Mapping Mimotopes for House Dust Mite Allergen Der f 7 Using a Specific Monoclonal Antibody

Background: The dust mite Dermatophagoides farinae is a common worldwide cause of indoor allergies induced by its proteins, including the mid-tier allergen Der f 7. Objective: To identify conformational epitopes in Der f 7 using mimotope mapping and computational modelling. Methods: Here, we used standard hybridoma technology to generate 3 new monoclonal antibodies against Der f 7 and performed mimotope mapping by probing a random peptide phage display library. Computational tools, including Minox and the DiscoTope-2.0 Server were used to assess the structure and potential position of antigenic residues within Der f 7. Results: Thirteen mimotopes sharing the common sequence --XX[LST]P[-E][LI]MLPLR[-S]- were identified. Further, computationally-predicted conformational epitopes were found at residues 1-7, 10, 27, 76-81, 92, and 130-133 of Der f 7, and the key amino acids for these epitopes were deduced to be 2P, 3I, 10E, 27E, 78E, 79E, 81I, 130S, and 132E based on the common mimotope sequence. Conclusion: We identified Der f 7 peptide mimotopes that may model binding sites for blocking antibodies. These may guide the development of immunotherapy for individuals with hypersensitivity to Der f 7.