Lectin microarray analysis of salivary gland glycoproteins from arboviral vector Aedes aegypti and malaria vector Anopheles stephensi

Abstract

Background & objectives: Salivary gland proteins but not glycoconjugates have been previously studied in mosquito vectors of human diseases. Glycoconjugates from salivary gland-derived proteins from human-feeding tick vectors can elicit hypersensitivity reactions which may also occur with mosquito bites. Protein glycoconjugate in salivary glands of the principal arboviral vector Aedes aegypti and the rapidly spreading malaria vector Anopheles stephensi were investigated. Methods: Forty different lectins in a microarray were used to analyse glycoconjugates in salivary gland proteins from both mosquito species. Results: Salivary gland glycoproteins of both mosquitoes possessed similar lectin-binding specificities. Lectin-binding profiles in both mosquitoes showed the significant presence of oligomannose N-linked glycans, O-linked glycans, a limited presence of glycan structures capped with terminal GalNAc, GlcNAc, β-linked Gal, αl-6 linked fucose, and no detectable sialic acids or terminal α-linked Gal in salivary gland glycoproteins. Interpretation & conclusion: Aedes aegypti and An. stephensi possess similar salivary gland protein glycoconjugates to mosquito larval tissues. They differ from arachnid ticks in lacking detectable α-gal epitopes that are responsible for red meat allergy caused by tick bites.