Project description:Natural killer (NK) cells are innate lymphoid cells that play a critical role in the direct immune defense against tumor cells and pathogens, and additionally have important immune regulatory functions by cytokine secretion. Whereas NK cell biology has been extensively studied in mouse models, transcriptional control of human NK cell differentiation is poorly understood. In this study, we generated ETS1-deficient human embryonic stem cell (hESC) clones using the CRISPR/Cas9 technology. In a complementary approach, we generated ETS1 loss-of-function cord blood hematopoietic stem cells (HSCs) by retroviral transduction of the dominant-negative ETS1 p27 isoform. We show that the transcription factor ETS1 is required for human NK cell differentiation. Transcriptome and ChIP analysis reveal that ETS1 directly regulates expression of several NK cell-linked transcription factors. Also, expression of genes involved in cytokine secretion and cytotoxic activity is ETS1-dependent, whereby these effector functions are decreased in residual NK cells developing from ETS1 loss-of-function cord blood hematopoietic stem cells. Our data show that ETS1 is a critical regulator of human NK cell development and function, and provide important insights in the underlying molecular mechanisms.
Project description:Natural killer (NK) cells are innate lymphoid cells that play a critical role in the direct immune defense against tumor cells and pathogens, and additionally have important immune regulatory functions by cytokine secretion. Whereas NK cell biology has been extensively studied in mouse models, transcriptional control of human NK cell differentiation is poorly understood. In this study, we generated ETS1-deficient human embryonic stem cell (hESC) clones using the CRISPR/Cas9 technology. In a complementary approach, we generated ETS1 loss-of-function cord blood hematopoietic stem cells (HSCs) by retroviral transduction of the dominant-negative ETS1 p27 isoform. We show that the transcription factor ETS1 is required for human NK cell differentiation. Transcriptome and ChIP analysis reveal that ETS1 directly regulates expression of several NK cell-linked transcription factors. Also, expression of genes involved in cytokine secretion and cytotoxic activity is ETS1-dependent, whereby these effector functions are decreased in residual NK cells developing from ETS1 loss-of-function cord blood hematopoietic stem cells. Our data show that ETS1 is a critical regulator of human NK cell development and function, and provide important insights in the underlying molecular mechanisms.
Project description:Expression profiling of Rag2-deficient Ets1++ and Rag2-deficient Ets1-- mature NK cells and WT bone marrow progenitors, WT T cells, and WT Pro B cells WT Hematopoietic progenitors, CD4 T cells, Pro B cells, and WT and Ets1-deficient NK cells were FACs sorted. RNA was subsequently extracted, labelled, and hybridized to Affymetrix microarrays. The goal if this experiment was to identify Ets1 dependent genes in NK cells
Project description:Expression profiling of Rag2-deficient Ets1++ and Rag2-deficient Ets1-- mature NK cells and WT bone marrow progenitors, WT T cells, and WT Pro B cells
Project description:RNA polymerase II (RNAPII) pausing release is a recently recognized checkpoint for transcriptional regulation. The biological roles of RNAPII pausing release and the mechanisms that by which extracellular signals control it are incompletely understood. Here we identify a novel mechanism by which VEGF stimulates RNAPII pausing-release through acetylation of ETS1, a master endothelial cell transcriptional regulator. In endothelial cells (ECs), ETS1 uniquely bound transcribed gene promoters and stimulated their expression by broadly increasing RNA polymerase II (RNAPII) pause release. VEGF enhanced ETS1 chromatin occupancy. Furthermore, VEGF increased ETS1 acetylation, enhancing its binding by BRD4 and thereby stimulating RNAPII pause release. This ETS1-mediated transduction of VEGF signaling to increase RNAPII pausing release was essential for EC angiogenic responses in vitro and in vivo. Together, our results define a new angiogenic pathway in which VEGF enhances ETS1-Brd4 interaction to broadly promote RNAPII pause release and drive angiogenesis.