Transcriptomics profile of mouse dendritic cell subsets during epicutaneous allergen immunotherapy (EPIT)

Epicutaneous immunotherapy (EPIT) protocols have recently been developed to restore tolerance in patients with food allergy (FA). The mechanisms by which EPIT protocols promote desensitization rely on a profound immune deviation of pathogenic T and B cell responses. To date, little is known about the contribution of skin dendritic cells (skDCs) to T cell remodelling and EPIT efficacy. Our results emphasize that the acquisition of distinct phenotypic and functional specializations by skDCs during EPIT is at the cornerstone of the desensitization process. We capitalized on a preclinical model of FA to ovalbumin (OVA), in which allergic C57BL/6 mice were desensitized by 8 weekly 48h-applications of OVA-containing patches. The phenotype and functions of OVA+ skDCs were monitored throughout the course of EPIT by flow cytometry, single-cell RNA sequencing and in vitro DC-T-cell co-culture assays.