IgE and IgG4 Epitopes of Dermatophagoides and Blomia Allergens before and after Sublingual Immunotherapy

Abstract

Sublingual immunotherapy (SLIT) is used worldwide to treat house dust mites (HDM) allergy. Epitope specific immunotherapy with peptide vaccines is used far less, but it is of great interest in the treatment of allergic reactions, as it precludes the drawbacks of allergen extracts. The ideal peptide candidates would bind to IgG, blocking IgE-binding. To better elucidate IgE and IgG4 epitope profiles during SLIT, sequences of main allergens, Der p 1, 2, 5, 7, 10, 23 and Blo t 5, 6, 12, 13, were included in a 15-mer peptide microarray and tested against pooled sera from 10 patients pre- and post-1-year SLIT. All allergens were recognized to some extent by at least one antibody isotype and peptide diversity was higher post-1-year SLIT for both antibodies. IgE recognition diversity varied among allergens and timepoints without a clear tendency. Der p 10, a minor allergen in temperate regions, was the molecule with more IgE-peptides and might be a major allergen in populations highly exposed to helminths and cockroaches, such as Brazil. SLIT-induced IgG4 epitopes were directed against several, but not all, IgE-binding regions. We selected a set of peptides that recognized only IgG4 or were able to induce increased ratios of IgG4:IgE after one year of treatment and might be potential targets for vaccines.

Structural Insights on Cross-Reactivity of Mite Allergens with Helminth Proteins

“…In our group-10 epitope-mapping analyses, we found only one epitope for Der p 10 [74], which has also highly conserved counterparts in shrimp [75][76][77]. However, our prediction failed to find other IgE epitopes that were highly conserved in shrimp tropomyosin [75,76].…”

Avaliação da segurança e eficácia terapêutica da imunoterapia sublingual com alérgenos perenes (Dermatophagoides pteronyssinus e Blomia tropicalis) em pacientes com rinite alérgica através de dados clínicos e laboratoriais

“…Quanto aos níveis isolados de IgG4 específica quanto a relação IgE /IgG4 específicas, vem questionando o uso destes como biomarcador da eficácia da ITA a nível individual, mas sim medidas funcionais do IgG4 (Shamji et al, 2021;Sahiner et al, 2023). Um estudo paralelo, analisou as medidas funcionais das IgG4 específicas de alguns dos nossos pacientes em uso de ITSL, encontrandose um aumento da diversidade de epítopos de IgG4, ou seja, uma maior capacidade de ligação do anticorpo IgG4 aos peptídeos alérgenos (Figo et al, 2023).…”