IgG memory B cells expressing IL4R and FCER2 are associated with atopic diseases.

Background: Atopic diseases are characterized by IgE antibody responses that are dependent on cognate CD4 T cell help and T cell‐produced IL‐4 and IL‐13. Current models of IgE cell differentiation point to the role of IgG memory B cells as precursors of pathogenic IgE plasma cells. The goal of this work was to identify intrinsic features of memory B cells that are associated with IgE production in atopic diseases. Methods: Peripheral blood B lymphocytes were collected from individuals with physician diagnosed asthma or atopic dermatitis (AD) and from non‐atopic individuals. These samples were analyzed by spectral flow cytometry, single cell RNA sequencing (scRNAseq), and in vitro activation assays. Results: We identified a novel population of IgG memory B cells characterized by the expression of IL‐4/IL‐13 regulated genes FCER2/CD23, IL4R, IL13RA1, and IGHE, denoting a history of differentiation during type 2 immune responses. CD23+IL4R+IgG+ memory B cells had increased occurrence in individuals with atopic disease. Importantly, the frequency of CD23+IL4R+IgG+ memory B cells correlated with levels of circulating IgE. Consistently, in vitro stimulated B cells from atopic individuals generated more IgE+ cells than B cells from non‐atopic subjects. Conclusions: These findings suggest that CD23+IL4R+ IgG+ memory B cells transcribing IGHE are potential precursors of IgE plasma cells and are linked to pathogenic IgE production. [ABSTRACT FROM AUTHOR]