TNFSF13 insufficiency disrupts human colonic epithelial cell-mediated B cell differentiation
Cytokines mediating epithelial and immune cell interactions modulate mucosal healing-a process that goes awry with chronic inflammation as in inflammatory bowel disease. TNFSF13 is a cytokine important for B cell maturation and function, but roles for epithelial TNFSF13 and putative contribution to inflammatory bowel disease are poorly understood. We evaluated functional consequences of a novel monoallelic TNFSF13 variant using biopsies, tissue-derived colonoids and induced pluripotent stem cell (iPSC)-derived colon organoids. TNFSF13 variant colonoids exhibited a >50% reduction in secreted TNFSF13, increased epithelial proliferation, and reduced apoptosis, which was confirmed in iPSC-derived colon organoids. Single cell RNA-sequencing, flow cytometry, and co-immunoprecipitation identified FAS as the predominant colonic epithelial receptor for TNFSF13. Imaging mass cytometry revealed an increase in epithelial-associated B cells in TNFSF13 variant colon tissue sections. Finally, TNFSF13 variant colonoids co-cultured with memory B cells demonstrated a reduction in the production of IgA+ plasma cells compared to control colonoid co-cultures. Our findings support a role for epithelial TNFSF13 as a regulator of colonic epithelial growth and epithelial crosstalk with B cells. SUMMARYEpithelial TNFSF13 regulates colonic epithelial growth and epithelial-B cell interactions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/614260v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@1e5b892org.highwire.dtl.DTLVardef@b8857forg.highwire.dtl.DTLVardef@448b95org.highwire.dtl.DTLVardef@2820e2_HPS_FORMAT_FIGEXP M_FIG C_FIG