scholarly journals Epigenetic Programming during thymic development sets the stage for optimal function in effector T cells via DNA demethylation

Author(s):  
Priya Issuree ◽  
Athmane Teghanemt ◽  
Priyanjali Pulipati ◽  
Kenneth Day ◽  
Matt Yorek ◽  
...  

Abstract The potential for early thymic developmental events to program epigenetic states that influence adult T cell physiology remains an important question in health. Herein using the Cd4 locus as a paradigm for early developmental programming, we demonstrate that DNA demethylation during thymic development is critical for the licensing of a novel stimulus-responsive element that serves to maintain CD4 gene expression in effector T cells. We document the importance of maintaining high CD4 expression during parasitic infection and show that by driving transcription, this stimulus-responsive element allows for the maintenance of H3K4me3 levels during T cell replication, which is critical for repelling de novo DNA methylation at the Cd4 promoter. A failure to undergo epigenetic programming during development leads to gene silencing during effector T cell replication, thus providing evidence that early development can program stimulus-responsive elements to propagate a stable epigenetic state in effector T cells, with important biological consequences.

2021 ◽  
Author(s):  
Athmane Teghanemt ◽  
Priyanjali Pulipati ◽  
Kenneth Day ◽  
Matthew S. Yorek ◽  
Ren Yi ◽  
...  

The repressive effect of DNA methylation at promoters is well-known. However, its role within conserved sequences in intragenic and intergenic regions is less clear. Using Cd4 as a model gene, here we show that DNA methylation regulates the function of stimulus-responsive regulatory elements in effector T cells. Two cis-elements orchestrate intra-and intergenic DNA demethylation of the Cd4 gene during thymic development, which in turn licenses a stimulusresponsive element, E4a, for its later function in effector cells. Deficiency in DNA demethylation leads to impaired E4a function, reduced H3K4me3 promoter levels and an inability to repel de novo DNA methylation during replication, ultimately leading to gene silencing. This physiological reduction in CD4 expression leads to a defect in Th1 polarization during cutaneous Leishmaniasis. Similar patterns of regulation were observed in a broad number of genes, highlighting an essential role for DNA demethylation during thymic development in modulating the function of stimulus-responsive elements.


2020 ◽  
Author(s):  
Caitlin C. Zebley ◽  
Hossam A. Abdelsamed ◽  
Hazem E. Ghoneim ◽  
Shanta Alli ◽  
Dalia Haydar ◽  
...  

SUMMARYCD8 T cell memory differentiation endows T cells with an ability to rapidly induce effector functions upon pathogen re-encounter. While it is well established that substantial epigenetic remodeling occurs during the effector stage of the immune response, the signaling events that imprint CD8 T cells with these stable epigenetic programs are not well-defined. To gain insight into the signaling determinants of effector-associated epigenetic programming among CD8 T cells, we explored the role of IL-12 in the imprinting of IFNg expression during human CD8 T cell priming. We observed that TCR-mediated stimulation of human naïve CD8 T cells is not sufficient to induce substantial demethylation of the IFNg promotor. However, TCR stimulation in the presence of the inflammatory cytokine, IL-12, resulted in significant and stable demethylation of the IFNg locus that was commensurate with an increase in IFNg expression. We further show that IL-12-associated demethylation of the IFNg locus is coupled to cell division through TET2-dependent passive demethylation in an ex vivo human CAR T cell model system and an in vivo immunologically competent murine system. Collectively, these data illustrate that IL-12 signaling promotes TET2-mediated effector epigenetic programming in CD8 T cells during the primary immune response and serve as proof of concept that signal 3 cytokines can be used to guide the induction of epigenetically regulated traits among T cells used for adoptive immunotherapies.


Blood ◽  
2011 ◽  
Vol 117 (7) ◽  
pp. 2200-2210 ◽  
Author(s):  
Rikke Bæk Sørensen ◽  
Sine Reker Hadrup ◽  
Inge Marie Svane ◽  
Mads Christian Hjortsø ◽  
Per thor Straten ◽  
...  

Abstract Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme that is implicated in suppressing T-cell immunity in normal and pathologic settings. Here, we describe that spontaneous cytotoxic T-cell reactivity against IDO exists not only in patients with cancer but also in healthy persons. We show that the presence of such IDO-specific CD8+ T cells boosted T-cell immunity against viral or tumor-associated antigens by eliminating IDO+ suppressive cells. This had profound effects on the balance between interleukin-17 (IL-17)–producing CD4+ T cells and regulatory T cells. Furthermore, this caused an increase in the production of the proinflammatory cytokines IL-6 and tumor necrosis factor-α while decreasing the IL-10 production. Finally, the addition of IDO-inducing agents (ie, the TLR9 ligand cytosine-phosphate-guanosine, soluble cytotoxic T lymphocyte–associated antigen 4, or interferon γ) induced IDO-specific T cells among peripheral blood mononuclear cells from patients with cancer as well as healthy donors. In the clinical setting, IDO may serve as an important and widely applicable target for immunotherapeutic strategies in which IDO plays a significant regulatory role. We describe for the first time effector T cells with a general regulatory function that may play a vital role for the mounting or maintaining of an effective adaptive immune response. We suggest terming such effector T cells “supporter T cells.”


1976 ◽  
Vol 144 (3) ◽  
pp. 776-787 ◽  
Author(s):  
R M Zinkernagel

In mice, primary footpad swelling after local infection with lymphocytic choriomeningitis virus (LCMV) and delayed-type hypersensitivity (DTH) adoptively transferred by LCMV immune lymphocytes are T-cell dependent. Nude mice do not develop primary footpad swelling, and T-cell depletion abrogates the capacity to transfer LCMV-specific DTH. Effector T cells involved in eliciting dose-dependent DTH are virus specific in that vaccinia virus-immune lymphocytes could not elicit DTH in LCMV-infected mice. The adoptive transfer of DTH is restricted to H-2K or H-2D compatible donor-recipient combinations. Distinct from the fowl-gamma-globulin DTH model, I-region compatibility is neither necessary nor alone sufficient. Whatever the mechanisms involved in this K- or D-region associated restriction in vivo, it most likely operates at the level of T-cell recognition of "altered self" coded in K or D. T cells associated with the I region (helper T cells and DTH-T cells to fowl-gamma-globulin) are specific for soluble, defined, and inert antigens. T cells associated with the K and D region (T cells cytotoxic in vitro and in vivo for acute LCMV-infected cells, DTH effector T cells, and anti-viral T cells) are specific for infectious, multiplying virus. The fact that T-cell specificity is differentially linked with the I region or with the K and D regions of H-2 may reflect the fundamental biological differences of these antigens. Although it cannot be excluded that separate functional subclasses of T-effector cells could have self-recognizers for different cell surface structures coded in I or K and D, it is more likely that the antigen parameters determine whether T cells are specific for "altered" I or "altered" K- or D-coded structures.


Hepatology ◽  
2017 ◽  
Vol 66 (5) ◽  
pp. 1570-1584 ◽  
Author(s):  
Rodrigo Liberal ◽  
Charlotte R. Grant ◽  
Muhammed Yuksel ◽  
Jonathon Graham ◽  
Alireza Kalbasi ◽  
...  

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2626-2626
Author(s):  
Chia-Chi Lin ◽  
Aung Naing ◽  
Manish R. Patel ◽  
Howard A. Burris III ◽  
Giuseppe Curigliano ◽  
...  

2626 Background: Inducible T-cell co-stimulator (ICOS) is an important co-stimulatory receptor on effector T cells (Teffs) that also promotes tumor growth due to its high expression on regulatory T cells (Tregs). KY1044 is a fully human IgG1 that targets ICOS, acting via a dual mode of action (MoA) by depleting ICOShigh Tregs and stimulating ICOSLow Teffs. A Phase 1/2 clinical trial (NCT03829501) is currently assessing the safety and preliminary efficacy of KY1044, as a single agent and in combination with atezolizumab, in subjects with advanced relapsed/refractory malignancies. Using longitudinal blood samples and tumor biopsies, we aim to correlate KY1044 target engagement levels with pharmacodynamic (PD) properties (e.g. dual MoA) in the tumor microenvironment (TME) and the circulation. Methods: Phase 1 subjects were enrolled in dose escalation and enrichment cohorts to evaluate the effect of KY1044 as monotherapy (0.8 – 240 mg) Q3W and in combination (0.8 – 80 mg) with atezolizumab (1200 mg) Q3W. PBMCs, plasma and tumor biopsies were collected over the first 3 cycles to confirm target engagement and KY1044 MoA. The sample analysis included: immunohistochemistry (IHC) of tumor samples (ICOS, FOXP3 and CD8); circulating T cell immunoprofiling and receptor occupancy by chip-cytometry; PBMC and tumor sample pre- and post-treatment transcriptomic analysis; and the assessment of circulating cytokines (e.g. GM-CSF). Results: As assessed in PBMCs, full/prolonged ICOS target engagement on T cells was confirmed in subjects receiving a flat dose of 8 to 240 mg, while partial/transient saturation was observed at lower doses (0.8-2.4 mg). The target engagement was not affected by atezolizumab. The immune cell profiling showed changes in some populations, but there was no significant depletion of peripheral ICOS+ cells. In contrast, pre- and post-treatment IHC analysis of ICOS+/FOXP3+ cells in tumor biopsies confirmed a KY1044-dose dependent reduction of ICOS+ Tregs and maintenance of CD8+ T cells in the TME. Together, this resulted in an increased intratumoral CD8+/ICOS+ Treg ratio at all doses, plateauing from subjects receiving a flat KY1044 dose of 8 mg. KY1044-dependent agonism was indirectly assessed by measuring circulating cytokine levels. A post-dosing transient induction of GM-CSF was evident in subjects dosed with KY1044 at the 0.8 and 2.4 mg dose, whereas minimal induction was observed at dose of 8 mg and higher. Conclusions: LongitudinalPDdata confirmed the expected KY1044 MoA, namely ICOS Treg depletion and increased CD8/ICOS Treg ratio in the TME as well as T cell co-stimulation. The observed PD responses are currently being further explored in a more homogenous patient population.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Tania A Nevers ◽  
Ane Salvador ◽  
Francisco Velazquez ◽  
Mark Aronovitz ◽  
Robert Blanton

Background: Cardiac fibrogenesis is a major pathogenic factor that occurs in heart failure (HF) and results in contractile dysfunction and ventricular dilation. Recently, we showed that T cell deficient mice (TCRα -/- ) do not develop cardiac fibrosis (CF) and have preserved cardiac function in the thoracic aortic constriction (TAC) mouse model of pressure overload (PO). Specifically, CD4 + T cells are activated in the cardiac draining lymph nodes and infiltrate the LV, where the Th1 and Th17 effector T cell signature transcription factors are significantly upregulated as compared with control mice. However, the T cell subsets involved and the mechanisms by which they contribute to CF and pathogenesis of non-ischemic HF remains to be determined. Thus, we hypothesize that heart infiltrated effector T cells perpetuate the fibrotic response by regulating the differentiation and activation of extracellular matrix-producing cardiac myofibroblasts. Methods and Results: Naïve or effector T cells differentiated in vitro or isolated from mice undergoing TAC or Sham surgery were co-cultured with adult C57BL/6 cardiac fibroblasts (CFB). In contrast with naïve T cells, effector T cells and PO activated T cells strongly adhered to CFB and mediated fibroblast to myofibroblasts transition as depicted by immunofluorescence expression of SMAα. Effector T cell supernatants only slightly mediated this transition, indicating that effector T cells direct contact with CFB, rather than cytokine release is required to mediate CFB transformation. Adoptive transfer of effector, but not naïve T cells, into TCRα -/- recipient mice in the onset of TAC resulted in T cells infiltration into the left ventricle and increased CF. Conclusions: Our data indicate that CD4+ effector T cells directly interact with CFB to induce CF in response to PO induced CF. Future studies will determine the adhesion mechanisms regulating this crosstalk and evaluate the pro-fibrotic mechanisms induced and whether this is a T effector cell specific subset. These results will provide an attractive tool to counteract the inflammatory/fibrotic process as an alternative option for the treatment of CF in non- ischemic HF.


2021 ◽  
Vol 12 ◽  
Author(s):  
Darina Ocadlikova ◽  
Mariangela Lecciso ◽  
Javier Martin Broto ◽  
Katia Scotlandi ◽  
Michele Cavo ◽  
...  

BackgroundHigh-grade sarcomas are a heterogeneous group of aggressive tumors arising in bone and soft tissues. After relapse, treatment options are limited. The multi-targeted receptor tyrosine kinase inhibitors (TKIs) sunitinib and inhibitor of PD-1 (anti-PD-1) nivolumab have shown antitumor activity in selected subtypes. In this study, we examine the role of TKIs and PD-1 based therapy in in vitro cocultures of sarcoma.MethodsThe human osteosarcoma (SaOS-2) and synovial sarcoma (SYO-1) cell lines were treated with sunitinib. After cell death and proliferation assessment, expression of PD-L1 was analyzed by flow cytometry. Sunitinib-treated sarcoma cells were cocultured with dendritic cells (DCs), and the phenotype of mature DCs was determined by flow cytometry. Mature DCs were cultured with autologous T cells. PD-1 expression on T cells, their proliferation, T regulatory cell (Tregs) induction and IFN-γ production, before and after nivolumab exposure, were analyzed.ResultsAlong with its anti-proliferative and direct pro-apoptotic effect on sarcoma cell lines, sunitinib prompted PD-L1 upregulation on sarcoma cells. Interestingly, sunitinib-treated sarcoma cells drive DCs to full maturation and increase their capacity to induce sarcoma-reactive T cells to produce IFN-γ. Conversely, no effect on T cell proliferation and T cell subpopulation composition was observed. Moreover, both bone and synovial sarcoma cell lines induced Tregs through DCs but sunitinib treatment completely abrogated Treg induction. Finally, sarcoma cell lines induced PD-1 upregulation on both effector T cells and Tregs when loaded into DCs, providing a rationale for using PD-1 blockade. Indeed, PD-1 blockade by nivolumab synergized with sunitinib in inducing IFN-γ-producing effector T cells.ConclusionsTaken together, our in vitro data indicate that the treatment of sarcoma cells with sunitinib can exert significant changes on immune cell subsets toward immune activation, leading to DC-based cross-priming of IFN-γ-producing effector T cells and reduced Treg induction. PD-1 blockade with nivolumab has a synergistic effect with sunitinib, supporting the use of TKI and anti-PD-1 approach in sarcomas, and perhaps in other cancers. DC-targeted drugs, including toll-like receptor 3 inhibitors and CD47 inhibitors, are under development and our preclinical model might help to better design their clinical application.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yunmeng Bai ◽  
Meiling Hu ◽  
Zixi Chen ◽  
Jinfen Wei ◽  
Hongli Du

T-cell exhaustion is one of the main reasons of tumor immune escape. Using single-cell transcriptome data of CD8+ T cells in multiple cancers, we identified different cell types, in which Pre_exhaust and exhausted T cells participated in negative regulation of immune system process. By analyzing the coexpression network patterns and differentially expressed genes of Pre_exhaust, exhausted, and effector T cells, we identified 35 genes related to T-cell exhaustion, whose high GSVA scores were associated with significantly poor prognosis in various cancers. In the differentially expressed genes, RGS1 showed the greatest fold change in Pre_exhaust and exhausted cells of three cancers compared with effector T cells, and high expression of RGS1 was also associated with poor prognosis in various cancers. Additionally, RGS1 protein was upregulated significantly in tumor tissues in the immunohistochemistry verification. Furthermore, RGS1 displayed positive correlation with the 35 genes, especially highly correlated with PDCD1, CTLA4, HAVCR2, and TNFRSF9 in CD8+ T cells and cancer tissues, indicating the important roles of RGS1 in CD8+ T-cell exhaustion. Considering the GTP-hydrolysis activity of RGS1 and significantly high mRNA and protein expression in cancer tissues, we speculated that RGS1 potentially mediate the T-cell retention to lead to the persistent antigen stimulation, resulting in T-cell exhaustion. In conclusion, our findings suggest that RGS1 is a new marker and promoting factor for CD8+ T-cell exhaustion and provide theoretical basis for research and immunotherapy of exhausted cells.


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