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[EMAIL PROTECTED] New Scientist Killer virus An engineered mouse virus leaves
us one step away from the ultimate bioweapon
A VIRUS that kills every one of its victims, by wiping out part of their
immune system, has been accidentally created by an Australian research team.
The virus, a modified mousepox, does not affect humans, but it is closely
related to smallpox, raising fears that the technology could be used in
biowarfare. The discovery highlights a growing problem. How do you stop
terrorists taking legitimate research and adapting it for their own nefarious
purposes?The Australian researchers had no intention of producing a killer
virus. They were merely trying to make a mouse contraceptive vaccine for pest
control. "But it's a good way to show how to alter smallpox to make it more
virulent," says Ken Alibek, former second-in-command of the civilian branch
of the Soviet germ-warfare programme.Ron Jackson of CSIRO's wildlife division
and Ian Ramshaw at the Aus! tralian National University, both in Canberra,
inserted into a mousepox virus a gene that creates large amounts of
interleukin 4. IL-4 is a molecule that occurs naturally in the body. As part
of a study aimed at creating a contraceptive vaccine, they were trying to
stimulate antibodies against mouse eggs, which would make the animals
infertile. The mousepox virus was merely a vehicle for transporting the egg
proteins into mice to trigger an antibody response. The researchers added the
gene for IL-4 to boost antibody production. The surprise was that it totally
suppressed the "cell-mediated response"-the arm of the immune system that
combats viral infection.Mousepox normally causes only mild symptoms in the
type of mice used in the study, but with the IL-4 gene added it wiped out all
the animals in nine days. "It would be safe to assume that if some idiot did
put human IL-4 into human smallpox they'd increase the lethality quite dramatically," says Jackson. "Seeing the consequences of what happened in the
mice, I wouldn't be the one who'd want to do the experiment."To make matters
worse, the engineered virus also appears unnaturally resistant to attempts to
vaccinate the mice. A vaccine that would normally protect mouse strains that
are susceptible to the virus only worked in half the mice exposed to the
killer version. "It's surprising how very, very bad the virus is," says Ann
Hill, a vaccine researcher from Oregon Health Sciences University in
Portland. If bioterrorists created a human version of the virus, vaccination
programmes would be of limited use.Alibek, who now works on developing novel
treatments for anthrax for the defence contractor Hadron in Virginia, says
this highlights the drawback of working on vaccines against bioweapons rather
than treatments. "I'd say any vaccine could be overcome by one or another
genetically engineered virus or! bacterium," he says.Is it possible that
research into new vaccines against cancer and other diseases could
inadvertently create lethal human viruses? Many of the most promising modern
vaccines depend on viruses to transport genes into the body, and contain
genes that directly alter the immune response. But researchers have not been
too concerned because the evidence until now suggested that changes in the
genetic make-up of viruses invariably makes them less virulent, not more. One
way to reduce the risk, says Gary Nabel of the National Institutes of Health,
is to use only viruses that cannot replicate. "There are some
replication-competent [viral vaccines] around, but there is increasing
concern about their use," he says.Defence experts are also worried about
preserving the freedom to publish medical findings while trying to stop the
information falling into the wrong hands. According to D. A. Henderson, a
former US preside! ntial adviser, and director of the Center for Civilian
Biodefense Studies at Johns Hopkins University in Baltimore, what are
effectively blueprints for making microorganisms more harmful regularly
appear in unclassified journals. "I can't for the life of me figure out how
we are going to deal with this," he says. The Australian researchers
consulted their country's Department of Defence before submitting the work
for publication, and only decided to go ahead after considerable thought. A
report will appear in a February issue of the Journal of Virology. "We wanted
to warn the general population that this potentially dangerous technology is
available," says Jackson. "We wanted to make it clear to the scientific
community that they should be careful, that it is not too difficult to create
severe organisms."
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Author: Rachel Nowak, Melbourne New Scientist issue: 13th January 2001 Please
mention New Scientist as the source of this story and, if publishing online,
please carry a hyperlink to: http://www.newscientist.com
http://www.eurekalert.org/releases/nsm-aem011001.html
