Project description:DNMT3a is a de novo DNA methyltransferase expressed robustly after T cell activation that regulates plasticity of CD4+ T cell cytokine expression. Here we show that DNMT3a is critical for directing early CD8+ T cell effector and memory fate decisions. While effector function of DNMT3a knockout T cells is normal, they develop more memory precursor and fewer terminal effector cells in a T cell intrinsic manner compared to wild-type animals. Rather than increasing plasticity of differentiated effector CD8+ T cells, loss of DNMT3a biases differentiation of early effector cells into memory precursor cells. This is attributed in part to ineffective repression of Tcf1 expression in knockout T cells, as DNMT3a localizes to the Tcf7 promoter and catalyzes its de novo methylation in early effector WT CD8+ T cells. This data identifies DNMT3a as a crucial regulator of CD8+ early effector cell differentiation and effector versus memory fate decisions. Examination of global genomic DNA methylation by MBD-seq in naïve CD8 T cells and CD8 T cells 8 days post Vaccinia-Ova infection, comparing OT1 TCR-Tg CD8 T cells isolated from WT and T cell conditional DNMT3a KO mice.
Project description:CD8+ T cells play a crucial role in the clearance of intracellular pathogens through the generation of cytotoxic effector cells that eliminate infected cells and long-lived memory cells that provide enhanced protection against reinfection. We have previously shown that the inhibitor of E protein transcription factors, Id2, is necessary for accumulation of effector and memory CD8+ T cells during infection. Here we show that CD8+ T cells lacking Id2 did not generate a robust terminally-differentiated KLRG1hi effector population, but displayed a cell-surface phenotype and cytokine profile consistent with memory precursors, raising the question as to whether loss of Id2 impairs the differentiation and/or survival of effector-memory cells. We found that deletion of Bim rescued Id2-deficient CD8+ cell survival during infection. However, the dramatic reduction in KLRG1hi cells caused by loss of Id2 remained in the absence of Bim, such that Id2/Bim double-deficient cells form an exclusively KLRG1loCD127hi memory precursor population. Thus we describe a role for Id2 in both the survival and differentation of normal CD8+ effector and memory populations. Gene-expression analysis of Wild-type, Id2KO, Id2KOBimKO and BimKO effector CD8+ cells on day 6 of Listeria infection. 2 or more replicates per sample were analyzed.
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 performed RNA-seq, ATAC-seq, and H3K27Ac ChIP-seq on P14 CD8 T cells during acute infection with LCMV Armstrong on days 0 (naïve cells), 9 (memory precursor effector cells (MPEC) and short-lived effector cells (SLECs)), and 40+ (memory cells) post infection.
Project description:We performed RNA-seq, ATAC-seq, and H3K27Ac ChIP-seq on P14 CD8 T cells during acute infection with LCMV Armstrong on days 0 (naïve cells), 9 (memory precursor effector cells (MPEC) and short-lived effector cells (SLECs)), and 40+ (memory cells) post infection.
Project description:We performed RNA-seq, ATAC-seq, and H3K27Ac ChIP-seq on P14 CD8 T cells during acute infection with LCMV Armstrong on days 0 (naïve cells), 9 (memory precursor effector cells (MPEC) and short-lived effector cells (SLECs)), and 40+ (memory cells) post infection.
Project description:Here we implemented a simple dendritic cell (DC)-mediated immunization approach to study the effects of commonly used adjuvants, Toll like receptor (TLR) ligands, on effector CD8 T cell differentiation and memory T cell development. To our surprise, we found that the TLR4 ligand LPS was far more superior to other TLR ligands in generating memory CD8 T cells upon immunization. LPS boosted clonal expansion similar to the other adjuvants, but fewer of the activated CD8 T cells died during contraction, generating a larger pool of memory cells. Intriguingly, monophosphoryl lipid A (MPLA), another TLR4 ligand, enhanced clonal expansion of effector CD8 T cells, but also promoted their terminal differentiation and contraction; thus, fewer memory CD8 T cells formed and MPLA-primed animals were less protected against secondary infection compared to those primed with LPS. Furthermore, gene expression profiling revealed that LPS-primed effector cells displayed a stronger pro-memory gene expression signature, whereas the gene expression profile of MPLA-primed effector cells had aligned closer with terminal effector CD8 T cells. Mice that contain small number of P14 CD8 T cells were immunized with DC-33 either alone or in combination with LPS or MPLA. KLRG1loIL-7Rhi MPECs were purified by FACS sort, and mRNA isolated from MPECs was subjected to whole-genome expression profiling using Illumina MouseWG-6 v2.0 Expression BeadChip.
Project description:Stem-like CD8 T cells maintain long-term antiviral CD8 immunity during chronic infection, and share regulatory pathways with memory precursor effector cells generated after acute infection. However, it is unclear whether stem-like CD8 T cells require dist
Project description:At the peak of the CD8 T cell response to acture viral and bacterial infections, expression of the Interleukin-7 Receptor (IL-7R) marks Memory Precursor Effector CD8 T Cells (MPECs) from other Short-Lived Effector CD8 T cells (SLECs), which are IL-7Rlo. This study was designed to determine the gene expression differences between these two subsets of effector CD8 T cells. Experiment Overall Design: This study compared IL-7Rhi and IL-7Rlo LCMV-specific P14 Transgenic CD8 T cells, sorted from LCMV armstrong infected recipient mice 6/7 days after infection. Data includes 3 independent replicates for the IL-7Rhi and IL-7Rlo groups.