Schreurs RRCE, Baumdick ME, Sagebiel AF, Kaufmann M, Mokry M, Klarenbeek PL, Schaltenberg N, Steinert FL, van Rijn JM, Drewniak A, The SML, Bakx R, Derikx JPM, de Vries N, Corpeleijn WE, Pals ST, Gagliani N, Friese MA, Middendorp S, Nieuwenhuis EES, Reinshagen K, Geijtenbeek TBH, van Goudoever JB, Bunders MJ.Although the fetal immune system is considered tolerogenic, preterm infants can suffer from severe intestinal inflammation, including necrotizing enterocolitis (NEC). Here, we demonstrate that human fetal intestines predominantly contain tumor necrosis factor-α (TNF-α)+CD4+CD69+ T effector memory (Tem) cells. Single-cell RNA sequencing of fetal intestinal CD4+ T cells showed a T helper 1 phenotype and expression of genes mediating epithelial growth and cell cycling. Organoid co-cultures revealed a dose-dependent, TNF-α-mediated effect of fetal intestinal CD4+ T cells on intestinal stem cell (ISC) development, in which low T cell numbers supported epithelial development, whereas high numbers abrogated ISC proliferation. CD4+ Tem cell frequencies were higher in inflamed intestines from preterm infants with NEC than in healthy infant intestines and showed enhanced TNF signaling. These findings reveal a distinct population of TNF-α-producing CD4+ T cells that promote mucosal development in fetal intestines but can also mediate inflammation upon preterm birth.
Immunity. 2019 Feb 19;50(2):462-476
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