Study reveals the mosquito defence against malaria
11 March 2009
In the study, scientists from Imperial College London discovered the mechanism by which the mosquito immune system detects the malaria parasite, and is able to kill 80 to 90 per cent of them.
Mosquitoes are extremely effective at dealing with the parasite. Only a few escape, though that can be sufficient to transmit the parasite to a human.
The study, published in the journal Science, found that two mosquito proteins, LRIM1 and APL1C, act as an intruder detection system. When infection occurs, the proteins activate another protein called TEP1 that seeks out the parasite and binds to its surface to help destroy it.
The researchers say this could lead to new genetic or chemical techniques that improve on the mechanism: if the mosquito could kill 100 per cent of parasites, this would reduce the transmission of malaria to humans.
"Now that we know exactly how [the mosquito] immune system attacks malaria parasites, we need to work out how a small number of parasites manage to evade detection by this system," said Dr George Christophides, who led the study.
"Only a few manage to get past the mosquito's defences, but that's all that's needed for the disease to be transmitted to humans. If we can figure out how some parasites manage to sneak through undetected, hopefully we can find a way to bolster the mosquito's defences to catch them all."
Moreover, LRIM1 and APL1C are part of a group of surveillance proteins specific to mosquitoes. The researchers believe that with further investigation, they may discover how to block other infectious diseases transmitted by mosquitoes, such as filiariasis, dengue and yellow fever.
Image credit: Wellcome Library
Reference
Leucine-rich repeat protein complex activates mosquito complement in defence against Plasmodium parasites. Science, published online before print 5 March 2009.