Leishmania major infections in Phlebotomus duboscqi fed on murine models immunized with L. major subcellular antigens and sandfly gut antigens

The ability of antibodies in bloodmeals of mice and hamsters immunized with Leishmania major subcellular fractions and sandfly (Phlebotomus duboscqi) gut antigens to inhibit development of L. major in its vector P. duboscqi was examined. Antibodies from animals immunized with either L. major subcellular fractions alone or sandfly gut antigen alone were not very effective in inhibiting development of L. major in the sandfly. When P. duboscqi were fed on blood from animals immunized with both parasite flagella and sandfly gut antigen, development of L. major was significantly inhibited (P<0,05). Control sandflies fed on naive animals displayed a normal pattern of parasite development to the metacyclic stage. Electron microscopy studies showed that one of the mechanisms through which antisandfly gut antibody can cause inhibition of parasite development is by lysing sandfly gut epithelium. This study has demonstrated that it is possible to reduce transmission of leishmaniosis through immunization against both the parasite and its sandfly vector.