Murine B-cell and T-cell epitopes of the allergen Hev b 5 from natural rubber latex

Abstract

Hev b 5, a proline-rich acidic protein with a predominantly random secondary structure, is a major allergen in natural rubber latex and a candidate for specific immunotherapy of latex allergy. As a first step in the identification of candidate peptides for immunotherapy, we have begun to identify the B-cell and T-cell epitopes of Hev b 5 in BALB/c mice. The mice were immunized with a Hev b 5 fusion protein. The B-cell epitopes were determined by the SPOTS method using overlapping octamers or by ELISA inhibition using a series of overlapping 20-mers. The T-cell epitopes were determined by the proliferation and cytokine release of splenocytes cultured in the presence of the 20-mers. Potential antibody binding regions included residues in regions 1–38, 55–74, 109–128 and 132–151. Examination of the binding sequences for common motifs suggested enhanced antibody binding to the KXEE or KEXE sequences, where X is empty, threonine or alanine. Splenocyte stimulation and cytokine release suggest T-cell epitopes with the regions 1–20, 37–56, 73–101 and 109–146. Since they may contain major T-cell epitopes but do not exhibit significant antibody binding, peptide regions 38–48 and 75–101 are candidates for specific immunotherapy to Hev b 5 in the BALB/c mouse model.