Abstract
Gut innate lymphoid cells (ILCs) show remarkable phenotypic diversity, yet microenvironmental factors that drive this plasticity are incompletely understood. The balance between NKp46+, IL-22–producing, group 3 ILCs (ILC3s) and interferon (IFN)-γ–producing group 1 ILCs (ILC1s) contributes to gut homeostasis. The gut mucosa is characterized by physiological hypoxia, and adaptation to low oxygen is mediated by hypoxia-inducible transcription factors (HIFs). However, the impact of HIFs on ILC phenotype and gut homeostasis is not well understood. Mice lacking the HIF-1α isoform in NKp46+ ILCs show a decrease in IFN-γ–expressing, T-bet+, NKp46+ ILC1s and a concomitant increase in IL-22–expressing, RORγt+, NKp46+ ILC3s in the gut mucosa. Single-cell RNA sequencing revealed HIF-1α as a driver of ILC phenotypes, where HIF-1α promotes the ILC1 phenotype by direct up-regulation of T-bet. Loss of HIF-1α in NKp46+ cells prevents ILC3-to-ILC1 conversion, increases the expression of IL-22–inducible genes, and confers protection against intestinal damage. Taken together, our results suggest that HIF-1α shapes the ILC phenotype in the gut.
Funding Information
  • Swiss National Fund (310030_179235)
  • Swiss Cancer League (KFS-4398-02-2018, KFS-5402-08-2021)
  • University of Zurich
  • Swiss National Centre for Competence in Research “Kidney.CH” (N-403-06-26 HCP)