Researchers identify a SARS antibody
Researchers at the Dana-Farber Cancer Institute in Boston announced yesterday that they have identified a human antibody that powerfully blocks infection by the SARS virus. The discovery could lead to a new treatment for the potentially deadly disease that could be tested on humans in as little as a year.
Isolation of the 80R antibody, one of the proteins in the bloodstream that fights off bacteria and viruses, continues an extraordinary run of breakthroughs in understanding and combating a virus blamed for killing nearly 800 people last year, mainly in Asia. In less than a year, researchers worldwide have completed SARS's genetic blueprint and identified potential ways to prevent or treat it.
"This is really a proof of principle for responding to emerging infectious diseases," said Dr. Wayne Marasco of the Dana-Farber, senior author of the paper, which appeared yesterday in the online early edition of the Proceedings of the National Academy of Sciences. "If the international community works together, it can make a serious dent in the [amount of] time it takes to develop protective treatments against these threats."
By comparison, researchers needed several years to identify the cause of AIDS, and several more to develop the first effective medicines.
SARS, or severe acute respiratory syndrome, alarmed health officials worldwide with its rapid spread. Since November 2002, it has sickened more than 8,000 people in more than two dozen countries, including eight confirmed cases in the United States. Though from the same family of viruses as the common cold, SARS is far more deadly, killing 10 percent of its victims.
Marasco's team identified 80R by systematically scanning his 27-billion antibody "library," looking for antibodies that specifically targeted SARS, chemically bonding with them and preventing them from entering healthy cells. The team, working with researchers from Brigham and Women's and Boston Children's hospitals as well as the Centers for Disease Control, found that 80R prevented the virus from entering healthy cells in the first place, by gumming up the machinery SARS uses to penetrate cell walls.
Marasco's lab has already started animal testing of 80R's effectiveness, and he predicts it will take up to a year to settle basic questions such as whether 80R works as a vaccine or only as after-the-fact treatment. After that, he said human tests could begin. "It would be very satisfying to see this go into humans and do good."
