ZEB2 regulates the development of CD11c+ atypical B cells

Abstract

CD11c+ atypical B cells (ABC) are an alternative memory B cell lineage identified both in normal immune responses as well as pathogenic responses in autoimmunity. While it is clear that ABCs have a distinct transcriptional program, the factors that direct this program have not been identified. Here, we generated a human tonsil single-cell RNA-seq dataset and identified candidate transcription factors associated with the ABC population. We selected 8 of these transcription factors for further analysis based on their conserved expression in mouse ABC bulk RNA-seq datasets. Using an optimized CRSPR-Cas9 knockdown method we found that only zinc finger E-box binding homeobox 2 (Zeb2) knock-out impaired ABC formation. To assess the role of Zeb2 in ABC formation in vivo we used Zeb2fl/fl mice crossed to a CD23Cre line. Germinal center and plasma cell responses in these mice after Plasmodium sporozoite immunization were largely unaltered but we observed a specific defect in ABC formation. We further determined that ZEB2 haploinsufficient Mowat Wilson syndrome patients also have decreased circulating ABCs in the blood, supporting a role for this transcription factor in humans as well as mice. In sum, we identified Zeb2 as a key TF governing the formation of ABCs.