao, a professor of pathology at UM
SOM. "These results give us crucial insight into how Zika affects cells.
We now have some really valuable clues for future research."
To test the virus, Dr. Zhao used fission yeast, a species that in
recent years has become a relatively common way to test how pathogens
affect cells. Fission yeast was originally used to make beer,
particularly in Africa, where it originated. (Its species name is
Schizosaccharomyces pombe; pombe means beer in Swahili.) Over decades,
fission yeast has been used by many scientists to find out mechanisms
and behavior of cells.
Dr. Zhao is a pioneer in using the fission yeast model to study HIV,
as well as the Yellow Barley Dwarf virus, a plant pathogen that causes
billions of dollars in crop damage every year throughout the world. So
he was very familiar with the fission yeast model. "With Zika we are in a
race against time," he says. "I asked myself what I can do to help. I
have this unique way of dissecting the genome. So I started on this."
For the experiment, Dr. Zhao and his colleagues separated each of
the virus's 14 proteins and small peptides from the overall virus. He
then exposed yeast cells to each of the 14 proteins, to see how the
cells responded. Seven of the 14 proteins harmed or damaged the yeast
cells in some way, inhibiting their growth, damaging them or killing
Dr. Zhao and his colleagues will continue to work on Zika. The next
step is to understand more about how these seven proteins work in
humans. It may be that some of them are more damaging than others, or
perhaps all of them work in concert to cause harm. Dr. Zhao is now
beginning research on how the virus interacts with rat and human cells,
in collaboration with one of the study's co-authors, J. Marc Simard, a
professor of Neurosurgery at UM SOM.
Another co-author is Robert C. Gallo, the director of the Institute of Human Virology.