Abstract
Food allergy is caused by allergen-specific IgE antibodies but little is known about the B cell memory of persistent IgE responses. Here we describe in human pediatric peanut allergy CD23 (+) IgG1 (+) memory B cells arising in type 2 responses that contain peanut specific clones and generate IgE cells on activation. These 'type2-marked' IgG1 (+) memory B cells differentially express IL-4/IL-13 regulated genes FCER2 / CD23, IL4R , and germline IGHE and carry highly mutated B cell receptors (BCRs). Further, high affinity memory B cells specific for the main peanut allergen Ara h 2 mapped to the population of 'type2-marked' IgG1 (+) memory B cells and included convergent BCRs across different individuals. Our findings indicate that CD23 (+) IgG1 (+) memory B cells transcribing germline IGHE are a unique memory population containing precursors of pathogenic IgE. ONE-SENTENCE SUMMARY: We describe a unique population of IgG (+) memory B cells poised to switch to IgE that contains high affinity allergen-specific clones in peanut allergy.