Sea cucumbers live on the ocean
floor
|
Sea cucumbers could
provide a potential weapon to block transmission
of the malaria parasite in your body, a study suggests.
The creature produces a protein, called lectin,
which impairs development of the parasites.
A team genetically engineered
mosquitoes that carry the malaria parasite to
produce the same protein in their gut when feeding.
The Pathogens study found the protein
disrupted development of the parasites inside the
insects' stomach.
Malaria causes severe illness in 500 million
people worldwide each year, and kills more than one
million.
It is estimated that 40% of the world's
population are at risk of the disease.
To stimulate the mosquitoes to produce lectin,
the researchers fused part of the gene from the sea
cucumber which produces the protein with a gene from
the insect.
The results showed that the technique was
effective against several of the parasites which
cause malaria.
Lectin is poisonous to the parasites when they
are still in an early stage of development called an
ookinete.
Usually, the ookinetes migrate through the
mosquito's stomach wall, and produce thousands of
daughter cells which invade the salivary glands, and
infect a human when the mosquito takes a blood meal.
But when exposed to lectin the ookinetes are
killed before they can start their deadly journey.
Work left
Researcher Professor Bob Sinden, from Imperial
College London, said: "These results are very
promising and show that genetically engineering
mosquitoes in this way has a clear impact on the
parasites' ability to multiply inside the mosquito
host."
However, he said much more work still had to be
done before the technique could be used to curb the
spread of malaria.
"Although the sea cucumber protein significantly
reduced the number of parasites in mosquitoes, it
did not totally remove them from all insects.
"At the current stage of development, the
genetically modified mosquitoes would remain
dangerous to humans.
"Ultimately, one aim of our field is to find a
way of genetically engineering mosquitoes so that
the malaria parasite cannot develop inside them."
Professor Sanjeev Krishna, an expert in malaria
at St George's Hospital Medical School, London, said
new treatments for malaria were vital, as there was
some sign that the parasites which cause the disease
were developing resistance to the current
artemisinin drugs.
He said: "This is a very important first step in
developing a potential new way to control this
infection."
Dr Ron Behrens, of the London School of Hygiene
and Tropical Medicine, said the technique showed
promise in theory - but he warned that introducing
genetically modified mosquitoes could be fraught
with practical difficulties.
"You would have to get the modified version to
become the predominant species, and that has never
been done in any setting before," he said.
Ultimately, one aim of our field
is to find a way of genetically
engineering mosquitoes so that the
malaria parasite cannot develop
inside them
