1
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Shin B, Chang SJ, MacNabb BW, Rothenberg EV. Transcriptional network dynamics in early T cell development. J Exp Med 2024; 221:e20230893. [PMID: 39167073 PMCID: PMC11338287 DOI: 10.1084/jem.20230893] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 06/07/2024] [Accepted: 07/10/2024] [Indexed: 08/23/2024] Open
Abstract
The rate at which cells enter the T cell pathway depends not only on the immigration of hematopoietic precursors into the strong Notch signaling environment of the thymus but also on the kinetics with which each individual precursor cell reaches T-lineage commitment once it arrives. Notch triggers a complex, multistep gene regulatory network in the cells in which the steps are stereotyped but the transition speeds between steps are variable. Progenitor-associated transcription factors delay T-lineage differentiation even while Notch-induced transcription factors within the same cells push differentiation forward. Progress depends on regulator cross-repression, on breaching chromatin barriers, and on shifting, competitive collaborations between stage-specific and stably expressed transcription factors, as reviewed here.
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Affiliation(s)
- Boyoung Shin
- Division of Biology and Biological Engineering California Institute of Technology , Pasadena, CA, USA
| | - Samantha J Chang
- Division of Biology and Biological Engineering California Institute of Technology , Pasadena, CA, USA
| | - Brendan W MacNabb
- Division of Biology and Biological Engineering California Institute of Technology , Pasadena, CA, USA
| | - Ellen V Rothenberg
- Division of Biology and Biological Engineering California Institute of Technology , Pasadena, CA, USA
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2
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Kanata E, Duffié R, Schulz EG. Establishment and maintenance of random monoallelic expression. Development 2024; 151:dev201741. [PMID: 38813842 PMCID: PMC11166465 DOI: 10.1242/dev.201741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
This Review elucidates the regulatory principles of random monoallelic expression by focusing on two well-studied examples: the X-chromosome inactivation regulator Xist and the olfactory receptor gene family. Although the choice of a single X chromosome or olfactory receptor occurs in different developmental contexts, common gene regulatory principles guide monoallelic expression in both systems. In both cases, an event breaks the symmetry between genetically and epigenetically identical copies of the gene, leading to the expression of one single random allele, stabilized through negative feedback control. Although many regulatory steps that govern the establishment and maintenance of monoallelic expression have been identified, key pieces of the puzzle are still missing. We provide an overview of the current knowledge and models for the monoallelic expression of Xist and olfactory receptors. We discuss their similarities and differences, and highlight open questions and approaches that could guide the study of other monoallelically expressed genes.
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Affiliation(s)
- Eleni Kanata
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Rachel Duffié
- Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Edda G. Schulz
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
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3
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Rückert T, Romagnani C. Extrinsic and intrinsic drivers of natural killer cell clonality. Immunol Rev 2024; 323:80-106. [PMID: 38506411 DOI: 10.1111/imr.13324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Clonal expansion of antigen-specific lymphocytes is the fundamental mechanism enabling potent adaptive immune responses and the generation of immune memory. Accompanied by pronounced epigenetic remodeling, the massive proliferation of individual cells generates a critical mass of effectors for the control of acute infections, as well as a pool of memory cells protecting against future pathogen encounters. Classically associated with the adaptive immune system, recent work has demonstrated that innate immune memory to human cytomegalovirus (CMV) infection is stably maintained as large clonal expansions of natural killer (NK) cells, raising questions on the mechanisms for clonal selection and expansion in the absence of re-arranged antigen receptors. Here, we discuss clonal NK cell memory in the context of the mechanisms underlying clonal competition of adaptive lymphocytes and propose alternative selection mechanisms that might decide on the clonal success of their innate counterparts. We propose that the integration of external cues with cell-intrinsic sources of heterogeneity, such as variegated receptor expression, transcriptional states, and somatic variants, compose a bottleneck for clonal selection, contributing to the large size of memory NK cell clones.
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Affiliation(s)
- Timo Rückert
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Immunology, Berlin, Germany
| | - Chiara Romagnani
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Immunology, Berlin, Germany
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4
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Ordway AJ, Helt RN, Johnston RJ. Transcriptional priming and chromatin regulation during stochastic cell fate specification. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230046. [PMID: 38432315 PMCID: PMC10909510 DOI: 10.1098/rstb.2023.0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/19/2024] [Indexed: 03/05/2024] Open
Abstract
Stochastic cell fate specification, in which a cell chooses between two or more fates with a set probability, diversifies cell subtypes in development. Although this is a vital process across species, a common mechanism for these cell fate decisions remains elusive. This review examines two well-characterized stochastic cell fate decisions to identify commonalities between their developmental programmes. In the fly eye, two subtypes of R7 photoreceptors are specified by the stochastic ON/OFF expression of a transcription factor, spineless. In the mouse olfactory system, olfactory sensory neurons (OSNs) randomly select to express one copy of an olfactory receptor (OR) gene out of a pool of 2800 alleles. Despite the differences in these sensory systems, both stochastic fate choices rely on the dynamic interplay between transcriptional priming, chromatin regulation and terminal gene expression. The coupling of transcription and chromatin modifications primes gene loci in undifferentiated neurons, enabling later expression during terminal differentiation. Here, we compare these mechanisms, examine broader implications for gene regulation during development and posit key challenges moving forward. This article is part of a discussion meeting issue 'Causes and consequences of stochastic processes in development and disease'.
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Affiliation(s)
- Alison J. Ordway
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Rina N. Helt
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Robert J. Johnston
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
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5
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Andersson E, Rothenberg EV, Peterson C, Olariu V. T-cell commitment inheritance-an agent-based multi-scale model. NPJ Syst Biol Appl 2024; 10:40. [PMID: 38632273 PMCID: PMC11024127 DOI: 10.1038/s41540-024-00368-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/08/2024] [Indexed: 04/19/2024] Open
Abstract
T-cell development provides an excellent model system for studying lineage commitment from a multipotent progenitor. The intrathymic development process has been thoroughly studied. The molecular circuitry controlling it has been dissected and the necessary steps like programmed shut off of progenitor genes and T-cell genes upregulation have been revealed. However, the exact timing between decision-making and commitment stage remains unexplored. To this end, we implemented an agent-based multi-scale model to investigate inheritance in early T-cell development. Treating each cell as an agent provides a powerful tool as it tracks each individual cell of a simulated T-cell colony, enabling the construction of lineage trees. Based on the lineage trees, we introduce the concept of the last common ancestors (LCA) of committed cells and analyse their relations, both at single-cell level and population level. In addition to simulating wild-type development, we also conduct knockdown analysis. Our simulations predicted that the commitment is a three-step process that occurs on average over several cell generations once a cell is first prepared by a transcriptional switch. This is followed by the loss of the Bcl11b-opposing function approximately two to three generations later. This is when our LCA analysis indicates that the decision to commit is taken even though in general another one to two generations elapse before the cell actually becomes committed by transitioning to the DN2b state. Our results showed that there is decision inheritance in the commitment mechanism.
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Affiliation(s)
- Emil Andersson
- Computational Science for Health and Environment, Centre for Environmental and Climate Science, Lund University, Lund, Sweden
| | - Ellen V Rothenberg
- Division of Biology and Biological Engineering, 156-29, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Carsten Peterson
- Computational Science for Health and Environment, Centre for Environmental and Climate Science, Lund University, Lund, Sweden
| | - Victor Olariu
- Computational Science for Health and Environment, Centre for Environmental and Climate Science, Lund University, Lund, Sweden.
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6
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Abadie K, Clark EC, Valanparambil RM, Ukogu O, Yang W, Daza RM, Ng KKH, Fathima J, Wang AL, Lee J, Nasti TH, Bhandoola A, Nourmohammad A, Ahmed R, Shendure J, Cao J, Kueh HY. Reversible, tunable epigenetic silencing of TCF1 generates flexibility in the T cell memory decision. Immunity 2024; 57:271-286.e13. [PMID: 38301652 PMCID: PMC10922671 DOI: 10.1016/j.immuni.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 10/09/2023] [Accepted: 12/07/2023] [Indexed: 02/03/2024]
Abstract
The immune system encodes information about the severity of a pathogenic threat in the quantity and type of memory cells it forms. This encoding emerges from lymphocyte decisions to maintain or lose self-renewal and memory potential during a challenge. By tracking CD8+ T cells at the single-cell and clonal lineage level using time-resolved transcriptomics, quantitative live imaging, and an acute infection model, we find that T cells will maintain or lose memory potential early after antigen recognition. However, following pathogen clearance, T cells may regain memory potential if initially lost. Mechanistically, this flexibility is implemented by a stochastic cis-epigenetic switch that tunably and reversibly silences the memory regulator, TCF1, in response to stimulation. Mathematical modeling shows how this flexibility allows memory T cell numbers to scale robustly with pathogen virulence and immune response magnitudes. We propose that flexibility and stochasticity in cellular decisions ensure optimal immune responses against diverse threats.
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Affiliation(s)
- Kathleen Abadie
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Elisa C Clark
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Rajesh M Valanparambil
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Obinna Ukogu
- Department of Applied Mathematics, University of Washington, Seattle, WA 98105, USA
| | - Wei Yang
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Riza M Daza
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Kenneth K H Ng
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Jumana Fathima
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Allan L Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Judong Lee
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Tahseen H Nasti
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Avinash Bhandoola
- T-Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institute of Health, Bethesda, MD 20892, USA
| | - Armita Nourmohammad
- Department of Applied Mathematics, University of Washington, Seattle, WA 98105, USA; Department of Physics, University of Washington, Seattle, WA 98105, USA; Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Rafi Ahmed
- Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA; Allen Discovery Center for Cell Lineage Tracing, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA.
| | - Junyue Cao
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Laboratory of Single-Cell Genomics and Population Dynamics, The Rockefeller University, New York, NY 10065, USA.
| | - Hao Yuan Kueh
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA.
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7
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Wither MJ, White WL, Pendyala S, Leanza PJ, Fowler DM, Kueh HY. Antigen perception in T cells by long-term Erk and NFAT signaling dynamics. Proc Natl Acad Sci U S A 2023; 120:e2308366120. [PMID: 38113261 PMCID: PMC10756264 DOI: 10.1073/pnas.2308366120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/20/2023] [Indexed: 12/21/2023] Open
Abstract
Immune system threat detection hinges on T cells' ability to perceive varying peptide-major histocompatibility complex (pMHC) antigens. As the Erk and NFAT pathways link T cell receptor engagement to gene regulation, their signaling dynamics may convey information about pMHC inputs. To test this idea, we developed a dual reporter mouse strain and a quantitative imaging assay that, together, enable simultaneous monitoring of Erk and NFAT dynamics in live T cells over day-long timescales as they respond to varying pMHC inputs. Both pathways initially activate uniformly across various pMHC inputs but diverge only over longer (9+ h) timescales, enabling independent encoding of pMHC affinity and dose. These late signaling dynamics are decoded via multiple temporal and combinatorial mechanisms to generate pMHC-specific transcriptional responses. Our findings underscore the importance of long timescale signaling dynamics in antigen perception and establish a framework for understanding T cell responses under diverse contexts.
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Affiliation(s)
- Matthew J. Wither
- University of Washington, Department of Bioengineering, Seattle, WA98195
| | - William L. White
- University of Washington, Department of Bioengineering, Seattle, WA98195
| | - Sriram Pendyala
- University of Washington, Department of Genome Sciences, Seattle, WA98195
| | - Paul J. Leanza
- University of Washington, Department of Bioengineering, Seattle, WA98195
| | - Douglas M. Fowler
- University of Washington, Department of Genome Sciences, Seattle, WA98195
| | - Hao Yuan Kueh
- University of Washington, Department of Bioengineering, Seattle, WA98195
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA98109
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8
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Andersson E, Rothenberg EV, Peterson C, Olariu V. T-cell commitment inheritance - an agent-based multi-scale model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.18.562905. [PMID: 37905091 PMCID: PMC10614897 DOI: 10.1101/2023.10.18.562905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
T-cell development provides an excellent model system for studying lineage commitment from a multipotent progenitor. The intrathymic development process has been thoroughly studied. The molecular circuitry controlling it has been dissected and the necessary steps like programmed shut off of progenitor genes and T-cell genes upregulation have been revealed. However, the exact timing between decision-making and commitment stage remains unexplored. To this end, we implemented an agent-based multi-scale model to investigate inheritance in early T-cell development. Treating each cell as an agent provides a powerful tool as it tracks each individual cell of a simulated T-cell colony, enabling the construction of lineage trees. Based on the lineage trees, we introduce the concept of the last common ancestors (LCA) of committed cells and analyse their relations, both at single-cell level and population level. In addition to simulating wild-type development, we also conduct knockdown analysis. Our simulations showed that the commitment is a three-step process over several cell generations where a cell is first prepared by a transcriptional switch. This is followed by the loss of the Bcl11b-opposing function two to three generations later which is when the decision to commit is taken. Finally, after another one to two generations, the cell becomes committed by transitioning to the DN2b state. Our results showed that there is inheritance in the commitment mechanism.
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Affiliation(s)
- Emil Andersson
- Computational Biology and Biological Physics, Centre for Environmental and Climate Science, Lund University, Lund, Sweden
| | - Ellen V. Rothenberg
- Division of Biology and Biological Engineering, 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Carsten Peterson
- Computational Biology and Biological Physics, Centre for Environmental and Climate Science, Lund University, Lund, Sweden
| | - Victor Olariu
- Computational Biology and Biological Physics, Centre for Environmental and Climate Science, Lund University, Lund, Sweden
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9
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Shin B, Zhou W, Wang J, Gao F, Rothenberg EV. Runx factors launch T cell and innate lymphoid programs via direct and gene network-based mechanisms. Nat Immunol 2023; 24:1458-1472. [PMID: 37563311 PMCID: PMC10673614 DOI: 10.1038/s41590-023-01585-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 07/12/2023] [Indexed: 08/12/2023]
Abstract
Runx factors are essential for lineage specification of various hematopoietic cells, including T lymphocytes. However, they regulate context-specific genes and occupy distinct genomic regions in different cell types. Here, we show that dynamic Runx binding shifts in mouse early T cell development are mostly not restricted by local chromatin state but regulated by Runx dosage and functional partners. Runx cofactors compete to recruit a limited pool of Runx factors in early T progenitor cells, and a modest increase in Runx protein availability at pre-commitment stages causes premature Runx occupancy at post-commitment binding sites. This increased Runx factor availability results in striking T cell lineage developmental acceleration by selectively activating T cell-identity and innate lymphoid cell programs. These programs are collectively regulated by Runx together with other, Runx-induced transcription factors that co-occupy Runx-target genes and propagate gene network changes.
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Affiliation(s)
- Boyoung Shin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Wen Zhou
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Program in Biochemistry and Molecular Biophysics, California Institute of Technology, Pasadena, CA, USA
- BillionToOne, Menlo Park, CA, USA
| | - Jue Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Program in Biochemistry and Molecular Biophysics, California Institute of Technology, Pasadena, CA, USA
| | - Fan Gao
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Bioinformatics Resource Center, Beckman Institute of California Institute of Technology, Pasadena, CA, USA
- Lyterian Therapeutics, South San Francisco, CA, USA
| | - Ellen V Rothenberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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10
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Sun YH, Wu YL, Liao BY. Phenotypic heterogeneity in human genetic diseases: ultrasensitivity-mediated threshold effects as a unifying molecular mechanism. J Biomed Sci 2023; 30:58. [PMID: 37525275 PMCID: PMC10388531 DOI: 10.1186/s12929-023-00959-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 07/26/2023] [Indexed: 08/02/2023] Open
Abstract
Phenotypic heterogeneity is very common in genetic systems and in human diseases and has important consequences for disease diagnosis and treatment. In addition to the many genetic and non-genetic (e.g., epigenetic, environmental) factors reported to account for part of the heterogeneity, we stress the importance of stochastic fluctuation and regulatory network topology in contributing to phenotypic heterogeneity. We argue that a threshold effect is a unifying principle to explain the phenomenon; that ultrasensitivity is the molecular mechanism for this threshold effect; and discuss the three conditions for phenotypic heterogeneity to occur. We suggest that threshold effects occur not only at the cellular level, but also at the organ level. We stress the importance of context-dependence and its relationship to pleiotropy and edgetic mutations. Based on this model, we provide practical strategies to study human genetic diseases. By understanding the network mechanism for ultrasensitivity and identifying the critical factor, we may manipulate the weak spot to gently nudge the system from an ultrasensitive state to a stable non-disease state. Our analysis provides a new insight into the prevention and treatment of genetic diseases.
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Affiliation(s)
- Y Henry Sun
- Institute of Molecular and Genomic Medicine, National Health Research Institute, Zhunan, Miaoli, Taiwan.
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
| | - Yueh-Lin Wu
- Institute of Molecular and Genomic Medicine, National Health Research Institute, Zhunan, Miaoli, Taiwan
- Division of Nephrology, Department of Internal Medicine, Wei-Gong Memorial Hospital, Miaoli, Taiwan
- Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan
- TMU Research Center of Urology and Kidney, Taipei Medical University, Taipei, Taiwan
- Division of Nephrology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei City, Taiwan
| | - Ben-Yang Liao
- Institute of Population Health Sciences, National Health Research Institute, Zhunan, Miaoli, Taiwan
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11
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Sun L, Su Y, Jiao A, Wang X, Zhang B. T cells in health and disease. Signal Transduct Target Ther 2023; 8:235. [PMID: 37332039 PMCID: PMC10277291 DOI: 10.1038/s41392-023-01471-y] [Citation(s) in RCA: 133] [Impact Index Per Article: 133.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 06/20/2023] Open
Abstract
T cells are crucial for immune functions to maintain health and prevent disease. T cell development occurs in a stepwise process in the thymus and mainly generates CD4+ and CD8+ T cell subsets. Upon antigen stimulation, naïve T cells differentiate into CD4+ helper and CD8+ cytotoxic effector and memory cells, mediating direct killing, diverse immune regulatory function, and long-term protection. In response to acute and chronic infections and tumors, T cells adopt distinct differentiation trajectories and develop into a range of heterogeneous populations with various phenotype, differentiation potential, and functionality under precise and elaborate regulations of transcriptional and epigenetic programs. Abnormal T-cell immunity can initiate and promote the pathogenesis of autoimmune diseases. In this review, we summarize the current understanding of T cell development, CD4+ and CD8+ T cell classification, and differentiation in physiological settings. We further elaborate the heterogeneity, differentiation, functionality, and regulation network of CD4+ and CD8+ T cells in infectious disease, chronic infection and tumor, and autoimmune disease, highlighting the exhausted CD8+ T cell differentiation trajectory, CD4+ T cell helper function, T cell contributions to immunotherapy and autoimmune pathogenesis. We also discuss the development and function of γδ T cells in tissue surveillance, infection, and tumor immunity. Finally, we summarized current T-cell-based immunotherapies in both cancer and autoimmune diseases, with an emphasis on their clinical applications. A better understanding of T cell immunity provides insight into developing novel prophylactic and therapeutic strategies in human diseases.
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Affiliation(s)
- Lina Sun
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China
- Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, Shaanxi, 710061, China
- Xi'an Key Laboratory of Immune Related Diseases, Xi'an, Shannxi, 710061, China
| | - Yanhong Su
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China
- Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, Shaanxi, 710061, China
- Xi'an Key Laboratory of Immune Related Diseases, Xi'an, Shannxi, 710061, China
| | - Anjun Jiao
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China
- Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, Shaanxi, 710061, China
- Xi'an Key Laboratory of Immune Related Diseases, Xi'an, Shannxi, 710061, China
| | - Xin Wang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China
- Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, Shaanxi, 710061, China
- Xi'an Key Laboratory of Immune Related Diseases, Xi'an, Shannxi, 710061, China
| | - Baojun Zhang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China.
- Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China.
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, Shaanxi, 710061, China.
- Xi'an Key Laboratory of Immune Related Diseases, Xi'an, Shannxi, 710061, China.
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Wither MJ, White WL, Pendyala S, Leanza PJ, Fowler D, Kueh HY. Antigen perception in T cells by long-term Erk and NFAT signaling dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.01.543260. [PMID: 37333368 PMCID: PMC10274683 DOI: 10.1101/2023.06.01.543260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Immune system threat detection hinges on T cells' ability to perceive varying peptide major-histocompatibility complex (pMHC) antigens. As the Erk and NFAT pathways link T cell receptor engagement to gene regulation, their signaling dynamics may convey information about pMHC inputs. To test this idea, we developed a dual reporter mouse strain and a quantitative imaging assay that, together, enable simultaneous monitoring of Erk and NFAT dynamics in live T cells over day-long timescales as they respond to varying pMHC inputs. Both pathways initially activate uniformly across various pMHC inputs, but diverge only over longer (9+ hrs) timescales, enabling independent encoding of pMHC affinity and dose. These late signaling dynamics are decoded via multiple temporal and combinatorial mechanisms to generate pMHC-specific transcriptional responses. Our findings underscore the importance of long timescale signaling dynamics in antigen perception, and establish a framework for understanding T cell responses under diverse contexts. SIGNIFICANCE STATEMENT To counter diverse pathogens, T cells mount distinct responses to varying peptide-major histocompatibility complex ligands (pMHCs). They perceive the affinity of pMHCs for the T cell receptor (TCR), which reflects its foreignness, as well as pMHC abundance. By tracking signaling responses in single living cells to different pMHCs, we find that T cells can independently perceive pMHC affinity vs dose, and encode this information through the dynamics of Erk and NFAT signaling pathways downstream of the TCR. These dynamics are jointly decoded by gene regulatory mechanisms to produce pMHC-specific activation responses. Our work reveals how T cells can elicit tailored functional responses to diverse threats and how dysregulation of these responses may lead to immune pathologies.
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13
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MacNabb BW, Rothenberg EV. Speed and navigation control of thymocyte development by the fetal T-cell gene regulatory network. Immunol Rev 2023; 315:171-196. [PMID: 36722494 PMCID: PMC10771342 DOI: 10.1111/imr.13190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
T-cell differentiation is a tightly regulated developmental program governed by interactions between transcription factors (TFs) and chromatin landscapes and affected by signals received from the thymic stroma. This process is marked by a series of checkpoints: T-lineage commitment, T-cell receptor (TCR)β selection, and positive and negative selection. Dynamically changing combinations of TFs drive differentiation along the T-lineage trajectory, through mechanisms that have been most extensively dissected in adult mouse T-lineage cells. However, fetal T-cell development differs from adult in ways that suggest that these TF mechanisms are not fully deterministic. The first wave of fetal T-cell differentiation occurs during a unique developmental window during thymic morphogenesis, shows more rapid kinetics of differentiation with fewer rounds of cell division, and gives rise to unique populations of innate lymphoid cells (ILCs) and invariant γδT cells that are not generated in the adult thymus. As the characteristic kinetics and progeny biases are cell-intrinsic properties of thymic progenitors, the differences could be based on distinct TF network circuitry within the progenitors themselves. Here, we review recent single-cell transcriptome data that illuminate the TF networks involved in T-cell differentiation in the fetal and adult mouse thymus.
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Affiliation(s)
- Brendan W MacNabb
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Ellen V Rothenberg
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, California, USA
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14
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Shin B, Rothenberg EV. Multi-modular structure of the gene regulatory network for specification and commitment of murine T cells. Front Immunol 2023; 14:1108368. [PMID: 36817475 PMCID: PMC9928580 DOI: 10.3389/fimmu.2023.1108368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 01/11/2023] [Indexed: 02/04/2023] Open
Abstract
T cells develop from multipotent progenitors by a gradual process dependent on intrathymic Notch signaling and coupled with extensive proliferation. The stages leading them to T-cell lineage commitment are well characterized by single-cell and bulk RNA analyses of sorted populations and by direct measurements of precursor-product relationships. This process depends not only on Notch signaling but also on multiple transcription factors, some associated with stemness and multipotency, some with alternative lineages, and others associated with T-cell fate. These factors interact in opposing or semi-independent T cell gene regulatory network (GRN) subcircuits that are increasingly well defined. A newly comprehensive picture of this network has emerged. Importantly, because key factors in the GRN can bind to markedly different genomic sites at one stage than they do at other stages, the genes they significantly regulate are also stage-specific. Global transcriptome analyses of perturbations have revealed an underlying modular structure to the T-cell commitment GRN, separating decisions to lose "stem-ness" from decisions to block alternative fates. Finally, the updated network sheds light on the intimate relationship between the T-cell program, which depends on the thymus, and the innate lymphoid cell (ILC) program, which does not.
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Affiliation(s)
- Boyoung Shin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Ellen V. Rothenberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
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15
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Kravitz SN, Ferris E, Love MI, Thomas A, Quinlan AR, Gregg C. Random allelic expression in the adult human body. Cell Rep 2023; 42:111945. [PMID: 36640362 PMCID: PMC10484211 DOI: 10.1016/j.celrep.2022.111945] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 10/17/2022] [Accepted: 12/15/2022] [Indexed: 01/07/2023] Open
Abstract
Genes are typically assumed to express both parental alleles similarly, yet cell lines show random allelic expression (RAE) for many autosomal genes that could shape genetic effects. Thus, understanding RAE in human tissues could improve our understanding of phenotypic variation. Here, we develop a methodology to perform genome-wide profiling of RAE and biallelic expression in GTEx datasets for 832 people and 54 tissues. We report 2,762 autosomal genes with some RAE properties similar to randomly inactivated X-linked genes. We found that RAE is associated with rapidly evolving regions in the human genome, adaptive signaling processes, and genes linked to age-related diseases such as neurodegeneration and cancer. We define putative mechanistic subtypes of RAE distinguished by gene overlaps on sense and antisense DNA strands, aggregation in clusters near telomeres, and increased regulatory complexity and inputs compared with biallelic genes. We provide foundations to study RAE in human phenotypes, evolution, and disease.
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Affiliation(s)
- Stephanie N Kravitz
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA; Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Elliott Ferris
- Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Michael I Love
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alun Thomas
- Department of Internal Medicine, Epidemiology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Aaron R Quinlan
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Christopher Gregg
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA; Neurobiology, University of Utah, Salt Lake City, UT, USA.
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16
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Ramanayake S, Moulding DA, Tanaka Y, Singh A, Bangham CRM. Dynamics and consequences of the HTLV-1 proviral plus-strand burst. PLoS Pathog 2022; 18:e1010774. [PMID: 36441826 PMCID: PMC9731428 DOI: 10.1371/journal.ppat.1010774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/08/2022] [Accepted: 11/15/2022] [Indexed: 11/30/2022] Open
Abstract
Expression of the transcriptional transactivator protein Tax, encoded on the proviral plus-strand of human T-cell leukaemia virus type 1 (HTLV-1), is crucial for the replication of the virus, but Tax-expressing cells are rarely detected in fresh blood ex vivo. The dynamics and consequences of the proviral plus-strand transcriptional burst remain insufficiently characterised. We combined time-lapse live-cell imaging, single-cell tracking and mathematical modelling to study the dynamics of Tax expression at single-cell resolution in two naturally-infected, non-malignant T-cell clones transduced with a short-lived enhanced green fluorescent protein (d2EGFP) Tax reporter system. Five different patterns of Tax expression were observed during the 30-hour observation period; the distribution of these patterns differed between the two clones. The mean duration of Tax expression in the two clones was 94 and 417 hours respectively, estimated from mathematical modelling of the experimental data. Tax expression was associated with a transient slowing in cell-cycle progression and proliferation, increased apoptosis, and enhanced activation of the DNA damage response pathways. Longer-term follow-up (14 days) revealed an increase in the proportion of proliferating cells and a decrease in the fraction of apoptotic cells as the cells ceased Tax expression, resulting in a greater net expansion of the initially Tax-positive population. Time-lapse live-cell imaging showed enhanced cell-to-cell adhesion among Tax-expressing cells, and decreased cell motility of Tax-expressing cells at the single-cell level. The results demonstrate the within-clone and between-clone heterogeneity in the dynamics and patterns of HTLV-1 plus-strand transcriptional bursts and the balance of positive and negative consequences of the burst for the host cell.
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Affiliation(s)
- Saumya Ramanayake
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Dale A. Moulding
- Light Microscopy Core Facility, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Yuetsu Tanaka
- Department of Infectious Disease and Immunology, Okinawa-Asia Research Center of Medical Science, Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware, United States of America
| | - Charles R. M. Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
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17
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Zamir A, Li G, Chase K, Moskovitch R, Sun B, Zaritsky A. Emergence of synchronized multicellular mechanosensing from spatiotemporal integration of heterogeneous single-cell information transfer. Cell Syst 2022; 13:711-723.e7. [PMID: 35921844 PMCID: PMC9509451 DOI: 10.1016/j.cels.2022.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/14/2021] [Accepted: 07/07/2022] [Indexed: 01/26/2023]
Abstract
Multicellular synchronization is a ubiquitous phenomenon in living systems. However, how noisy and heterogeneous behaviors of individual cells are integrated across a population toward multicellular synchronization is unclear. Here, we study the process of multicellular calcium synchronization of the endothelial cell monolayer in response to mechanical stimuli. We applied information theory to quantify the asymmetric information transfer between pairs of cells and defined quantitative measures to how single cells receive or transmit information within a multicellular network. Our analysis revealed that multicellular synchronization was established by gradual enhancement of information spread from the single cell to the multicellular scale. Synchronization was associated with heterogeneity in the cells' communication properties, reinforcement of the cells' state, and information flow. Altogether, we suggest a phenomenological model where cells gradually learn their local environment, adjust, and reinforce their internal state to stabilize the multicellular network architecture to support information flow from local to global scales toward multicellular synchronization.
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Affiliation(s)
- Amos Zamir
- Department of Software and Information Systems Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Guanyu Li
- Department of Physics, Oregon State University, Corvallis, OR 97331, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Katelyn Chase
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Robert Moskovitch
- Department of Software and Information Systems Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Bo Sun
- Department of Physics, Oregon State University, Corvallis, OR 97331, USA.
| | - Assaf Zaritsky
- Department of Software and Information Systems Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
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18
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Richard AC. Divide and Conquer: Phenotypic and Temporal Heterogeneity Within CD8 + T Cell Responses. Front Immunol 2022; 13:949423. [PMID: 35911755 PMCID: PMC9334874 DOI: 10.3389/fimmu.2022.949423] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 06/22/2022] [Indexed: 11/23/2022] Open
Abstract
The advent of technologies that can characterize the phenotypes, functions and fates of individual cells has revealed extensive and often unexpected levels of diversity between cells that are nominally of the same subset. CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs), are no exception. Investigations of individual CD8+ T cells both in vitro and in vivo have highlighted the heterogeneity of cellular responses at the levels of activation, differentiation and function. This review takes a broad perspective on the topic of heterogeneity, outlining different forms of variation that arise during a CD8+ T cell response. Specific attention is paid to the impact of T cell receptor (TCR) stimulation strength on heterogeneity. In particular, this review endeavors to highlight connections between variation at different cellular stages, presenting known mechanisms and key open questions about how variation between cells can arise and propagate.
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19
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Kissiov DU, Ethell A, Chen S, Wolf NK, Zhang C, Dang SM, Jo Y, Madsen KN, Paranjpe I, Lee AY, Chim B, Muljo SA, Raulet DH. Binary outcomes of enhancer activity underlie stable random monoallelic expression. eLife 2022; 11:e74204. [PMID: 35617021 PMCID: PMC9135403 DOI: 10.7554/elife.74204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
Mitotically stable random monoallelic gene expression (RME) is documented for a small percentage of autosomal genes. We developed an in vivo genetic model to study the role of enhancers in RME using high-resolution single-cell analysis of natural killer (NK) cell receptor gene expression and enhancer deletions in the mouse germline. Enhancers of the RME NK receptor genes were accessible and enriched in H3K27ac on silent and active alleles alike in cells sorted according to allelic expression status, suggesting enhancer activation and gene expression status can be decoupled. In genes with multiple enhancers, enhancer deletion reduced gene expression frequency, in one instance converting the universally expressed gene encoding NKG2D into an RME gene, recapitulating all aspects of natural RME including mitotic stability of both the active and silent states. The results support the binary model of enhancer action, and suggest that RME is a consequence of general properties of gene regulation by enhancers rather than an RME-specific epigenetic program. Therefore, many and perhaps all genes may be subject to some degree of RME. Surprisingly, this was borne out by analysis of several genes that define different major hematopoietic lineages, that were previously thought to be universally expressed within those lineages: the genes encoding NKG2D, CD45, CD8α, and Thy-1. We propose that intrinsically probabilistic gene allele regulation is a general property of enhancer-controlled gene expression, with previously documented RME representing an extreme on a broad continuum.
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Affiliation(s)
- Djem U Kissiov
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Alexander Ethell
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Sean Chen
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Natalie K Wolf
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Chenyu Zhang
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Susanna M Dang
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Yeara Jo
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Katrine N Madsen
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Ishan Paranjpe
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Angus Y Lee
- Cancer Research Laboratory, University of California, BerkeleyBerkeleyUnited States
| | - Bryan Chim
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
| | - Stefan A Muljo
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
| | - David H Raulet
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
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20
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Mukund A, Bintu L. Temporal signaling, population control, and information processing through chromatin-mediated gene regulation. J Theor Biol 2022; 535:110977. [PMID: 34919934 PMCID: PMC8757591 DOI: 10.1016/j.jtbi.2021.110977] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/03/2021] [Accepted: 12/05/2021] [Indexed: 01/02/2023]
Abstract
Chromatin regulation is a key pathway cells use to regulate gene expression in response to temporal stimuli, and is becoming widely used as a platform for synthetic biology applications. Here, we build a mathematical framework for analyzing the response of genetic circuits containing chromatin regulators to temporal signals in mammalian cell populations. Chromatin regulators can silence genes in an all-or-none fashion at the single-cell level, with individual cells stochastically transitioning between active, reversibly silent, and irreversibly silent gene states at constant rates over time. We integrate this mode of regulation with classical gene regulatory motifs, such as autoregulatory and incoherent feedforward loops, to determine the types of responses achievable with duration-dependent signaling. We demonstrate that repressive regulators without long-term epigenetic memory can filter out high frequency noise, and as part of an autoregulatory loop can precisely tune the fraction of cells in a population that expresses a gene of interest. Additionally, we find that repressive regulators with epigenetic memory can sum up and encode the total duration of their recruitment in the fraction of cells irreversibly silenced and, when included in a feed forward loop, enable perfect adaptation. Last, we use an information theoretic approach to show that all-or-none stochastic silencing can be used by populations to transmit information reliably and with high fidelity even in very simple genetic circuits. Altogether, we show that chromatin-mediated gene control enables a repertoire of complex cell population responses to temporal signals and can transmit higher information levels than previously measured in gene regulation.
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Affiliation(s)
- Adi Mukund
- Biophysics Program, Stanford University, Stanford, CA 94305, USA.
| | - Lacramioara Bintu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
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21
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Heydari T, A. Langley M, Fisher CL, Aguilar-Hidalgo D, Shukla S, Yachie-Kinoshita A, Hughes M, M. McNagny K, Zandstra PW. IQCELL: A platform for predicting the effect of gene perturbations on developmental trajectories using single-cell RNA-seq data. PLoS Comput Biol 2022; 18:e1009907. [PMID: 35213533 PMCID: PMC8906617 DOI: 10.1371/journal.pcbi.1009907] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 03/09/2022] [Accepted: 02/08/2022] [Indexed: 01/03/2023] Open
Abstract
The increasing availability of single-cell RNA-sequencing (scRNA-seq) data from various developmental systems provides the opportunity to infer gene regulatory networks (GRNs) directly from data. Herein we describe IQCELL, a platform to infer, simulate, and study executable logical GRNs directly from scRNA-seq data. Such executable GRNs allow simulation of fundamental hypotheses governing developmental programs and help accelerate the design of strategies to control stem cell fate. We first describe the architecture of IQCELL. Next, we apply IQCELL to scRNA-seq datasets from early mouse T-cell and red blood cell development, and show that the platform can infer overall over 74% of causal gene interactions previously reported from decades of research. We will also show that dynamic simulations of the generated GRN qualitatively recapitulate the effects of known gene perturbations. Finally, we implement an IQCELL gene selection pipeline that allows us to identify candidate genes, without prior knowledge. We demonstrate that GRN simulations based on the inferred set yield results similar to the original curated lists. In summary, the IQCELL platform offers a versatile tool to infer, simulate, and study executable GRNs in dynamic biological systems.
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Affiliation(s)
- Tiam Heydari
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew A. Langley
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Cynthia L. Fisher
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Daniel Aguilar-Hidalgo
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shreya Shukla
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Notch Therapeutics, Vancouver, British Columbia, Canada
| | - Ayako Yachie-Kinoshita
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Michael Hughes
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Kelly M. McNagny
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Peter W. Zandstra
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
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22
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Laghmach R, Di Pierro M, Potoyan D. A Liquid State Perspective on Dynamics of Chromatin Compartments. Front Mol Biosci 2022; 8:781981. [PMID: 35096966 PMCID: PMC8793688 DOI: 10.3389/fmolb.2021.781981] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022] Open
Abstract
The interior of the eukaryotic cell nucleus has a crowded and heterogeneous environment packed with chromatin polymers, regulatory proteins, and RNA molecules. Chromatin polymer, assisted by epigenetic modifications, protein and RNA binders, forms multi-scale compartments which help regulate genes in response to cellular signals. Furthermore, chromatin compartments are dynamic and tend to evolve in size and composition in ways that are not fully understood. The latest super-resolution imaging experiments have revealed a much more dynamic and stochastic nature of chromatin compartments than was appreciated before. An emerging mechanism explaining chromatin compartmentalization dynamics is the phase separation of protein and nucleic acids into membraneless liquid condensates. Consequently, concepts and ideas from soft matter and polymer systems have been rapidly entering the lexicon of cell biology. In this respect, the role of computational models is crucial for establishing a rigorous and quantitative foundation for the new concepts and disentangling the complex interplay of forces that contribute to the emergent patterns of chromatin dynamics and organization. Several multi-scale models have emerged to address various aspects of chromatin dynamics, ranging from equilibrium polymer simulations, hybrid non-equilibrium simulations coupling protein binding and chromatin folding, and mesoscopic field-theoretic models. Here, we review these emerging theoretical paradigms and computational models with a particular focus on chromatin’s phase separation and liquid-like properties as a basis for nuclear organization and dynamics.
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Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, IA, United States
| | - Michele Di Pierro
- Department of Physics, Northeastern University, Boston, MA, United States
| | - Davit Potoyan
- Department of Chemistry, Iowa State University, Ames, IA, United States
- *Correspondence: Davit Potoyan,
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23
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Menon G, Howard M. Investigating Histone Modification Dynamics by Mechanistic Computational Modeling. Methods Mol Biol 2022; 2529:441-473. [PMID: 35733026 DOI: 10.1007/978-1-0716-2481-4_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The maintenance of transcriptional states regulated by histone modifications and controlled switching between these states are fundamental concepts in our understanding of nucleosome-mediated epigenetic memory. Any approach relying on genome-wide bioinformatic analyses alone offers limited scope for dissecting the molecular mechanisms involved in maintenance and switching. Mechanistic mathematical models-describing the dynamics of histone modifications at individual genomic loci-offer an alternative way to investigate these mechanisms. These models, in conjunction with quantitative experimental data-ChIP data, quantification of mRNA levels, and single-cell fluorescence tracking in clonal lineages-can generate predictions that drive more targeted experiments, allowing us to understand mechanisms that would be challenging to unravel by a purely experimental approach. In this chapter, we describe a generic stochastic modeling framework that can be used to capture histone modification dynamics and associated molecular processes-including transcription and read-write feedback by chromatin modifying complexes-at individual genomic loci. Using a specific example-transcriptional silencing by Polycomb-mediated H3K27 methylation-we demonstrate how to construct and simulate a stochastic histone modification model. We provide a step-by-step guide to programming simulations for such a model and discuss how to analyze the simulation output.
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Affiliation(s)
- Govind Menon
- Department of Computational and Systems Biology, John Innes Centre, Norwich, UK
| | - Martin Howard
- Department of Computational and Systems Biology, John Innes Centre, Norwich, UK.
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24
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Nguyen P, Chien S, Dai J, Monnat RJ, Becker PS, Kueh HY. Unsupervised discovery of dynamic cell phenotypic states from transmitted light movies. PLoS Comput Biol 2021; 17:e1009626. [PMID: 34968384 PMCID: PMC8754342 DOI: 10.1371/journal.pcbi.1009626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 01/12/2022] [Accepted: 11/09/2021] [Indexed: 11/26/2022] Open
Abstract
Identification of cell phenotypic states within heterogeneous populations, along with elucidation of their switching dynamics, is a central challenge in modern biology. Conventional single-cell analysis methods typically provide only indirect, static phenotypic readouts. Transmitted light images, on the other hand, provide direct morphological readouts and can be acquired over time to provide a rich data source for dynamic cell phenotypic state identification. Here, we describe an end-to-end deep learning platform, UPSIDE (Unsupervised Phenotypic State IDEntification), for discovering cell states and their dynamics from transmitted light movies. UPSIDE uses the variational auto-encoder architecture to learn latent cell representations, which are then clustered for state identification, decoded for feature interpretation, and linked across movie frames for transition rate inference. Using UPSIDE, we identified distinct blood cell types in a heterogeneous dataset. We then analyzed movies of patient-derived acute myeloid leukemia cells, from which we identified stem-cell associated morphological states as well as the transition rates to and from these states. UPSIDE opens up the use of transmitted light movies for systematic exploration of cell state heterogeneity and dynamics in biology and medicine.
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Affiliation(s)
- Phuc Nguyen
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
- Molecular Engineering and Sciences Institute, University of Washington, Seattle, Washington, United States of America
| | - Sylvia Chien
- Division of Hematology, University of Washington, Seattle, Washington, United States of America
| | - Jin Dai
- Division of Hematology, University of Washington, Seattle, Washington, United States of America
| | - Raymond J. Monnat
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Pamela S. Becker
- Division of Hematology, University of Washington, Seattle, Washington, United States of America
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, California, United States of America
- Chao Family Comprehensive Cancer Center Cancer Research Institute, University of California, Irvine, California, United States of America
| | - Hao Yuan Kueh
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
- Molecular Engineering and Sciences Institute, University of Washington, Seattle, Washington, United States of America
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States of America
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25
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Barreto VM, Kubasova N, Alves-Pereira CF, Gendrel AV. X-Chromosome Inactivation and Autosomal Random Monoallelic Expression as "Faux Amis". Front Cell Dev Biol 2021; 9:740937. [PMID: 34631717 PMCID: PMC8495168 DOI: 10.3389/fcell.2021.740937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 08/30/2021] [Indexed: 12/23/2022] Open
Abstract
X-chromosome inactivation (XCI) and random monoallelic expression of autosomal genes (RMAE) are two paradigms of gene expression regulation where, at the single cell level, genes can be expressed from either the maternal or paternal alleles. X-chromosome inactivation takes place in female marsupial and placental mammals, while RMAE has been described in mammals and also other species. Although the outcome of both processes results in random monoallelic expression and mosaicism at the cellular level, there are many important differences. We provide here a brief sketch of the history behind the discovery of XCI and RMAE. Moreover, we review some of the distinctive features of these two phenomena, with respect to when in development they are established, their roles in dosage compensation and cellular phenotypic diversity, and the molecular mechanisms underlying their initiation and stability.
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Affiliation(s)
- Vasco M Barreto
- Chronic Diseases Research Centre, CEDOC, Nova Medical School, Lisbon, Portugal
| | - Nadiya Kubasova
- Chronic Diseases Research Centre, CEDOC, Nova Medical School, Lisbon, Portugal
| | - Clara F Alves-Pereira
- Department of Genetics, Smurfit Institute of Genetics, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Anne-Valerie Gendrel
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
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26
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Semicoordinated allelic-bursting shape dynamic random monoallelic expression in pregastrulation embryos. iScience 2021; 24:102954. [PMID: 34458702 PMCID: PMC8379509 DOI: 10.1016/j.isci.2021.102954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 07/27/2021] [Accepted: 07/30/2021] [Indexed: 01/14/2023] Open
Abstract
Recently, allele-specific single-cell RNA-seq analysis has demonstrated widespread dynamic random monoallelic expression of autosomal genes (aRME) in different cell types. However, the prevalence of dynamic aRME during pregastrulation remains unknown. Here, we show that dynamic aRME is widespread in different lineages of pregastrulation embryos. Additionally, the origin of dynamic aRME remains elusive. It is believed that independent transcriptional bursting from each allele leads to dynamic aRME. Here, we show that allelic burst is not perfectly independent; instead it happens in a semicoordinated fashion. Importantly, we show that semicoordinated allelic bursting of genes, particularly with low burst frequency, leads to frequent asynchronous allelic bursting, thereby contributing to dynamic aRME. Furthermore, we found that coordination of allelic bursting is lineage specific and genes regulating the development have a higher degree of coordination. Altogether, our study provides significant insights into the prevalence and origin of dynamic aRME and their developmental relevance during early development. Dynamic aRME is widespread in different lineages of pregastrulation embryos Semicoordinated bursting of genes with low burst frequency leads to dynamic aRME Degree of coordination of allelic bursting is lineage specific Developmental genes have higher degree of coordination of allelic bursting
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27
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Marion-Poll L, Forêt B, Zielinski D, Massip F, Attia M, Carter AC, Syx L, Chang HY, Gendrel AV, Heard E. Locus specific epigenetic modalities of random allelic expression imbalance. Nat Commun 2021; 12:5330. [PMID: 34504093 PMCID: PMC8429725 DOI: 10.1038/s41467-021-25630-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/19/2021] [Indexed: 01/02/2023] Open
Abstract
Most autosomal genes are thought to be expressed from both alleles, with some notable exceptions, including imprinted genes and genes showing random monoallelic expression (RME). The extent and nature of RME has been the subject of debate. Here we investigate the expression of several candidate RME genes in F1 hybrid mouse cells before and after differentiation, to define how they become persistently, monoallelically expressed. Clonal monoallelic expression is not present in embryonic stem cells, but we observe high frequencies of monoallelism in neuronal progenitor cells by assessing expression status in more than 200 clones. We uncover unforeseen modes of allelic expression that appear to be gene-specific and epigenetically regulated. This non-canonical allelic regulation has important implications for development and disease, including autosomal dominant disorders and opens up therapeutic perspectives.
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Affiliation(s)
- Lucile Marion-Poll
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
- Directors' research, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
| | - Benjamin Forêt
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
| | - Dina Zielinski
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
- Institut Curie, PSL Research University, INSERM U900, Mines ParisTech, Paris, France
| | - Florian Massip
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Mikael Attia
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
| | - Ava C Carter
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
| | - Laurène Syx
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
- Institut Curie, PSL Research University, INSERM U900, Mines ParisTech, Paris, France
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
| | - Anne-Valerie Gendrel
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
| | - Edith Heard
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
- Directors' research, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
- Collège de France, Paris, France.
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28
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Lövkvist C, Mikulski P, Reeck S, Hartley M, Dean C, Howard M. Hybrid protein assembly-histone modification mechanism for PRC2-based epigenetic switching and memory. eLife 2021; 10:66454. [PMID: 34473050 PMCID: PMC8412945 DOI: 10.7554/elife.66454] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 08/03/2021] [Indexed: 12/31/2022] Open
Abstract
The histone modification H3K27me3 plays a central role in Polycomb-mediated epigenetic silencing. H3K27me3 recruits and allosterically activates Polycomb Repressive Complex 2 (PRC2), which adds this modification to nearby histones, providing a read/write mechanism for inheritance through DNA replication. However, for some PRC2 targets, a purely histone-based system for epigenetic inheritance may be insufficient. We address this issue at the Polycomb target FLOWERING LOCUS C (FLC) in Arabidopsis thaliana, as a narrow nucleation region of only ~three nucleosomes within FLC mediates epigenetic state switching and subsequent memory over many cell cycles. To explain the memory's unexpected persistence, we introduce a mathematical model incorporating extra protein memory storage elements with positive feedback that persist at the locus through DNA replication, in addition to histone modifications. Our hybrid model explains many features of epigenetic switching/memory at FLC and encapsulates generic mechanisms that may be widely applicable.
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Affiliation(s)
- Cecilia Lövkvist
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, United Kingdom
| | - Pawel Mikulski
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, United Kingdom
| | - Svenja Reeck
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, United Kingdom.,Cell and Developmental Biology, John Innes Centre, Norwich Research Park, United Kingdom
| | - Matthew Hartley
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, United Kingdom
| | - Caroline Dean
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, United Kingdom
| | - Martin Howard
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, United Kingdom
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29
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Hosokawa H, Koizumi M, Masuhara K, Romero-Wolf M, Tanaka T, Nakayama T, Rothenberg EV. Stage-specific action of Runx1 and GATA3 controls silencing of PU.1 expression in mouse pro-T cells. J Exp Med 2021; 218:e20202648. [PMID: 34180951 PMCID: PMC8241539 DOI: 10.1084/jem.20202648] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/01/2021] [Accepted: 06/10/2021] [Indexed: 12/16/2022] Open
Abstract
PU.1 (encoded by Spi1), an ETS-family transcription factor with many hematopoietic roles, is highly expressed in the earliest intrathymic T cell progenitors but must be down-regulated during T lineage commitment. The transcription factors Runx1 and GATA3 have been implicated in this Spi1 repression, but the basis of the timing was unknown. We show that increasing Runx1 and/or GATA3 down-regulates Spi1 expression in pro-T cells, while deletion of these factors after Spi1 down-regulation reactivates its expression. Leveraging the stage specificities of repression and transcription factor binding revealed an unconventional but functional site in Spi1 intron 2. Acute Cas9-mediated deletion or disruption of the Runx and GATA motifs in this element reactivates silenced Spi1 expression in a pro-T cell line, substantially more than disruption of other candidate elements, and counteracts the repression of Spi1 in primary pro-T cells during commitment. Thus, Runx1 and GATA3 work stage specifically through an intronic silencing element in mouse Spi1 to control strength and maintenance of Spi1 repression during T lineage commitment.
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Affiliation(s)
- Hiroyuki Hosokawa
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
- Institute of Medical Sciences, Tokai University, Isehara, Kanagawa, Japan
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA
| | - Maria Koizumi
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Kaori Masuhara
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Maile Romero-Wolf
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA
| | - Tomoaki Tanaka
- Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba, Japan
| | - Toshinori Nakayama
- Department of Immunology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba, Japan
| | - Ellen V Rothenberg
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA
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30
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Nguyen P, Pease NA, Kueh HY. Scalable control of developmental timetables by epigenetic switching networks. J R Soc Interface 2021; 18:20210109. [PMID: 34283940 DOI: 10.1098/rsif.2021.0109] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
During development, progenitor cells follow timetables for differentiation that span many cell generations. These developmental timetables are robustly encoded by the embryo, yet scalably adjustable by evolution, facilitating variation in organism size and form. Epigenetic switches, involving rate-limiting activation steps at regulatory gene loci, control gene activation timing in diverse contexts, and could profoundly impact the dynamics of gene regulatory networks controlling developmental lineage specification. Here, we develop a mathematical framework to model regulatory networks with genes controlled by epigenetic switches. Using this framework, we show that such epigenetic switching networks uphold developmental timetables that robustly span many cell generations, and enable the generation of differentiated cells in precisely defined numbers and fractions. Changes to epigenetic switching networks can readily alter the timing of developmental events within a timetable, or alter the overall speed at which timetables unfold, enabling scalable control over differentiated population sizes. With their robust, yet flexibly adjustable nature, epigenetic switching networks could represent central targets on which evolution acts to manufacture diversity in organism size and form.
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Affiliation(s)
- Phuc Nguyen
- Molecular Engineering and Sciences Program, University of Washington, Seattle, WA, USA
| | - Nicholas A Pease
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Hao Yuan Kueh
- Department of Bioengineering, University of Washington, Seattle, WA, USA.,Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
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31
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Oh S, Gray DHD, Chong MMW. Single-Cell RNA Sequencing Approaches for Tracing T Cell Development. THE JOURNAL OF IMMUNOLOGY 2021; 207:363-370. [PMID: 34644259 DOI: 10.4049/jimmunol.2100408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/20/2021] [Indexed: 01/17/2023]
Abstract
T cell development occurs in the thymus, where uncommitted progenitors are directed into a range of sublineages with distinct functions. The goal is to generate a TCR repertoire diverse enough to recognize potential pathogens while remaining tolerant of self. Decades of intensive research have characterized the transcriptional programs controlling critical differentiation checkpoints at the population level. However, greater precision regarding how and when these programs orchestrate differentiation at the single-cell level is required. Single-cell RNA sequencing approaches are now being brought to bear on this question, to track the identity of cells and analyze their gene expression programs at a resolution not previously possible. In this review, we discuss recent advances in the application of these technologies that have the potential to yield unprecedented insight to T cell development.
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Affiliation(s)
- Seungyoul Oh
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,Department of Medicine (St. Vincent's), The University of Melbourne, Fitzroy, Victoria, Australia
| | - Daniel H D Gray
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; and.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Mark M W Chong
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; .,Department of Medicine (St. Vincent's), The University of Melbourne, Fitzroy, Victoria, Australia
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32
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Aghaallaei N, Dick AM, Tsingos E, Inoue D, Hasel E, Thumberger T, Toyoda A, Leptin M, Wittbrodt J, Bajoghli B. αβ/γδ T cell lineage outcome is regulated by intrathymic cell localization and environmental signals. SCIENCE ADVANCES 2021; 7:7/29/eabg3613. [PMID: 34261656 PMCID: PMC8279519 DOI: 10.1126/sciadv.abg3613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 05/28/2021] [Indexed: 05/07/2023]
Abstract
αβ and γδ T cells are two distinct sublineages that develop in the vertebrate thymus. Thus far, their differentiation from a common progenitor is mostly understood to be regulated by intrinsic mechanisms. However, the proportion of αβ/γδ T cells varies in different vertebrate taxa. How this process is regulated in species that tend to produce a high frequency of γδ T cells is unstudied. Using an in vivo teleost model, the medaka, we report that progenitors first enter a thymic niche where their development into γδ T cells is favored. Translocation from this niche, mediated by chemokine receptor Ccr9b, is a prerequisite for their differentiation into αβ T cells. On the other hand, the thymic niche also generates opposing gradients of the cytokine interleukin-7 and chemokine Ccl25a, and, together, they influence the lineage outcome. We propose a previously unknown mechanism that determines the proportion of αβ/γδ lineages within species.
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Affiliation(s)
- Narges Aghaallaei
- Department of Hematology, Oncology, Immunology, and Rheumatology, University Hospital of Tübingen, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Advaita M Dick
- Department of Hematology, Oncology, Immunology, and Rheumatology, University Hospital of Tübingen, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany
| | - Erika Tsingos
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Daigo Inoue
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Eva Hasel
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Thomas Thumberger
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, Department of Genomics and Evolutionary Biology, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Maria Leptin
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
- EMBO, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Joachim Wittbrodt
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Baubak Bajoghli
- Department of Hematology, Oncology, Immunology, and Rheumatology, University Hospital of Tübingen, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany.
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
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33
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Gregg C. Starvation and Climate Change—How to Constrain Cancer Cell Epigenetic Diversity and Adaptability to Enhance Treatment Efficacy. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.693781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Advanced metastatic cancer is currently not curable and the major barrier to eliminating the disease in patients is the resistance of subpopulations of tumor cells to drug treatments. These resistant subpopulations can arise stochastically among the billions of tumor cells in a patient or emerge over time during therapy due to adaptive mechanisms and the selective pressures of drug therapies. Epigenetic mechanisms play important roles in tumor cell diversity and adaptability, and are regulated by metabolic pathways. Here, I discuss knowledge from ecology, evolution, infectious disease, species extinction, metabolism and epigenetics to synthesize a roadmap to a clinically feasible approach to help homogenize tumor cells and, in combination with drug treatments, drive their extinction. Specifically, cycles of starvation and hyperthermia could help synchronize tumor cells and constrain epigenetic diversity and adaptability by limiting substrates and impairing the activity of chromatin modifying enzymes. Hyperthermia could also help prevent cancer cells from entering dangerous hibernation-like states. I propose steps to a treatment paradigm to help drive cancer extinction that builds on the successes of fasting, hyperthermia and immunotherapy and is achievable in patients. Finally, I highlight the many unknowns, opportunities for discovery and that stochastic gene and allele level epigenetic mechanisms pose a major barrier to cancer extinction that warrants deeper investigation.
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34
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Runx1 and Runx3 drive progenitor to T-lineage transcriptome conversion in mouse T cell commitment via dynamic genomic site switching. Proc Natl Acad Sci U S A 2021; 118:2019655118. [PMID: 33479171 DOI: 10.1073/pnas.2019655118] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Runt domain-related (Runx) transcription factors are essential for early T cell development in mice from uncommitted to committed stages. Single and double Runx knockouts via Cas9 show that target genes responding to Runx activity are not solely controlled by the dominant factor, Runx1. Instead, Runx1 and Runx3 are coexpressed in single cells; bind to highly overlapping genomic sites; and have redundant, collaborative functions regulating genes pivotal for T cell development. Despite stable combined expression levels across pro-T cell development, Runx1 and Runx3 preferentially activate and repress genes that change expression dynamically during lineage commitment, mostly activating T-lineage genes and repressing multipotent progenitor genes. Furthermore, most Runx target genes are sensitive to Runx perturbation only at one stage and often respond to Runx more for expression transitions than for maintenance. Contributing to this highly stage-dependent gene regulation function, Runx1 and Runx3 extensively shift their binding sites during commitment. Functionally distinct Runx occupancy sites associated with stage-specific activation or repression are also distinguished by different patterns of partner factor cobinding. Finally, Runx occupancies change coordinately at numerous clustered sites around positively or negatively regulated targets during commitment. This multisite binding behavior may contribute to a developmental "ratchet" mechanism making commitment irreversible.
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35
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Menon G, Schulten A, Dean C, Howard M. Digital paradigm for Polycomb epigenetic switching and memory. CURRENT OPINION IN PLANT BIOLOGY 2021; 61:102012. [PMID: 33662809 PMCID: PMC8250048 DOI: 10.1016/j.pbi.2021.102012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 05/04/2023]
Abstract
How epigenetic memory states are established and maintained is a central question in gene regulation. A major epigenetic process important for developmental biology involves Polycomb-mediated chromatin silencing. Significant progress has recently been made on elucidating Polycomb silencing in plant systems through analysis of Arabidopsis FLOWERING LOCUS C (FLC). Quantitative silencing of FLC by prolonged cold exposure was shown to represent an ON to OFF switch in an increasing proportion of cells. Here, we review the underlying all-or-nothing, digital paradigm for Polycomb epigenetic silencing. We then examine other Arabidopsis Polycomb-regulated targets where digital regulation may also be relevant.
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Affiliation(s)
- Govind Menon
- Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Anna Schulten
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Caroline Dean
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Martin Howard
- Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK.
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36
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Rothenberg EV. Logic and lineage impacts on functional transcription factor deployment for T-cell fate commitment. Biophys J 2021; 120:4162-4181. [PMID: 33838137 PMCID: PMC8516641 DOI: 10.1016/j.bpj.2021.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/22/2021] [Accepted: 04/02/2021] [Indexed: 11/19/2022] Open
Abstract
Transcription factors are the major agents that read the regulatory sequence information in the genome to initiate changes in expression of specific genes, both in development and in physiological activation responses. Their actions depend on site-specific DNA binding and are largely guided by their individual DNA target sequence specificities. However, their action is far more conditional in a real developmental context than would be expected for simple reading of local genomic DNA sequence, which is common to all cells in the organism. They are constrained by slow-changing chromatin states and by interactions with other transcription factors, which affect their occupancy patterns of potential sites across the genome. These mechanisms lead to emergent discontinuities in function even for transcription factors with minimally changing expression. This is well revealed by diverse lineages of blood cells developing throughout life from hematopoietic stem cells, which use overlapping combinations of transcription factors to drive strongly divergent gene regulation programs. Here, using development of T lymphocytes from hematopoietic multipotent progenitor cells as a focus, recent evidence is reviewed on how binding specificity and dynamics, transcription factor cooperativity, and chromatin state changes impact the effective regulatory functions of key transcription factors including PU.1, Runx1, Notch-RBPJ, and Bcl11b.
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Affiliation(s)
- Ellen V Rothenberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California.
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37
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Clark HR, McKenney C, Livingston NM, Gershman A, Sajjan S, Chan IS, Ewald AJ, Timp W, Wu B, Singh A, Regot S. Epigenetically regulated digital signaling defines epithelial innate immunity at the tissue level. Nat Commun 2021; 12:1836. [PMID: 33758175 PMCID: PMC7988009 DOI: 10.1038/s41467-021-22070-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 02/26/2021] [Indexed: 02/08/2023] Open
Abstract
To prevent damage to the host or its commensal microbiota, epithelial tissues must match the intensity of the immune response to the severity of a biological threat. Toll-like receptors allow epithelial cells to identify microbe associated molecular patterns. However, the mechanisms that mitigate biological noise in single cells to ensure quantitatively appropriate responses remain unclear. Here we address this question using single cell and single molecule approaches in mammary epithelial cells and primary organoids. We find that epithelial tissues respond to bacterial microbe associated molecular patterns by activating a subset of cells in an all-or-nothing (i.e. digital) manner. The maximum fraction of responsive cells is regulated by a bimodal epigenetic switch that licenses the TLR2 promoter for transcription across multiple generations. This mechanism confers a flexible memory of inflammatory events as well as unique spatio-temporal control of epithelial tissue-level immune responses. We propose that epigenetic licensing in individual cells allows for long-term, quantitative fine-tuning of population-level responses.
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Affiliation(s)
- Helen R Clark
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Oncology Department, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Biochemistry, Cellular, and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Connor McKenney
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Oncology Department, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Biochemistry, Cellular, and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nathan M Livingston
- The Biochemistry, Cellular, and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ariel Gershman
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Biochemistry, Cellular, and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Seema Sajjan
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Oncology Department, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Isaac S Chan
- Oncology Department, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrew J Ewald
- Oncology Department, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Winston Timp
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Bin Wu
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Abhyudai Singh
- Electrical and Computer Engineering, University of Delaware, Newark, DE, USA
| | - Sergi Regot
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Oncology Department, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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38
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Pease NA, Nguyen PHB, Woodworth MA, Ng KKH, Irwin B, Vaughan JC, Kueh HY. Tunable, division-independent control of gene activation timing by a polycomb switch. Cell Rep 2021; 34:108888. [PMID: 33761349 PMCID: PMC8024876 DOI: 10.1016/j.celrep.2021.108888] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/17/2020] [Accepted: 03/01/2021] [Indexed: 01/09/2023] Open
Abstract
During development, progenitors often differentiate many cell generations after receiving signals. These delays must be robust yet tunable for precise population size control. Polycomb repressive mechanisms, involving histone H3 lysine-27 trimethylation (H3K27me3), restrain the expression of lineage-specifying genes in progenitors and may delay their activation and ensuing differentiation. Here, we elucidate an epigenetic switch controlling the T cell commitment gene Bcl11b that holds its locus in a heritable inactive state for multiple cell generations before activation. Integrating experiments and modeling, we identify a mechanism where H3K27me3 levels at Bcl11b, regulated by methyltransferase and demethylase activities, set the time delay at which the locus switches from a compacted, silent state to an extended, active state. This activation delay robustly spans many cell generations, is tunable by chromatin modifiers and transcription factors, and is independent of cell division. With their regulatory flexibility, such timed epigenetic switches may broadly control timing in development.
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Affiliation(s)
- Nicholas A Pease
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Phuc H B Nguyen
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Molecular Engineering and Sciences Institute, University of Washington, Seattle, WA 98195, USA
| | - Marcus A Woodworth
- Biological Physics, Structure and Design Program, University of Washington, Seattle, WA 98195, USA; Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Kenneth K H Ng
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Blythe Irwin
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Joshua C Vaughan
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA; Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Hao Yuan Kueh
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195, USA.
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39
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Larsson AJM, Ziegenhain C, Hagemann-Jensen M, Reinius B, Jacob T, Dalessandri T, Hendriks GJ, Kasper M, Sandberg R. Transcriptional bursts explain autosomal random monoallelic expression and affect allelic imbalance. PLoS Comput Biol 2021; 17:e1008772. [PMID: 33690599 PMCID: PMC7978379 DOI: 10.1371/journal.pcbi.1008772] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/19/2021] [Accepted: 02/03/2021] [Indexed: 12/02/2022] Open
Abstract
Transcriptional bursts render substantial biological noise in cellular transcriptomes. Here, we investigated the theoretical extent of allelic expression resulting from transcriptional bursting and how it compared to the amount biallelic, monoallelic and allele-biased expression observed in single-cell RNA-sequencing (scRNA-seq) data. We found that transcriptional bursting can explain the allelic expression patterns observed in single cells, including the frequent observations of autosomal monoallelic gene expression. Importantly, we identified that the burst frequency largely determined the fraction of cells with monoallelic expression, whereas the burst size had little effect on monoallelic observations. The high consistency between the bursting model predictions and scRNA-seq observations made it possible to assess the heterogeneity of a group of cells as their deviation in allelic observations from the expected. Finally, both burst frequency and size contributed to allelic imbalance observations and reinforced that studies of allelic imbalance can be confounded from the inherent noise in transcriptional bursting. Altogether, we demonstrate that allele-level transcriptional bursting renders widespread, although predictable, amounts of monoallelic and biallelic expression in single cells and cell populations. Genes are transcribed into RNA and further translated into proteins. The maternal and paternal copy of each gene are typically transcribed independently, and transcription itself occur in discrete stochastic bursts (transcriptional bursts). Pioneering single-cell analysis of RNA across cells revealed abundant fluctuations in the amounts of maternal and paternal RNA in cells, with frequent observations of RNA from only the maternal or paternal gene copy (monoallelic expression). In this study, we investigated to which extent the observed monoallelic expression across single cells can be explained by transcriptional bursting. We demonstrate that the process of transcriptional bursting is sufficient to explain the amount of monoallelic expression, and we further demonstrate that the frequency of bursts mainly determines the frequency of monoallelic observations. Furthermore, we show that transcriptional bursts may lead to false positive observations of monoallelic expression across cell populations. Therefore, stochastic transcription renders large fluctuations in allelic origin of RNA in cells over time, including frequent monoallelic observations when profiling single cells.
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Affiliation(s)
- Anton J. M. Larsson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Christoph Ziegenhain
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Björn Reinius
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Tina Jacob
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Tim Dalessandri
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Gert-Jan Hendriks
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Kasper
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Rickard Sandberg
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
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40
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Chu JM, Pease NA, Kueh HY. In search of lost time: Enhancers as modulators of timing in lymphocyte development and differentiation. Immunol Rev 2021; 300:134-151. [PMID: 33734444 PMCID: PMC8005465 DOI: 10.1111/imr.12946] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/15/2020] [Accepted: 12/23/2020] [Indexed: 12/21/2022]
Abstract
Proper timing of gene expression is central to lymphocyte development and differentiation. Lymphocytes often delay gene activation for hours to days after the onset of signaling components, which act on the order of seconds to minutes. Such delays play a prominent role during the intricate choreography of developmental events and during the execution of an effector response. Though a number of mechanisms are sufficient to explain timing at short timescales, it is not known how timing delays are implemented over long timescales that may span several cell generations. Based on the literature, we propose that a class of cis-regulatory elements, termed "timing enhancers," may explain how timing delays are controlled over these long timescales. By considering chromatin as a kinetic barrier to state switching, the timing enhancer model explains experimentally observed dynamics of gene expression where other models fall short. In this review, we elaborate on features of the timing enhancer model and discuss the evidence for its generality throughout development and differentiation. We then discuss potential molecular mechanisms underlying timing enhancer function. Finally, we explore recent evidence drawing connections between timing enhancers and genetic risk for immunopathology. We argue that the timing enhancer model is a useful framework for understanding how cis-regulatory elements control the central dimension of timing in lymphocyte biology.
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Affiliation(s)
- Jonathan M Chu
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, Seattle, WA, USA
| | - Nicholas A Pease
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, Seattle, WA, USA
| | - Hao Yuan Kueh
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, Seattle, WA, USA
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41
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Hosokawa H, Rothenberg EV. How transcription factors drive choice of the T cell fate. Nat Rev Immunol 2021; 21:162-176. [PMID: 32918063 PMCID: PMC7933071 DOI: 10.1038/s41577-020-00426-6] [Citation(s) in RCA: 135] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2020] [Indexed: 12/21/2022]
Abstract
Recent evidence has elucidated how multipotent blood progenitors transform their identities in the thymus and undergo commitment to become T cells. Together with environmental signals, a core group of transcription factors have essential roles in this process by directly activating and repressing specific genes. Many of these transcription factors also function in later T cell development, but control different genes. Here, we review how these transcription factors work to change the activities of specific genomic loci during early intrathymic development to establish T cell lineage identity. We introduce the key regulators and highlight newly emergent insights into the rules that govern their actions. Whole-genome deep sequencing-based analysis has revealed unexpectedly rich relationships between inherited epigenetic states, transcription factor-DNA binding affinity thresholds and influences of given transcription factors on the activities of other factors in the same cells. Together, these mechanisms determine T cell identity and make the lineage choice irreversible.
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Affiliation(s)
- Hiroyuki Hosokawa
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Ellen V Rothenberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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42
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Hosokawa H, Masuhara K, Koizumi M. Transcription factors regulate early T cell development via redeployment of other factors: Functional dynamics of constitutively required factors in cell fate decisions. Bioessays 2021; 43:e2000345. [PMID: 33624856 DOI: 10.1002/bies.202000345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/30/2021] [Accepted: 02/08/2021] [Indexed: 01/02/2023]
Abstract
Establishment of cell lineage identity from multipotent progenitors is controlled by cooperative actions of lineage-specific and stably expressed transcription factors, combined with input from environmental signals. Lineage-specific master transcription factors activate and repress gene expression by recruiting consistently expressed transcription factors and chromatin modifiers to their target loci. Recent technical advances in genome-wide and multi-omics analysis have shed light on unexpected mechanisms that underlie more complicated actions of transcription factors in cell fate decisions. In this review, we discuss functional dynamics of stably expressed and continuously required factors, Notch and Runx family members, throughout developmental stages of early T cell development in the thymus. Pre- and post-commitment stage-specific transcription factors induce dynamic redeployment of Notch and Runx binding genomic regions. Thus, together with stage-specific transcription factors, shared transcription factors across distinct developmental stages regulate acquisition of T lineage identity.
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Affiliation(s)
- Hiroyuki Hosokawa
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan.,Institute of Medical Sciences, Tokai University, Isehara, Kanagawa, Japan
| | - Kaori Masuhara
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Maria Koizumi
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
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43
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Using computational modelling to reveal mechanisms of epigenetic Polycomb control. Biochem Soc Trans 2021; 49:71-77. [PMID: 33616630 PMCID: PMC7925002 DOI: 10.1042/bst20190955] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 11/17/2022]
Abstract
The Polycomb system is essential for stable gene silencing in many organisms. This regulation is achieved in part through addition of the histone modifications H3K27me2/me3 by Polycomb Repressive Complex 2 (PRC2). These modifications are believed to be the causative epigenetic memory elements of PRC2-mediated silencing. As these marks are stored locally in the chromatin, PRC2-based memory is a cis-acting system. A key feature of stable epigenetic memory in cis is PRC2-mediated, self-reinforcing feedback from K27-methylated histones onto nearby histones in a read-write paradigm. However, it was not clear under what conditions such feedback can lead to stable memory, able, for example, to survive the perturbation of histone dilution at DNA replication. In this context, computational modelling has allowed a rigorous exploration of possible underlying memory mechanisms and has also greatly accelerated our understanding of switching between active and silenced states. Specifically, modelling has predicted that switching and memory at Polycomb loci is digital, with a locus being either active or inactive, rather than possessing intermediate, smoothly varying levels of activation. Here, we review recent advances in models of Polycomb control, focusing on models of epigenetic switching through nucleation and spreading of H3K27me2/me3. We also examine models that incorporate transcriptional feedback antagonism and those including bivalent chromatin states. With more quantitative experimental data on histone modification kinetics, as well as single-cell resolution data on transcription and protein levels for PRC2 targets, we anticipate an expanded need for modelling to help dissect increasingly interconnected and complex memory mechanisms.
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44
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Olariu V, Yui MA, Krupinski P, Zhou W, Deichmann J, Andersson E, Rothenberg EV, Peterson C. Multi-scale Dynamical Modeling of T Cell Development from an Early Thymic Progenitor State to Lineage Commitment. Cell Rep 2021; 34:108622. [PMID: 33440162 DOI: 10.1016/j.celrep.2020.108622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/24/2020] [Accepted: 12/18/2020] [Indexed: 01/13/2023] Open
Abstract
Intrathymic development of committed progenitor (pro)-T cells from multipotent hematopoietic precursors offers an opportunity to dissect the molecular circuitry establishing cell identity in response to environmental signals. This transition encompasses programmed shutoff of stem/progenitor genes, upregulation of T cell specification genes, proliferation, and ultimately commitment. To explain these features in light of reported cis-acting chromatin effects and experimental kinetic data, we develop a three-level dynamic model of commitment based upon regulation of the commitment-linked gene Bcl11b. The levels are (1) a core gene regulatory network (GRN) architecture from transcription factor (TF) perturbation data, (2) a stochastically controlled chromatin-state gate, and (3) a single-cell proliferation model validated by experimental clonal growth and commitment kinetic assays. Using RNA fluorescence in situ hybridization (FISH) measurements of genes encoding key TFs and measured bulk population dynamics, this single-cell model predicts state-switching kinetics validated by measured clonal proliferation and commitment times. The resulting multi-scale model provides a mechanistic framework for dissecting commitment dynamics.
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Affiliation(s)
- Victor Olariu
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Mary A Yui
- Division of Biology and Biological Engineering, 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Pawel Krupinski
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Wen Zhou
- Division of Biology and Biological Engineering, 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Julia Deichmann
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Emil Andersson
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Ellen V Rothenberg
- Division of Biology and Biological Engineering, 156-29, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Carsten Peterson
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden.
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45
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Golub R. The Notch signaling pathway involvement in innate lymphoid cell biology. Biomed J 2020; 44:133-143. [PMID: 33863682 PMCID: PMC8178581 DOI: 10.1016/j.bj.2020.12.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/11/2020] [Accepted: 12/16/2020] [Indexed: 12/30/2022] Open
Abstract
The role of Notch in the immune system was first described in the late 90s. Reports revealed that Notch is one of the most conserved developmental pathways involved in diverse biological processes such as the development, differentiation, survival and functions of many immune populations. Here, we provide an extended view of the pleiotropic effects of the Notch signaling on the innate lymphoid cell (ILC) biology. We review the current knowledge on Notch signaling in the regulation of ILC differentiation, plasticity and functions in diverse tissue types and at both the fetal and adult developmental stages. ILCs are early responder cells that secrete a large panel of cytokines after stimulation. By controlling the abundance of ILCs and the specificity of their release, the Notch pathway is also implicated in the regulation of their functions. The Notch pathway is therefore an important player in both ILC cell fate decision and ILC immune response.
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Affiliation(s)
- Rachel Golub
- Unit of Lymphocytes and Immunity, Department of Immunology, Institut Pasteur, Paris, France.
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46
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Daher MT, Bausero P, Agbulut O, Li Z, Parlakian A. Bcl11b/Ctip2 in Skin, Tooth, and Craniofacial System. Front Cell Dev Biol 2020; 8:581674. [PMID: 33363142 PMCID: PMC7758212 DOI: 10.3389/fcell.2020.581674] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/19/2020] [Indexed: 12/20/2022] Open
Abstract
Ctip2/Bcl11b is a zinc finger transcription factor with dual action (repression/activation) that couples epigenetic regulation to gene transcription during the development of various tissues. It is involved in a variety of physiological responses under healthy and pathological conditions. Its role and mechanisms of action are best characterized in the immune and nervous systems. Furthermore, its implication in the development and homeostasis of other various tissues has also been reported. In the present review, we describe its role in skin development, adipogenesis, tooth formation and cranial suture ossification. Experimental data from several studies demonstrate the involvement of Bcl11b in the control of the balance between cell proliferation and differentiation during organ formation and repair, and more specifically in the context of stem cell self-renewal and fate determination. The impact of mutations in the coding sequences of Bcl11b on the development of diseases such as craniosynostosis is also presented. Finally, we discuss genome-wide association studies that suggest a potential influence of single nucleotide polymorphisms found in the 3’ regulatory region of Bcl11b on the homeostasis of the cardiovascular system.
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Affiliation(s)
- Marie-Thérèse Daher
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Pedro Bausero
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Onnik Agbulut
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Zhenlin Li
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Ara Parlakian
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
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47
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Charest J, Daniele T, Wang J, Bykov A, Mandlbauer A, Asparuhova M, Röhsner J, Gutiérrez-Pérez P, Cochella L. Combinatorial Action of Temporally Segregated Transcription Factors. Dev Cell 2020; 55:483-499.e7. [PMID: 33002421 PMCID: PMC7704111 DOI: 10.1016/j.devcel.2020.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/30/2020] [Accepted: 09/01/2020] [Indexed: 01/05/2023]
Abstract
Combinatorial action of transcription factors (TFs) with partially overlapping expression is a widespread strategy to generate novel gene-expression patterns and, thus, cellular diversity. Known mechanisms underlying combinatorial activity require co-expression of TFs within the same cell. Here, we describe the mechanism by which two TFs that are never co-expressed generate a new, intersectional expression pattern in C. elegans embryos: lineage-specific priming of a gene by a transiently expressed TF generates a unique intersection with a second TF acting on the same gene four cell divisions later; the second TF is expressed in multiple cells but only activates transcription in those where priming occurred. Early induction of active transcription is necessary and sufficient to establish a competent state, maintained by broadly expressed regulators in the absence of the initial trigger. We uncover additional cells diversified through this mechanism. Our findings define a mechanism for combinatorial TF activity with important implications for generation of cell-type diversity. Lineage-specific priming enables asymmetric gene expression in L/R neuron pairs Transient, lineage-specific TFs prime a locus for later activation by a bilateral TF An early active transcriptional state is necessary and sufficient for priming Maintenance of asymmetric primed state occurs in a symmetric regulatory environment
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Affiliation(s)
- Julien Charest
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Thomas Daniele
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Jingkui Wang
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Aleksandr Bykov
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Ariane Mandlbauer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Mila Asparuhova
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Josef Röhsner
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Paula Gutiérrez-Pérez
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Luisa Cochella
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
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48
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Hosokawa H, Romero-Wolf M, Yang Q, Motomura Y, Levanon D, Groner Y, Moro K, Tanaka T, Rothenberg EV. Cell type-specific actions of Bcl11b in early T-lineage and group 2 innate lymphoid cells. J Exp Med 2020; 217:jem.20190972. [PMID: 31653691 PMCID: PMC7037248 DOI: 10.1084/jem.20190972] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/16/2019] [Accepted: 09/27/2019] [Indexed: 01/16/2023] Open
Abstract
Bcl11b binds to distinctive genomic regions with different partners and regulates completely different target genes in pro-T and ILC2 cells. Despite these divergences in Bcl11b function, a shared enhancer supports initial Bcl11b locus opening in both pro-T and ILC2 lineages. The zinc finger transcription factor, Bcl11b, is expressed in T cells and group 2 innate lymphoid cells (ILC2s) among hematopoietic cells. In early T-lineage cells, Bcl11b directly binds and represses the gene encoding the E protein antagonist, Id2, preventing pro-T cells from adopting innate-like fates. In contrast, ILC2s co-express both Bcl11b and Id2. To address this contradiction, we have directly compared Bcl11b action mechanisms in pro-T cells and ILC2s. We found that Bcl11b binding to regions across the genome shows distinct cell type–specific motif preferences. Bcl11b occupies functionally different sites in lineage-specific patterns and controls totally different sets of target genes in these cell types. In addition, Bcl11b bears cell type–specific post-translational modifications and organizes different cell type–specific protein complexes. However, both cell types use the same distal enhancer region to control timing of Bcl11b activation. Therefore, although pro-T cells and ILC2s both need Bcl11b for optimal development and function, Bcl11b works substantially differently in these two cell types.
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Affiliation(s)
- Hiroyuki Hosokawa
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA.,Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Maile Romero-Wolf
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA
| | - Qi Yang
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY
| | - Yasutaka Motomura
- Laboratory for Innate Immune Systems, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan.,Laboratory for Innate Immune Systems, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | | | | | - Kazuyo Moro
- Laboratory for Innate Immune Systems, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan.,Laboratory for Innate Immune Systems, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Tomoaki Tanaka
- Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan.,Agency for Medical Research and Development - Core Research for Evolutionary Medical Science and Technology (AMED-CREST), Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Ellen V Rothenberg
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA
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49
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Abstract
Transcription in several organisms from certain bacteria to humans has been observed to be stochastic in nature: toggling between active and inactive states. Periods of active nascent RNA synthesis known as bursts represent individual gene activation events in which multiple polymerases are initiated. Therefore, bursting is the single locus illustration of both gene activation and repression. Although transcriptional bursting was originally observed decades ago, only recently have technological advances enabled the field to begin elucidating gene regulation at the single-locus level. In this review, we focus on how biochemical, genomic, and single-cell data describe the regulatory steps of transcriptional bursts.
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Affiliation(s)
- Joseph Rodriguez
- National Institute of Environmental Health Sciences, Durham, North Carolina 27709, USA
| | - Daniel R. Larson
- Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
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50
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Falo-Sanjuan J, Bray SJ. Decoding the Notch signal. Dev Growth Differ 2019; 62:4-14. [PMID: 31886523 DOI: 10.1111/dgd.12644] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 01/04/2023]
Abstract
Notch signalling controls many key cellular processes which differ according to the context where the pathway is deployed due to the transcriptional activation of specific sets of genes. The pathway is unusual in its lack of amplification, also raising the question of how it can efficiently activate transcription with limited amounts of nuclear activity. Here, we focus on mechanisms that enable Notch to produce appropriate transcriptional responses and speculate on models that could explain the current gaps in knowledge.
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Affiliation(s)
- Julia Falo-Sanjuan
- Department of Physiology Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Sarah J Bray
- Department of Physiology Development and Neuroscience, University of Cambridge, Cambridge, UK
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