Yellow jacket venom allergens, hyaluronidase and phospholipase: sequence similarity and antigenic cross-reactivity with their hornet and wasp homologs and possible implications for clinical allergy.

Three known allergens of yellow jacket (Vespula vulgaris) venom are antigen 5, hyaluronidase, and phospholipase. Yellow jacket antigen 5 has been previously cloned and expressed in bacteria; it contains 204 amino acid residues, and it has 69% and 60% sequence identities with the homologous proteins of white-faced hornet (Dolichovespula maculata) and wasp (Polistes annularis), respectively. These studies are now extended to yellow jacket hyaluronidase and phospholipase; they contain 331 and 300 amino acid residues, respectively, and they show 92% and 67% sequence identity with their homologs of white-faced hornet. Tests with the natural and the recombinant vespid allergens in mice indicate partial antigenic cross-reactivity of their homologous proteins at both B- and T-cell levels. There is greater cross-reactivity among hornet and yellow jacket allergens than that among hornet or yellow jacket and wasp allergens. The order of cross-reaction of the three vespid allergens is hyaluronidase > antigen 5 > phospholipase. The continuous (linear) B-cell epitopes of vespid allergens show greater cross-reactivity than their discontinuous epitopes do. The discontinuous B-cell epitopes are immunodominant for all vespid allergens. The low degree of cross-reactivity of the immunodominant discontinuous B-cell epitopes of vespid allergens should be taken into consideration in selection of venoms for immunotherapy of patients with sensitivity to multiple vespids.