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Beilinson HA, Erickson SA, Golovkina T. The endogenous Mtv8 locus and the immunoglobulin repertoire. Front Immunol 2024; 15:1345467. [PMID: 38504980 PMCID: PMC10948529 DOI: 10.3389/fimmu.2024.1345467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/16/2024] [Indexed: 03/21/2024] Open
Abstract
The vast diversity of mammalian adaptive antigen receptors allows for robust and efficient immune responses against a wide number of pathogens. The antigen receptor repertoire is built during the recombination of B and T cell receptor (BCR, TCR) loci and hypermutation of BCR loci. V(D)J recombination rearranges these antigen receptor loci, which are organized as an array of separate V, (D), and J gene segments. Transcription activation at the recombining locus leads to changes in the local three-dimensional architecture, which subsequently contributes to which gene segments are utilized for recombination. The endogenous retrovirus (ERV) mouse mammary tumor provirus 8 (Mtv8) resides on mouse chromosome 6 interposed within the large array of light chain kappa V gene segments. As ERVs contribute to changes in genomic architecture by driving high levels of transcription of neighboring genes, it was suggested that Mtv8 could influence the BCR repertoire. We generated Mtv8-deficient mice to determine if the ERV influences V(D)J recombination to test this possibility. We find that Mtv8 does not influence the BCR repertoire.
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Affiliation(s)
- Helen A Beilinson
- Department of Microbiology, University of Chicago, Chicago, IL, United States
| | - Steven A Erickson
- Department of Immunobiology, Yale University, New Haven, CT, United States
| | - Tatyana Golovkina
- Department of Microbiology, University of Chicago, Chicago, IL, United States
- Committee on Microbiology, University of Chicago, Chicago, IL, United States
- Committee on Immunology, University of Chicago, Chicago, IL, United States
- Committee on Genetics, Genomics and System Biology, University of Chicago, Chicago, IL, United States
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2
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Gao Z, Smith AL, Scott JF, Bevington S, Boyes J. Temporal analyses reveal a pivotal role for sense and antisense enhancer RNAs in coordinate immunoglobulin lambda locus activation. Nucleic Acids Res 2023; 51:10344-10363. [PMID: 37702072 PMCID: PMC10602925 DOI: 10.1093/nar/gkad741] [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: 03/16/2023] [Revised: 08/24/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023] Open
Abstract
Transcription enhancers are essential activators of V(D)J recombination that orchestrate non-coding transcription through complementary, unrearranged gene segments. How transcription is coordinately increased at spatially distinct promoters, however, remains poorly understood. Using the murine immunoglobulin lambda (Igλ) locus as model, we find that three enhancer-like elements in the 3' Igλ domain, Eλ3-1, HSCλ1 and HSE-1, show strikingly similar transcription factor binding dynamics and close spatial proximity, suggesting that they form an active enhancer hub. Temporal analyses show coordinate recruitment of complementary V and J gene segments to this hub, with comparable transcription factor binding dynamics to that at enhancers. We find further that E2A, p300, Mediator and Integrator bind to enhancers as early events, whereas YY1 recruitment and eRNA synthesis occur later, corresponding to transcription activation. Remarkably, the interplay between sense and antisense enhancer RNA is central to both active enhancer hub formation and coordinate Igλ transcription: Antisense Eλ3-1 eRNA represses Igλ activation whereas temporal analyses demonstrate that accumulating levels of sense eRNA boost YY1 recruitment to stabilise enhancer hub/promoter interactions and lead to coordinate transcription activation. These studies therefore demonstrate for the first time a critical role for threshold levels of sense versus antisense eRNA in locus activation.
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Affiliation(s)
- Zeqian Gao
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Alastair L Smith
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - James N F Scott
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Sarah L Bevington
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Joan Boyes
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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3
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Mielczarek O, Rogers CH, Zhan Y, Matheson LS, Stubbington MJT, Schoenfelder S, Bolland DJ, Javierre BM, Wingett SW, Várnai C, Segonds-Pichon A, Conn SJ, Krueger F, Andrews S, Fraser P, Giorgetti L, Corcoran AE. Intra- and interchromosomal contact mapping reveals the Igh locus has extensive conformational heterogeneity and interacts with B-lineage genes. Cell Rep 2023; 42:113074. [PMID: 37676766 PMCID: PMC10548092 DOI: 10.1016/j.celrep.2023.113074] [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: 02/27/2023] [Revised: 06/28/2023] [Accepted: 08/18/2023] [Indexed: 09/09/2023] Open
Abstract
To produce a diverse antibody repertoire, immunoglobulin heavy-chain (Igh) loci undergo large-scale alterations in structure to facilitate juxtaposition and recombination of spatially separated variable (VH), diversity (DH), and joining (JH) genes. These chromosomal alterations are poorly understood. Uncovering their patterns shows how chromosome dynamics underpins antibody diversity. Using tiled Capture Hi-C, we produce a comprehensive map of chromatin interactions throughout the 2.8-Mb Igh locus in progenitor B cells. We find that the Igh locus folds into semi-rigid subdomains and undergoes flexible looping of the VH genes to its 3' end, reconciling two views of locus organization. Deconvolution of single Igh locus conformations using polymer simulations identifies thousands of different structures. This heterogeneity may underpin the diversity of V(D)J recombination events. All three immunoglobulin loci also participate in a highly specific, developmentally regulated network of interchromosomal interactions with genes encoding B cell-lineage factors. This suggests a model of interchromosomal coordination of B cell development.
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Affiliation(s)
- Olga Mielczarek
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Carolyn H Rogers
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; Immunology Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Yinxiu Zhan
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Louise S Matheson
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; Immunology Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Michael J T Stubbington
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Stefan Schoenfelder
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Daniel J Bolland
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; Immunology Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Biola M Javierre
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Steven W Wingett
- Bioinformatics Group, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Csilla Várnai
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Anne Segonds-Pichon
- Bioinformatics Group, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Simon J Conn
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Felix Krueger
- Bioinformatics Group, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Simon Andrews
- Bioinformatics Group, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Peter Fraser
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Luca Giorgetti
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Anne E Corcoran
- Nuclear Dynamics Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; Immunology Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
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4
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Hill L, Wutz G, Jaritz M, Tagoh H, Calderón L, Peters JM, Goloborodko A, Busslinger M. Igh and Igk loci use different folding principles for V gene recombination due to distinct chromosomal architectures of pro-B and pre-B cells. Nat Commun 2023; 14:2316. [PMID: 37085514 PMCID: PMC10121685 DOI: 10.1038/s41467-023-37994-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 04/04/2023] [Indexed: 04/23/2023] Open
Abstract
Extended loop extrusion across the immunoglobulin heavy-chain (Igh) locus facilitates VH-DJH recombination following downregulation of the cohesin-release factor Wapl by Pax5, resulting in global changes in the chromosomal architecture of pro-B cells. Here, we demonstrate that chromatin looping and VK-JK recombination at the Igk locus were insensitive to Wapl upregulation in pre-B cells. Notably, the Wapl protein was expressed at a 2.2-fold higher level in pre-B cells compared with pro-B cells, which resulted in a distinct chromosomal architecture with normal loop sizes in pre-B cells. High-resolution chromosomal contact analysis of the Igk locus identified multiple internal loops, which likely juxtapose VK and JK elements to facilitate VK-JK recombination. The higher Wapl expression in Igμ-transgenic pre-B cells prevented extended loop extrusion at the Igh locus, leading to recombination of only the 6 most 3' proximal VH genes and likely to allelic exclusion of all other VH genes in pre-B cells. These results suggest that pro-B and pre-B cells with their distinct chromosomal architectures use different chromatin folding principles for V gene recombination, thereby enabling allelic exclusion at the Igh locus, when the Igk locus is recombined.
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Affiliation(s)
- Louisa Hill
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria
| | - Gordana Wutz
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria
| | - Markus Jaritz
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria
| | - Hiromi Tagoh
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria
| | - Lesly Calderón
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria
| | - Anton Goloborodko
- Institute of Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, A-1030, Vienna, Austria
| | - Meinrad Busslinger
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, A-1030, Vienna, Austria.
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5
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Barajas-Mora EM, Lee L, Lu H, Valderrama JA, Bjanes E, Nizet V, Feeney AJ, Hu M, Murre C. Enhancer-instructed epigenetic landscape and chromatin compartmentalization dictate a primary antibody repertoire protective against specific bacterial pathogens. Nat Immunol 2023; 24:320-336. [PMID: 36717722 PMCID: PMC10917333 DOI: 10.1038/s41590-022-01402-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 12/06/2022] [Indexed: 01/31/2023]
Abstract
Antigen receptor loci are organized into variable (V), diversity (D) and joining (J) gene segments that rearrange to generate antigen receptor repertoires. Here, we identified an enhancer (E34) in the murine immunoglobulin kappa (Igk) locus that instructed rearrangement of Vκ genes located in a sub-topologically associating domain, including a Vκ gene encoding for antibodies targeting bacterial phosphorylcholine. We show that E34 instructs the nuclear repositioning of the E34 sub-topologically associating domain from a recombination-repressive compartment to a recombination-permissive compartment that is marked by equivalent activating histone modifications. Finally, we found that E34-instructed Vκ-Jκ rearrangement was essential to combat Streptococcus pneumoniae but not methicillin-resistant Staphylococcus aureus or influenza infections. We propose that the merging of Vκ genes with Jκ elements is instructed by one-dimensional epigenetic information imposed by enhancers across Vκ and Jκ genomic regions. The data also reveal how enhancers generate distinct antibody repertoires that provide protection against lethal bacterial infection.
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Affiliation(s)
| | - Lindsay Lee
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Hanbin Lu
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - J Andrés Valderrama
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Elisabet Bjanes
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, USA
| | - Ann J Feeney
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA, USA
| | - Ming Hu
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
| | - Cornelis Murre
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA, USA.
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6
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Szukiewicz D. Epigenetic regulation and T-cell responses in endometriosis – something other than autoimmunity. Front Immunol 2022; 13:943839. [PMID: 35935991 PMCID: PMC9355085 DOI: 10.3389/fimmu.2022.943839] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Endometriosis is defined as the presence of endometrial-like glands and stroma located outside the uterine cavity. This common, estrogen dependent, inflammatory condition affects up to 15% of reproductive-aged women and is a well-recognized cause of chronic pelvic pain and infertility. Despite the still unknown etiology of endometriosis, much evidence suggests the participation of epigenetic mechanisms in the disease etiopathogenesis. The main rationale is based on the fact that heritable phenotype changes that do not involve alterations in the DNA sequence are common triggers for hormonal, immunological, and inflammatory disorders, which play a key role in the formation of endometriotic foci. Epigenetic mechanisms regulating T-cell responses, including DNA methylation and posttranslational histone modifications, deserve attention because tissue-resident T lymphocytes work in concert with organ structural cells to generate appropriate immune responses and are functionally shaped by organ-specific environmental conditions. Thus, a failure to precisely regulate immune cell transcription may result in compromised immunological integrity of the organ with an increased risk of inflammatory disorders. The coexistence of endometriosis and autoimmunity is a well-known occurrence. Recent research results indicate regulatory T-cell (Treg) alterations in endometriosis, and an increased number of highly active Tregs and macrophages have been found in peritoneal fluid from women with endometriosis. Elimination of the regulatory function of T cells and an imbalance between T helper cells of the Th1 and Th2 types have been reported in the endometria of women with endometriosis-associated infertility. This review aims to present the state of the art in recognition epigenetic reprogramming of T cells as the key factor in the pathophysiology of endometriosis in the context of T-cell-related autoimmunity. The new potential therapeutic approaches based on epigenetic modulation and/or adoptive transfer of T cells will also be outlined.
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7
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Florini F, Visone JE, Deitsch KW. Shared Mechanisms for Mutually Exclusive Expression and Antigenic Variation by Protozoan Parasites. Front Cell Dev Biol 2022; 10:852239. [PMID: 35350381 PMCID: PMC8957917 DOI: 10.3389/fcell.2022.852239] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/17/2022] [Indexed: 01/05/2023] Open
Abstract
Cellular decision-making at the level of gene expression is a key process in the development and evolution of every organism. Variations in gene expression can lead to phenotypic diversity and the development of subpopulations with adaptive advantages. A prime example is the mutually exclusive activation of a single gene from within a multicopy gene family. In mammals, this ranges from the activation of one of the two immunoglobulin (Ig) alleles to the choice in olfactory sensory neurons of a single odorant receptor (OR) gene from a family of more than 1,000. Similarly, in parasites like Trypanosoma brucei, Giardia lamblia or Plasmodium falciparum, the process of antigenic variation required to escape recognition by the host immune system involves the monoallelic expression of vsg, vsp or var genes, respectively. Despite the importance of this process, understanding how this choice is made remains an enigma. The development of powerful techniques such as single cell RNA-seq and Hi-C has provided new insights into the mechanisms these different systems employ to achieve monoallelic gene expression. Studies utilizing these techniques have shown how the complex interplay between nuclear architecture, physical interactions between chromosomes and different chromatin states lead to single allele expression. Additionally, in several instances it has been observed that high-level expression of a single gene is preceded by a transient state where multiple genes are expressed at a low level. In this review, we will describe and compare the different strategies that organisms have evolved to choose one gene from within a large family and how parasites employ this strategy to ensure survival within their hosts.
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8
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Dauphars DJ, Mihai A, Wang L, Zhuang Y, Krangel MS. Trav15-dv6 family Tcrd rearrangements diversify the Tcra repertoire. J Exp Med 2022; 219:212913. [PMID: 34910107 PMCID: PMC8679779 DOI: 10.1084/jem.20211581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/04/2021] [Accepted: 12/02/2021] [Indexed: 11/20/2022] Open
Abstract
The Tcra repertoire is generated by multiple rounds of Vα-Jα rearrangement. However, Tcrd recombination precedes Tcra recombination within the complex Tcra-Tcrd locus. Here, by ablating Tcrd recombination, we report that Tcrd rearrangement broadens primary Vα use to diversify the Tcra repertoire in mice. We reveal that use of Trav15-dv6 family V gene segments in Tcrd recombination imparts diversity in the Tcra repertoire by instigating use of central and distal Vα segments. Moreover, disruption of the regions containing these genes and their cis-regulatory elements identifies the Trav15-dv6 family as being responsible for driving central and distal Vα recombinations beyond their roles as substrates for Tcrd recombination. Our study demonstrates an indispensable role for Tcrd recombination in general, and the Trav15-dv6 family in particular, in the generation of a combinatorially diverse Tcra repertoire.
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Affiliation(s)
| | - Ariana Mihai
- Department of Immunology, Duke University Medical Center, Durham, NC
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC
| | - Yuan Zhuang
- Department of Immunology, Duke University Medical Center, Durham, NC
| | - Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC
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9
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van Schoonhoven A, Huylebroeck D, Hendriks RW, Stadhouders R. 3D genome organization during lymphocyte development and activation. Brief Funct Genomics 2021; 19:71-82. [PMID: 31819944 PMCID: PMC7115705 DOI: 10.1093/bfgp/elz030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/24/2019] [Accepted: 09/20/2019] [Indexed: 12/20/2022] Open
Abstract
Chromosomes have a complex three-dimensional (3D) architecture comprising A/B compartments, topologically associating domains and promoter-enhancer interactions. At all these levels, the 3D genome has functional consequences for gene transcription and therefore for cellular identity. The development and activation of lymphocytes involves strict control of gene expression by transcription factors (TFs) operating in a three-dimensionally organized chromatin landscape. As lymphocytes are indispensable for tissue homeostasis and pathogen defense, and aberrant lymphocyte activity is involved in a wide range of human morbidities, acquiring an in-depth understanding of the molecular mechanisms that control lymphocyte identity is highly relevant. Here we review current knowledge of the interplay between 3D genome organization and transcriptional control during B and T lymphocyte development and antigen-dependent activation, placing special emphasis on the role of TFs.
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Affiliation(s)
- Anne van Schoonhoven
- Department of Pulmonary Medicine, Erasmus MC, Rotterdam, the Netherlands.,Department of Cell Biology,Erasmus MC, Rotterdam, the Netherlands
| | | | - Rudi W Hendriks
- Department of Pulmonary Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Ralph Stadhouders
- Department of Pulmonary Medicine, Erasmus MC, Rotterdam, the Netherlands.,Department of Cell Biology,Erasmus MC, Rotterdam, the Netherlands
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10
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Scourzic L, Salataj E, Apostolou E. Deciphering the Complexity of 3D Chromatin Organization Driving Lymphopoiesis and Lymphoid Malignancies. Front Immunol 2021; 12:669881. [PMID: 34054841 PMCID: PMC8160312 DOI: 10.3389/fimmu.2021.669881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/26/2021] [Indexed: 12/18/2022] Open
Abstract
Proper lymphopoiesis and immune responses depend on the spatiotemporal control of multiple processes, including gene expression, DNA recombination and cell fate decisions. High-order 3D chromatin organization is increasingly appreciated as an important regulator of these processes and dysregulation of genomic architecture has been linked to various immune disorders, including lymphoid malignancies. In this review, we present the general principles of the 3D chromatin topology and its dynamic reorganization during various steps of B and T lymphocyte development and activation. We also discuss functional interconnections between architectural, epigenetic and transcriptional changes and introduce major key players of genomic organization in B/T lymphocytes. Finally, we present how alterations in architectural factors and/or 3D genome organization are linked to dysregulation of the lymphopoietic transcriptional program and ultimately to hematological malignancies.
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Affiliation(s)
| | | | - Effie Apostolou
- Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, United States
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11
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Ott JA, Ohta Y, Flajnik MF, Criscitiello MF. Lost structural and functional inter-relationships between Ig and TCR loci in mammals revealed in sharks. Immunogenetics 2021; 73:17-33. [PMID: 33449123 PMCID: PMC7909615 DOI: 10.1007/s00251-020-01183-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 10/26/2020] [Indexed: 12/19/2022]
Abstract
Immunoglobulins and T cell receptors (TCR) have obvious structural similarities as well as similar immunogenetic diversification and selection mechanisms. Nevertheless, the two receptor systems and the loci that encode them are distinct in humans and classical murine models, and the gene segments comprising each repertoire are mutually exclusive. Additionally, while both B and T cells employ recombination-activating genes (RAG) for primary diversification, immunoglobulins are afforded a supplementary set of activation-induced cytidine deaminase (AID)-mediated diversification tools. As the oldest-emerging vertebrates sharing the same adaptive B and T cell receptor systems as humans, extant cartilaginous fishes allow a potential view of the ancestral immune system. In this review, we discuss breakthroughs we have made in studies of nurse shark (Ginglymostoma cirratum) T cell receptors demonstrating substantial integration of loci and diversification mechanisms in primordial B and T cell repertoires. We survey these findings in this shark model where they were first described, while noting corroborating examples in other vertebrate groups. We also consider other examples where the gnathostome common ancestry of the B and T cell receptor systems have allowed dovetailing of genomic elements and AID-based diversification approaches for the TCR. The cartilaginous fish seem to have retained this T/B cell plasticity to a greater extent than more derived vertebrate groups, but representatives in all vertebrate taxa except bony fish and placental mammals show such plasticity.
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Affiliation(s)
- Jeannine A Ott
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Yuko Ohta
- Department of Microbiology and Immunology, University of Maryland Baltimore School of Medicine, Baltimore, MD, 21201, USA
| | - Martin F Flajnik
- Department of Microbiology and Immunology, University of Maryland Baltimore School of Medicine, Baltimore, MD, 21201, USA
| | - Michael F Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA.
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas A&M University, College Station, TX, 77843, USA.
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12
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Meluzzi D, Arya G. Computational approaches for inferring 3D conformations of chromatin from chromosome conformation capture data. Methods 2020; 181-182:24-34. [PMID: 31470090 PMCID: PMC7044057 DOI: 10.1016/j.ymeth.2019.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/24/2019] [Accepted: 08/23/2019] [Indexed: 02/08/2023] Open
Abstract
Chromosome conformation capture (3C) and its variants are powerful experimental techniques for probing intra- and inter-chromosomal interactions within cell nuclei at high resolution and in a high-throughput, quantitative manner. The contact maps derived from such experiments provide an avenue for inferring the 3D spatial organization of the genome. This review provides an overview of the various computational methods developed in the past decade for addressing the very important but challenging problem of deducing the detailed 3D structure or structure population of chromosomal domains, chromosomes, and even entire genomes from 3C contact maps.
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Affiliation(s)
- Dario Meluzzi
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States
| | - Gaurav Arya
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, United States.
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13
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DNA-PKcs phosphorylation at the T2609 cluster alters the repair pathway choice during immunoglobulin class switch recombination. Proc Natl Acad Sci U S A 2020; 117:22953-22961. [PMID: 32868446 DOI: 10.1073/pnas.2007455117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK), which is composed of the KU heterodimer and the large catalytic subunit (DNA-PKcs), is a classical nonhomologous end-joining (cNHEJ) factor. Naïve B cells undergo class switch recombination (CSR) to generate antibodies with different isotypes by joining two DNA double-strand breaks at different switching regions via the cNHEJ pathway. DNA-PK and the cNHEJ pathway play important roles in the DNA repair phase of CSR. To initiate cNHEJ, KU binds to DNA ends and recruits and activates DNA-PK. Activated DNA-PK phosphorylates DNA-PKcs at the S2056 and T2609 clusters. Loss of T2609 cluster phosphorylation increases radiation sensitivity but whether T2609 phosphorylation has a role in physiological DNA repair remains elusive. Using the DNA-PKcs 5A mouse model carrying alanine substitutions at the T2609 cluster, here we show that loss of T2609 phosphorylation of DNA-PKcs does not affect the CSR efficiency. Yet, the CSR junctions recovered from DNA-PKcs 5A/5A B cells reveal increased chromosomal translocations, extensive use of distal switch regions (consistent with end resection), and preferential usage of microhomology-all signs of the alternative end-joining pathway. Thus, these results uncover a role of DNA-PKcs T2609 phosphorylation in promoting cNHEJ repair pathway choice during CSR.
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14
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Ott JA, Harrison J, Flajnik MF, Criscitiello MF. Nurse shark T-cell receptors employ somatic hypermutation preferentially to alter alpha/delta variable segments associated with alpha constant region. Eur J Immunol 2020; 50:1307-1320. [PMID: 32346855 DOI: 10.1002/eji.201948495] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/02/2020] [Accepted: 04/24/2020] [Indexed: 12/25/2022]
Abstract
In addition to canonical TCR and BCR, cartilaginous fish assemble noncanonical TCR that employ various B-cell components. For example, shark T cells associate alpha (TCR-α) or delta (TCR-δ) constant (C) regions with Ig heavy chain (H) variable (V) segments or TCR-associated Ig-like V (TAILV) segments to form chimeric IgV-TCR, and combine TCRδC with both Ig-like and TCR-like V segments to form the doubly rearranging NAR-TCR. Activation-induced (cytidine) deaminase-catalyzed somatic hypermutation (SHM), typically used for B-cell affinity maturation, also is used by TCR-α during selection in the shark thymus presumably to salvage failing receptors. Here, we found that the use of SHM by nurse shark TCR varies depending on the particular V segment or C region used. First, SHM significantly alters alpha/delta V (TCRαδV) segments using TCR αC but not δC. Second, mutation to IgHV segments associated with TCR δC was reduced compared to mutation to TCR αδV associated with TCR αC. Mutation was present but limited in V segments of all other TCR chains including NAR-TCR. Unexpectedly, we found preferential rearrangement of the noncanonical IgHV-TCRδC over canonical TCR αδV-TCRδC receptors. The differential use of SHM may reveal how activation-induced (cytidine) deaminase targets V regions.
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Affiliation(s)
- Jeannine A Ott
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Jenna Harrison
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Martin F Flajnik
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Michael F Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.,Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas A&M University, College Station, TX, USA
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15
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Allyn BM, Lee KD, Bassing CH. Genome Topology Control of Antigen Receptor Gene Assembly. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 204:2617-2626. [PMID: 32366683 PMCID: PMC7440635 DOI: 10.4049/jimmunol.1901356] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/22/2020] [Indexed: 02/02/2023]
Abstract
The past decade has increased our understanding of how genome topology controls RAG endonuclease-mediated assembly of lymphocyte AgR genes. New technologies have illuminated how the large IgH, Igκ, TCRα/δ, and TCRβ loci fold into compact structures that place their numerous V gene segments in similar three-dimensional proximity to their distal recombination center composed of RAG-bound (D)J gene segments. Many studies have shown that CTCF and cohesin protein-mediated chromosome looping have fundamental roles in lymphocyte lineage- and developmental stage-specific locus compaction as well as broad usage of V segments. CTCF/cohesin-dependent loops have also been shown to direct and restrict RAG activity within chromosome domains. We summarize recent work in elucidating molecular mechanisms that govern three-dimensional chromosome organization and in investigating how these dynamic mechanisms control V(D)J recombination. We also introduce remaining questions for how CTCF/cohesin-dependent and -independent genome architectural mechanisms might regulate compaction and recombination of AgR loci.
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Affiliation(s)
- Brittney M Allyn
- Immunology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; and
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Kyutae D Lee
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Craig H Bassing
- Immunology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; and
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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16
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Bortnick A, He Z, Aubrey M, Chandra V, Denholtz M, Chen K, Lin YC, Murre C. Plasma Cell Fate Is Orchestrated by Elaborate Changes in Genome Compartmentalization and Inter-chromosomal Hubs. Cell Rep 2020; 31:107470. [PMID: 32268089 PMCID: PMC10871151 DOI: 10.1016/j.celrep.2020.03.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/31/2020] [Accepted: 03/12/2020] [Indexed: 12/27/2022] Open
Abstract
The transition from the follicular B to the plasma cell stage is associated with large-scale changes in cell morphology. Here, we examine whether plasma cell development is also associated with changes in nuclear architecture. We find that the onset of plasma cell development is concomitant with a decline in remote genomic interactions; a gain in euchromatic character at loci encoding for factors that specify plasma cell fate, including Prdm1 and Atf4; and establishment of de novo inter-chromosomal hubs. We find that, in developing plasma cells and concurrent with transcriptional silencing, the Ebf1 locus repositions from an euchromatic to peri-centromeric heterochromatic environment. Finally, we find that inter-chromosomal hubs are enriched for the deposition of either H3K27Ac or H3K27me3. These data indicate that plasma cell fate is orchestrated by elaborate changes in genome topology and that epigenetic marks, linked with super-enhancers or transcriptionally repressed regions, are enriched at inter-chromosomal hubs.
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Affiliation(s)
- Alexandra Bortnick
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zhaoren He
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Megan Aubrey
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Vivek Chandra
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Matthew Denholtz
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kenian Chen
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75246, USA
| | - Yin C Lin
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75246, USA
| | - Cornelis Murre
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA.
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17
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Cresswell KG, Dozmorov MG. TADCompare: An R Package for Differential and Temporal Analysis of Topologically Associated Domains. Front Genet 2020; 11:158. [PMID: 32211023 PMCID: PMC7076128 DOI: 10.3389/fgene.2020.00158] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 02/11/2020] [Indexed: 12/02/2022] Open
Abstract
Recent research using chromatin conformation capture technologies, such as Hi-C, has demonstrated the importance of topologically associated domains (TADs) and smaller chromatin loops, collectively referred hereafter as "interacting domains." Many such domains change during development or disease, and exhibit cell- and condition-specific differences. Quantification of the dynamic behavior of interacting domains will help to better understand genome regulation. Methods for comparing interacting domains between cells and conditions are highly limited. We developed TADCompare, a method for differential analysis of boundaries of interacting domains between two or more Hi-C datasets. TADCompare is based on a spectral clustering-derived measure called the eigenvector gap, which enables a loci-by-loci comparison of boundary differences. Using this measure, we introduce methods for identifying differential and consensus boundaries of interacting domains and tracking boundary changes over time. We further propose a novel framework for the systematic classification of boundary changes. Colocalization- and gene enrichment analysis of different types of boundary changes demonstrated distinct biological functionality associated with them. TADCompare is available on https://github.com/dozmorovlab/TADCompare and Bioconductor (submitted).
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18
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Barajas-Mora EM, Feeney AJ. Enhancers as regulators of antigen receptor loci three-dimensional chromatin structure. Transcription 2019; 11:37-51. [PMID: 31829768 DOI: 10.1080/21541264.2019.1699383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Enhancers are defined as regulatory elements that control transcription in a cell-type and developmental stage-specific manner. They achieve this by physically interacting with their cognate gene promoters. Significantly, these interactions can occur through long genomic distances since enhancers may not be near their cognate promoters. The optimal coordination of enhancer-regulated transcription is essential for the function and identity of the cell. Although great efforts to fully understand the principles of this type of regulation are ongoing, other potential functions of the long-range chromatin interactions (LRCIs) involving enhancers are largely unexplored. We recently uncovered a new role for enhancer elements in determining the three-dimensional (3D) structure of the immunoglobulin kappa (Igκ) light chain receptor locus suggesting a structural function for these DNA elements. This enhancer-mediated locus configuration shapes the resulting Igκ repertoire. We also propose a role for enhancers as critical components of sub-topologically associating domain (subTAD) formation and nuclear spatial localization.
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Affiliation(s)
- E Mauricio Barajas-Mora
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA.,Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Ann J Feeney
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
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19
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Brumbaugh J, Di Stefano B, Hochedlinger K. Reprogramming: identifying the mechanisms that safeguard cell identity. Development 2019; 146:146/23/dev182170. [PMID: 31792064 DOI: 10.1242/dev.182170] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Development and homeostasis rely upon concerted regulatory pathways to establish the specialized cell types needed for tissue function. Once a cell type is specified, the processes that restrict and maintain cell fate are equally important in ensuring tissue integrity. Over the past decade, several approaches to experimentally reprogram cell fate have emerged. Importantly, efforts to improve and understand these approaches have uncovered novel molecular determinants that reinforce lineage commitment and help resist cell fate changes. In this Review, we summarize recent studies that have provided insights into the various chromatin factors, post-transcriptional processes and features of genomic organization that safeguard cell identity in the context of reprogramming to pluripotency. We also highlight how these factors function in other experimental, physiological and pathological cell fate transitions, including direct lineage conversion, pluripotency-to-totipotency reversion and cancer.
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Affiliation(s)
- Justin Brumbaugh
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Bruno Di Stefano
- Department of Molecular Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.,Center for Regenerative Medicine, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.,Cancer Center, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.,Harvard Stem Cell Institute, 1350 Massachusetts Avenue, Cambridge, MA 02138, USA
| | - Konrad Hochedlinger
- Department of Molecular Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA .,Center for Regenerative Medicine, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.,Cancer Center, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.,Harvard Stem Cell Institute, 1350 Massachusetts Avenue, Cambridge, MA 02138, USA
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20
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Ciccone DN, Namiki Y, Chen C, Morshead KB, Wood AL, Johnston CM, Morris JW, Wang Y, Sadreyev R, Corcoran AE, Matthews AGW, Oettinger MA. The murine IgH locus contains a distinct DNA sequence motif for the chromatin regulatory factor CTCF. J Biol Chem 2019; 294:13580-13592. [PMID: 31285261 PMCID: PMC6746451 DOI: 10.1074/jbc.ra118.007348] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 06/13/2019] [Indexed: 01/03/2023] Open
Abstract
Antigen receptor assembly in lymphocytes involves stringently-regulated coordination of specific DNA rearrangement events across several large chromosomal domains. Previous studies indicate that transcription factors such as paired box 5 (PAX5), Yin Yang 1 (YY1), and CCCTC-binding factor (CTCF) play a role in regulating the accessibility of the antigen receptor loci to the V(D)J recombinase, which is required for these rearrangements. To gain clues about the role of CTCF binding at the murine immunoglobulin heavy chain (IgH) locus, we utilized a computational approach that identified 144 putative CTCF-binding sites within this locus. We found that these CTCF sites share a consensus motif distinct from other CTCF sites in the mouse genome. Additionally, we could divide these CTCF sites into three categories: intergenic sites remote from any coding element, upstream sites present within 8 kb of the VH-leader exon, and recombination signal sequence (RSS)-associated sites characteristically located at a fixed distance (∼18 bp) downstream of the RSS. We noted that the intergenic and upstream sites are located in the distal portion of the VH locus, whereas the RSS-associated sites are located in the DH-proximal region. Computational analysis indicated that the prevalence of CTCF-binding sites at the IgH locus is evolutionarily conserved. In all species analyzed, these sites exhibit a striking strand-orientation bias, with >98% of the murine sites being present in one orientation with respect to VH gene transcription. Electrophoretic mobility shift and enhancer-blocking assays and ChIP–chip analysis confirmed CTCF binding to these sites both in vitro and in vivo.
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Affiliation(s)
- David N Ciccone
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Yuka Namiki
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Changfeng Chen
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Katrina B Morshead
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Andrew L Wood
- Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Colette M Johnston
- Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - John W Morris
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Yanqun Wang
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Ruslan Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
| | - Anne E Corcoran
- Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Adam G W Matthews
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114.,Department of Biological Sciences and Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481
| | - Marjorie A Oettinger
- Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114
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21
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22
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Gilgenast TG, Phillips-Cremins JE. Systematic Evaluation of Statistical Methods for Identifying Looping Interactions in 5C Data. Cell Syst 2019; 8:197-211.e13. [PMID: 30904376 DOI: 10.1016/j.cels.2019.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 10/19/2018] [Accepted: 02/19/2019] [Indexed: 01/18/2023]
Abstract
Chromosome-Conformation-Capture-Carbon-Copy (5C) is a molecular technology based on proximity ligation that enables high-resolution and high-coverage inquiry of long-range looping interactions. Computational pipelines for analyzing 5C data involve a series of interdependent normalization procedures and statistical methods that markedly influence downstream biological results. A detailed analysis of the trade-offs inherent to all stages of 5C data analysis has not been reported. Here, we provide a comparative assessment of method performance at each step in the 5C analysis pipeline, including sequencing depth and library complexity correction, bias mitigation, spatial noise reduction, distance-dependent expected and variance estimation, statistical modeling, and loop detection. We discuss methodological advantages and disadvantages at each step and provide a full suite of algorithms, lib5C, to allow investigators to test the range of approaches on their own 5C data. Principles learned from our comparative analyses can be applied to protein-independent proximity ligation-based data, including Hi-C, 4C, and Capture-C.
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Affiliation(s)
- Thomas G Gilgenast
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer E Phillips-Cremins
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA.
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23
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Kinase-dependent structural role of DNA-PKcs during immunoglobulin class switch recombination. Proc Natl Acad Sci U S A 2018; 115:8615-8620. [PMID: 30072430 DOI: 10.1073/pnas.1808490115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is a classical nonhomologous end-joining (cNHEJ) factor. Loss of DNA-PKcs diminished mature B cell class switch recombination (CSR) to other isotypes, but not IgG1. Here, we show that expression of the kinase-dead DNA-PKcs (DNA-PKcsKD/KD ) severely compromises CSR to IgG1. High-throughput sequencing analyses of CSR junctions reveal frequent accumulation of nonproductive interchromosomal translocations, inversions, and extensive end resection in DNA-PKcsKD/KD , but not DNA-PKcs-/- , B cells. Meanwhile, the residual joints from DNA-PKcsKD/KD cells and the efficient Sµ-Sγ1 junctions from DNA-PKcs-/- B cells both display similar preferences for small (2-6 nt) microhomologies (MH). In DNA-PKcs-/- cells, Sµ-Sγ1 joints are more resistant to inversions and extensive resection than Sµ-Sε and Sµ-Sµ joints, providing a mechanism for the isotype-specific CSR defects. Together, our findings identify a kinase-dependent role of DNA-PKcs in suppressing MH-mediated end joining and a structural role of DNA-PKcs protein in the orientation of CSR.
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24
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Affiliation(s)
- Ralph Stadhouders
- Department of Pulmonary Medicine, Erasmus MC, Rotterdam, The Netherlands. .,Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands.
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25
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Carico ZM, Roy Choudhury K, Zhang B, Zhuang Y, Krangel MS. Tcrd Rearrangement Redirects a Processive Tcra Recombination Program to Expand the Tcra Repertoire. Cell Rep 2018; 19:2157-2173. [PMID: 28591585 DOI: 10.1016/j.celrep.2017.05.045] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 04/21/2017] [Accepted: 05/13/2017] [Indexed: 01/01/2023] Open
Abstract
Adaptive immunity depends on diverse T cell receptor repertoires generated by variable, diversity, and joining (V[D]J) recombination. Here, we define the principles by which combinatorial diversity is generated in the murine Tcra repertoire. Tcra and Tcrd gene segments share the Tcra-Tcrd locus, with interspersed Vα and Vδ segments undergoing Vδ-Dδ-Jδ rearrangement in CD4-CD8- thymocytes and then multiple rounds of Vα-Jα rearrangement in CD4+CD8+ thymocytes. We document stepwise, highly coordinated proximal-to-distal progressions of Vα and Jα use on individual Tcra alleles, limiting combinatorial diversity. This behavior is supported by an extended chromatin conformation in CD4+CD8+ thymocytes, with only nearby Vα and Jα segments contacting each other. Tcrd rearrangements can use distal Vδ segments due to a contracted Tcra-Tcrd conformation in CD4-CD8- thymocytes. These rearrangements expand the Tcra repertoire by truncating the Vα array to permit otherwise disfavored Vα-Jα combinations. Therefore, recombination events at two developmental stages with distinct chromatin conformations synergize to promote Tcra repertoire diversity.
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Affiliation(s)
- Zachary M Carico
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | - Kingshuk Roy Choudhury
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA
| | - Baojun Zhang
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yuan Zhuang
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
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26
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Hauser J, Grundström C, Kumar R, Grundström T. Regulated localization of an AID complex with E2A, PAX5 and IRF4 at the Igh locus. Mol Immunol 2016; 80:78-90. [DOI: 10.1016/j.molimm.2016.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 12/11/2022]
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27
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Chen L, Zhao L, Alt FW, Krangel MS. An Ectopic CTCF Binding Element Inhibits Tcrd Rearrangement by Limiting Contact between Vδ and Dδ Gene Segments. THE JOURNAL OF IMMUNOLOGY 2016; 197:3188-3197. [PMID: 27613698 DOI: 10.4049/jimmunol.1601124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 08/16/2016] [Indexed: 11/19/2022]
Abstract
Chromatin looping mediated by the CCCTC binding factor (CTCF) regulates V(D)J recombination at Ag receptor loci. CTCF-mediated looping can influence recombination signal sequence (RSS) accessibility by regulating enhancer activation of germline promoters. CTCF-mediated looping has also been shown to limit directional tracking of the RAG recombinase along chromatin, and to regulate long-distance interactions between RSSs, independent of the RAG recombinase. However, in all prior instances in which CTCF-mediated looping was shown to influence V(D)J recombination, it was not possible to fully resolve the relative contributions to the V(D)J recombination phenotype of changes in accessibility, RAG tracking, and RAG-independent long-distance interactions. In this study, to assess mechanisms by which CTCF-mediated looping can impact V(D)J recombination, we introduced an ectopic CTCF binding element (CBE) immediately downstream of Eδ in the murine Tcra-Tcrd locus. The ectopic CBE impaired inversional rearrangement of Trdv5 in the absence of measurable effects on Trdv5 transcription and chromatin accessibility. The ectopic CBE also limited directional RAG tracking from the Tcrd recombination center, demonstrating that a single CBE can impact the distribution of RAG proteins along chromatin. However, such tracking cannot account for Trdv5-to-Trdd2 inversional rearrangement. Rather, the defect in Trdv5 rearrangement could only be attributed to a reconfigured chromatin loop organization that limited RAG-independent contacts between the Trdv5 and Trdd2 RSSs. We conclude that CTCF can regulate V(D)J recombination by segregating RSSs into distinct loop domains and inhibiting RSS synapsis, independent of any effects on transcription, RSS accessibility, and RAG tracking.
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Affiliation(s)
- Liang Chen
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Lijuan Zhao
- Howard Hughes Medical Institute, Boston, MA 02115.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115; and.,Department of Genetics, Harvard Medical School, Boston, MA 02115
| | - Frederick W Alt
- Howard Hughes Medical Institute, Boston, MA 02115.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115; and.,Department of Genetics, Harvard Medical School, Boston, MA 02115
| | - Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC 27710;
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28
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New roles for DNA cytosine modification, eRNA, anchors, and superanchors in developing B cell progenitors. Proc Natl Acad Sci U S A 2015; 112:12776-81. [PMID: 26417104 DOI: 10.1073/pnas.1512995112] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
B-cell fate is orchestrated by a series of well-characterized developmental regulators. Here, we found that the onset of B-cell development was accompanied by large-scale changes in DNA cytosine modifications associated with promoters, enhancers, and anchors. These changes were tightly linked to alterations in transcription factor occupancy and nascent RNA (eRNA) transcription. We found that the prepro-B to the pro-B-cell transition was associated with a global exchange of DNA cytosine modifications for polycomb-mediated repression at CpG islands. Hypomethylated regions were found exclusively in the active/permissive compartment of the nucleus and were predominantly associated with regulatory elements or anchors that orchestrate the folding patterns of the genome. We identified superanchors, characterized by clusters of hypomethylated CCCTC-binding factor (CTCF)-bound elements, which were predominantly located at boundaries that define topological associated domains. A particularly prominent hypomethylated superanchor was positioned down-stream of the Ig heavy chain (Igh) locus. Analysis of global formaldehyde-cross-linking studies indicated that the Igh locus superanchor interacts with the VH region repertoire across vast genomic distances. We propose that the Igh locus superanchor sequesters the VH and DHJH regions into a spatial confined geometric environment to promote rapid first-passage times. Collectively, these studies demonstrate how, in developing B cells, DNA cytosine modifications associated with regulatory and architectural elements affect patterns of gene expression, folding patterns of the genome, and antigen receptor assembly.
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29
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Ebert A, Hill L, Busslinger M. Spatial Regulation of V-(D)J Recombination at Antigen Receptor Loci. Adv Immunol 2015; 128:93-121. [PMID: 26477366 DOI: 10.1016/bs.ai.2015.07.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lymphocytes express a diverse repertoire of antigen receptors, which are able to recognize a large variety of foreign pathogens. Functional antigen receptor genes are assembled by V(D)J recombination in immature B cells (Igh and Igk) and T cells (Tcr b and Tcra/d). V(D)J recombination takes place in the 3' proximal domain containing the D, J, and C gene segments, whereas 31 (Tcrb) to 200 (Igh) V genes are spread over a large region of 0.67 (Tcrb) to 3 (Igk) megabase pairs. The spatial regulation of V(D)J recombination has been best studied for the Igh locus, which undergoes reversible contraction by long-range looping in pro-B cells. This large-scale contraction brings distantly located VH genes into close proximity of the DJH-rearranged gene segment, which facilitates VH-DJH recombination. The B-cell-specific Pax5, ubiquitous YY1, and architectural CTCF/cohesin proteins regulate Igh locus contraction in pro-B cells by binding to multiple sites in the VH gene cluster. These regulators also control the pro-B-cell-specific activity of the distally located PAIR elements, which may be involved in the regulation of VH-DJH recombination by promoting locus contraction. Moreover, the large VH gene cluster of the Igh locus undergoes flexible long-range looping, which guarantees similar participation of all VH genes in VH-DJH recombination to generate a diverse antibody repertoire. Importantly, long-range looping is a more general regulatory principle, as other antigen receptor loci also undergo reversible contraction at the developmental stage, where they engage in V-(D)J recombination.
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Affiliation(s)
- Anja Ebert
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Louisa Hill
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Meinrad Busslinger
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria.
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30
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A discrete chromatin loop in the mouse Tcra-Tcrd locus shapes the TCRδ and TCRα repertoires. Nat Immunol 2015; 16:1085-93. [PMID: 26258942 PMCID: PMC4575630 DOI: 10.1038/ni.3232] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/24/2015] [Indexed: 12/18/2022]
Abstract
The Tcra-Tcrd locus undergoes V(D)J recombination in CD4−CD8−double-negative thymocytes and CD4+CD8+ double-positive thymocytes to generate diverse TCRδ and TCRα repertoires, respectively. Here we reveal a Tcra-Tcrd locus chromatin interaction network in double-negative thymocytes that was formed by interactions between CTCF-binding elements. Disruption of a discrete chromatin loop encompassing Tcrd diversity, joining and constant gene segments allowed a single variable gene segment to frequently contact and rearrange to diversity and joining gene segments and dominate the adult TCRδ repertoire. Disruption of this loop also narrowed the TCRα repertoire, which, we believe, follows as a consequence of the restricted TCRδ repertoire. Hence, a single CTCF-mediated chromatin loop directly regulates TCRδ diversity and indirectly regulates TCRα diversity.
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31
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Abstract
The modular, noncontiguous architecture of the antigen receptor genes necessitates their assembly through V(D)J recombination. This program of DNA breakage and rejoining occurs during early lymphocyte development, and depends on the RAG1 and RAG2 proteins, whose collaborative endonuclease activity targets specific DNA motifs enriched in the antigen receptor loci. This essential gene shuffling reaction requires lymphocytes to traverse several developmental stages wherein DNA breakage is tolerated, while minimizing the expense to overall genome integrity. Thus, RAG activity is subject to stringent temporal and spatial regulation. The RAG proteins themselves also contribute autoregulatory properties that coordinate their DNA cleavage activity with target chromatin structure, cell cycle status, and DNA repair pathways. Even so, lapses in regulatory restriction of RAG activity are apparent in the aberrant V(D)J recombination events that underlie many lymphomas. In this review, we discuss the current understanding of the RAG endonuclease, its widespread binding in the lymphocyte genome, its noncleavage activities that restrain its enzymatic potential, and the growing evidence of its evolution from an ancient transposase.
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32
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Manoharan A, Du Roure C, Rolink AG, Matthias P. De novo DNA Methyltransferases Dnmt3a and Dnmt3b regulate the onset of Igκ light chain rearrangement during early B-cell development. Eur J Immunol 2015; 45:2343-55. [PMID: 26059604 DOI: 10.1002/eji.201445035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 04/24/2015] [Accepted: 05/19/2015] [Indexed: 02/01/2023]
Abstract
Immunoglobulin genes V(D)J rearrangement during early lymphopoiesis is a critical process involving sequential recombination of the heavy and light chain loci. A number of transcription factors act together with temporally activated recombinases and chromatin accessibility changes to regulate this complex process. Here, we deleted the de novo DNA methyltransferases Dnmt3a and Dnmt3b in early B cells of conditionally targeted mice, and monitored the process of V(D)J recombination. Dnmt3a and Dnmt3b deletion resulted in precocious recombination of the immunoglobulin κ light chain without impairing the differentiation of mature B cells or overall B-cell development. Ex vivo culture of IL-7 restricted early B-cell progenitors lacking Dnmt3a and Dnmt3b showed precocious Vκ-Jκ rearrangements that are limited to the proximal Vκ genes. Furthermore, B-cell progenitors deficient in Dnmt3a and Dnmt3b showed elevated levels of germline transcripts at the proximal Vκ genes, alterations in methylation patterns at Igκ enhancer sites and increased expression of the transcription factor E2A. Our data suggest that Dnmt3a and Dnmt3b are critical to regulate the onset of Igκ light chain rearrangement during early B-cell development.
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Affiliation(s)
- Anand Manoharan
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Camille Du Roure
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | | | - Patrick Matthias
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Faculty of Sciences, University of Basel, Basel, Switzerland
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33
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Wagatsuma K, Tani-ichi S, Liang B, Shitara S, Ishihara K, Abe M, Miyachi H, Kitano S, Hara T, Nanno M, Ishikawa H, Sakimura K, Nakao M, Kimura H, Ikuta K. STAT5 Orchestrates Local Epigenetic Changes for Chromatin Accessibility and Rearrangements by Direct Binding to the TCRγ Locus. THE JOURNAL OF IMMUNOLOGY 2015. [PMID: 26195811 DOI: 10.4049/jimmunol.1302456] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The transcription factor STAT5, which is activated by IL-7R, controls chromatin accessibility and rearrangements of the TCRγ locus. Although STAT-binding motifs are conserved in Jγ promoters and Eγ enhancers, little is known about their precise roles in rearrangements of the TCRγ locus in vivo. To address this question, we established two lines of Jγ1 promoter mutant mice: one harboring a deletion in the Jγ1 promoter, including three STAT motifs (Jγ1P(Δ/Δ)), and the other carrying point mutations in the three STAT motifs in that promoter (Jγ1P(mS/mS)). Both Jγ1P(Δ/Δ) and Jγ1P(mS/mS) mice showed impaired recruitment of STAT5 and chromatin remodeling factor BRG1 at the Jγ1 gene segment. This resulted in severe and specific reduction in germline transcription, histone H3 acetylation, and histone H4 lysine 4 methylation of the Jγ1 gene segment in adult thymus. Rearrangement and DNA cleavage of the segment were severely diminished, and Jγ1 promoter mutant mice showed profoundly decreased numbers of γδ T cells of γ1 cluster origin. Finally, compared with controls, both mutant mice showed a severe reduction in rearrangements of the Jγ1 gene segment, perturbed development of γδ T cells of γ1 cluster origin in fetal thymus, and fewer Vγ3(+) dendritic epidermal T cells. Furthermore, interaction with the Jγ1 promoter and Eγ1, a TCRγ enhancer, was dependent on STAT motifs in the Jγ1 promoter. Overall, this study strongly suggests that direct binding of STAT5 to STAT motifs in the Jγ promoter is essential for local chromatin accessibility and Jγ/Eγ chromatin interaction, triggering rearrangements of the TCRγ locus.
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Affiliation(s)
- Keisuke Wagatsuma
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan; Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Shizue Tani-ichi
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Bingfei Liang
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan; Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Soichiro Shitara
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan; Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Ko Ishihara
- Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto 860-0811, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Hitoshi Miyachi
- Reproductive Engineering Team, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Satsuki Kitano
- Reproductive Engineering Team, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Takahiro Hara
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Masanobu Nanno
- Yakult Central Institute, Kunitachi, Tokyo 186-8650, Japan
| | | | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Mitsuyoshi Nakao
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan; Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Hiroshi Kimura
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan; Graduate School of Frontier Bioscience, Osaka University, Suita 565-0871, Japan; and Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Koichi Ikuta
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan;
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34
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Hao B, Naik AK, Watanabe A, Tanaka H, Chen L, Richards HW, Kondo M, Taniuchi I, Kohwi Y, Kohwi-Shigematsu T, Krangel MS. An anti-silencer- and SATB1-dependent chromatin hub regulates Rag1 and Rag2 gene expression during thymocyte development. ACTA ACUST UNITED AC 2015; 212:809-24. [PMID: 25847946 PMCID: PMC4419350 DOI: 10.1084/jem.20142207] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/12/2015] [Indexed: 12/12/2022]
Abstract
Rag1 and Rag2 gene expression in CD4(+)CD8(+) double-positive (DP) thymocytes depends on the activity of a distant anti-silencer element (ASE) that counteracts the activity of an intergenic silencer. However, the mechanistic basis for ASE activity is unknown. Here, we show that the ASE physically interacts with the distant Rag1 and Rag2 gene promoters in DP thymocytes, bringing the two promoters together to form an active chromatin hub. Moreover, we show that the ASE functions as a classical enhancer that can potently activate these promoters in the absence of the silencer or other locus elements. In thymocytes lacking the chromatin organizer SATB1, we identified a partial defect in Tcra gene rearrangement that was associated with reduced expression of Rag1 and Rag2 at the DP stage. SATB1 binds to the ASE and Rag promoters, facilitating inclusion of Rag2 in the chromatin hub and the loading of RNA polymerase II to both the Rag1 and Rag2 promoters. Our results provide a novel framework for understanding ASE function and demonstrate a novel role for SATB1 as a regulator of Rag locus organization and gene expression in DP thymocytes.
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Affiliation(s)
- Bingtao Hao
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Abani Kanta Naik
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Akiko Watanabe
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Hirokazu Tanaka
- RIKEN Centre for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan
| | - Liang Chen
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Hunter W Richards
- Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA 94720
| | - Motonari Kondo
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Ichiro Taniuchi
- RIKEN Centre for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan
| | - Yoshinori Kohwi
- Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA 94720
| | - Terumi Kohwi-Shigematsu
- Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA 94720
| | - Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
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35
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Carico Z, Krangel MS. Chromatin Dynamics and the Development of the TCRα and TCRδ Repertoires. Adv Immunol 2015; 128:307-61. [DOI: 10.1016/bs.ai.2015.07.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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36
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de Almeida CR, Hendriks RW, Stadhouders R. Dynamic Control of Long-Range Genomic Interactions at the Immunoglobulin κ Light-Chain Locus. Adv Immunol 2015; 128:183-271. [DOI: 10.1016/bs.ai.2015.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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37
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Magadan S, Sunyer OJ, Boudinot P. Unique Features of Fish Immune Repertoires: Particularities of Adaptive Immunity Within the Largest Group of Vertebrates. Results Probl Cell Differ 2015; 57:235-64. [PMID: 26537384 PMCID: PMC5124013 DOI: 10.1007/978-3-319-20819-0_10] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Fishes (i.e., teleost fishes) are the largest group of vertebrates. Although their immune system is based on the fundamental receptors, pathways, and cell types found in all groups of vertebrates, fishes show a diversity of particular features that challenge some classical concepts of immunology. In this chapter, we discuss the particularities of fish immune repertoires from a comparative perspective. We examine how allelic exclusion can be achieved when multiple Ig loci are present, how isotypic diversity and functional specificity impact clonal complexity, how loss of the MHC class II molecules affects the cooperation between T and B cells, and how deep sequencing technologies bring new insights about somatic hypermutation in the absence of germinal centers. The unique coexistence of two distinct B-cell lineages respectively specialized in systemic and mucosal responses is also discussed. Finally, we try to show that the diverse adaptations of immune repertoires in teleosts can help in understanding how somatic adaptive mechanisms of immunity evolved in parallel in different lineages across vertebrates.
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Affiliation(s)
- Susana Magadan
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Jouy-en-Josas, France.
| | - Oriol J Sunyer
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Pierre Boudinot
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Jouy-en-Josas, France.
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38
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Marquet M, Garot A, Bender S, Carrion C, Rouaud P, Lecardeur S, Denizot Y, Cogné M, Pinaud E. The Eμ enhancer region influences H chain expression and B cell fate without impacting IgVH repertoire and immune response in vivo. THE JOURNAL OF IMMUNOLOGY 2014; 193:1171-83. [PMID: 24965776 DOI: 10.4049/jimmunol.1302868] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The IgH intronic enhancer region Eμ is a combination of both a 220-bp core enhancer element and two 310-350-bp flanking scaffold/matrix attachment regions named MARsEμ. In the mouse, deletion of the core-enhancer Eμ element mainly affects VDJ recombination with minor effects on class switch recombination. We carried out endogenous deletion of the full-length Eμ region (core plus MARsEμ) in the mouse genome to study VH gene repertoire and IgH expression in developing B-lineage cells. Despite a severe defect in VDJ recombination with partial blockade at the pro-B cell stage, Eμ deletion (core or full length) did not affect VH gene usage. Deletion of this regulatory region induced both a decrease of pre-B cell and newly formed B cell compartments and a strong orientation toward the marginal zone B cell subset. Because Igμ H chain expression was decreased in Eμ-deficient pre-B cells, we propose that modification of B cell homeostasis in deficient animals was caused by "weak" pre-B cell and BCR expression. Besides imbalances in B cell compartments, Ag-specific Ab responses were not impaired in animals carrying the Eμ deletion. In addition to its role in VDJ recombination, our study points out that the full-length Eμ region does not influence VH segment usage but ensures efficient Igμ-chain expression required for strong signaling through pre-B cells and newly formed BCRs and thus participates in B cell inflow and fate.
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Affiliation(s)
- Marie Marquet
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France
| | - Armand Garot
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France
| | - Sébastien Bender
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France; Centre Hospitalier Universitaire Dupuytren, Centre de Référence des Amyloses, 87042 Limoges, France; and
| | - Claire Carrion
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France
| | - Pauline Rouaud
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France
| | - Sandrine Lecardeur
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France
| | - Yves Denizot
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France
| | - Michel Cogné
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France; Institut Universitaire de France, 75005 Paris, France
| | - Eric Pinaud
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7276, Université de Limoges, 87025 Limoges, France;
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39
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Busslinger M, Tarakhovsky A. Epigenetic control of immunity. Cold Spring Harb Perspect Biol 2014; 6:6/6/a019307. [PMID: 24890513 DOI: 10.1101/cshperspect.a019307] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Immunity relies on the heterogeneity of immune cells and their ability to respond to pathogen challenges. In the adaptive immune system, lymphocytes display a highly diverse antigen receptor repertoire that matches the vast diversity of pathogens. In the innate immune system, the cell's heterogeneity and phenotypic plasticity enable flexible responses to changes in tissue homeostasis caused by infection or damage. The immune responses are calibrated by the graded activity of immune cells that can vary from yeast-like proliferation to lifetime dormancy. This article describes key epigenetic processes that contribute to the function of immune cells during health and disease.
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Affiliation(s)
- Meinrad Busslinger
- Research Institute of Molecular Pathology, Vienna Biocenter, A-1030 Vienna, Austria
| | - Alexander Tarakhovsky
- Laboratory of Lymphocyte Signaling, The Rockefeller University, New York, New York 10021
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40
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Stadhouders R, de Bruijn MJW, Rother MB, Yuvaraj S, de Almeida CR, Kolovos P, Van Zelm MC, van Ijcken W, Grosveld F, Soler E, Hendriks RW. Pre-B cell receptor signaling induces immunoglobulin κ locus accessibility by functional redistribution of enhancer-mediated chromatin interactions. PLoS Biol 2014; 12:e1001791. [PMID: 24558349 PMCID: PMC3928034 DOI: 10.1371/journal.pbio.1001791] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 01/08/2014] [Indexed: 12/13/2022] Open
Abstract
Chromatin conformation analyses provide novel insights into how variable segments in the immunoglobulin light chain gene become accessible for recombination in precursor B lymphocytes. During B cell development, the precursor B cell receptor (pre-BCR) checkpoint is thought to increase immunoglobulin κ light chain (Igκ) locus accessibility to the V(D)J recombinase. Accordingly, pre-B cells lacking the pre-BCR signaling molecules Btk or Slp65 showed reduced germline Vκ transcription. To investigate whether pre-BCR signaling modulates Vκ accessibility through enhancer-mediated Igκ locus topology, we performed chromosome conformation capture and sequencing analyses. These revealed that already in pro-B cells the κ enhancers robustly interact with the ∼3.2 Mb Vκ region and its flanking sequences. Analyses in wild-type, Btk, and Slp65 single- and double-deficient pre-B cells demonstrated that pre-BCR signaling reduces interactions of both enhancers with Igκ locus flanking sequences and increases interactions of the 3′κ enhancer with Vκ genes. Remarkably, pre-BCR signaling does not significantly affect interactions between the intronic enhancer and Vκ genes, which are already robust in pro-B cells. Both enhancers interact most frequently with highly used Vκ genes, which are often marked by transcription factor E2a. We conclude that the κ enhancers interact with the Vκ region already in pro-B cells and that pre-BCR signaling induces accessibility through a functional redistribution of long-range chromatin interactions within the Vκ region, whereby the two enhancers play distinct roles. B lymphocyte development involves the generation of a functional antigen receptor, comprising two heavy chains and two light chains arranged in a characteristic “Y” shape. To do this, the receptor genes must first be assembled by ordered genomic recombination events, starting with the immunoglobulin heavy chain (IgH) gene segments. On successful rearrangement, the resulting IgH μ protein is presented on the cell surface as part of a preliminary version of the B cell receptor—the “pre-BCR.” Pre-BCR signaling then redirects recombination activity to the immunoglobulin κ light chain gene. The activity of two regulatory κ enhancer elements is known to be crucial for opening up the gene, but it remains largely unknown how the hundred or so Variable (V) segments in the κ locus gain access to the recombination system. Here, we studied a panel of pre-B cells from mice lacking specific signaling molecules, reflecting absent, partial, or complete pre-BCR signaling. We identify gene regulatory changes that are dependent on pre-BCR signaling and occur via long-range chromatin interactions between the κ enhancers and the V segments. Surprisingly the light chain gene initially contracts, but the interactions then become more functionally redistributed when pre-BCR signaling occurs. Interestingly, we find that the two enhancers play distinct roles in the process of coordinating chromatin interactions towards the V segments. Our study combines chromatin conformation techniques with data on transcription factor binding to gain unique insights into the functional role of chromatin dynamics.
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MESH Headings
- Animals
- Cells, Cultured
- Chromatin/genetics
- Chromatin/metabolism
- Chromatin Assembly and Disassembly
- Enhancer Elements, Genetic
- Epistasis, Genetic
- Histones/metabolism
- Immunoglobulin kappa-Chains/genetics
- Immunoglobulin kappa-Chains/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Precursor Cells, B-Lymphoid/metabolism
- Protein Processing, Post-Translational
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Signal Transduction
- Transcriptome
- V(D)J Recombination
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Affiliation(s)
| | | | | | - Saravanan Yuvaraj
- Department of Pulmonary Medicine, Erasmus MC Rotterdam, The Netherlands
| | | | - Petros Kolovos
- Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands
| | | | | | - Frank Grosveld
- Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands
- The Cancer Genomics Center, Erasmus MC Rotterdam, The Netherlands
| | - Eric Soler
- Department of Cell Biology, Erasmus MC Rotterdam, The Netherlands
- The Cancer Genomics Center, Erasmus MC Rotterdam, The Netherlands
- INSERM UMR967 and French Alternative Energies and Atomic Energy Commission (CEA), Fontenay-aux-Roses, France
| | - Rudi W. Hendriks
- Department of Pulmonary Medicine, Erasmus MC Rotterdam, The Netherlands
- * E-mail:
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41
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Fugmann SD. Form follows function - the three-dimensional structure of antigen receptor gene loci. Curr Opin Immunol 2014; 27:33-7. [PMID: 24549092 DOI: 10.1016/j.coi.2014.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 01/22/2014] [Indexed: 01/17/2023]
Abstract
Antigen receptor genes are assembled during lymphocyte development from individual gene segments by a somatic gene rearrangement process named V(D)J recombination. This process is tightly regulated to ensure the generation of an unbiased broad primary repertoire of immunoglobulins and T cell receptors, and to prevent aberrant recombination products that could initiate lymphomagenesis. One important mode of regulation that has recently been discovered for the immunoglobulin heavy chain (IGH) gene locus is the adoption of distinct three-dimensional structures of the locus. Changes in the spatial conformation are thought to ensure the appropriate access of the V(D)J recombinase machinery at each developmental stage, and the formation of extensive chromosome loops has been implicated in allowing equal access to widely dispersed gene elements.
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Affiliation(s)
- Sebastian D Fugmann
- Department of Biomedical Sciences, Chang Gung University, 259 Wenhua 1st Rd, Kwei-Shan, Tao-Yuan 333, Taiwan.
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42
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Atchison ML. Function of YY1 in Long-Distance DNA Interactions. Front Immunol 2014; 5:45. [PMID: 24575094 PMCID: PMC3918653 DOI: 10.3389/fimmu.2014.00045] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 01/27/2014] [Indexed: 11/13/2022] Open
Abstract
During B cell development, long-distance DNA interactions are needed for V(D)J somatic rearrangement of the immunoglobulin (Ig) loci to produce functional Ig genes, and for class switch recombination (CSR) needed for antibody maturation. The tissue-specificity and developmental timing of these mechanisms is a subject of active investigation. A small number of factors are implicated in controlling Ig locus long-distance interactions including Pax5, Yin Yang 1 (YY1), EZH2, IKAROS, CTCF, cohesin, and condensin proteins. Here we will focus on the role of YY1 in controlling these mechanisms. YY1 is a multifunctional transcription factor involved in transcriptional activation and repression, X chromosome inactivation, Polycomb Group (PcG) protein DNA recruitment, and recruitment of proteins required for epigenetic modifications (acetylation, deacetylation, methylation, ubiquitination, sumoylation, etc.). YY1 conditional knock-out indicated that YY1 is required for B cell development, at least in part, by controlling long-distance DNA interactions at the immunoglobulin heavy chain and Igκ loci. Our recent data show that YY1 is also required for CSR. The mechanisms implicated in YY1 control of long-distance DNA interactions include controlling non-coding antisense RNA transcripts, recruitment of PcG proteins to DNA, and interaction with complexes involved in long-distance DNA interactions including the cohesin and condensin complexes. Though common rearrangement mechanisms operate at all Ig loci, their distinct temporal activation along with the ubiquitous nature of YY1 poses challenges for determining the specific mechanisms of YY1 function in these processes, and their regulation at the tissue-specific and B cell stage-specific level. The large numbers of post-translational modifications that control YY1 functions are possible candidates for regulation.
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Affiliation(s)
- Michael L Atchison
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania , Philadelphia, PA , USA
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43
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Vigano MA, Ivanek R, Balwierz P, Berninger P, van Nimwegen E, Karjalainen K, Rolink A. An epigenetic profile of early T-cell development from multipotent progenitors to committed T-cell descendants. Eur J Immunol 2014; 44:1181-93. [PMID: 24374622 DOI: 10.1002/eji.201344022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 12/04/2013] [Accepted: 12/20/2013] [Indexed: 01/01/2023]
Abstract
Cellular differentiation of the T-cell branch of the immune system begins with the HSC, which undergoes a series of stages characterized by progressive restriction in multipotency and acquisition of specific lineage identity At the molecular level, the restriction of cell potential, commitment, and differentiation to a specific lineage is achieved through the coordinated control of gene expression and epigenetic mechanisms. Here, we analyzed and compared the gene expression profiles and the genome-wide histone modification marks H3K4me3 (H3 lysine 4 trimethylation) and H3K27me3 (H3 lysine 27 trimethylation) in (i) in vitro propagated HSCs, (ii) in vitro generated and propagated pro-T cells derived from these stem cells, and (iii) double-positive thymocytes derived from these pro-T cells after injection into Rag-deficient mice. The combined analyses of the different datasets in this unique experimental system highlighted the importance of both transcriptional and epigenetic repression in shaping the early phases of T-cell development.
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Affiliation(s)
- Maria Alessandra Vigano
- Developmental and Molecular Immunology Group, Department of Biomedicine, University of Basel, Basel, Switzerland
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Hauser J, Grundström C, Grundström T. Allelic exclusion of IgH through inhibition of E2A in a VDJ recombination complex. THE JOURNAL OF IMMUNOLOGY 2014; 192:2460-70. [PMID: 24470503 DOI: 10.4049/jimmunol.1302216] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A key feature of the immune system is the paradigm that one lymphocyte has only one Ag specificity that can be selected for or against. This requires that only one of the alleles of genes for AgR chains is made functional. However, the molecular mechanism of this allelic exclusion has been an enigma. In this study, we show that B lymphocytes with E2A that cannot be inhibited by calmodulin are dramatically defective in allelic exclusion of the IgH locus. Furthermore, we provide data supporting that E2A, PAX5, and the RAGs are in a VDJ recombination complex bound to key sequences on the Igh gene. We show that pre-BCR activation releases the VDJ recombination complex through calmodulin binding to E2A. We also show that pre-BCR signaling downregulates several components of the recombination machinery, including RAG1, RAG2, and PAX5, through calmodulin inhibition of E2A.
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Affiliation(s)
- Jannek Hauser
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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Horowitz JE, Bassing CH. Noncore RAG1 regions promote Vβ rearrangements and αβ T cell development by overcoming inherent inefficiency of Vβ recombination signal sequences. THE JOURNAL OF IMMUNOLOGY 2014; 192:1609-19. [PMID: 24415779 DOI: 10.4049/jimmunol.1301599] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The RAG proteins are comprised of core endonuclease domains and noncore regions that modulate endonuclease activity. Mutation or deletion of noncore RAG regions in humans causes immunodeficiency and altered TCR repertoire, and mice expressing core but not full-length Rag1 (Rag1(C/C)) or Rag2 (Rag2(C/C)) exhibit lymphopenia, reflecting impaired V(D)J recombination and lymphocyte development. Rag1(C/C) mice display reduced D-to-J and V-to-DJ rearrangements of TCRβ and IgH loci, whereas Rag2(C/C) mice show decreased V-to-DJ rearrangements and altered Vβ/VH repertoire. Because Vβs/VHs only recombine to DJ complexes, the Rag1(C/C) phenotype could reflect roles for noncore RAG1 regions in promoting recombination during only the D-to-J step or during both steps. In this study, we demonstrate that a preassembled TCRβ gene, but not a preassembled DβJβ complex or the prosurvival BCL2 protein, completely rescues αβ T cell development in Rag1(C/C) mice. We find that Rag1(C/C) mice exhibit altered Vβ utilization in Vβ-to-DJβ rearrangements, increased usage of 3'Jα gene segments in Vα-to-Jα rearrangements, and abnormal changes in Vβ repertoire during αβ TCR selection. Inefficient Vβ/VH recombination signal sequences (RSSs) have been hypothesized to cause impaired V-to-DJ recombination on the background of a defective recombinase as in core-Rag mice. We show that replacement of the Vβ14 RSS with a more efficient RSS increases Vβ14 recombination and rescues αβ T cell development in Rag1(C/C) mice. Our data indicate that noncore RAG1 regions establish a diverse TCR repertoire by overcoming Vβ RSS inefficiency to promote Vβ recombination and αβ T cell development, and by modulating TCRβ and TCRα gene segment utilization.
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Affiliation(s)
- Julie E Horowitz
- Division of Cancer Pathobiology, Department of Pathology and Laboratory Medicine, Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Abramson Family Cancer Research Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
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Kenter AL, Wuerffel R, Kumar S, Grigera F. Genomic Architecture may Influence Recurrent Chromosomal Translocation Frequency in the Igh Locus. Front Immunol 2013; 4:500. [PMID: 24416036 PMCID: PMC3874557 DOI: 10.3389/fimmu.2013.00500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 12/18/2013] [Indexed: 11/29/2022] Open
Affiliation(s)
- Amy L Kenter
- Department of Microbiology and Immunology, University of Illinois College of Medicine , Chicago, IL , USA
| | - Robert Wuerffel
- Department of Microbiology and Immunology, University of Illinois College of Medicine , Chicago, IL , USA
| | - Satyendra Kumar
- Department of Microbiology and Immunology, University of Illinois College of Medicine , Chicago, IL , USA
| | - Fernando Grigera
- Department of Microbiology and Immunology, University of Illinois College of Medicine , Chicago, IL , USA
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Medvedovic J, Ebert A, Tagoh H, Tamir IM, Schwickert TA, Novatchkova M, Sun Q, Huis In 't Veld PJ, Guo C, Yoon HS, Denizot Y, Holwerda SJB, de Laat W, Cogné M, Shi Y, Alt FW, Busslinger M. Flexible long-range loops in the VH gene region of the Igh locus facilitate the generation of a diverse antibody repertoire. Immunity 2013; 39:229-44. [PMID: 23973221 DOI: 10.1016/j.immuni.2013.08.011] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 05/13/2013] [Indexed: 12/18/2022]
Abstract
The immunoglobulin heavy-chain (Igh) locus undergoes large-scale contraction in pro-B cells, which facilitates VH-DJH recombination by juxtaposing distal VH genes next to the DJH-rearranged gene segment in the 3' proximal Igh domain. By using high-resolution mapping of long-range interactions, we demonstrate that local interaction domains established the three-dimensional structure of the extended Igh locus in lymphoid progenitors. In pro-B cells, these local domains engaged in long-range interactions across the Igh locus, which depend on the regulators Pax5, YY1, and CTCF. The large VH gene cluster underwent flexible long-range interactions with the more rigidly structured proximal domain, which probably ensures similar participation of all VH genes in VH-DJH recombination to generate a diverse antibody repertoire. These long-range interactions appear to be an intrinsic feature of the VH gene cluster, because they are still generated upon mutation of the Eμ enhancer, IGCR1 insulator, or 3' regulatory region in the proximal Igh domain.
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Affiliation(s)
- Jasna Medvedovic
- Research Institute of Molecular Pathology, Vienna Biocenter, Dr. Bohr-Gasse 7, 1030 Vienna, Austria
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Deep sequencing of the T-cell receptor repertoire in CD8+ T-large granular lymphocyte leukemia identifies signature landscapes. Blood 2013; 122:4077-85. [PMID: 24149287 DOI: 10.1182/blood-2013-05-506386] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
New massively parallel sequencing technology enables, through deep sequencing of rearranged T-cell receptor (TCR) Vβ complementarity-determining region 3 (CDR3) regions, a previously inaccessible level of TCR repertoire analysis. The CDR3 repertoire diversity reflects clonal composition, the potential antigenic recognition spectrum, and the quantity of available T-cell responses. In this context, T-large granular lymphocyte (T-LGL) leukemia is a chronic clonal lymphoproliferation of cytotoxic T cells often associated with autoimmune diseases and various cytopenias. Using CD8(+) T-LGL leukemia as a model disease, we set out to evaluate and compare the TCR deep-sequencing spectra of both patients and healthy controls to better understand how TCR deep sequencing could be used in the diagnosis and monitoring of not only T-LGL leukemia but also reactive processes such as autoimmune disease and infection. Our data demonstrate, with high resolution, significantly decreased diversity of the T-cell repertoire in CD8(+) T-LGL leukemia and suggest that many T-LGL clonotypes may be private to the disease and may not be present in the general public, even at the basal level.
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Phillips-Cremins JE, Corces VG. Chromatin insulators: linking genome organization to cellular function. Mol Cell 2013; 50:461-74. [PMID: 23706817 DOI: 10.1016/j.molcel.2013.04.018] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A growing body of evidence suggests that insulators have a primary role in orchestrating the topological arrangement of higher-order chromatin architecture. Insulator-mediated long-range interactions can influence the epigenetic status of the genome and, in certain contexts, may have important effects on gene expression. Here we discuss higher-order chromatin organization as a unifying mechanism for diverse insulator actions across the genome.
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Shih HY, Krangel MS. Chromatin architecture, CCCTC-binding factor, and V(D)J recombination: managing long-distance relationships at antigen receptor loci. THE JOURNAL OF IMMUNOLOGY 2013; 190:4915-21. [PMID: 23645930 DOI: 10.4049/jimmunol.1300218] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The rearrangement of T and B lymphocyte Ag receptor loci occurs within a highly complex chromosomal environment and is orchestrated through complex mechanisms. During the past decade, a large body of literature has highlighted the significance of chromatin architecture at Ag receptor loci in supporting the genomic assembly process: in preparation for recombination, these loci tend to contract and form multiple loops that shorten the distances between gene segments and facilitate recombination events. CCCTC-binding factor, CTCF, has received much attention in this regard since it has emerged as an important regulator of chromatin organization and transcription. In this review, we summarize recent work outlining conformational dynamics at Ag receptor loci during lymphocyte development and we discuss the role of CTCF in Ag receptor locus conformation and repertoire development.
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Affiliation(s)
- Han-Yu Shih
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
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