Project description:During acute viral infections, effector CD8+ T cells differentiate into memory precursors or short-lived terminal effectors. miR-17-92a over-expression skews CD8+ effector cells to the terminal differentiation. We used microarray to identify the genes that are differentially expressed caused by miR-17-92a over-expression. CD8+ T cells from P14 TCR transgenic mice were infected with miR-17-92a-MSCV-IRES-Thy1.1 vector and transfer to C57BL6 recipients. Chimeras were infected with LCMV Armstrong. Thy1.1+ miR-17-92a-MSCV-IRES-Thy1.1 transduced P14 cells and Thy1.1- non-transduced P14 cells were sorted by FACS. RNA was extracted from samples, labeled, and hybridized to Affymetrix microarrays.
Project description:During acute viral infections, effector CD8+ T cells differentiate into memory precursors or short-lived terminal effectors. miR-17-92a over-expression skews CD8+ effector cells to the terminal differentiation. We used microarray to identify the genes that are differentially expressed caused by miR-17-92a over-expression.
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:ABSTRACT: OBJECTIVE. Smoking suppresses PD-1 expression in patients with rheumatoid arthritis (RA). In this study, we assess if smoking changed the epigenetic control over CD8+ T cell memory formation through a microRNA (miR) dependent mechanism. METHODS. Phenotypes of CD8+ T cells from smokers and non-smokers, RA and healthy, were analyzed by flow cytometry. A microarray analysis was used to screen for differences in miR expression. Sorted CD8+ cells were in vitro stimulated with nicotine and analyzed for transcription of miRs and genes related to memory programming by qPCR. RESULTS. CD27+CD107a–CD8+ T cells, defining a naïve-memory population, had low expression of PD-1. Additionally, the CD27+ population was more frequent in smokers (p=0.0089). Smokers were recognized by differential expression of 8 miRs. Let-7c-5p, let-7d-5p and let-7e-5p, miR-92a-3p, miR-150-5p and miR-181-5p were up regulated, while miR-3196 and miR-4723-5p were down regulated. These miRs were predicted to target proteins within the FOXO-signaling pathway involved in CD8+ memory programming. Furthermore, miR-92a-3p was differentially expressed in CD8+ cells with naïve-memory predominance. Nicotine exposure of CD8+ cells induced the expression of miR-150-5p and miR-181a-5p in the naïve-memory cells in vitro. Additionally, nicotine exposure inverted the ratio between mRNAs of proteins in the FOXO pathway and their targeting miRs. CONCLUSIONS. Smokers have a high prevalence of CD8+ T cells with a naïve-memory phenotype. These cells express a miR profile that interacts with the memory programming conducted through the FOXO pathway.
Project description:MicroRNA-155 (miR-155) is upregulated in primary effector CD8 T cells but is expressed at low amounts in naïve cells. Anti-viral CD8 T cell responses and viral clearance were impaired in miR-155 deficient (bic-/-) mice, and this defect was intrinsic to CD8 T cells, as adoptively transferred bic-/- CD8 T cells generated greatly reduced primary and memory responses during infection. To understand the mechanism by which miR-155 regulates CD8 T cell activation, we analyzed the gene expression profiles of naive and in vitro activated wild-type and bic-/- CD8 T cells. CD8 T cells were purified from uninfected C57BL/6 mice and stimulated in vitro with plate-bound anti-CD3 and anti-CD28 antibodies for 48 h or left unstimulated. RNA from these CD8 T cells was processed, amplified, labeled, and hybridized to Affymetrix GeneChip MoGene 1.0 st microarrays.
Project description:This SuperSeries is composed of the following subset Series: GSE34216: miRNA signatures of antigen specific CD8+ T cells at different stages of immune response to LCMV infection GSE34217: Expression profile of miR-17-92a-MSCV-IRES-Thy1.1 transduced P14 CD8+ T cells Refer to individual Series
Project description:Differentiation of CD8+ T lymphocytes into effector and memory cells is key for an adequate immune response and relies on complex interplay of pathways that convey signals from cell surface to nucleus. In this study, we fractionated four CD8+ T cell subtypes; naïve, recently activated effector, effector and memory cells into membrane, cytosol, soluble nucleus, chromatin-bound and cytoskeleton compartments. Using LC-MS/MS analysis, identified peptides were matched to human peptides/proteins (SwissProt). Compartment fractionation and gel-LC-MS separation identified 2399 proteins in total. Among these 735 were detected in all five, 241 in four, 257 in three, 368 in two and 798 found in only one fraction. Comparison between the two most different subsets, naïve and effector, yielded 146 significantly regulated proteins.
Project description:Disturbed expression of microRNAs (miRNAs) in regulatory T-cells (Tregs) leads to development of autoimmunity in experimental mouse models. However, the miRNA expression signature characterizing Tregs of autoimmune diseases, such as rheumatoid arthritis (RA) has not been determined yet. Moreover, the technical limitations prevented the analysis of such minute T-cell population as naive and memory Tregs. In this study we have used a microarray approach to comprehensively analyze miRNA expression signatures of naive Tregs (CD4+CD45RO-CD25++), memory Tregs (CD4+CD45RO+CD25+++), as well as conventional naive (CD4+CD45RO-CD25-) and memory (CD4+CD45RO+CD25-) T-cells (Tconvs) derived from peripheral blood of RA patients, and matched healthy controls. Differential expression of selected miRNAs was validated by TaqMan-based qRT-PCR. We found a positive correlation between increased expression of miR-451 in T-cells of RA patients and disease activity score (DAS28), ESR levels, and serum levels of IL-6. Moreover, we found characteristic, disease and treatment independent, global miRNA expression signatures defining naive Tregs, memory Tregs, naive Tconvs and memory Tconvs. The analysis allowed us to define miRNAs characteristic for a general naive phenotype (e.g. miR-92a), a general memory phenotype (e.g. miR-21, miR-155), and most importantly miRNAs specifically expressed in both naive and memory Tregs, defining as such the Treg phenotype (i.e. miR-146a, miR-3162, miR-1202, miR-1246a, and miR-4281). MicroRNA profiling was performed in four CD4+ T-cell subsets: naive Tconventional (CD3+CD8-CD45RO-CD25-), naive Tregulatory (CD3+CD8-CD45RO-CD25+), memory Tconventional (CD3+CD8-CD45RO+CD25-), and memory Tregulatory (CD3+CD8-CD45RO+CD25+) derived from 2 healthy controls, and 6 rheumatoid arthritis patients (total n=8).
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.