The hevein domain of the major latex-glove allergen Hev b 6.01 contains dominant T cell reactive sites

• Published in: Clinical and experimental allergy Vol. 34; no. 4; pp. 611 - 618
• Main Authors: De Silva, H. D., Gardner, L. M., Drew, A. C., Beezhold, D. H., Rolland, J. M., O'Hehir, R. E.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.04.2004; Blackwell; Wiley Subscription Services, Inc
• Subjects: Adult; Aged; Allergens - analysis; Allergens - genetics; Allergens - immunology; Allergic diseases; allergy; Amino Acid Sequence; Antigens, Plant; Antimicrobial Cationic Peptides; Biological and medical sciences; Cell Line; Cells, Cultured; Cytokines - biosynthesis; Epitope Mapping; Epitopes, T-Lymphocyte - analysis; Female; Gloves, Protective - adverse effects; Hev b 6.01; Hevea brasiliensis; hevein; Humans; Immunoglobulin E - blood; Immunopathology; latex; Latex - immunology; Latex Hypersensitivity - immunology; Lymphocyte Activation - immunology; Medical sciences; Middle Aged; Molecular Sequence Data; Occupational Diseases - immunology; peptides; Plant Lectins - immunology; Plant Proteins - analysis; Plant Proteins - genetics; Plant Proteins - immunology; T cell epitopes; T cells; T-Lymphocytes - immunology; Allergy; Hevea brasiliensis; Immunopathology; Glove; T cell epitopes; peptides; Natural rubber; T cells; Latex; Hev b 6.01; hevein; Immunology; Dicotyledones; Angiospermae; T-Lymphocyte; Euphorbiaceae; Spermatophyta; Allergen
• ISSN: 0954-7894; 1365-2222
• DOI: 10.1111/j.1365-2222.2004.1919.x

Summary Background Sensitization to natural rubber latex (Hevea brasiliensis) is a major cause of occupational asthma and rhinitis affecting frequent latex‐glove users. Hev b 6.01, a known major latex allergen, is cleaved naturally into hevein (4.7 kDa) and a C‐terminal fragment (14 kDa). Hevein is an abundant protein in latex‐glove extracts. As the immune response to allergens is initiated by activation of allergen‐specific CD4+ T cells, identification of dominant T cell epitopes is crucial for the development of specific immunotherapy. Objective To identify dominant T cell epitopes of Hev b 6.01 in latex‐allergic glove users. Methods Ten latex‐allergic frequent glove users and six non‐latex‐allergic atopic control subjects were selected, based on clinical symptoms and positive latex‐specific serum IgE. Serum IgE reactivity to glove extract and recombinant Hev b 6.01 (rHev b 6.01) were analysed by ELISA. Latex‐specific short‐term oligoclonal T cell lines were generated from peripheral blood of latex‐allergic subjects. These lines were tested for proliferative responses to overlapping 20‐mer peptides of the Hev b 6.01 molecule. CD4+ T cell intracellular cytokines, IL‐4 and IFN‐γ were assessed following stimulation with immobilized anti‐CD3 in the presence of IL‐2. Results All ten of the latex‐allergic patients showed serum IgE binding to glove extract while eight of these also showed IgE binding to rHev b 6.01 by ELISA. Western blotting confirmed reactivity with rHev b 6.01 at around 20 kDa. T cell proliferation assays showed that latex‐specific T cell lines from all subjects responded to one or more peptides, with greatest frequency of reactivity to peptides Hev b 6.01 p(10–29) and Hev b 6.01 p(19–38) in the hevein domain. An allergic‐type cytokine profile with considerable IL‐4 in addition to IFN‐γ was evident from intracellular cytokine staining. Conclusion Hevein is an important T cell as well as B cell immunogen and contains dominant T cell reactive sites.