Project description:iNKT cells are innate-like lymphocytes that protect against infection, autoimmune disease, and cancer. However, little is known about epigenetic regulation of iNKT cell development. Here, we show that the H3K27me3 histone demethylase UTX is an essential cell-intrinsic factor that controls an iNKT lineage specific gene expression program and epigenetic landscape in a demethylase activity dependent manner. UTX deficient iNKT cells exhibit impaired expression of iNKT signature genes due to a decrease in activation-associated H3K4me3 and an increase in repressive H3K27me3 marks within the promoters that UTX occupies. Notably, we identified JunB as a novel regulator of iNKT development that partners with UTX to establish an iNKT lineage specific gene expression program. Moreover, we demonstrate that UTX-mediated regulation of super-enhancer accessibility is a key mechanism for iNKT lineage commitment. These findings uncover how UTX regulates iNKT cell development through multiple epigenetic mechanisms.
Project description:NKT cells are innate-like lymphocytes that protect against infection, autoimmune disease, and cancer. However, little is known about epigenetic regulation of iNKT cell development. Here, we show that the H3K27me3 histone demethylase UTX is an essential cell-intrinsic factor that controls an iNKT lineage specific gene expression program and epigenetic landscape in a demethylase activity dependent manner. UTX-deficient iNKT cells exhibit impaired expression of iNKT signature genes due to a decrease in activation-associated H3K4me3 and an increase in repressive H3K27me3 marks within the promoters that UTX occupies. Notably, we identified JunB as a novel regulator of iNKT development that partners with UTX to establish an iNKT lineage specific gene expression program. Moreover, we demonstrate that UTX-mediated regulation of super-enhancer accessibility is a key mechanism for iNKT lineage commitment. These findings uncover how UTX regulates iNKT cell development through multiple epigenetic mechanisms.
Project description:KDM6A (UTX) controls the balance of basal and luminal mammary epithelium through regulating lineage-specific genes independent of its demethylase activity
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
Project description:Invariant Natural killer T (iNKT) cells are a separate lineage of T lymphocytes with innate effector functions. They express an invariant TCR specific for lipids presented by CD1d and their development and effector differentiation rely on a unique gene expression program. We asked whether this program includes microRNAs, small non-coding RNAs that regulate gene expression posttranscriptionally and play key role in the control of cellular differentiation programs. We identified a miRNA profile specific for iNKT cells, which exhibits features of activated/effector T lymphocytes.
Project description:PGCs undergo two distinct stages of demethylation before reaching a hypomethylated ground state at E13.5. Stage 1 occurs between E7.25- E9.5 in which PGCs experience a global loss of cytosine methylation. However, discreet loci escape this global loss of methylation and between E10.5-E13.5, stage 2 of demethylation takes place. In this stage these loci are targeted by Tet1 and Tet2 leading to the loss of the remaining methylation and resulting in the epigenetic ground state. Our data shows that Dnmt1 is responsible for maintaining the methylation of loci that escape stage 1 demethylation, and that it functions in a UHRF1 independent manner. Our data further demonstrates that when these loci lose methylation prior to stage 2 it results in early activation of the meiotic program, which leads to precocious differentiation of the germ line resulting in a decreased pool of PGCs in the embryo and subsequent infertility in adult mice.