Immune response to mosquito allergens is associated with cross-reactive bee venom components: the importance of cross-reactive carbohydrate determinants (CCDs) in the Bee-Mosquito Syndrome

SUMMARY

Background. Mosquitoes are a family of the order Diptera. Throughout the world, there are two groups able to suck human blood and transmit diseases: the anophelines and the culicines comprise several genera such as Culex, Aedes and Aedes communis (Ac). Previous study has demostrated a significant relationship between Ac sensitization and either extract or single bee venom components suggesting a “bee-mosquito syndrome” occurrence. The aim of the study was to identify bands of cross reactivity between the extracts of Mosquito and Bee venom, with IgE positive sera. Methods. Serum from 21 different Mosquito and A. mellifera allergic individuals were combined with extracts of Mosquito (in house) and A. mellifera. SDS-PAGE and (IB) were carried out with/without CCD inhibitor. Results. The data without CCD inhibitor suggests IgE binding to common bands between Culex male, Culex female and Aedes of approx ~21kDa, ~35kDa, ~40kDa and ~55kDa. Whilst IgE binding has been observed to protein bands from the A. mellifera extract, these bands do not align with any present in the mosquito extracts. Data with CCD inhibitor results in differences in IgE binding. Bands that were previously observed in the A. mellifera venom sample at 40 and 90 kDa, disappeared. No major differences in banding pattern were observed for the mosquito samples, although the blot appears cleaner. Conclusions. IB data suggests that the use of CCD inhibitor prevents binding of IgE from mosquito allergic patients to multiple bands from A. mellifera venom. It may be inferred that bands originally present at 40kDa and 90 kDa may have been due to a CCD interaction. Two bands remain present in the A. mellifera sample between 15-20 kDa, however do not align with any bands present in the mosquito extracts. Further experiments must be done to determine whether the reactive bands from A. mellifera are unrelated proteins or whether the proteins are related homologues of varying MW.

KEY WORDS