Characterization of Aedes communis, Aedes aegypti and Anopheles stephensi mosquito saliva antigens by immunoblotting

Background: Mosquito bites cause immediate wheals and delayed bite papules in sensitized subjects having saliva-specific IgE and IgG4 antibodies. At present, mosquito saliva antigens are not well characterized. Methods: To identify immunogenic proteins in mosquito saliva and study their cross-reactivity we immunized mice with Aedes communis, Aedes aegypti and Anopheles stephensi bites. Immune sera were used in immunoblotting and immunoblot inhibition experiments. Results: The main A. communis saliva antigens were 22-, 30-, and 36-kD, A. aegypti saliva antigens 31-, 36-, 46- and 64- to 66-kD, and A. stephensi saliva antigen 46-kD proteins. Most of the saliva antigens appeared to be species-specific and only weak cross-reactivity was observed with heterologous immune sera. Distinct cross-reactivity was observed only between saliva proteins of A. communis and Aedes punctor, two taxonomically closely related species. Human IgE and IgG4 antibodies from mosquito-bite-sensitive children bound to the same saliva proteins as antibodies from the immunized animals. Conclusions: This study disclosed several immunogenic proteins in Aedes and Anopheles mosquito saliva and suggests that these proteins can also be allergenic in man.