bims-imseme Biomed News
on Immunosenescence and T cell metabolism
Issue of 2021‒07‒11
23 papers selected by
Pierpaolo Ginefra
Ludwig Institute for Cancer Research

  1. Immunity. 2021 Jun 29. pii: S1074-7613(21)00251-X. [Epub ahead of print]
      Antigen-specific CD8+ T cells in chronic viral infections and tumors functionally deteriorate, a process known as exhaustion. Exhausted T cells are sustained by precursors of exhausted (Tpex) cells that self-renew while continuously generating exhausted effector (Tex) cells. However, it remains unknown how Tpex cells maintain their functionality. Here, we demonstrate that Tpex cells sustained mitochondrial fitness, including high spare respiratory capacity, while Tex cells deteriorated metabolically over time. Tpex cells showed early suppression of mTOR kinase signaling but retained the ability to activate this pathway in response to antigen receptor signals. Early transient mTOR inhibition improved long-term T cell responses and checkpoint inhibition. Transforming growth factor-β repressed mTOR signaling in exhausted T cells and was a critical determinant of Tpex cell metabolism and function. Overall, we demonstrate that the preservation of cellular metabolism allows Tpex cells to retain long-term functionality to sustain T cell responses during chronic infection.
    Keywords:  OXPHOS; T cell exhaustion; T cell function; TCF1; checkpoint inhibition; mitochondria; precursors of exhausted T cells; progenitor T cells; rapamycin; stem-like T cells
  2. Cell. 2021 Jun 25. pii: S0092-8674(21)00708-X. [Epub ahead of print]
      Polyamine synthesis represents one of the most profound metabolic changes during T cell activation, but the biological implications of this are scarcely known. Here, we show that polyamine metabolism is a fundamental process governing the ability of CD4+ helper T cells (TH) to polarize into different functional fates. Deficiency in ornithine decarboxylase, a crucial enzyme for polyamine synthesis, results in a severe failure of CD4+ T cells to adopt correct subset specification, underscored by ectopic expression of multiple cytokines and lineage-defining transcription factors across TH cell subsets. Polyamines control TH differentiation by providing substrates for deoxyhypusine synthase, which synthesizes the amino acid hypusine, and mice in which T cells are deficient for hypusine develop severe intestinal inflammatory disease. Polyamine-hypusine deficiency caused widespread epigenetic remodeling driven by alterations in histone acetylation and a re-wired tricarboxylic acid (TCA) cycle. Thus, polyamine metabolism is critical for maintaining the epigenome to focus TH cell subset fidelity.
    Keywords:  T cells; eIF5A; hypusine; immunity; immunometabolism; metabolism; polyamines
  3. Cell Rep. 2021 Jul 06. pii: S2211-1247(21)00715-4. [Epub ahead of print]36(1): 109339
      The ability of regulatory T (Treg) cells to control the immune response and limit the development of autoimmune diseases is determined by distinct molecular processes, which are not fully understood. We show here that serine/arginine-rich splicing factor 1 (SRSF1), which is decreased in T cells from patients with systemic lupus erythematosus, is necessary for the homeostasis and proper function of Treg cells, because its conditional absence in these cells leads to profound autoimmunity and organ inflammation by elevating the glycolytic metabolism and mTORC1 activity and the production of proinflammatory cytokines. Our data reveal a molecular mechanism that controls Treg cell plasticity and offer insights into the pathogenesis of autoimmune disease.
    Keywords:  SRSF1; T cells; Treg; autoimmunity; cytokines; immune homeostasis; immune regulation; inflammation; mTOR pathway; splicing factor
  4. Front Immunol. 2021 ;12 691997
      Phosphoinositide 3-kinase p110 delta (PI3K p110δ) is pivotal for CD8+ T cell immune responses. The current study explores PI3K p110δ induction and repression of antigen receptor and cytokine regulated programs to inform how PI3K p110δ directs CD8+ T cell fate. The studies force a revision of the concept that PI3K p110δ controls metabolic pathways in T cells and reveal major differences in PI3K p110δ regulated transcriptional programs between naïve and effector cytotoxic T cells (CTL). These differences include differential control of the expression of cytolytic effector molecules and costimulatory receptors. Key insights from the work include that PI3K p110δ signalling pathways repress expression of the critical inhibitory receptors CTLA4 and SLAMF6 in CTL. Moreover, in both naïve and effector T cells the dominant role for PI3K p110δ is to restrain the production of the chemokines that orchestrate communication between adaptive and innate immune cells. The study provides a comprehensive resource for understanding how PI3K p110δ uses multiple processes mediated by Protein Kinase B/AKT, FOXO1 dependent and independent mechanisms and mitogen-activated protein kinases (MAPK) to direct CD8+ T cell fate.
    Keywords:  CD8+ T cells; PI3K; TCR signalling; chemokines; cytokines; p110δ; transcriptomics
  5. Immunobiology. 2021 Jul 01. pii: S0171-2985(21)00059-0. [Epub ahead of print]226(4): 152111
      T cell dysfunction is a common characteristic in leukemia patients that significantly impacts clinical treatment and prognosis. However, the mechanism underlying T cell dysfunction and its reversal remains unclear. In this study, in accordance with our previous findings, we found that the expression of NFAT2 and pri-miR-17 ~ 92 are lower in peripheral blood CD3+ T cells from chronic myelogenous leukemia (CML) patients by gene expression analysis. We further demonstrate that the NFAT2-induced activation, differentiation, and expression of cytokines in human umbilical cord blood CD8+ naïve T cells are miR-20a-5p dependent. We also preliminarily explored the relationship between NFAT2 and miR-20a-5p in naive T cells. These results suggest that NFAT2 and miR-20a are crucial for regulating functional CD8+ T cells. Additionally, their alteration may be related to CD8+ T cell dysfunction in CML patients; thus, NFAT2 and miR-20a-5p may be considered potential targets for revising T cell function in leukemia immunotherapy.
    Keywords:  CD8(+) T cell; CML; Immunotherapy; NFAT2; T cell dysfunction; miR-20a-5p
  6. Cell. 2021 Jun 29. pii: S0092-8674(21)00700-5. [Epub ahead of print]
      Metabolism is a major regulator of immune cell function, but it remains difficult to study the metabolic status of individual cells. Here, we present Compass, an algorithm to characterize cellular metabolic states based on single-cell RNA sequencing and flux balance analysis. We applied Compass to associate metabolic states with T helper 17 (Th17) functional variability (pathogenic potential) and recovered a metabolic switch between glycolysis and fatty acid oxidation, akin to known Th17/regulatory T cell (Treg) differences, which we validated by metabolic assays. Compass also predicted that Th17 pathogenicity was associated with arginine and downstream polyamine metabolism. Indeed, polyamine-related enzyme expression was enhanced in pathogenic Th17 and suppressed in Treg cells. Chemical and genetic perturbation of polyamine metabolism inhibited Th17 cytokines, promoted Foxp3 expression, and remodeled the transcriptome and epigenome of Th17 cells toward a Treg-like state. In vivo perturbations of the polyamine pathway altered the phenotype of encephalitogenic T cells and attenuated tissue inflammation in CNS autoimmunity.
    Keywords:  DFMO; T helper 17 cell; experimental autoimmune encephalomyelitis; immunometabolism; in silico metabolic modeling; multiple sclerosis; polyamines; putrescine; single cell transcriptomics; spermidine
  7. Nature. 2021 Jul 07.
      T follicular helper (TFH) cells are crucial for B cell-mediated humoral immunity1. Although transcription factors such as BCL6 drive the differentiation of TFH cells2,3, it is unclear whether and how post-transcriptional and metabolic programs enforce TFH cell programming. Here we show that the cytidine diphosphate (CDP)-ethanolamine pathway co-ordinates the expression and localization of CXCR5 with the responses of TFH cells and humoral immunity. Using in vivo CRISPR-Cas9 screening and functional validation in mice, we identify ETNK1, PCYT2, and SELENOI-enzymes in the CDP-ethanolamine pathway for de novo synthesis of phosphatidylethanolamine (PE)-as selective post-transcriptional regulators of TFH cell differentiation that act by promoting the surface expression and functional effects of CXCR5. TFH cells exhibit unique lipid metabolic programs and PE is distributed to the outer layer of the plasma membrane, where it colocalizes with CXCR5. De novo synthesis of PE through the CDP-ethanolamine pathway co-ordinates these events to prevent the internalization and degradation of CXCR5. Genetic deletion of Pcyt2, but not of Pcyt1a (which mediates the CDP-choline pathway), in activated T cells impairs the differentiation of TFH cells, and this is associated with reduced humoral immune responses. Surface levels of PE and CXCR5 expression on B cells also depend on Pcyt2. Our results reveal that phospholipid metabolism orchestrates post-transcriptional mechanisms for TFH cell differentiation and humoral immunity, highlighting the metabolic control of context-dependent immune signalling and effector programs.
  8. Sci Adv. 2021 Jul;pii: eabg5859. [Epub ahead of print]7(28):
      T lymphocytes encounter complex mechanical cues during an immune response. The mechanosensitive ion channel, Piezo1, drives inflammatory responses to bacterial infections, wound healing, and cancer; however, its role in helper T cell function remains unclear. In an animal model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), we found that mice with genetic deletion of Piezo1 in T cells showed diminished disease severity. Unexpectedly, Piezo1 was not essential for lymph node homing, interstitial motility, Ca2+ signaling, T cell proliferation, or differentiation into proinflammatory T helper 1 (TH1) and TH17 subsets. However, Piezo1 deletion in T cells resulted in enhanced transforming growth factor-β (TGFβ) signaling and an expanded pool of regulatory T (Treg) cells. Moreover, mice with deletion of Piezo1 specifically in Treg cells showed significant attenuation of EAE. Our results indicate that Piezo1 selectively restrains Treg cells, without influencing activation events or effector T cell functions.
  9. Cell Death Dis. 2021 Jul 03. 12(7): 671
      The balanced functionality of cellular proteostatic modules is central to both proteome stability and mitochondrial physiology; thus, the age-related decline of proteostasis also triggers mitochondrial dysfunction, which marks multiple degenerative disorders. Non-functional mitochondria are removed by mitophagy, including Parkin/Pink1-mediated mitophagy. A common feature of neuronal or muscle degenerative diseases, is the accumulation of damaged mitochondria due to disrupted mitophagy rates. Here, we exploit Drosophila as a model organism to investigate the functional role of Parkin/Pink1 in regulating mitophagy and proteostatic responses, as well as in suppressing degenerative phenotypes at the whole organism level. We found that Parkin or Pink1 knock down in young flies modulated proteostatic components in a tissue-dependent manner, increased cell oxidative load, and suppressed mitophagy in neuronal and muscle tissues, causing mitochondrial aggregation and neuromuscular degeneration. Concomitant to Parkin or Pink1 knock down cncC/Nrf2 overexpression, induced the proteostasis network, suppressed oxidative stress, restored mitochondrial function, and elevated mitophagy rates in flies' tissues; it also, largely rescued Parkin or Pink1 knock down-mediated neuromuscular degenerative phenotypes. Our in vivo findings highlight the critical role of the Parkin/Pink1 pathway in mitophagy, and support the therapeutic potency of Nrf2 (a druggable pathway) activation in age-related degenerative diseases.
  10. Cancer Lett. 2021 Jul 05. pii: S0304-3835(21)00327-X. [Epub ahead of print]
      Cellular senescence is a stress response that imposes a growth arrest on cancer and nonmalignant cells during cancer therapy. By secreting a plethora of proinflammatory factors collectively termed the senescence-associated secretory phenotype (SASP), therapy-induced senescent cells can promote tumorigenesis. Moreover, the SASP from senescent cells is also able to drive therapy resistance and mediate many adverse effects of cancer therapy. Because senescent cell production often occurs during cancer therapy, it is important to carefully consider these potential detrimental effects. Senotherapy, which refers to selective removal of senescent cells, has been proposed as a promising adjuvant approach to eliminate the adverse effects of senescent cells. Thus, in this review we summarize in detail the mechanisms by which senescent cells contribute to tumorigenesis and therapeutic resistance. Also, we thoroughly discuss the potential strategies regarding how to effectively circumvent the undesirable effects of therapy-induced senescent cells.
    Keywords:  Cancer therapy; Cellular senescence; SASP; Senolysis; Senotherapy
  11. Immunology. 2021 Jul 08.
      Neutrophils are the most abundant leukocytes in human blood, promptly recruited to the site of tissue injury, where they orchestrate inflammation and tissue repair. The multifaceted functions of neutrophils have been more appreciated during the recent decade, and these cells are now recognized as sophisticated and essential players in infection, cancer, and chronic inflammatory diseases. Consequently, our understanding of the role of neutrophils in inflammatory bowel disease (IBD), their immune responses, and their ability to shape adaptive immunity in the gut have been recognized. Here, current knowledge on neutrophil responses in IBD and their capacity to influence T cells are summarized with an emphasis on the role of these cells in human disease.
    Keywords:  CD; IBD; IL-22; IL-23; LL-37; T cells; Th17; UC; human; mucosal immunology; neutrophils
  12. Dis Model Mech. 2021 Jul 01. 14(7): 1-17
      Cancer cells constantly reprogram their metabolism as the disease progresses. However, our understanding of the metabolic complexity of cancer remains incomplete. Extensive research in the fruit fly Drosophila has established numerous tumor models ranging from hyperplasia to neoplasia. These fly tumor models exhibit a broad range of metabolic profiles and varying nutrient sensitivity. Genetic studies show that fly tumors can use various alternative strategies, such as feedback circuits and nutrient-sensing machinery, to acquire and consolidate distinct metabolic profiles. These studies not only provide fresh insights into the causes and functional relevance of metabolic reprogramming but also identify metabolic vulnerabilities as potential targets for cancer therapy. Here, we review the conceptual advances in cancer metabolism derived from comparing and contrasting the metabolic profiles of fly tumor models, with a particular focus on the Warburg effect, mitochondrial metabolism, and the links between diet and cancer.
    Keywords:   Drosophila cancer models; Aerobic glycolysis; Metabolic reprogramming; Mitochondria
  13. Nat Med. 2021 Jul 08.
      Inhibitors of the PD-1-PD-L1 axis have been approved as therapy for many human cancers. In spite of the evidence for their widespread clinical activity, little is known about the immunological alterations that occur in human cancer tissue after PD-1 blockade. We developed and employed a patient-derived tumor fragment platform to dissect the early immunological response of human tumor tissue to ex vivo PD-1 blockade. We observed that the capacity of immune cells to be reactivated ex vivo was predictive of clinical response, and perturbation analyses identified tumor-resident T cells as a key component of this immunological response. In addition, through combined analysis of baseline properties and immune response capacity, we identified a new subgroup of infiltrated tumors that lacks the capacity to respond to PD-1 blockade. Finally, the baseline presence of tertiary lymphoid structures and their components correlated with the capacity of cancers to undergo intratumoral immune cell reactivation.
  14. Elife. 2021 Jul 09. pii: e69975. [Epub ahead of print]10
      Signals from the pre-T cell receptor and Notch coordinately instruct b-selection of CD4-CD8- double negative (DN) thymocytes to generate ab T cells in the thymus. However, how these signals ensure a high-fidelity proteome and safeguard the clonal diversification of the pre-selection TCR repertoire given the considerable translational activity imposed by b-selection is largely unknown. Here, we identify the endoplasmic reticulum (ER)-associated degradation (ERAD) machinery as a critical proteostasis checkpoint during b-selection. Expression of the SEL1L-HRD1 complex, the most conserved branch of ERAD, is directly regulated by the transcriptional activity of the Notch intracellular domain. Deletion of Sel1l impaired DN3 to DN4 thymocyte transition and severely impaired mouse ab T cell development. Mechanistically, Sel1l deficiency induced unresolved ER stress that triggered thymocyte apoptosis through the PERK pathway. Accordingly, genetically inactivating PERK rescued T cell development from Sel1l-deficient thymocytes. In contrast, IRE1a/XBP1 pathway was induced as a compensatory adaptation to alleviate Sel1l-deficiency induced ER stress. Dual loss of Sel1l and Xbp1 markedly exacerbated the thymic defect. Our study reveals a critical developmental signal controlled proteostasis mechanism that enforces T cell development to ensure a healthy adaptive immunity.
    Keywords:  developmental biology; immunology; inflammation; mouse
  15. Sci Rep. 2021 Jul 06. 11(1): 13912
      Anti-PD-L1 antibodies benefit many cancer patients, even those with "non-inflamed tumor". Determining which patients will benefit remains an important clinical goal. In a non-inflamed tumor mouse model, we found that PD-L1 was highly expressed on antigen-presenting cells (APCs) especially on CD103+ CD11c+ dendritic cells in tumor-draining lymph nodes (dLNs), suppressing T-cell priming by APCs. In this model, anti-PD-L1 antibodies enhanced T-cell priming and increased CXCR3+ activated T-cells in dLNs, which was followed by the trafficking of T-cells to tumors in response to CXCR3 ligands. As predictive biomarker, each APCs-related gene expression (AP score) alone or T-cells trafficking-related chemokine gene expression (T score) alone were still less than perfect among the 17 mouse models examined. However a combining score of AP score and T score (AP/T score) precisely identified anti-PD-L1-sensitive tumors. In the phase 3 trial of atezolizumab vs docetaxel in advanced NSCLC patients (OAK), the AP/T score could identify atezolizumab-treated NSCLC patients who achieved significant improvement in overall survival. This biomarker concept would be a clinically valuable for prediction of anti-PD-L1 antibody efficacy.
  16. Front Pharmacol. 2021 ;12 671929
      Silent information regulator 2-related enzyme 1 (SIRT1) is an NAD+-dependent class III deacetylase and a key component of the cellular metabolic sensing pathway. The requirement of NAD+ for SIRT1 activity led us to assume that NQO1, an NADH oxidoreductase producing NAD+, regulates SIRT1 activity. We show here that SIRT1 is capable of increasing NQO1 (NAD(P)H Dehydrogenase Quinone 1) transcription and protein levels. NQO1 physically interacts with SIRT1 but not with an enzymatically dead SIRT1 H363Y mutant. The interaction of NQO1 with SIRT1 is markedly increased under mitochondrial inhibition. Interestingly, under this condition the nuclear pool of NQO1 is elevated. Depletion of NQO1 compromises the role of SIRT1 in inducing transcription of several target genes and eliminates the protective role of SIRT1 following mitochondrial inhibition. Our results suggest that SIRT1 and NQO1 form a regulatory loop where SIRT1 regulates NQO1 expression and NQO1 binds and mediates the protective role of SIRT1 during mitochondrial stress. The interplay between an NADH oxidoreductase enzyme and an NAD+ dependent deacetylase may act as a rheostat in sensing mitochondrial stress.
    Keywords:  NADH/NAD ratio; PGC1 alpha; SIRT1 activity; mitochondria stress; quinone oxidoreductase 1
  17. Nat Med. 2021 Jul 08.
      Treatment with combined immune checkpoint blockade (CICB) targeting CTLA-4 and PD-1 is associated with clinical benefit across tumor types, but also a high rate of immune-related adverse events. Insights into biomarkers and mechanisms of response and toxicity to CICB are needed. To address this, we profiled the blood, tumor and gut microbiome of 77 patients with advanced melanoma treated with CICB, with a high rate of any ≥grade 3 immune-related adverse events (49%) with parallel studies in pre-clinical models. Tumor-associated immune and genomic biomarkers of response to CICB were similar to those identified for ICB monotherapy, and toxicity from CICB was associated with a more diverse peripheral T-cell repertoire. Profiling of gut microbiota demonstrated a significantly higher abundance of Bacteroides intestinalis in patients with toxicity, with upregulation of mucosal IL-1β in patient samples of colitis and in pre-clinical models. Together, these data offer potential new therapeutic angles for targeting toxicity to CICB.
  18. Cell Rep. 2021 Jul 06. pii: S2211-1247(21)00710-5. [Epub ahead of print]36(1): 109334
      Persistent senescent cells (SCs) are known to underlie aging-related chronic disorders, but it is now recognized that SCs may be at the center of tissue remodeling events, namely during development or organ repair. In this study, we show that two distinct senescence profiles are induced in the context of a spinal cord injury between the regenerative zebrafish and the scarring mouse. Whereas induced SCs in zebrafish are progressively cleared out, they accumulate over time in mice. Depletion of SCs in spinal-cord-injured mice, with different senolytic drugs, improves locomotor, sensory, and bladder functions. This functional recovery is associated with improved myelin sparing, reduced fibrotic scar, and attenuated inflammation, which correlate with a decreased secretion of pro-fibrotic and pro-inflammatory factors. Targeting SCs is a promising therapeutic strategy not only for spinal cord injuries but potentially for other organs that lack regenerative competence.
  19. Cell Rep. 2021 Jul 06. pii: S2211-1247(21)00708-7. [Epub ahead of print]36(1): 109332
      Gut interleukin-17A (IL-17)-producing γδ T cells are tissue-resident cells that are involved in both host defense and regulation of intestinal inflammation. However, factors that regulate their functions are poorly understood. In this study, we find that the gut microbiota represses IL-17 production by cecal γδ T cells. Treatment with vancomycin, a Gram-positive bacterium-targeting antibiotic, leads to decreased production of short-chain fatty acids (SCFAs) by the gut microbiota. Our data reveal that these microbiota-derived metabolites, particularly propionate, reduce IL-17 and IL-22 production by intestinal γδ T cells. Propionate acts directly on γδ T cells to inhibit their production of IL-17 in a histone deacetylase-dependent manner. Moreover, the production of IL-17 by human IL-17-producing γδ T cells from patients with inflammatory bowel disease (IBD) is regulated by propionate. These data contribute to a better understanding of the mechanisms regulating gut γδ T cell functions and offer therapeutic perspectives of these cells.
    Keywords:  IL-17; SCFA; T cells; gut; propionate; γδ
  20. Cell Metab. 2021 Jul 06. pii: S1550-4131(21)00278-3. [Epub ahead of print]33(7): 1274-1275
      Numerous preclinical studies implicate the decline in NAD+ signaling in developing aging- and obesity-associated metabolic disorders. Yoshino et al. (2021) now provide the clinical evidence that an NAD+ booster increases muscle insulin sensitivity in postmenopausal prediabetic women, validating the therapeutic promises of NAD+ boosters in humans.
  21. Nat Commun. 2021 Jul 06. 12(1): 4166
      Classically considered a by-product of anaerobic metabolism, lactate is now viewed as a fundamental fuel for oxidative phosphorylation in mitochondria, and preferred over glucose by many tissues. Lactate is also a signaling molecule of increasing medical relevance. Lactate levels in the blood can increase in both normal and pathophysiological conditions (e.g., hypoxia, physical exercise, or sepsis), however the manner by which these changes are sensed and induce adaptive responses is unknown. Here we show that the carotid body (CB) is essential for lactate homeostasis and that CB glomus cells, the main oxygen sensing arterial chemoreceptors, are also lactate sensors. Lactate is transported into glomus cells, leading to a rapid increase in the cytosolic NADH/NAD+ ratio. This in turn activates membrane cation channels, leading to cell depolarization, action potential firing, and Ca2+ influx. Lactate also decreases intracellular pH and increases mitochondrial reactive oxygen species production, which further activates glomus cells. Lactate and hypoxia, although sensed by separate mechanisms, share the same final signaling pathway and jointly activate glomus cells to potentiate compensatory cardiorespiratory reflexes.
  22. Sci Rep. 2021 Jul 07. 11(1): 13970
      Early "T cell activation" events are initiated within the lipid microenvironment of the plasma membrane. Role of lipid membrane order (Lo) in spatiotemporal signaling through the antigen receptor in T cells is posited but remains unclear. We have examined the role of membrane order (Lo)/disorder (Ld) in antigen specific CD4+ T cell activation and clonal expansion by first creating membrane disorder, and then reconstituting membrane order by inserting cholesterol into the disordered plasma membrane. Significant revival of antigen specific CD4+ T cell proliferative response was observed after reconstituting the disrupted membrane order with cholesterol. These reconstitution experiments illustrate Koch's postulate by demonstrating that cholesterol-dependent membrane order (Lo) is critical for responses generated by CD4+ T cells and point to the importance of membrane order and lipid microenvironment in signaling through T cell membrane antigen receptors.
  23. Sci Rep. 2021 Jul 08. 11(1): 14101
      T-cell activation induces context-specific gene expression programs that promote energy generation and biosynthesis, progression through the cell cycle and ultimately cell differentiation. The aim of this study was to apply the omni ATAC-seq method to characterize the landscape of chromatin changes induced by T-cell activation in mature naïve CD4+ T-cells. Using a well-established ex vivo protocol of canonical T-cell receptor signaling, we generated genome-wide chromatin maps of naïve T-cells from pediatric donors in quiescent or recently activated states. We identified thousands of individual chromatin accessibility peaks that are associated with T-cell activation, the majority of which were annotated intronic and intergenic enhancer regions. A core set of 3268 gene promoters underwent chromatin remodeling and concomitant changes in gene expression in response to activation, and were enriched in multiple pathways controlling cell cycle regulation, metabolism, inflammatory response genes and cell survival. Leukemia inhibitory factor (LIF) was among those factors that gained the highest accessibility and expression, in addition to IL2-STAT5 dependent chromatin remodeling in the T-cell activation response. Using publicly available data we found the chromatin response was far more dynamic at 24-h compared with 72-h post-activation. In total 546 associations were reproduced at both time-points with similar strength of evidence and directionality of effect. At the pathways level, the IL2-STAT5, KRAS signalling and UV response pathways were replicable at both time-points, although differentially modulated from 24 to 72 h post-activation.