Detection of species-specific antibody response of humans and mice bitten by sand flies

Sand fly saliva plays an important role in Leishmania transmission. We characterized the host antibody response to saliva from 3 sand fly species. Specific IgG was observed in sera from experimentally bitten mice as well as in sera from individuals living in the endemic area of Leishmania tropica in Sanliurfa, Turkey. Sera of Sanliurfa inhabitants showed high IgG levels against saliva of Phlebotomus sergenti and P. papatasi, the 2 most abundant sand fly species in this area, but did not react with saliva of the New World sand fly, Lutzomyia longipalpis. Patients with active Le. tropica lesions possessed significantly higher anti-P. sergenti IgG levels than the healthy individuals from the same place while anti-P. papatasi IgG levels were equal in both groups. Major protein bands in P. papatasi and P. sergenti saliva reacted with both, human and mice sera; in P. papatasi, however, mouse IgG recognized preferentially the 42 kDa protein band while the human IgG reacted strongly with the 30 kDa band. Our data suggest that the antibody response to sand fly saliva could be used for monitoring the exposure of humans and other hosts to sand flies and might be used as a marker of risks for Leishmania transmission in endemic areas.