Differential Regulation of Transcription Factor T-bet Induction during NK Cell Development and Th1 Cell Differentiation
Ontology highlight
ABSTRACT: Adaptive CD4 T helper cells and their innate counterparts, innate lymphoid cells, utilize an identical set of lineage-determining transcription factors (LDTFs) for their differentiation and functions. However, the similarities and differences in the induction of the LDTFs in these lymphocytes are still elusive. Here we show that type 1 T helper (Th1) cells and natural killer (NK) cells displayed distinct epigenomes at the Tbx21 locus, which encodes T-bet, the LDTF for type 1 lymphocytes. The initial induction of T-bet in NK precursors was partially dependent on the NK-specific DNase I hypersensitive site Tbx21-CNS-3 and the expression of IL-18 receptor; IL-18 induced T-bet expression through RUNX3, which binds to Tbx21-CNS-3. By contrast, Tbx21-CNS-12 containing STAT binding motifs was critical for IL-12-induced T-bet expression during Th1 cell differentiation both in vitro and in vivo. Thus, innate and adaptive lymphocytes of same class may utilize distinct enhancer elements for their development and differentiation.
Project description:T-bet is a critical transcription factor for T helper 1 (Th1) cell differentiation. To study the regulation and functions of T-bet, we developed a T-bet-ZsGreen reporter mouse strain, in which GFP faithfully reflects the expression of T-bet. By using this tool, we report that signals elicited by IL-12 and IFNg are redundant in inducing T-bet in mice infected with Toxoplasma gondii and that T-bet does not contribute to its own expression when induced by IL-12 and IFNg. While both T-bet and Stat4 are critical for IFNg production, IFNg signaling is dispensable. Strikingly, loss of T-bet results in activation of an endogenous Th2 program in cells expressing T-bet-ZsGreen. Genome-wide analyses suggest T-bet directly induces Th1-related genes but indirectly suppresses Th2-related genes. Our study revealed redundancy and synergy among several Th1-inducing pathways in regulating the expression of T-bet and IFNg, and a critical role of T-bet in suppressing an endogenous Th2 program. RNA-Seq experiments were performed using total RNAs isolated from both wild type and Tbx21-/- Th1 cells in duplicates. Tbet ChIP-seq was performed using wild type Th1 cells. H3K4me1 and H3K27me3 ChIP-seq was performed using both wild type and Tbx21-/- Th1 cells.
Project description:Semi-invariant natural killer T (NKT) cells are thymus-derived innate lymphocytes that modulate microbial and tumour immunity as well as autoimmune diseases. These immunoregulatory properties of NKT cells are acquired during their development. Much has been learnt regarding the molecular and cellular cues that promote NKT cell development, yet how these cells are maintained in the thymus and the periphery and how they acquire functional competence are incompletely understood. We found that IL-15 induced several Bcl-2 family survival factors in thymic and splenic NKT cells in vitro. Yet, IL15-mediated thymic and peripheral NKT cell survival critically depended on Bcl-xL expression. Additionally, IL-15 regulated thymic developmental stage 2 (ST2) to ST3 lineage progression and terminal NKT cell differentiation. Global gene expression analyses and validation revealed that IL-15 regulated Tbx21 (T-bet) expression in thymic ST3 NKT cells. The loss of IL15-dependent T-bet expression resulted in poor expression of IFN-γ and several NK cell receptors in NKT cells. Taken together, our findings reveal a critical role for IL-15 in NKT cell survival, which is mediated by Bcl-xL, and effector differentiation, which is regulated by T-bet. Gene expression was measured in NKT cells sorted from pooled thymi of wild-type (3 replicates) or IL-15 deficient (2 replicates) mice.
Project description:This a model from the article:
Sequential polarization and imprinting of type 1 T helper lymphocytes by interferon-gamma and interleukin-12.
Schulz EG, Mariani L, Radbruch A, Höfer T.
Immunity.2009;30(5):666-8.
19409816,
Abstract:
Differentiation of naive T lymphocytes into type I T helper (Th1) cells requires interferon-gamma and interleukin-12. It is puzzling that interferon-gamma induces the Th1 transcription factor T-bet, whereas interleukin-12 mediates Th1 cell lineage differentiation. We use mathematical modeling to analyze the expression kinetics of T-bet, interferon-gamma, and the IL-12 receptor beta2 chain (IL-12Rbeta2) during Th1 cell differentiation, in the presence or absence of interleukin-12 or interferon-gamma signaling. We show that interferon-gamma induced initial T-bet expression, whereas IL-12Rbeta2 was repressed by T cell receptor (TCR) signaling. The termination of TCR signaling permitted upregulation of IL-12Rbeta2 by T-bet and interleukin-12 signaling that maintained T-bet expression. This late expression of T-bet, accompanied by the upregulation of the transcription factors Runx3 and Hlx, was required to imprint the Th cell for interferon-gamma re-expression. Thus initial polarization and subsequent imprinting of Th1 cells are mediated by interlinked, sequentially acting positive feedback loops of TCR-interferon-gamma-Stat1-T-bet and interleukin-12-Stat4-T-bet signaling.
The original model was created by:
Edda G. Schulz
schulz@drfz.de
Theoretical Biophysics, Institute of Biology, Humboldt Universität, Invalidenstrasse 42, 10115 Berlin, Germany.
This model originates from BioModels Database: A Database of Annotated Published Models. It is copyright (c) 2005-2009 The BioModels Team.For more information see the terms of use.To cite BioModels Database, please use Le Novère N., Bornstein B., Broicher A., Courtot M., Donizelli M., Dharuri H., Li L., Sauro H., Schilstra M., Shapiro B., Snoep J.L., Hucka M. (2006) BioModels Database: A Free, Centralized Database of Curated, Published, Quantitative Kinetic Models of Biochemical and Cellular Systems Nucleic Acids Res., 34: D689-D691.
Project description:Semi-invariant natural killer T (NKT) cells are thymus-derived innate lymphocytes that modulate microbial and tumour immunity as well as autoimmune diseases. These immunoregulatory properties of NKT cells are acquired during their development. Much has been learnt regarding the molecular and cellular cues that promote NKT cell development, yet how these cells are maintained in the thymus and the periphery and how they acquire functional competence are incompletely understood. We found that IL-15 induced several Bcl-2 family survival factors in thymic and splenic NKT cells in vitro. Yet, IL15-mediated thymic and peripheral NKT cell survival critically depended on Bcl-xL expression. Additionally, IL-15 regulated thymic developmental stage 2 (ST2) to ST3 lineage progression and terminal NKT cell differentiation. Global gene expression analyses and validation revealed that IL-15 regulated Tbx21 (T-bet) expression in thymic ST3 NKT cells. The loss of IL15-dependent T-bet expression resulted in poor expression of IFN-γ and several NK cell receptors in NKT cells. Taken together, our findings reveal a critical role for IL-15 in NKT cell survival, which is mediated by Bcl-xL, and effector differentiation, which is regulated by T-bet.
Project description:Thymocyte selection-associated high mobility group box protein family member 2 (TOX2) is a transcription factor belonging to the TOX family that shares a highly conserved high mobility group DNA binding domain with the other TOX members. While TOX1 has been shown to be an essential regulator of T-cell and natural killer (NK) cell differentiation in mice, little is known about the roles of the other TOX family members in lymphocyte development, particularly in humans. In this study, we found that TOX2 was preferentially expressed in mature human NK cells and was upregulated during in vitro differentiation of NK cells from human umbilical cord blood (UCB)M-bM-^@M-^Sderived CD34+ cells. Gene silencing of TOX2 intrinsically hindered the transition between early developmental stages of NK cells, while overexpression of TOX2 enhanced the development of mature NK cells from UCB CD34+ cells. We subsequently found that TOX2 was independent of ETS-1 but could directly upregulate the transcription of TBX21 (encoding T-BET). Overexpression of T-BET rescued the TOX2 knockdown phenotypes. Given the essential function of T-BET in NK cell differentiation, TOX2 therefore plays a crucial role in controlling normal NK cell development by acting upstream of TBX21 transcriptional regulation. survey of NK cells over time
Project description:Interferon-gamma (IFN-gamma) is a key cytokine in response to viral or intracellular bacterial infection in mammals. While a number of enhancers are described to promote IFN-gamma responses, no silencers for the Ifng gene have been identified. By examining H3K4me1 histone modification in naïve CD4+ T cells within Ifng locus, we identified an unrecognized silencer (CNS–28) that is responsible for restraining Ifng expression. Mechanistic study further demonstrates that CNS–28 maintains Ifng silence by diminishing enhancer-promoter interactions within Ifng locus in a T-bet independent manner. Functionally, CNS–28 restrains Ifng transcription in Th1, Tc1, and NK cells during both innate and adaptive immune responses. Moreover, CNS–28 deficiency resulted in repressed type 2 responses due to elevated IFN-gamma expression, shifting Th1 and Th2 paradigm. Thus, CNS–28 activity ensures immune cell quiescence by cooperating with other regulatory cis elements within the Ifng gene locus to minimize autoimmunity.
Project description:Natural killer (NK) cells are innate lymphocytes that play a major role in immunosurveillance against tumor initiation and metastasis spread. Signals and checkpoints that regulate NK cell fitness and function in the tumor microenvironment are not well defined. Transforming grow factor (TGF)- is a recognized suppressor of NK cells that inhibits IL-15 dependent signaling events and induces cellular transdifferentiation, however the role of other SMAD signaling pathways in NK cells is unknown. We used a global, label-free proteomics approach to compare the protein expression profiles of NK cells in the presence of TGF-b or activin-A.
Project description:Natural killer (NK) cells are a type of innate lymphocytes that play key roles in immune surveillance against tumors and viral infection. NK cells distinguish abnormal cells from healthy cells by cell-cell interaction with cell surface proteins and then attack target cells via multiple mechanisms involving TRAIL, Fas Ligand, cytokine secretion, perforin, and granzymes. In addition, extracellular vesicles (EVs), including exosomes derived from NK cells (NK-EVs), possess cytotoxic capacity against tumor cells, but their characteristics and regulation by cytokines remain unknown. Here, we report that EVs derived from human NK-92 cells stimulated with IL-15 + IL-21 show enhanced cytotoxic capacity against tumor cells in a granzyme B independent manner. In addition, small RNA-seq and mass spectrometry analyses indicate that miRNA and protein profiles in EVs are altered by cytokine stimulation. We also show NK-EVs are taken up by target cells via macropinocytosis. Collectively, our findings reveal novel characteristics of NK-EVs and the mechanism of their incorporation into target cells.
Project description:Innate lymphoid cell (ILC) subsets that mirror helper T cells in their effector cytokine profiles have recently emerged as central players in both homeostatic and inflammatory conditions. Like their Th1, Th2 and Th17/Th22 helper T cell counterparts, ILC subsets are categorized based on their expression of specific transcription factors and effector cytokines: group 1 ILC (ILC1) express T-bet and IFN-γ; group 2 ILC (ILC2) express GATA-3 and type 2 effector cytokines such as IL-13 and IL-5; and group 3 ILC (ILC3) express RORgt and the cytokines IL-22 and/or IL-17. Under this nomenclature, natural killer (NK) cells and lymphoid tissue inducers (LTi) are considered ILC1 and ILC3, respectively. ILC1 contain both CD4+ and CD4- populations, but whether this phenotypic characteristic reflects functional differences between these two populations is unknown. These studies examine the gene expression profiles of CD4+ vs CD4- ILC1 in a cohort of healthy control subjects. ILC subsets were isolated from the peripheral blood of healthy control subjects. cDNA was isolated and amplified from sorted populations, and gene expression was analyzed by RNAseq
Project description:Innate lymphocytes are integral components of the cellular immune system that coordinates host defense against a multitude of challenges and can trigger immunopathology when dysregulated. Natural killer (NK) cells and innate lymphoid cells (ILCs) are innate immune effectors postulated to functionally mirror conventional cytotoxic T lymphocytes and helper T cells, respectively. Here, we show that the cytolytic molecule granzyme C was surprisingly expressed in cells with the phenotype of type 1 ILCs (ILC1s) in mouse liver and salivary gland. Cell fate-mapping and transfer studies revealed that granzyme C-expressing innate lymphocytes could be derived from ILC progenitors and did not interconvert with NK cells, ILC2s, or ILC3s. Granzyme C defined a maturation state of ILC1s, which required the transcription factor T-bet and to a lesser extent Eomes specifically in the salivary gland for their maintenance. Furthermore, transforming growth factor-b (TGF-b) signaling promoted maintenance of granzyme C-expressing ILC1s in the salivary gland and in the tumor of a transgenic breast cancer model, and their depletion caused accelerated tumor growth. ILC1s gained granzyme C expression following interleukin-15 (IL-15) stimulation, which enabled perforin-mediated cytotoxicity. Strikingly, constitutive activation of the IL-15-regulated transcription factor Stat5 in granzyme C-fate-mapped ILC1s triggered lethal perforin-dependent autoimmunity in neonatal mice. Thus, granzyme C marks a cytotoxic effector state of ILC1s, broadening their function beyond ‘helper-like’ lymphocytes.