Project description:<p>Natural killer (NK) cells are forced to cope with different oxygen environments even under resting conditions. The adaptation to low oxygen is regulated by oxygen-sensitive transcription factors, the hypoxia-inducible factors (HIFs). The function of HIFs for NK cell activation and metabolic rewiring remains controversial. Activated NK cells are predominantly glycolytic, but the metabolic programs that ensure the maintenance of resting NK cells are enigmatic. By combining <em>in situ</em> metabolomic and transcriptomic analyses in resting murine NK cells, our study defines HIF-1a as a regulator of tryptophan metabolism and cellular nicotinamide adenine dinucleotide (NAD+) levels. The HIF-1a/NAD+ axis prevents ROS production during oxidative phosphorylation (OxPhos) and thereby blocks DNA damage and NK cell apoptosis under steadystate conditions. In contrast, in activated NK cells under hypoxia, HIF-1a is required for glycolysis, and forced HIF-1a expression boosts glycolysis and NK cell performance <em>in vitro</em> and <em>in vivo</em>. Our data highlight two distinct pathways by which HIF-1a interferes with NK cell metabolism. While HIF-1a-driven glycolysis is essential for NK cell activation, resting NK cell homeostasis relies on HIF-1a-dependent tryptophan/NAD+ metabolism.</p><p><br></p><p><strong>Linked cross omic data sets:</strong></p><p>RNA-seq data associated with this study are available in ArrayExpress (BioStudies): accession <a href='https://www.ebi.ac.uk/biostudies/arrayexpress/studies/E-MTAB-12082' rel='noopener noreferrer' target='_blank'>E-MTAB-12082</a>.</p>
Project description:ChIP-seq was conducted using freshly isolated splenic WT NK cells from IL-15/Ra treated mice with anti-Runx3 antibody (Ab) and non-immune serum (NIS) as control. Runx3 and NIS IP from splenic NK cells of IL-15/Ra treated WT mice, isolated by negative selection using NK cell isolation kit (R&D) followed by sorting of NKp46+ cells.
