Occupational allergy to bumblebees: Allergens of Bombus terrestris

Background: With the increase in commercial vegetable production in greenho uses, occupational sensitization to bumble-bee venom is becoming more commo n. Studies using sera from subjects thus sensitized allow evaluation of the allergenic specificity of bumblebee sensitization. Objective: The purposes of this study were to determine the degree of speci es group specificity of bumblebee venom allergens in sera of allergic patie nts and to investigate the structural basis of this specificity. Methods: Allergens were purified from bumblebee venom, studied serologicall y by direct binding and inhibition techniques, and characterized by enzyme analysis and amino acid sequencing. Three-dimensional models of the phospho lipases were constructed and analyzed. Results: Bombus terrestris venom contains phospholipase A(2), venom proteas e, hyaluronidase, and acid phosphatase allergens. The protease and phosphol ipase A(2) allergens contain IgE-reactive epitopes that are different from those seen in Bombus pennsylvanicus, a North American species. Bumblebee ph ospholipase A(2) is only 53% identical to honeybee phospholipase A(2),. The results of 3-dimensional modeling are consistent with the immunologic obse rvations. Conclusions: Patients with primary bumblebee sensitization should be diagno sed and treated with venom from the appropriate species group of bumblebees . Bumblebee venom phospholipase A(2) and protease are antigenically distinc t from honeybee venom proteins. There are significant species group-specifi c epitopes on bumblebee venom proteins.