Researchers at UT Southwestern Medical Center have discovered the genetic factors that make some mosquitoes resistant to malaria.
The researchers say that TEP1 protein in the mosquito's immune system is the key to their finding.
When a mosquito is infected with a parasite that causes malaria, a biochemical reaction is triggered that physically transforms TEP1 into an active state capable of grabbing on to the parasite's surface and targeting it for termination, they say.
In a study, reported online in the Proceedings of the National Academy of Sciences, the researchers used a method called X-ray crystallography to uncover TEP1's three-dimensional structure.
It was found that the genetic differences between mosquitoes resistant to or susceptible to malarial parasite manifest mainly in a region of the TEP1 protein called "the warhead", the portion that grabs the parasite.
"TEP1 is a scout that finds the enemy, in this case malarial parasites, then plants a homing signal on the enemy and calls in the air strike," said lead study author Dr. Richard Baxter, a postdoctoral researcher in biochemistry at UT Southwestern.
He said that the understanding as to how some mosquitoes are able to fend off malaria might someday lead to reducing or even eliminating the insect's capacity to transmit the devastating disease.
"We have been trying to cure people of malaria for over a century. Only recently have people started to think about curing mosquitoes of malaria," said Dr. Baxter, who also is a research associate with the Howard Hughes Medical Institute at UT Southwestern.
Nobel laureate Dr. Johann Deisenhofer, who is senior author of the study, said that the new findings were the indication that just like humans, mosquitoes also want to get rid of malaria.
"This finding opened my eyes to the fact that mosquitoes are almost as unhappy about malaria as we are. They try to get rid of it." Dr. Johann Deisenhofer, who was awarded the 1988 Nobel Prize in chemistry for using X-ray crystallography to describe the structure of a protein involved in photosynthesis.
The researchers are now planning to genetically manipulate the warhead to study its binding properties. Dr. Baxter says that further research is needed to determine what other elements of the mosquito's immune system are activated once TEP1 binds to an invader.