Project description:The transcription factor Thpok is essential for CD4 T cell development in the thymus and remains expressed in post-thymic CD4 T cells. We post-thymically inactivated Thpok and compared microarray gene expression in Thpok-deficient CD4 T cells to that in their wildtype CD4 or CD8 counterparts We show that Thpok constrains the transcriptional circuitry to maintain CD4+-lineage integrity in naM-CM-/ve cells and to couple effector differentiation to environmental cues after antigenic stimulation. Redundantly with the related factor LRF, Thpok is continuously needed to prevent the trans-differentiation of mature CD4+ into -CD8+ T cells. We activated naM-CM-/ve CD4 T cells (either wild-type or Thpok-deficient) and CD8 T cells (wild-type) in vitro under Th1 conditions. Differentiated effectors were sorted 4 days after activation into CD4+CD8- and CD4-CD8+ (wild-type) and CD4+CD8- and CD4+CD8+ (Thpok-deficient) subsets. Total RNA was extracted from sorted subsets and processed for microarray analyses (Affymetrix Mouse Exon 1.0 ST array) at the NCI microarray facility, following the manufacturerM-bM-^@M-^Ys recommendation. Data is from 3 replicates (except wild-type CD4-CD8+ cells, for which two samples only were processed), generated from two distinct cell preparations.
Project description:The Tec-family kinase Itk plays an important role during T-cell activation and function, and controls also conventional versus innate-like T-cell development. We have characterized the transcriptome of Itk-deficient CD3+ T-cells, including CD4+ and CD8+ subsets, using Affymetrix microarrays. The largest difference between Itk-/- and Wt CD3+ T-cells was found in unstimulated cells, e.g. for killer cell lectin-like receptors. Compared to anti-CD3-stimulation, anti-CD3/CD28 significantly decreased the number of transcripts suggesting that the CD28 co-stimulatory pathway is mainly independent of Itk. The signatures of CD4+ and CD8+ T-cell subsets identified a greater differential expression than in total CD3+ cells. Cyclosporin (CsA)-treatment had a stronger effect on transcriptional regulation than Itk-deficiency, suggesting that only a fraction of TCR-mediated calcineurin/NFAT-activation is dependent on Itk. Bioinformatic analysis of NFAT-sites of the group of transcripts similarly regulated by Itk-deficiency and CsA-treatment, followed by chromatin-immunoprecipitation, revealed NFATc1-binding to the Bub1, IL7R, Ctla2a, Ctla2b, and Schlafen1 genes. Finally, to identify transcripts that are regulated by Tec-family kinases in general, we compared the expression profile of Itk-deficient T-cells with that of Btk-deficient B-cells and a common set of transcripts was found. Taken together, our study provides a general overview about the global transcriptional changes in the absence of Itk. Experiment Overall Design: CD3+ CD4+ and CD8+ T-cells from pooled suspensions of spleen and lymph nodes of Wt and Itk knockout mice on C57BL/6 background were isolated after negative depletion. Unstimulated as well as stimulated T-cells were studied. Stimulations were done with anti-CD3 (1 mg/ml) for 24 hrs. For the CD4+ T-cells we collected triplicates from the Itk knockout mice and duplicates from the Wt group. For the CD8+ T-cells, we got duplicates from Itk knockout , while we obtained a single sample from Wt owing to the low cell yield for resting Wt CD8+ T-cells. After CD3-stimulation we got a single sample from the CD8+ subset of both Wt and Itk knockout, while for the CD4+ subsets we collected duplicates.
Project description:T cells develop from progenitors that migrate from the bone marrow into the thymus. Thymocytes are subdivided roughly as being double negative (DN), double positive (DP), or single positive (SP), based on the expression of the CD4 and CD8 coreceptors. The DN stage is heterogeneous and can be subdivided into four distinct subsets in mice based on the expression of CD44 and CD25. In human, three distinct DN stages can be recognized: a CD34+CD38−CD1a− stage that represents the most immature thymic subset and the consecutive CD34+CD38+CD1a− and CD34+CD38+CD1a+ stages. Human DN thymocytes mature via an immature single positive (ISP CD4+) and a DP stage into CD4+ or CD8+ SP T cells that express functional T cell receptors (TCR) and that exit the thymus. In this study, gene expression was measured in each of these nine stages.
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:Many autoimmune diseases are characterized by the production of autoantibodies. The current view is that CD4+ Tfh cells are the main subset regulating autoreactive B cells. Here, we discover a distinct novel CXCR5+PD1+ Tfh subset of CD8+ T cells whose development and function are negatively regulated by Stat5. These CD8+ Tfh cells regulate the GC B cell response and control autoantibody production. Deficiency of Stat5 in CD8+ T cells leads to an increase of CD8+ Tfh cells, resulting in the breakdown of B cell tolerance and autoantibody production. CD8+ Tfh share similar gene signatures with CD4+ Tfh and require CD40L/CD40 and TCR/MHCI interactions to deliver help to B cells. Our study highlights the diversity of follicular T cell subsets that contribute to the breakdown of B-cell tolerance
Project description:Many autoimmune diseases are characterized by the production of autoantibodies. The current view is that CD4+ Tfh cells are the main subset regulating autoreactive B cells. Here, we discover a novel CXCR5+PD1+ Tfh subset of CD8+ T cells whose development and function are negatively regulated by Stat5. These CD8+ Tfh cells regulate the GC B cell response and control autoantibody production. Deficiency of Stat5 in CD8+ T cells leads to an increase of CD8+ Tfh cells, resulting in the breakdown of B cell tolerance and autoantibody production. CD8+ Tfh cells share similar gene signatures with CD4+ Tfh cells and require CD40L/CD40 and TCR/MHCI interactions to deliver help to B cells. Our study highlights the diversity of follicular T cell subsets that contribute to the breakdown of B-cell tolerance
Project description:This study aimed to look for transcriptional differences between stage-matched thymic T cell subsets isolated from wildtype and condensin II mutant mice CD4+CD8+ cells from 8-12 week animals were separated according to the expression of CD71, in order to isolate proliferative and non-proliferative subsets Total RNA from FACS purified CD4+CD8+CD71+ and CD4+CD8+CD71- was isolated, and comparisons were drawn between immunophenotypically matched cells from wildtype and Caph2 mutant (I15N) mice.
Project description:Mouse thymocytes can be classified into four major subsets based on expression of CD4 and CD8 co-receptors. CD4-CD8- (double negative, DN) cells become CD4+CD8+ (double positive, DP) cells following productive T cell receptor (TCR) beta chain rearrangement. A small proportion of DP cells are selected through interaction of clonal TCRalpha/beta and MHC self peptide complex expressed on thymic stromal cells. DP cell expressing MHC class I-restricted TCR become CD4-CD8+ cells, which will finally differentiate into cytotoxic T cells, while MHC class II restricted selection generates CD4+CD8- helper lineage T cells. We used microarrays to identify genes important for thymocyte differentiation and lineage determination by profiling gene expression in different thymocyte subsets. Mouse thymocytes were divided into four subsets based on CD4, CD8a, and TCRb expression and purified by flw cytometry. FACS purified DN (CD4-CD8a-TCRb-), DP (CD4+CD8a+), CD4SP (CD4+CD8a-TCRbhi) and CD8SP (CD4-CD8a+TCRbhi) populations were lysed in Trizol, and provided to the Genomics Core Facility of the Memorial Sloan-Kettering Cancer Center (MSKCC) for quality control, quantification, reverse transcription, labeling and hybridization to MOE430A 2.0 microarray chips (Affymetrix). Arrays were scanned per the manufacturer’s specifications for the Affymetrix MOE430v2 chip.