FcεRI expression and IgE binding by dendritic cells and basophils in allergic rhinitis and upon allergen immunotherapy

• Published in: Clinical and experimental allergy Vol. 48; no. 8; pp. 970 - 980
• Main Authors: Berings, M., Gevaert, P., De Ruyck, N., Derycke, L., Holtappels, G., Pilette, C., Bachert, C., Lambrecht, B. N., Dullaers, M.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.08.2018
• Subjects: Adolescent; Adult; Allergens; Allergic rhinitis; Allergies; Animals; Antigens, Dermatophagoides - immunology; basophil activation; basophils; Basophils - immunology; Basophils - metabolism; Biomarkers; Dendritic cells; Dendritic Cells - immunology; Dendritic Cells - metabolism; Desensitization, Immunologic; Female; Flow Cytometry; Gene Expression; high‐affinity IgE receptor; Histamine; house dust mite; Humans; Hypersensitivity; IgA; IgE; IgG4; Immunoglobulin E; Immunoglobulin E - immunology; Immunohistochemistry; Immunotherapy; Leukocytes (basophilic); Male; Protein Binding; Pyroglyphidae - immunology; Receptors, IgE - genetics; Receptors, IgE - metabolism; Rhinitis, Allergic - etiology; Rhinitis, Allergic - metabolism; Rhinitis, Allergic - therapy; Young Adult; high-affinity IgE receptor; IgA; dendritic cells; house dust mite; IgE; basophil activation; immunotherapy; IgG4; allergic rhinitis; basophils
• ISSN: 0954-7894; 1365-2222; 1365-2222
• DOI: 10.1111/cea.13157

Summary Background In humans, both basophils and dendritic cells (DCs) express the high‐affinity IgE receptor (FcεRI). Objective To gain more insight into the relation between serum IgE levels and FcεRI expression and IgE binding by DCs and basophils in house dust mite (HDM) allergy and during subcutaneous immunotherapy (SCIT). Methods We measured FcεRI, IgE and HDM allergen on DCs (conventional type 2 DCs, cDC2s; plasmacytoid dendritic cells, pDCs) and basophils by flow cytometry in 22 non‐allergic vs 52 allergic subjects and upon HDM SCIT in 28 allergic subjects. IgE levels were measured in serum. Results Serum IgE correlated differentially with FcεRI expression and IgE binding depending on cell type and allergic status. In non‐allergic subjects, FcεRI/IgE surface densities increased with serum IgE to a significantly stronger degree on basophils compared to cDC2s. By contrast, in allergic subjects FcεRI/IgE surface densities increased with serum IgE to a slightly stronger degree on cDC2s compared to basophils. In addition, the data set suggests sequential loading of IgE onto FcεRI expressed by these cells (basophils>cDC2s>pDCs). Finally, HDM SCIT induced a temporary increase in serum IgE, which was paralleled by a peak in FcεRI and IgE on DCs, but not on basophils. Conclusions & Clinical Relevance This study provides a comprehensive insight into the relation between serum IgE and FcεRI/IgE on basophils and DC subsets. The novel finding that HDM SCIT induces a temporary increase in FcεRI expression on DCs, but not on basophils, can be an incentive for future research on the potential tolerogenic role of IgE/FcεRI signalling in DCs in the setting of allergen immunotherapy.