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Mosquito salivary allergen Aed a 3: cloning, comprehensive molecular analysis, and clinical evaluation
Author(s) -
Peng Z.,
Xu W. W.,
Sham Y.,
Lam H.,
Sun D.,
Cheng L.,
Rasic N. F.,
Guan Q.,
James A. A.,
Simons F. E. R.
Publication year - 2016
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/all.12812
Subject(s) - allergen , medicine , immunology , virology , allergy
Background Allergic reactions to mosquito bites are an increasing clinical concern. Due to the lack of availability of mosquito salivary allergens, they are underdiagnosed. Here, we reported a newly cloned mosquito Aedes ( Ae .) aegypti salivary allergen. Methods A cDNA encoding a 30‐ kD a Ae. aegypti salivary protein, designated Aed a 3, was isolated from an expression library. The full‐length cDNA was cloned into a baculovirus expression vector, and recombinant Aed a 3 ( rA ed a 3) was expressed, purified, and characterized. Skin prick tests with purified rA ed a 3 and Ae. aegypti bite tests were performed in 43 volunteers. Serum rA ed a 3‐specific IgE levels were measured in 28 volunteers. Results The primary nucleotide sequence, deduced amino acid sequence, and IgE‐binding sites of Aed a 3 were identified. rA ed a 3‐selected antibodies recognized a 30‐ kD a Ae. aegypti saliva protein. rA ed a 3 bound IgE in mosquito‐allergic volunteers and the binding could be inhibited by the addition of natural mosquito extract dose dependently. Immediate skin test reactions to rA ed a 3 correlated significantly with mosquito bite‐induced reactions. Of the bite test‐positive volunteers, 32% had a positive rA ed a 3 skin test and 46% had specific IgE. No bite test‐negative volunteers reacted to rA ed a 3 in either the skin tests or the IgE assays, confirming the specificity of the assay. Conclusions Aed a 3 that corresponds to the Aegyptin protein is a major mosquito salivary allergen. Its recombinant form has biological activity and is suitable for use in skin tests and specific IgE assays in mosquito‐allergic individuals.