Fly spit protein holds back parasite infection in monkeys

sand fly

Proteins from the saliva of sand flies such as Phlebotomus papatasi (shown) and Phlebotomus duboscqi may help scientists develop a vaccine for leishmaniasis, a disfiguring and deadly parasitic infection.

Frank Collins/CDC

A protein found in sand fly spit hints at hope for creating a vaccine to combat leishmaniasis, a deadly parasitic scourge spread by sand flies.

Monkeys given a shot containing the protein PdSP15 had smaller skin sores and fewer Leishmania parasites circulating in their blood after infection than monkeys that received a shot without the protein. Blood taken from humans who had been bitten by sand flies not infected with Leishmania parasites produced a high level of antibodies in response to the protein, showing that PdSP15 itself spurs an immune response. The results, which appear June 3 in Science Translational Medicine, support earlier studies pointing to proteins in sand fly saliva as valuable components for developing a vaccine for leishmaniasis.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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