A vaccine created from research in space may soon be put to
the test in human trials for the first time.
The Astrogenetix company, based in Austin, Texas, has begun applying
for approval to begin testing their space-designed salmonella
vaccine on humans. Salmonella
are disease-causing bacteria responsible for about 40,000 infections in the
United States each year, according to the Centers for Disease Control and
Prevention. Eating contaminated food is one primary means of infection.
"If all the stars are aligned, we could potentially be in
human trials sometime next year," said Astrogenetix CEO John Porter.
"That's a real milestone."
The company created its vaccine
candidate based on research conducted on NASA's space shuttle flights.
Astrogenetix has sent up experiments on 23 shuttle missions so far - most
recently on Discovery's flight earlier this month. The company plans to
continue with the six remaining missions on NASA's current schedule.
If their vaccine gets approval to go forward with human
trials, it will be the first time a medicine created from space-based research
has gone that far.
Stronger bugs in space
The key to new vaccines lies in an important difference in
the way things grow in space. Many bacteria and viruses have been shown to grow
more quickly in the microgravity of space, as well as become more
virulent or more infectious.
"We don't fully understand why these bugs show
increased virulence," Porter told SPACE.com. "But when you see
increased virulence it helps you to target potential therapeutic candidates at
a particular disease."
The changes that occur in weightlessness help speed up
experiments, and help point researchers toward the causes of virulence, not
just in space but on Earth as well.
Astrogenetix scientists have used their experiments to try
to hunt down the genes responsible for virulence in various diseases. Once they
have identified potential genes responsible, they can try to remove those genes
to create a vaccine.
"A vaccine is the bacteria itself, but changed in some
way so that it doesn't have the same infectious characteristics, so you can
expose the body to it but not make a person sick," Porter said. "Once
we can determine the genes that are the root cause of virulence, we can delete
the gene to delete the virulence."
That's just what Astrogenetix did for salmonella.
Over the course of many experiments, researchers homed in on a pattern of genes
that seemed to be responsible for virulence in the bacteria, and then removed
them to create a test vaccine.
Astronauts aboard space shuttle flights helped carry out the
research. Once in space, an astronaut would activate the experiment, beginning
the growth cycle of the bacteria. Simultaneously, a control experiment would
run on the ground. Once the shuttle flights landed, Astrogenetix would collect
the canisters carrying the experiments, and analyze the data.
Other illness in the crosshairs
Astrogenetix doesn't intend to stop at salmonella. Its
scientists are also hard at work on a vaccine to prevent infection from Methicillin-resistant
Staphylococcus aureus (MRSA) - a bacterium that causes a certain
type of staph infection. This strain is common in hospitals, and is especially
hard to treat because the bacteria are resistant to a large number of
antibiotics.
"It's a really bad disease," Porter said. "Our
research shows that 19,000 people in the U.S. alone die from this a year."
The researchers are still in the information-gathering
phase, trying to close in on the genes responsible for its infectious nature. Astrogenetix's
last MSRA experiment flew on the STS-128
mission of the shuttle Discovery, which landed Sept. 11.
The company hopes to continue this work both on future
shuttle missions, and on long-duration experiments on the International Space
Station.
"We're designing medicines using the microgravity
environment of space, but these medicines are for use on Earth," Porter
said. "These are true medicines that can be pushed out in the world."
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