Unique and shared IgE epitopes of Hev b 1 and Hev b 3 in latex allergy

Of the several latex proteins cloned and expressed, the rubber elongation f actor, Hev b 1, and the closely related Hev b 3, represent two major allerg ens associated with latex allergy. Although both allergens demonstrated IgE binding with sera from latex allergic patients, it was not known whether t hese two molecules shared any epitopes. Hence, in the present study using h ealth care workers (HCW) and spina bifida (SB) patients with latex allergy, we investigated the IEE binding epitopes in Hev b 1 and Hev b 3. Recombina nt Hev b 1 and Hev b 3 were expressed in a prokaryotic expression system, w hile overlapping decapeptides of Hev b 1 and Hev b 3 were synthesized on de rivatized cellulose membrane. Eight IgE binding epitopes for Hev b 1 and el even for Hev b 3 were identified using sera from latex allergic patients wi th SB. On further analysis of synthetic peptides encompassing these epitope s, similar IgE antibody reactivity was demonstrated with three Hev b 1 epit opes b1E3, b1E5, b1E6 and two Hev b 3 epitopes; b3E10 and b3E 11. For Hev b 1, a unique IgE binding epitope was identified in the region of amino acid residues 16-25. In competitive ELISA, peptides b1E2 and b1E4 together inhi bited 58% of IgE binding of Hev b 1, while b3E5 showed 22% inhibition in th e IgE binding of Hev b 3. The results of the present study suggest that the understanding of linear and conformational IgE epitopes in the major latex allergens may provide better insight into the structure-function relations hip of the allergens, and may lead to the development of better patient car e and management strategies in latex allergy. (C) 2001 Elsevier Science Ltd . All rights reserved.