Mosquitoes inhibit the hemostatic defenses of their vertebrate hosts with a variety of salivary components, many of which are antigenic. Blood feeding therefore also involves elements of both the innate and acquired immune responses. We are examining the ability of Anopheles stephensi saliva to modulate these responses, using a BALB/c and DO11 mouse model. Salivary gland extract (SGE) inhibits mitogen- and antigen-induced proliferation of both T-cells and B-cells in a dose dependent manner. In contrast to another mosquito, Aedes aegypti, this inhibition does not appear to involve induced apoptosis in these cell types. SGE also decreases the proportion of CD4+ T-cells secreting IFN-gamma, IL-2, and IL-10; proportions of IL-4-secreting cells were relatively unaffected. In addition, ELISA assays indicated dose-dependent reductions in secreted IFN-gamma, IL-2, and TNF-alpha from splenocytes. Secretion of IL-4 and IL-5 was not reduced by exposure to up to 10 salivary gland pair equivalents. Effects of SGE on neutrophil and macrophage function will also be discussed. These results are in agreement with the hypothesis that vectors modify the host immune response, and they may alter the context in which parasite antigens are perceived by the host.
Species 1: Diptera Culicidae Anopheles stephensi
Keywords: immunomodulation, blood feeding
Back to Display Presentations, Section D. Medical and Veterinary Entomology
Back to Posters
Back to The 2003 ESA Annual Meeting and Exhibition