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:We investigated the genomic landscape of histone modifications in antigen-experienced CD8+ T cells. Using a ChIP-Seq approach coupled with global gene expression profiling [GSE67825], we generated genome-wide histone H3 lysine 4 (H3K4me3) and H3 lysine 27 (H3K27me3) trimethylation maps in distinct subsets of CD8+ T cells - naïve, stem cell memory, central memory, and effector memory. To gain insight into how histone architecture is remodeled during the differentiation of activated T cells
Project description:CD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells. Experiment Overall Design: An important question in memory development is understanding the differences between effector CD8 T cells that die versus effector cells that survive and give rise to memory cells. In this study we have performed genomic profiling of terminal effectors and memory precursors as defined by CD25 heterogeneity, towards better understanding the generation of these subsets. The two effector subsets were FACS purified based on the amount of cell surface CD25 expression into CD25lo and CD25hi subsets during the early expansion phase (Days 3-4 post-infection) and analyzed for their gene expression profiles (by genome-wide microarray analyses).
Project description:We investigated the genomic landscape of histone modifications in antigen-experienced CD8+ T cells. Using a ChIP-Seq approach coupled with global gene expression profiling [GSE67825], we generated genome-wide histone H3 lysine 4 (H3K4me3) and H3 lysine 27 (H3K27me3) trimethylation maps in distinct subsets of CD8+ T cells - naïve, stem cell memory, central memory, and effector memory.
Project description:The mechanisms underlying human NK cell phenotypic and functional heterogeneity are unknown. Here, we describe the emergence of diverse subsets of human NK cells selectively lacking expression of signaling proteins following cytomegalovirus (CMV) infection. The absence of B and myeloid cell-related signaling protein expression in these NK cell subsets correlated with promoter DNA hypermethylation. Intriguingly, geneome-wide analyses revealed patterns of DNA methylation that were strikingly similar between CMV-associated adaptive NK cells and cytotoxic effector CD8+ T cells, but differed from those of canonical NK cells. A total of 23 samples were analyzed (4 sorted NK cell subsets and 2 sorted T cell subsets each from 4 individual donors). In one donor only 5 subsets were analyzed. Bisulfite-converted genomic DNA was hybridized to the Illumina Human Methylation450 BeadChip