* Finding published in peer-reviewed journal
* 200,000 antibodies taken from 100 recovered patients
* Plans to kick off human trials
By Tan Ee Lyn
HONG KONG, June 21 (Reuters) - Scientists say they have extracted a powerful antibody from a recovered dengue patient in Singapore that can smother and choke the virus to death, a discovery that they hope may offer a new weapon to control the deadly disease.
There is currently no cure for dengue which kills 20,000 people a year, many of them children. Physicians can only manage the symptoms.
The antibody recovered from Singapore was among 200,000 taken from 100 recovered patients and appeared capable of killing all known strains of the subtype 1 dengue virus, said a paper published on Thursday in the journal Science Translational Medicine.
There are four disparate subtypes of the dengue virus, which causes an intensely painful fever.
"It kills the dengue virus even before it can get a chance to infect any cell," said Lok Shee-Mei of the Duke-NUS Graduate Medical School and a member of the research team.
In mice experiments, the researchers saw how the antibody stretched itself across the surface proteins of the virus, smothering it and locking it down.
"When the virus wants to infect cells, it needs to breathe and expand, so its surface proteins undergo slight changes ... but this antibody binds across the surface proteins, so the proteins cannot change in any sense. The virus is unable to infect," Lok said by telephone from Singapore.
Compared to some other anti-dengue chemical compounds in development, the antibody killed more viruses and acted quicker, said lead author Paul MacAry, microbiology associate professor at the National University of Singapore's faculty of medicine.
The researchers plan to test the antibody soon in people infected with dengue subtype 1 in clinical trials in Singapore.
Meanwhile, the team is combing its library and hopes to find similarly powerful antibodies that specifically target dengue subtypes 2, 3 and 4.
MacAry said his team have discovered an antibody that targets subtype 2, but it was still in the early phase of testing.
"Ninety percent of all dengue in Singapore is either type 1 or 2. This means that within the next 6 months to a year, we are going to have two antibodies that will allow us to treat most patients in Singapore," he said. (Editing by Jeremy Laurence)