IMMUNOBLOT ANALYSIS OF SALIVARY ALLERGENS IN 10 MOSQUITO SPECIES WITHWORLDWIDE DISTRIBUTION AND THE HUMAN IGE RESPONSES AS THESE ALLERGENS

Background: Most people develop skin reactions to mosquito bites, howe ver, little is known about mosquito salivary aller gens and the IgE re sponses to them.Objectives: We sought to identify these allergens and the specific IgE responses the elicit, Methods: Saliva or salivary gla nd extracts were prepared from 10 mosquito species, including seven sp ecies with worldwide distribution: Aedes (AE.) aegypti, Ae. vexans, Ae . albopictus, Ae. togoi, Ae. triseriatus, Culex (Cx.) quinquefasciatus , Cx. pipiens, Cx. tarsalis, Anopheles (An.) sinensis, and Culiseta (C s.) inornata. Proteins from these preparations were separated by sodiu m dodecylsulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes, which were immunoblotted by sequential incu bations with human serum, monoclonal anti-human IgE, and enzyme-conjug ated goat anti-mouse IgG. Salivary allergens were analyzed by using a pooled serum from subjects allergic to mos quitos. Individual IgE resp onses to each allergen were evaluated in 12 subjects allergic to mosqu itos living in Canada, the United States, and China, as well as in fiv e subjects not allergic to mosquito bites. To study species-shared all ergens, the membranes were immunoblotted with two rabbit antibodies sp ecific to recombinant mosquito salivary proteins. Results: Three to si xteen salivary allergens with molecular masses ranging from 16 to 95 k d were found in each species. Both species-shared and species-specific allergens were identified by molecular masses, binding to the two rab bit antibodies, and individual IgE responses to species indigenous to and absent from the regions where the subjects lived. Salivary allerge ns, especially from Ae. aegypti, Ae. vexans, and Ae. albopictus, elici ted higher IgE responses in subjects allergic to mosquitos than in non allergic subjects. Conclusions: Species-shared and species-specific al lergens that cause IgE responses in subjects allergic to mosquitos are immunologically identified, Species-shared allergens are the most imp ortant for potential use in diagnosis and immunotherapy.