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.

Atypical B cells consist of subsets with distinct effector functions

“…The up or down regulation of various genes in these clusters as compared to resting switched memory B cells in cluster 3 was consistent with previous reports ( Figure 3A ). Two manuscripts recently posted on bioRxiv showed that the transcription factor ZEB2 acts as an important regulator for the development of atypical B cells ( 24, 25 ). ZEB2 was also expressed significantly higher in clusters 1, 4, and 5 as compared to cluster 3 ( Figure 3A ).…”

Single-cell Landscape Analysis Unravels Molecular Programming of the Human B Cell Compartment in Chronic GVHD

“…5D,E ), and Regnase-1 deficiency at earlier stages of B cell development in mice produces severe autoimmune immunopathology and early mortality, accompanied by ABC expansion ( 88 ). TBX21 (encoding TBET ), ZEB2 and EGR3 are important and potential master regulators of ABC development and/or function in mice and humans ( 23, 25, 26, 49 ), and each were Up DEGs in either ‘memory’ Cluster 5 ( TBX21 , ZEB2 ) or activated Cluster 9 ( EGR3 ), Fig. 5C,E .…”

“…TBX21 (encoding TBET), ZEB2 and EGR3 are important and potential master regulators of ABC development and/or function in mice and humans (23,25,26,49), and each were Up DEGs in either 'memory' Cluster 5 (TBX21, ZEB2) or activated Cluster 9 (EGR3), Fig. 5C,E.…”

“…Importantly, the ‘memory’ cluster contained potentially-pathogenic ‘atypical/age-related’ B cell (ABC) populations found in both health and autoimmune disease ( 17, 18 ). Other notable DEGs in the ‘memory’ B cell cluster included increased TBX21 ( TBET) and ZEB2 , each required for the function or expansion of ABCs ( 17, 19, 20 ). We further confirmed significant expansion of ABC subsets in Active cGVHD using high-dimensional flow cytometry analysis, along with other subset distinctions between allo-HCT patients in general and healthy individuals.…”

“…Homing and cell cycle genes including GPR183 and CKS2 , respectively, were overexpressed in circulating transitional, activated and memory subsets, suggesting potential roles in B cell dysfunction from the time B cells first emerge in the periphery, and then after alloantigen BCR stimulation. We found that after allo-HCT, the ‘memory’ cluster contained potentially-pathogenic ‘atypical/age-related’ B cell (ABC) populations found in both health and autoimmune disease ( 23, 24 ), and drivers of ABCs including TBX21 ( TBET) and ZEB2 ( 23, 25, 26 ) were increased DEGs within this cluster. We further confirmed significant expansion of ABC subsets in Active cGVHD using high-dimensional flow cytometry analysis.…”