Dengue is a potentially deadly tropical illness that infects up to 100 million people per year. Unfortunately, no effective vaccine exists for the disease spread by the Aedes aegypti mosquito. But Malcolm Fraser Jr., Notre Dame professor of biology, thinks a nifty bit of genetic judo he invented may be able to turn the virus against itself.
Fraser’s idea, which recently earned a $2.5 million grant from the Grand Challenges in Global Health initiative, is to use genetic engineering techniques to produce a strain of Aedes aegypti mosquito immune to the dengue virus and thus unable to transmit it. Basically the idea is to load mosquito cells with an apoptosis-inducing gene targeted specifically to splice onto the dengue virus. Apoptosis is the scientific term for the natural process by which old or damaged cells essentially commit suicide.
When the dengue virus infects the mosquito cell, the suicide gene is activated and, whammo, the cell dies. Since the virus needs the cell to replicate, the virus dies when the cell dies. The insect then is immune and incapable of passing the virus. “The beauty is you don’t need an abundance to suppress the virus. A low level should do the trick,” Fraser says.
Ultimately the plan is to release these genetically altered mosquitos into endemic areas, which should then reduce the dengue-bearing mosquito population. If the novel technique is successful with dengue, Fraser believes it could work with other mosquito-borne illnesses, such as yellow fever, Saint Louis encephalitis or West Nile encephalitis.