The bite of a tsetse fly transmits African trypanosomes, single-cell parasites that cause devastating diseases in humans as well as domesticated animals throughout large swaths of Africa.
Strategies used to curtail the spread of these diseases, which rely primarily on reducing the tsetse fly populations with traps and insecticides, and on curing infected individuals, are only somewhat effective. The presence of animal reservoirs further complicates disease control and necessitates more effective controls, such as a vaccine.
The development of effective anti-trypanosomal vaccines has been unsuccessful because the parasite constantly displays different surface coat antigens (a process called antigenic variation) within its mammalian host. Researchers in the lab of Professor Serap Aksoy, Ph.D., are working to develop novel strategies to prevent trypanosome-induced disease by learning more about parasite development in tsetse, with the intention of inhibiting transmission from the fly to mammalian hosts.
More specifically, Aksoy’s team is developing a transmission-blocking vaccine that would prevent trypanosomes present in tsetse saliva from establishing an infection in the mammalian host bite site. Tsetse’s salivary glands harbor several developmental forms of the parasite, only one of which, the metacyclic, is able to establish an infection in mammals after the bite of an infectious fly. Aksoy and colleagues performed single-cell RNA sequencing of trypanosomes present in tsetse’s salivary glands and identified metacyclic cell genetic signatures that encode proteins unique to the surface of metacyclic cells.