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 and flow cytometry suggested FAS as the predominant colonic epithelial receptor for TNFSF13, which was confirmed by co-immunoprecipitation and binding assays. 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 immunoglobulin-producing plasma cells compared to control colonoid cocultures. Our findings support a role for epithelial TNFSF13 as a regulator of colonic epithelial growth and epithelial crosstalk with B cells.
Xianghui Ma, Shaneice K. Nettleford, Yuhua Tian, Noor Dawany, Ayano Kondo, Yalan Li, Kelly Maurer, Tatiana A. Karakasheva, Rawan Shraim, Patrick A. Williams, Louis R. Parham, Lauren A. Simon, Charles H. Danan, Maire A. Conrad, David A. Piccoli, Marcella Devoto, Neil Romberg, Kathleen E. Sullivan, Klaus H. Kaestner, Judith R. Kelsen, Kathryn E. Hamilton