LONDON Aug 13 Scientists studying the lethal
Ebola virus say they have found how it blocks and disables the
body's ability to battle infections in a discovery that should
help the search for potential cures and vaccines.
In the largest and deadliest outbreak of the disease yet
recorded, Ebola has killed more than 1,000 people in West Africa
A group of scientists in the United States found that Ebola
carries a protein called VP24 that interferes with a molecule
called interferon, which is vital to the immune response.
"One of the key reasons that Ebola virus is so deadly is
because it disrupts the body's immune response to the
infection," said Chris Basler of the Icahn School of Medicine at
Mount Sinai, New York, who worked on the study.
"Figuring out how VP24 promotes this disruption will suggest
new ways to defeat the virus."
The team, lead by Gaya Amarasinghe from Washington
University School of Medicine, found that VP24 works by stopping
something called "transcription factor STAT1" - which carries
interferon's antiviral message - from entering the nucleus of a
cell and initiating an immune response.
"This study shows just how nefarious the Ebola virus can
be," said Ben Neuman, a virologist at Britain's university of
Reading who was not directly involved in this study.
"Ebola virus carries a small tool that intercepts the cell's
distress signals, and when this happens, it disables some of the
most useful machinery that our bodies have for fighting Ebola.
That leaves the body with only crude defences that are less
effective at stopping the virus, and end up causing much of the
damage that can eventually lead to death."
Ebola is one of the most deadly diseases known in humans and
has a case fatality rate of up to 90 percent. In the current
epidemic in West Africa, the virus has infected more than 1,800
people. So far, 1,013 of these have died, the vast majority in
Guinea, Liberia and Sierra Leone.
There are no proven treatments or vaccines to prevent Ebola,
although several biotech companies and research teams have
potential drugs in development.
Amarasingh's team, whose work was published in the journal
Cell on Wednesday, said understanding how Ebola disarms immune
defences will be crucial in the development of new treatments.
A World Health Organisation-convened panel of experts said
on Tuesday that patients infected with Ebola in the West African
outbreak could be offered experimental drugs.
The WHO's panel of medical ethicists said several drugs had
passed the laboratory and animal study phases of development and
should be fast-tracked into clinical trials and made available
for compassionate use.
(Editing by Crispian Balmer)