Sequential epitopes of Dermatophagoides farinae allergens identified using peptide microarray‐based immunoassay

Abstract House dust mites produce over 30 proteins proposed to induce immunoglobulin E (IgE) antibody production in patients. Continued identification of IgE‐binding epitopes of these allergens is critical to advancing diagnosis and treatment of allergic disease. To identify possible sequential IgE‐binding epitopes of the major‐ and mid‐potency allergens from the house dust mite Dermatophagoides farinae by peptide microarray‐based immunoassay, nucleotide sequences of D. farinae allergens (Der f) 1, 2, 4, 5, and 7 were used to generate overlapping peptides covering the full protein sequences minus signal peptides. Short peptides were printed onto microarray chips. Because asthma occurs as a symptom of mite allergy more commonly among children than adults, the peptide chips were exposed to sera pooled from six serum‐positive pediatric patients with D. farinae hypersensitivity and six serum‐negative control children for screening sequential IgE‐binding epitopes by IgE immunolabeling. Higher‐than‐average immunolabel signal intensity was observed for 21 short peptides in the serum‐positive group ( P  < 0.01). Due to sequence overlap, these 21 signals represented four fragments of Der f 1 (amino acid positions 46–53, 71–78, 99–110, 179–186), three fragments of Der f 2 (15–22, 80–89, 106–113), six fragments of Der f 4 (69–82, 107–116, 225–232, 261–268, 355–365, 483–496), one fragment of Der f 5 (102–109), and three fragments of Der f 7 (32–39, 52–64, 100–107). These findings not only demonstrate the utility of a peptide microarray immunoassay in identifying epitopes for these allergens, but also provide a foundation for future exploration of specific immunotherapies. © 2016 IUBMB Life, 68(10):792–798, 2016