Specificity of anti‐saliva immune response in mice repeatedly bitten by Phlebotomus sergenti

Abstract

Sand flies are bloodsucking insects transmitting parasites of genus Leishmania, the causative agents of diseases in humans and dogs. Experimental hosts repeatedly exposed to sand fly saliva can control Leishmania infection. Cell-mediated anti-saliva immune response is most likely responsible for this protective effect; however, there is no study so far concerning its antigenic specificity towards different sand fly vectors. In this study, splenocytes from BALB/c mice repeatedly exposed to the bites of Phlebotomus sergenti were challenged ex vivo with salivary gland homogenates from three different sand fly vectors -P. sergenti, P. papatasi, or P. arabicus. Mice bitten by P. sergenti had higher proliferative response to homologous antigen than splenocytes from naive mice. Splenocytes from P. sergenti bitten mice as well as anti-P. sergenti antibodies partially cross-reacted with P. papatasi saliva. In contrast, no cross-reactivity was found with P. arabicus saliva. Our data indicate that both arms of the immune system, cellular and humoral, react in a species-specific manner. Therefore, the presence of antibodies against salivary components of a certain species indicates the specificity of cell-mediated immune response as well. The data suggest that unique transmission-blocking vaccine would be required for each vector -Leishmania combination.

Expression plasticity of Phlebotomus papatasi salivary gland genes in distinct ecotopes through the sand fly season

“…Intra-species DNA vaccination studies with a specific gene, indicate that cross-species protection is possible [49]. However, protection may be limited to vaccination with specific proteins as only partial species cross reactivity was detected in mice exposed to P. sergenti bites [50] and no protection resulted with cross genera challenge in L. longipalpis s.l . exposed mice [45].…”

Assessing key safety concerns of a Wolbachia-based strategy to control dengue transmission by Aedes mosquitoes

“…This same band was not detected when blots were incubated with the human sera from either BFs (which would recognize potential Wolbachia antigens) or non BFs. As a control, extracts from Wolbachia-uninfected mosquitoes were loaded on gels and the blots were incubated with human sera or with a mouse anti-mosquito saliva antibody [developed as shown by Drahota et al (2009)] to detect whether volunteers were responding to mosquito bites (Fig. 1B).…”

Phlebotomus papatasi exposure cross-protects mice against Leishmania major co-inoculated with Phlebotomus duboscqi salivary gland homogenate

“…Salivary antigens of sand flies are mostly species-specific with possible cross-reactions occurring only between closely related species (Drahota et al, 2009;Rohousova et al, 2005;Thiakaki et al, 2005;Volf and Rohousová, 2001). However, sharing similar salivary antigens is one of the conditions required for the successful cross-protection against Leishmania infection.…”

“…Indeed, the immunity elicited by sand fly salivary proteins (Drahota et al, 2009;Rohousova et al, 2005;Volf and Rohousová, 2001) as well as the protection (Thiakaki et al, 2005) was shown to be species-specific. On the other hand, the vaccine could be cross-protective between phylogenetically related vector species with more conserved salivary proteins (Ribeiro et al, 2010;Rohoušová et al, 2012;Volf et al, 2000) and as such could be applicable in more endemic foci.…”