Anaphylaxis from insect venom is mostly caused by Hymenoptera stings, including vespids of the genera Vespula, Vespa Dolichovespula, and Polistes and by apids of the genera Apis and Bombus.Three ant genera are also of importance: Solenopsis, Myrmecia and Pachycondyla . Many cases of wasp allergy with severe allergic reactions have been documented. The symptoms induced by wasp allergy include itch, urticaria, angioedema, bronchial constriction, shock, pharyngeal constriction, shortness of breath, unconsciousness, nausea, vomiting, shivers and profuse perspiration, which are similar to the allergic symptoms induced by stinging from other insects of the order of Hymenoptera.There are more than 24 species in the genus of Vespa wasps, but allergens are only found in the venoms of Vespa crabro .Due to poor diagnostic facilities and a lack of medical alertness, allergy to Vespa wasps may be underestimated.
In order to further understand the possible components in the allergens of the wasp venom, based on the experiences of the purification of allergens in the horsefly Tabanus yao, the research team led by Prof. Lai Ren of Kunming institute of zoology, CAS has developed a serials of methods to effectively purification and characterization the allergens in the wasp venom by combinating different technical methods including chromatography, immunoblots, etc. We have purified two new allergens Vespa ma5 and Vespa ma2 from the venom of vespa magnifica by using this method. These two allergens are 25-KDa Antigen V protein and 35-KDa hyaluronidase respectively. Thirty and 31 of 33 (91.0% and 93.9%) of subjects’ sera with Vespa wasp allergy reacted to Vesp ma 5 and Vesp ma 2, respectively, as measured by the immunoblotting technique. Our previous work showed that Tab y 5 and Tab y 2 reacted with 32 and 34 of 37 (86.5% and 91.8%) of subjects’ sera presenting horsefly allergy, respectively. The elisa inhibition assay shows the maximal inhibition by vesp ma5 and vesp ma2 was 39.5% and 39.4% respectively, while the maximal inhibition by Tab y5 and Tab y2 was 25.3% and 23.8%. Skin prick test shows 73% and 80% of patients had positive reactions to Vesp ma5 and Vesp ma2. The above results prove that vesp ma5 and vesp ma2 are two major allergens in the venom of vespa magnifica, meanwhile it provides a strong evidence for so called wasp-horsefly syndrome.
This work furthered our understanding for the allergen components in the wasp venom and it will have a deep meaning for prevention and diagnosis of the allergic reaction caused by insects sting. This work has been published on Plos One 7(2): e31920. doi:10.1371/journal.pone.0031920。
The research project has been supported by Chinese National Natural Science Foundation.
