Project description:Goal of this study was to compare transcriptional changes in CTL cells compared to Tc17 cells We used microarray to detail the global programme of gene expression underlying CTL and Tc17 cell differentiation and identified distinct classes of upregulated genes thereby
Project description:IL-17-producing CD8+ (Tc17)T cells are implicated in the pathogenesis of multiple sclerosis (MS), thereby representing a promising target for therapy. We found that dimethyl fumarate (DMF), a first-line medication for MS upregulated reactive oxygen species (ROS) by glutathione depletion in murine Tc17 cells, which limited IL-17 and diverted Tc17 cells towards cytotoxic T lymphocyte (CTL) signature. DMF enhanced PI3K-AKT-FOXO1-T-bet- as well as STAT5-signaling leading to restricted permissive histone state at the Il17 locus. T-bet-deficiency, inhibiting PI3K-AKT, STAT5 or histone deacetylases prevented DMF-ROS-mediated IL-17 suppression. In MS patients with stable response, DMF suppressed IL-17 production by CD8+ T-cells and triggered diversion from Tc17 towards CTL signature along with enriched ROS-, PI3K-AKT-FOXO1-signaling, demonstrating comparable regulation across species. Accordingly, in the mouse model for MS, DMF limited Tc17-encephalitogenicity. Our findings disclose DMF-ROS-AKT-driven pathway, which selectively modulates Tc17 fate to ameliorate MS, thus opening avenue to develop markers and targets for specific therapy.
Project description:IL-17-producing cells are important mediators of graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). Here we demonstrate that a distinct CD8+ Tc17 population develops rapidly after SCT but fails to maintain lineage fidelity such that they are unrecognizable in the absence of a fate reporter. Tc17 differentiation is dependent on alloantigen presentation by host-DC together with IL-6. Tc17 cells express high levels of multiple prototypic lineage-defining transcription factors (e.g. RORgt, T-bet) and cytokines (e.g. IL-17A, IL-22, IFNg, GM-CSF, IL-13). Targeted depletion of Tc17 early after transplant protects from lethal acute GVHD, however Tc17 cells are non-cytolytic and fail to mediate graft–versus–leukemia (GVL) effects. Thus, the Tc17 differentiation program during GVHD culminates in a highly plastic, hyper-inflammatory, poorly-cytolytic effector population which we term inflammatory Tc17 (iTc17). Since iTc17 mediate GVHD without contributing to GVL, therapeutic inhibition of iTc17 development in a clinical setting represents an attractive approach for separating GVHD and GVL. Single colour, Illumina MouseRef-8 v2.0 Beadarrays.
Project description:In cytotoxic T cells (CTL), Protein Kinase B /Akt is activated by the T cell antigen receptor (TCR) and the cytokine Interleukin 2 (IL2), in part by phosophorylation of Akt by Phospholipid dependent kinase 1 (PDK1). The role of PDK1 and Akt in CTL has however not been fully defined. In order to explore the relative roles of these kinases in CTL we used microarrays to profile the gene expression of control and PDK1 null CTL. In separate experiments we compared the gene expression profiles of control and Akt inhibitor treated CTL.
Project description:In cytotoxic T cells (CTL), Protein Kinase B /Akt is activated by the T cell antigen receptor (TCR) and the cytokine Interleukin 2 (IL2), in part by phosophorylation of Akt by Phospholipid dependent kinase 1 (PDK1). The role of PDK1 and Akt in CTL has however not been fully defined. In order to explore the relative roles of these kinases in CTL we used microarrays to profile the gene expression of control and PDK1 null CTL. In separate experiments we compared the gene expression profiles of control and Akt inhibitor treated CTL. CTL were generated from 3 mice each carrying two loxP flanked PDK1 alleles plus a tamoxifen inducible Cre transgene. PDK1 was then deleted from these CTL by tamoxifen treatment and the gene expression pattern determined by microarray. Tamoxifen treated PDK1wt/wt TamoxCre+ CTL generated from 3 PDK1wt/wt TamocCre+ mice were used as a control. In separate experiments CTL were were generated from 3 wild-type mice and then half the CTL generated from each mouse were treated with the Akt inhibitor AktI-1/2. The gene expression patterns of the AktI treated and the untreated CTL were then compared by microarray.
Project description:Comparison of transcriptional profile of CD8 cytotoxic T lymphocytes terated with the mTORC1 inhibitor rapamycin or the mTOR inhibitor KU-0063794 and comparison with proteomic analysis. Abstract: High resolution mass spectrometry maps the cytotoxic T lymphocyte (CTL) proteome and the impact of mammalian target of rapamycin complex 1 (mTORC1) on CTL. We show that the CTL proteome is dominated by metabolic regulators and granzymes and that mTORC1 selectively represses and promotes expression of a protein subset (~10%) including key CTL effector molecules and signaling proteins. mTORC1 also controlled flux through a subset of metabolic pathways rather than acting as an on/off switch for global CTL metabolism. Proteomic data highlighted the potential for mTORC1 negative control of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) production in CTL. Further work revealed that mTORC1 represses PIP3 production and determines the mTORC2 requirement for activation of the serine/threonine kinase AKT. Unbiased proteomic analysis thus provides a comprehensive understanding of CTL identity and mTORC1 control of CTL function.
Project description:Gene expression analysis of WT and IL-2Ra-deficient CTL (P14) isolated 8 days after inffection with LCMV. The goals of the study are to assess the impact of IL-2 signals on effector and memory CTL differentiation.
Project description:The differentiation of naive CD8+ T cells into effector cells is important for establishing immunity. However, the effect of heterogeneous naive CD8+ T cell populations is not fully understood. Here, we demonstrate that steady-state naive CD8+ T cells are composed of functionally heterogeneous subpopulations that differ in their ability to differentiate into type 17 cytotoxic effector cells (Tc17) in inflammatory disease models. The differential ability of Tc17 differentiation was not related to T-cell receptor (TCR) diversity and antigen specificity but was inversely correlated with self-reactivity acquired during development. Mechanistically, this phenomenon was linked to differential levels of intrinsic TCR sensitivity and basal SMAD3 expression, generating a wide spectrum of Tc17 differentiation potential within naive CD8+ T cell populations. These findings suggest that developmental self-reactivity can determine the fate of naive CD8+ T cells to generate functionally distinct effector populations and achieve immense diversity and complexity in antigen-specific T-cell immune responses.
Project description:IL-17-producing cells are important mediators of graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). Here we demonstrate that a distinct CD8+ Tc17 population develops rapidly after SCT but fails to maintain lineage fidelity such that they are unrecognizable in the absence of a fate reporter. Tc17 differentiation is dependent on alloantigen presentation by host-DC together with IL-6. Tc17 cells express high levels of multiple prototypic lineage-defining transcription factors (e.g. RORgt, T-bet) and cytokines (e.g. IL-17A, IL-22, IFNg, GM-CSF, IL-13). Targeted depletion of Tc17 early after transplant protects from lethal acute GVHD, however Tc17 cells are non-cytolytic and fail to mediate graft–versus–leukemia (GVL) effects. Thus, the Tc17 differentiation program during GVHD culminates in a highly plastic, hyper-inflammatory, poorly-cytolytic effector population which we term inflammatory Tc17 (iTc17). Since iTc17 mediate GVHD without contributing to GVL, therapeutic inhibition of iTc17 development in a clinical setting represents an attractive approach for separating GVHD and GVL.