Scientists engineer malaria blocking mosquito immune systems

Johns Hopkins Malaria Research Institute scientists have demonstrated that the innate immune system of the anopheles mosquito can be genetically engineered to block the transmission of malaria-causing parasites to humans.
The researchers also showed that the genetic modification had only a limited impact on the mosquito's fitness in laboratory conditions. The scientists' findings were published in Thursday's PLoS Pathogens journal.
George Dimopoulos and his colleagues genetically engineered anopheles mosquitoes to produce more than normal levels of the immune system protein Rel2 when they feed on blood. Rel2 acts against the malaria parasite in the mosquito by starting an immune attack that involves various anti-parasitic molecules. This allowed the researchers to use one of the insect's own genes to strengthen its parasite-fighting capabilities instead of introducing a new gene into the DNA of the mosquito.
According to the researchers, this genetically modified mosquito could be used to convert malaria-transmitting populations into Plasmodium-resistant populations. One potential obstacle to this approach is that the genetically-modified malaria-resistant mosquitoes would need to compete with the natural malaria-transmitting mosquitoes. In the study, the Rel2 genetically-modified mosquito strain lived as long and laid as many eggs as the non-modified wild type.
"Malaria is one of world's most serious public health problems," Dimopoulos said. "Mosquitoes and the malaria parasite are becoming more resistant to insecticides and drugs, and new control methods are urgently needed. We've taken a giant step towards the development of new mosquito strains that could be released to limit malaria transmission, but further studies are needed to render this approach safe and fail-proof."