A novel inhalation allergen present in the working environment of beekeepers.

BACKGROUND: Inhalation allergies, caused by allergens from various kinds of pollen, house dust mites, animal epithelium, and mould fungi, are strongly increasing in frequency. In 2.6% of the cases the allergen source remains unidentified. The present paper describes a so far unknown inhalation allergy which was observed in the case of a patient working with hives. METHODS AND RESULTS: The allergen was characterized by immunoblotting, enzyme-linked immunosorbent assay inhibition, and isoelectrofocusing, using the serum of the patient. It is present in both the bee bodies and the larvae, has a molecular mass of 13 kDa, and an isoelectric point of 5.85. It is thermolabile and does not cross-react with allergens from birch, mugwort and timothy grass pollen, mould fungi, or bee venom. The N-terminal amino acid sequence of allergen from larvae was determined to be (2)QIEELKTRLHT(12). A similar allergen of 13 kDa was also found in Varroa mite accompanying bee populations. CONCLUSION: Honey bees (including the larva stadium) and Varroa mite contain a 13-kDa protein causing an allergic reaction. Presently, there is no evidence whether the case described is a singular phenomenon or whether this allergen is a more common inducer of allergies among subjects exposed to honey bees. However, a bee and Varroa mite allergy has to be considered for beekeepers after exclusion of known inhalation allergies.

Inhibition of brain protein synthesis by cycloheximide does not affect formation of long-term memory in honeybees after olfactory conditioning.

The honeybee forms a long-term memory in different training situations that lasts for a lifetime, but the cellular mechanisms of long-term memory formation are not known. We analyzed the dependency of long-term memory on the de novo brain protein synthesis. The protein synthesis inhibitor cycloheximide was injected via the median ocellus directly into the brain. 3H-leucine incorporation into brain proteins was inhibited by > 95% for > 3 hr. The time of protein synthesis inhibition was prolonged by a second injection of the same dose. Worker honeybees were conditioned to an olfactory stimulus at different times before and after injection. The proboscis extension response (PER) of bees restrained in tubes was classically conditioned with sugar water applied first to the antennae followed by feeding (unconditioned stimulus) paired with odor presentation (conditioned stimulus). The bees were tested by presenting the odor alone at different times up to 24 hr after injection. No significant reduction in the probability of the conditioned response in cycloheximide-treated bees was found when compared to the Ringer-injected controls in 4 series of experiments. Since protein synthesis was inhibited between 7 hr pre- and 7 hr postconditioning without affecting the formation of long-term memory, a possible role of de novo protein synthesis in the formation of long-term memory after olfactory conditioning of the PER is not supported by these experiments.