Researchers in the Department of Microbiology, Immunology and Pathology have received a $100,000 Grand Challenges Explorations grant from the Bill and Melinda Gates Foundation. The one-year grant will support an innovative global health research project to develop a vaccine system that attacks the saliva of sand flies to prevent them from spreading infectious diseases like leishmaniasis.
The project, led by Drs. William Wheat, Richard Titus and John Spencer, is one of 81 grants announced by the Gates Foundation in the second funding round of Grand Challenges Explorations, an initiative to help scientists around the world explore bold and largely unproven ways to improve health in developing countries. The grants were provided to scientists in 17 countries on six continents. Grand Challenges Explorations is a five-year, $100 million initiative of the Gates Foundation to promote innovation in global health.
To receive funding, Drs. Wheat, Titus and Spencer showed in a two-page application how their idea falls outside current scientific paradigms and might lead to significant advances in global health. The initiative is highly competitive, receiving more than 3,000 proposals in this round.
Leishmaniasis is particularly problematic in Afghanistan, Iraq, Mexico and regions near the equator. The research will focus on a compound found in the saliva of sand flies called maxadilan. Research overseen by Dr. Titus has recently shown that maxadilan amplifies the impact of parasites that cause leishmaniasis. The microscopic parasites are passed to a victim through sand fly saliva. Leishmaniasis is a disfiguring skin disease and, in some cases, may be fatal.
Researchers know that if a host is injected with a needle filled with the parasites that cause leishmaniasis, they would need to use thousands more of the parasites to mimic the transmission of the disease caused by a single sand fly bite to a host, according to Dr. Wheat. That led to the discovery of how maxadilan plays a key role in amplifying the impact of the parasites on the host. It makes the saliva/parasite mix present in an actual bite much more potent than parasites alone.
Although maxadilan exists only in sand flies, the concept that saliva plays an important role in the spread of infectious diseases carried by insects is likely applicable to other diseases such as West Nile disease, bubonic plague, Dengue fever, malaria and other insect-borne diseases. If the researchers can discover a way to turn off the effect of saliva in an infectious insect bite, the knowledge could be widely applied to help develop an inexpensive vaccine effective against multiple diseases.