Antigenic relationships between adult and larval Anopheles tessellatus midgut glycoproteins and the midguts of other vector mosquitoes.

Abstract

Glycoproteins expressed on the surface of midgut (MG) epithelium and the peritrophic matrix (PM) of vector mosquitoes (Diptera: Culicidae) are candidate molecules for interacting with pathogens. Antisera produced against Anopheles tessellatus Theobald female MG lectin-binding proteins (concanavalin A and wheat germ agglutinin) were used in Western blots to investigate MG/PM antigenic relationships between adult and larval An. tessellatus and with the MG glycoproteins of other vector mosquitoes: Anopheles culicifacies Giles, An. subpictus Grassi, An. varuna Iyengar, Aedes aegypti (L.) and Culex quinquefasciatus Say. Within An. tessellatus, strong antigenic cross-reactions were observed between adult and larval MG proteins, and between adult MG and PM proteins. Anopheles tessellatus adult MG antisera reacted with MG antigens from adult females of the other five mosquito species, with interspecific contrasts of relative molecular mass (Mr) of nearly all reacting antigens, except the strong 36 kDa band shared by An. tessellatus and Cx. quinquefasciatus. Cross-reactivity within female An. tessellatus may be due to the MG containing precursors to the PM glycoproteins and/or some common fully processed proteins, or perhaps carbohydrate epitopes that are shared between related or unrelated MG and PM glycoproteins. Cross-reactions between adult MG proteins from different mosquito species, mostly with differential Mr, reflect the presence of homologous proteins that may be relevant to specific vector competence.