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A de novo transcription-dependent TAD boundary underpins critical multiway interactions during antibody class switch recombination. Mol Cell 2023; 83:681-697.e7. [PMID: 36736317 DOI: 10.1016/j.molcel.2023.01.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 11/04/2022] [Accepted: 01/09/2023] [Indexed: 02/05/2023]
Abstract
Interactions between transcription and cohesin-mediated loop extrusion can influence 3D chromatin architecture. However, their relevance in biology is unclear. Here, we report a direct role for such interactions in the mechanism of antibody class switch recombination (CSR) at the murine immunoglobulin heavy chain locus (Igh). Using Tri-C to measure higher-order multiway interactions on single alleles, we find that the juxtaposition (synapsis) of transcriptionally active donor and acceptor Igh switch (S) sequences, an essential step in CSR, occurs via the interaction of loop extrusion complexes with a de novo topologically associating domain (TAD) boundary formed via transcriptional activity across S regions. Surprisingly, synapsis occurs predominantly in proximity to the 3' CTCF-binding element (3'CBE) rather than the Igh super-enhancer, suggesting a two-step mechanism whereby transcription of S regions is not topologically coupled to synapsis, as has been previously proposed. Altogether, these insights advance our understanding of how 3D chromatin architecture regulates CSR.
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2
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Martin OA, Thomas M, Marquet M, Bruzeau C, Garot A, Brousse M, Bender S, Carrion C, Choi JE, Vuong BQ, Gearhart PJ, Maul RW, Le Noir S, Pinaud E. The IgH Eµ-MAR regions promote UNG-dependent error-prone repair to optimize somatic hypermutation. Front Immunol 2023; 14:1030813. [PMID: 36865553 PMCID: PMC9971809 DOI: 10.3389/fimmu.2023.1030813] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 01/13/2023] [Indexed: 02/16/2023] Open
Abstract
Intoduction Two scaffold/matrix attachment regions (5'- and 3'-MARsEµ ) flank the intronic core enhancer (cEµ) within the immunoglobulin heavy chain locus (IgH). Besides their conservation in mice and humans, the physiological role of MARsEµ is still unclear and their involvement in somatic hypermutation (SHM) has never been deeply evaluated. Methods Our study analyzed SHM and its transcriptional control in a mouse model devoid of MARsEµ , further combined to relevant models deficient for base excision repair and mismatch repair. Results We observed an inverted substitution pattern in of MARsEµ -deficient animals: SHM being decreased upstream from cEµ and increased downstream of it. Strikingly, the SHM defect induced by MARsEµ -deletion was accompanied by an increase of sense transcription of the IgH V region, excluding a direct transcription-coupled effect. Interestingly, by breeding to DNA repair-deficient backgrounds, we showed that the SHM defect, observed upstream from cEµ in this model, was not due to a decrease in AID deamination but rather the consequence of a defect in base excision repair-associated unfaithful repair process. Discussion Our study pointed out an unexpected "fence" function of MARsEµ regions in limiting the error-prone repair machinery to the variable region of Ig gene loci.
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Affiliation(s)
- Ophélie A Martin
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Morgane Thomas
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Marie Marquet
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Charlotte Bruzeau
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Armand Garot
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Mylène Brousse
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Sébastien Bender
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France.,Centre Hospitalier Universitaire Dupuytren, Service d'Immunopathologie, Limoges, France
| | - Claire Carrion
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Jee Eun Choi
- The Graduate Center, The City University of New York, New York, NY, United States
| | - Bao Q Vuong
- The Graduate Center, The City University of New York, New York, NY, United States
| | - Patricia J Gearhart
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Robert W Maul
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Sandrine Le Noir
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
| | - Eric Pinaud
- Laboratoire Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Université de Limoges, CNRS Unité Mixte de Recherche 7276, Inserm Unité 1262, Limoges, France
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Laffleur B, Batista CR, Zhang W, Lim J, Yang B, Rossille D, Wu L, Estrella J, Rothschild G, Pefanis E, Basu U. RNA exosome drives early B cell development via noncoding RNA processing mechanisms. Sci Immunol 2022; 7:eabn2738. [PMID: 35658015 DOI: 10.1126/sciimmunol.abn2738] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
B cell development is linked to successful V(D)J recombination, allowing B cell receptor expression and ultimately antibody secretion for adaptive immunity. Germline noncoding RNAs (ncRNAs) are produced at immunoglobulin (Ig) loci during V(D)J recombination, but their function and posttranscriptional regulation are incompletely understood. Patients with trichohepatoenteric syndrome, characterized by RNA exosome pathway component mutations, exhibit lymphopenia, thus demonstrating the importance of ncRNA surveillance in B cell development in humans. To understand the role of RNA exosome in early B cell development in greater detail, we generated mouse models harboring a B cell-specific cre allele (Mb1cre), coupled to conditional inversion-deletion alleles of one RNA exosome core component (Exosc3) or RNase catalytic subunits (Exosc10 or Dis3). We noticed increased expression of RNA exosome subunits during V(D)J recombination, whereas a B cell developmental blockade at the pro-B cell stage was observed in the different knockout mice, overlapping with a lack of productive rearrangements of VDJ genes at the Ig heavy chain (Igh). This unsuccessful recombination prevented differentiation into pre-B cells, with accumulation of ncRNAs and up-regulation of the p53 pathway. Introduction of a prearranged Igh VDJ allele partly rescued the pre-B cell population in Dis3-deficient cells, although V-J recombination defects were observed at Ig light chain kappa (Igκ), preventing subsequent B cell development. These observations demonstrated that the RNA exosome complex is important for Igh and Igκ recombination and establish the relevance of RNA processing for optimal diversification at these loci during B cell development.
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Affiliation(s)
- Brice Laffleur
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Carolina R Batista
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Wanwei Zhang
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Junghyun Lim
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Biao Yang
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Delphine Rossille
- Universite of Rennes, INSERM, EFS Bretagne, CHU Rennes, UMR 1236, Rennes, France
| | - Lijing Wu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Jerson Estrella
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gerson Rothschild
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | | | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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4
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Karbalivand M, Almada LL, Ansell SM, Fernandez-Zapico ME, Elsawa SF. MLL1 inhibition reduces IgM levels in Waldenström macroglobulinemia. Leuk Res 2022; 116:106841. [DOI: 10.1016/j.leukres.2022.106841] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/06/2022] [Accepted: 04/15/2022] [Indexed: 12/26/2022]
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5
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Ferrad M, Ghazzaui N, Issaoui H, Marchiol T, Cook-Moreau J, Denizot Y. Deletion of the 3'RR cis-enhancer IgH element affects DNA repair junctions during B-cell class switch recombination. Immunol Lett 2021; 240:12-14. [PMID: 34599945 DOI: 10.1016/j.imlet.2021.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 09/23/2021] [Indexed: 01/18/2023]
Affiliation(s)
- Melissa Ferrad
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, Université de Limoges, CBRS, rue Pr. Descottes, 87025 Limoges, France
| | - Nour Ghazzaui
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, Université de Limoges, CBRS, rue Pr. Descottes, 87025 Limoges, France
| | - Hussein Issaoui
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, Université de Limoges, CBRS, rue Pr. Descottes, 87025 Limoges, France
| | - Tiffany Marchiol
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, Université de Limoges, CBRS, rue Pr. Descottes, 87025 Limoges, France
| | - Jeanne Cook-Moreau
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, Université de Limoges, CBRS, rue Pr. Descottes, 87025 Limoges, France
| | - Yves Denizot
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, Université de Limoges, CBRS, rue Pr. Descottes, 87025 Limoges, France.
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Dauba A, Khamlichi AA. Long-Range Control of Class Switch Recombination by Transcriptional Regulatory Elements. Front Immunol 2021; 12:738216. [PMID: 34594340 PMCID: PMC8477019 DOI: 10.3389/fimmu.2021.738216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 08/17/2021] [Indexed: 01/18/2023] Open
Abstract
Immunoglobulin class switch recombination (CSR) plays a crucial role in adaptive immune responses through a change of the effector functions of antibodies and is triggered by T-cell-dependent as well as T-cell-independent antigens. Signals generated following encounter with each type of antigen direct CSR to different isotypes. At the genomic level, CSR occurs between highly repetitive switch sequences located upstream of the constant gene exons of the immunoglobulin heavy chain locus. Transcription of switch sequences is mandatory for CSR and is induced in a stimulation-dependent manner. Switch transcription takes place within dynamic chromatin domains and is regulated by long-range regulatory elements which promote alignment of partner switch regions in CSR centers. Here, we review recent work and models that account for the function of long-range transcriptional regulatory elements and the chromatin-based mechanisms involved in the control of CSR.
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Affiliation(s)
- Audrey Dauba
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, Toulouse, France
| | - Ahmed Amine Khamlichi
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, Toulouse, France
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7
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Oudinet C, Braikia FZ, Dauba A, Khamlichi AA. Mechanism and regulation of class switch recombination by IgH transcriptional control elements. Adv Immunol 2020; 147:89-137. [PMID: 32981636 DOI: 10.1016/bs.ai.2020.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Class switch recombination (CSR) plays an important role in humoral immunity by generating antibodies with different effector functions. CSR to a particular antibody isotype is induced by external stimuli, and occurs between highly repetitive switch (S) sequences. CSR requires transcription across S regions, which generates long non-coding RNAs and secondary structures that promote accessibility of S sequences to activation-induced cytidine deaminase (AID). AID initiates DNA double-strand breaks (DSBs) intermediates that are repaired by general DNA repair pathways. Switch transcription is controlled by various regulatory elements, including enhancers and insulators. The current paradigm posits that transcriptional control of CSR involves long-range chromatin interactions between regulatory elements and chromatin loops-stabilizing factors, which promote alignment of partner S regions in a CSR centre (CSRC) and initiation of CSR. In this review, we focus on the role of IgH transcriptional control elements in CSR and the chromatin-based mechanisms underlying this control.
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Affiliation(s)
- Chloé Oudinet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France
| | - Fatima-Zohra Braikia
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France
| | - Audrey Dauba
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France
| | - Ahmed Amine Khamlichi
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, CNRS, Université Paul Sabatier, Toulouse, France.
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8
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Ferrad M, Ghazzaui N, Issaoui H, Cook-Moreau J, Denizot Y. Mouse Models of c-myc Deregulation Driven by IgH Locus Enhancers as Models of B-Cell Lymphomagenesis. Front Immunol 2020; 11:1564. [PMID: 32793219 PMCID: PMC7390917 DOI: 10.3389/fimmu.2020.01564] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/15/2020] [Indexed: 01/18/2023] Open
Abstract
Chromosomal translocations linking various oncogenes to transcriptional enhancers of the immunoglobulin heavy chain (IgH) locus are often implicated as the cause of B-cell malignancies. Two major IgH transcriptional enhancers have been reported so far. The Eμ enhancer located upstream of the Cμ gene controls early events in B-cell maturation such as VDJ recombination. The 3' regulatory region (3'RR) located downstream from the Cα gene controls late events in B-cell maturation such as IgH transcription, somatic hypermutation, and class switch recombination. Convincing demonstrations of the essential contributions of both Eμ and 3'RR in B-cell lymphomagenesis have been provided by transgenic and knock-in animal models which bring the oncogene c-myc under Eμ/3'RR transcriptional control. This short review summarizes the different mouse models so far available and their interests/limitations for progress in our understanding of human c-myc-induced B-cell lymphomagenesis.
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Affiliation(s)
- Melissa Ferrad
- Inserm U1262, UMR CNRS 7276, Equipe Labellisée LIGUE 2018, Université de Limoges, Limoges, France
| | - Nour Ghazzaui
- Inserm U1262, UMR CNRS 7276, Equipe Labellisée LIGUE 2018, Université de Limoges, Limoges, France
| | - Hussein Issaoui
- Inserm U1262, UMR CNRS 7276, Equipe Labellisée LIGUE 2018, Université de Limoges, Limoges, France
| | - Jeanne Cook-Moreau
- Inserm U1262, UMR CNRS 7276, Equipe Labellisée LIGUE 2018, Université de Limoges, Limoges, France
| | - Yves Denizot
- Inserm U1262, UMR CNRS 7276, Equipe Labellisée LIGUE 2018, Université de Limoges, Limoges, France
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9
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Vecchio E, Fiume G, Correnti S, Romano S, Iaccino E, Mimmi S, Maisano D, Nisticò N, Quinto I. Insights about MYC and Apoptosis in B-Lymphomagenesis: An Update from Murine Models. Int J Mol Sci 2020; 21:E4265. [PMID: 32549409 PMCID: PMC7352788 DOI: 10.3390/ijms21124265] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 01/18/2023] Open
Abstract
The balance between cell survival and cell death represents an essential part of human tissue homeostasis, while altered apoptosis contributes to several pathologies and can affect the treatment efficacy. Impaired apoptosis is one of the main cancer hallmarks and some types of lymphomas harbor mutations that directly affect key regulators of cell death (such as BCL-2 family members). The development of novel techniques in the field of immunology and new animal models has greatly accelerated our understanding of oncogenic mechanisms in MYC-associated lymphomas. Mouse models are a powerful tool to reveal multiple genes implicated in the genesis of lymphoma and are extensively used to clarify the molecular mechanism of lymphoma, validating the gene function. Key features of MYC-induced apoptosis will be discussed here along with more recent studies on MYC direct and indirect interactors, including their cooperative action in lymphomagenesis. We review our current knowledge about the role of MYC-induced apoptosis in B-cell malignancies, discussing the transcriptional regulation network of MYC and regulatory feedback action of miRs during MYC-driven lymphomagenesis. More importantly, the finding of new modulators of apoptosis now enabling researchers to translate the discoveries that have been made in the laboratory into clinical practice to positively impact human health.
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Affiliation(s)
- Eleonora Vecchio
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, 88100 Catanzaro, Italy; (G.F.); (S.C.); (S.R.); (E.I.); (S.M.); (D.M.); (N.N.)
| | | | | | | | | | | | | | | | - Ileana Quinto
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, 88100 Catanzaro, Italy; (G.F.); (S.C.); (S.R.); (E.I.); (S.M.); (D.M.); (N.N.)
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10
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An Erg-driven transcriptional program controls B cell lymphopoiesis. Nat Commun 2020; 11:3013. [PMID: 32541654 PMCID: PMC7296042 DOI: 10.1038/s41467-020-16828-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 05/24/2020] [Indexed: 01/09/2023] Open
Abstract
B lymphoid development is initiated by the differentiation of hematopoietic stem cells into lineage committed progenitors, ultimately generating mature B cells. This highly regulated process generates clonal immunological diversity via recombination of immunoglobulin V, D and J gene segments. While several transcription factors that control B cell development and V(D)J recombination have been defined, how these processes are initiated and coordinated into a precise regulatory network remains poorly understood. Here, we show that the transcription factor ETS Related Gene (Erg) is essential for early B lymphoid differentiation. Erg initiates a transcriptional network involving the B cell lineage defining genes, Ebf1 and Pax5, which directly promotes expression of key genes involved in V(D)J recombination and formation of the B cell receptor. Complementation of Erg deficiency with a productively rearranged immunoglobulin gene rescued B lineage development, demonstrating that Erg is an essential and stage-specific regulator of the gene regulatory network controlling B lymphopoiesis. B cell development is tightly regulated in a stepwise manner to ensure proper generation of repertoire diversity via somatic gene rearrangements. Here, the authors show that a transcription factor, Erg, functions at the earliest stage to critically control two downstream factors, Ebf1 and Pax5, for modulating this gene rearrangement process.
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Ghazzaui N, Issaoui H, Ferrad M, Carrion C, Cook-Moreau J, Denizot Y, Boyer F. Eμ and 3'RR transcriptional enhancers of the IgH locus cooperate to promote c-myc-induced mature B-cell lymphomas. Blood Adv 2020; 4:28-39. [PMID: 31899800 PMCID: PMC6960469 DOI: 10.1182/bloodadvances.2019000845] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/12/2019] [Indexed: 01/18/2023] Open
Abstract
Numerous B-cell lymphomas feature translocations linking oncogenes to different locations in the immunoglobulin heavy chain (IgH) locus. During Burkitt lymphoma (BL), IgH breakpoints for c-myc translocation stand either close to JH segments or within switch regions. Transcription, accessibility, and remodeling of the IgH locus are under the control of the 2 potent cis-acting enhancer elements: Eμ and the 3' regulatory region (3'RR). To ensure their respective contributions to oncogene deregulation in the context of the endogenous IgH locus, we studied transgenic mice harboring a knock-in of c-myc in various positions of the IgH locus (3' to JH segments, 5' to Cμ with Eμ deletion and Cα). The observed spectrum of tumors, kinetics of emergence, and transcriptome analysis provide strong evidence that both Eμ and 3'RR deregulate c-myc and cooperate together to promote B-cell lymphomagenesis. Transgenics mimicking endemic BL (with c-myc placed 3' to JH segments) exhibited the highest rate of B-cell lymphoma emergence, the highest Ki67 index of proliferation, and the highest transcriptomic similarities to human BL. The 3'RR enhancer alone deregulated c-myc and initiated the development of BL-like lymphomas, suggesting that its targeting would be of therapeutic interest to reduce c-myc oncogenicity in vivo.
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Affiliation(s)
- Nour Ghazzaui
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Hussein Issaoui
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Mélissa Ferrad
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Claire Carrion
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Jeanne Cook-Moreau
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Yves Denizot
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - François Boyer
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
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12
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Issaoui H, Ghazzaui N, Ferrad M, Boyer F, Denizot Y. Class switch recombination junctions are not affected by the absence of the immunoglobulin heavy chain E μ enhancer. Cell Mol Immunol 2019; 16:671-673. [PMID: 30967637 DOI: 10.1038/s41423-019-0229-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/16/2019] [Indexed: 01/18/2023] Open
Affiliation(s)
- Hussein Issaoui
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, University of Limoges, CBRS, rue Pr. Descottes, 87025, Limoges, France
| | - Nour Ghazzaui
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, University of Limoges, CBRS, rue Pr. Descottes, 87025, Limoges, France
| | - Mélissa Ferrad
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, University of Limoges, CBRS, rue Pr. Descottes, 87025, Limoges, France
| | - François Boyer
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, University of Limoges, CBRS, rue Pr. Descottes, 87025, Limoges, France
| | - Yves Denizot
- UMR CNRS 7276, INSERM U1262, Equipe Labellisée LIGUE 2018, University of Limoges, CBRS, rue Pr. Descottes, 87025, Limoges, France.
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13
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Ghazzaui N, Issaoui H, Boyer F, Martin OA, Saintamand A, Denizot Y. 3'RR and 5'E μ immunoglobulin heavy chain enhancers are independent engines of locus remodeling. Cell Mol Immunol 2018; 16:198-200. [PMID: 30305688 DOI: 10.1038/s41423-018-0171-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 09/17/2018] [Indexed: 02/06/2023] Open
Affiliation(s)
- Nour Ghazzaui
- CNRS UMR 7276, Inserm U1262, Université de Limoges, Limoges, France
| | - Hussein Issaoui
- CNRS UMR 7276, Inserm U1262, Université de Limoges, Limoges, France
| | - François Boyer
- CNRS UMR 7276, Inserm U1262, Université de Limoges, Limoges, France
| | | | - Alexis Saintamand
- CNRS UMR 7276, Inserm U1262, Université de Limoges, Limoges, France.,Inserm U1236, Université Rennes 1, Rennes, France
| | - Yves Denizot
- CNRS UMR 7276, Inserm U1262, Université de Limoges, Limoges, France.
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14
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Delgado-Benito V, Rosen DB, Wang Q, Gazumyan A, Pai JA, Oliveira TY, Sundaravinayagam D, Zhang W, Andreani M, Keller L, Kieffer-Kwon KR, Pękowska A, Jung S, Driesner M, Subbotin RI, Casellas R, Chait BT, Nussenzweig MC, Di Virgilio M. The Chromatin Reader ZMYND8 Regulates Igh Enhancers to Promote Immunoglobulin Class Switch Recombination. Mol Cell 2018; 72:636-649.e8. [PMID: 30293785 PMCID: PMC6242708 DOI: 10.1016/j.molcel.2018.08.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 07/01/2018] [Accepted: 08/25/2018] [Indexed: 01/18/2023]
Abstract
Class switch recombination (CSR) is a DNA recombination reaction that diversifies the effector component of antibody responses. CSR is initiated by activation-induced cytidine deaminase (AID), which targets transcriptionally active immunoglobulin heavy chain (Igh) switch donor and acceptor DNA. The 3′ Igh super-enhancer, 3′ regulatory region (3′RR), is essential for acceptor region transcription, but how this function is regulated is unknown. Here, we identify the chromatin reader ZMYND8 as an essential regulator of the 3′RR. In B cells, ZMYND8 binds promoters and super-enhancers, including the Igh enhancers. ZMYND8 controls the 3′RR activity by modulating the enhancer transcriptional status. In its absence, there is increased 3′RR polymerase loading and decreased acceptor region transcription and CSR. In addition to CSR, ZMYND8 deficiency impairs somatic hypermutation (SHM) of Igh, which is also dependent on the 3′RR. Thus, ZMYND8 controls Igh diversification in mature B lymphocytes by regulating the activity of the 3′ Igh super-enhancer. ZMYND8 is required for GLT of acceptor S regions and Class Switch Recombination ZMYND8 supports efficient somatic hypermutation of the Igh variable regions ZMYND8 binds B cell super-enhancers, including the 3′ Igh enhancer ZMYND8 modulates the transcriptional status and activity of the 3′ Igh enhancer
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Affiliation(s)
- Verónica Delgado-Benito
- Laboratory of DNA Repair and Maintenance of Genome Stability, The Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Daniel B Rosen
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Qiao Wang
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Anna Gazumyan
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Joy A Pai
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Thiago Y Oliveira
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Devakumar Sundaravinayagam
- Laboratory of DNA Repair and Maintenance of Genome Stability, The Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Wenzhu Zhang
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Matteo Andreani
- Laboratory of DNA Repair and Maintenance of Genome Stability, The Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Lisa Keller
- Laboratory of DNA Repair and Maintenance of Genome Stability, The Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | | | | | - Seolkyoung Jung
- Lymphocyte Nuclear Biology, NIAMS, NCI, NIH, Bethesda, MD 20892, USA
| | - Madlen Driesner
- Laboratory of DNA Repair and Maintenance of Genome Stability, The Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Roman I Subbotin
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Rafael Casellas
- Lymphocyte Nuclear Biology, NIAMS, NCI, NIH, Bethesda, MD 20892, USA
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Michela Di Virgilio
- Laboratory of DNA Repair and Maintenance of Genome Stability, The Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany.
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15
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The IgH 3' regulatory region and c-myc-induced B-cell lymphomagenesis. Oncotarget 2018; 8:7059-7067. [PMID: 27729620 PMCID: PMC5351691 DOI: 10.18632/oncotarget.12535] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/05/2016] [Indexed: 01/18/2023] Open
Abstract
Deregulation and mutations of c-myc have been reported in multiple mature B-cell malignancies such as Burkitt lymphoma, myeloma and plasma cell lymphoma. After translocation into the immunoglobulin heavy chain (IgH) locus, c-myc is constitutively expressed under the control of active IgH cis-regulatory enhancers. Those located in the IgH 3 regulatory region (3RR) are master control elements of transcription. Over the past decade numerous convincing demonstrations of 3RRs contribution to mature c-myc-induced lymphomagenesis have been made using transgenic models with various types of IgH-c-myc translocations and transgenes. This review highlights how IgH 3RR physiological functions play a critical role in c-myc deregulation during lymphomagenesis.
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16
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Saintamand A, Ghazzaui N, Issaoui H, Denizot Y. [The IgH 3'RR: Doctor Jekyll and Mister Hyde of B-cell maturation and lymphomagenesis]. Med Sci (Paris) 2017; 33:963-970. [PMID: 29200394 DOI: 10.1051/medsci/20173311013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The four transcriptional enhancers located in the 3' regulatory region (3'RR) of the IgH locus control the late phases of B-cell maturation, namely IgH locus transcription, somatic hypermutation and class switch recombination. Doctor Jekyll by nature, the 3'RR acts as Mister Hyde in case of oncogenic translocation at the IgH locus taking under its transcriptional control the translocated oncogene. The aim of this review is to show this duality on the basis of the latest scientific advances in the structure and function of the 3'RR and to hIghlight the targeting of the 3'RR as a potential therapeutic approach in mature B-cell lymphomas.
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Affiliation(s)
- Alexis Saintamand
- UMR CNRS 7276, Université de Limoges, rue Pr Descottes, 87025 Limoges, France
| | - Nour Ghazzaui
- UMR CNRS 7276, Université de Limoges, rue Pr Descottes, 87025 Limoges, France
| | - Hussein Issaoui
- UMR CNRS 7276, Université de Limoges, rue Pr Descottes, 87025 Limoges, France
| | - Yves Denizot
- UMR CNRS 7276, Université de Limoges, rue Pr Descottes, 87025 Limoges, France
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17
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Le Noir S, Laffleur B, Carrion C, Garot A, Lecardeur S, Pinaud E, Denizot Y, Skok J, Cogné M. The IgH locus 3' cis-regulatory super-enhancer co-opts AID for allelic transvection. Oncotarget 2017; 8:12929-12940. [PMID: 28088785 PMCID: PMC5355067 DOI: 10.18632/oncotarget.14585] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 01/01/2017] [Indexed: 11/25/2022] Open
Abstract
Immunoglobulin heavy chain (IgH) alleles have ambivalent relationships: they feature both allelic exclusion, ensuring monoallelic expression of a single immunoglobulin (Ig) allele, and frequent inter-allelic class-switch recombination (CSR) reassembling genes from both alleles. The IgH locus 3' regulatory region (3'RR) includes several transcriptional cis-enhancers promoting activation-induced cytidine deaminase (AID)-dependent somatic hypermutation (SHM) and CSR, and altogether behaves as a strong super-enhancer. It can also promote deregulated expression of translocated oncogenes during lymphomagenesis. Besides these rare, illegitimate and pathogenic interactions, we now show that under physiological conditions, the 3'RR super-enhancer supports not only legitimate cis- , but also trans-recruitment of AID, contributing to IgH inter-allelic proximity and enabling the super-enhancer on one allele to stimulate biallelic SHM and CSR. Such inter-allelic activating interactions define transvection, a phenomenon well-known in drosophila but rarely observed in mammalian cells, now appearing as a unique feature of the IgH 3'RR super-enhancer.
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Affiliation(s)
- Sandrine Le Noir
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Brice Laffleur
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Claire Carrion
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Armand Garot
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Sandrine Lecardeur
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Eric Pinaud
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Yves Denizot
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
| | - Jane Skok
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Michel Cogné
- UMR 7276 CNRS and Université de Limoges: Contrôle de la Réponse Immune B et Lymphoprolifération, Limoges, France
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18
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Liang Y, Zou Q, Yu W. Steering Against Wind: A New Network of NamiRNAs and Enhancers. GENOMICS PROTEOMICS & BIOINFORMATICS 2017; 15:331-337. [PMID: 28882787 PMCID: PMC5673672 DOI: 10.1016/j.gpb.2017.05.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 05/19/2017] [Accepted: 06/14/2017] [Indexed: 02/07/2023]
Abstract
MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs with regulatory functions. Traditionally, miRNAs are thought to play a negative regulatory role in the cytoplasm by binding to the 3′UTR of target genes to degrade mRNA or inhibit translation. However, it remains a challenge to interpret the potential function of many miRNAs located in the nucleus. Recently, we reported a new type of miRNAs present in the nucleus, which can activate gene expression by binding to the enhancer, and named them nuclear activating miRNAs (NamiRNAs). The discovery of NamiRNAs showcases a complementary regulatory mechanism of miRNA, demonstrating their differential roles in the nucleus and cytoplasm. Here, we reviewed miRNAs in nucleus to better understand the function of NamiRNAs in their interactions with the enhancers. Accordingly, we propose a NamiRNA–enhancer–target gene activation network model to better understand the crosstalk between NamiRNAs and enhancers in regulating gene transcription. Moreover, we hypothesize that NamiRNAs may be involved in cell identity or cell fate determination during development, although further study is needed to elucidate the underlying mechanisms in detail.
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Affiliation(s)
- Ying Liang
- Laboratory of RNA Epigenetics, Institutes of Biomedical Sciences & Department of General Surgery, Huashan Hospital, Cancer Metastasis Institute, Fudan University, Shanghai 200032, China; Department of Biochemistry and Molecular Biology, Shanghai Medical College, MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Molecular Biology, Fudan University, Shanghai 200032, China; Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Qingping Zou
- Laboratory of RNA Epigenetics, Institutes of Biomedical Sciences & Department of General Surgery, Huashan Hospital, Cancer Metastasis Institute, Fudan University, Shanghai 200032, China; Department of Biochemistry and Molecular Biology, Shanghai Medical College, MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Molecular Biology, Fudan University, Shanghai 200032, China; Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Wenqiang Yu
- Laboratory of RNA Epigenetics, Institutes of Biomedical Sciences & Department of General Surgery, Huashan Hospital, Cancer Metastasis Institute, Fudan University, Shanghai 200032, China; Department of Biochemistry and Molecular Biology, Shanghai Medical College, MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Molecular Biology, Fudan University, Shanghai 200032, China; Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China.
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19
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Saintamand A, Vincent-Fabert C, Marquet M, Ghazzaui N, Magnone V, Pinaud E, Cogné M, Denizot Y. E μ and 3'RR IgH enhancers show hierarchic unilateral dependence in mature B-cells. Sci Rep 2017; 7:442. [PMID: 28348365 PMCID: PMC5428668 DOI: 10.1038/s41598-017-00575-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/03/2017] [Indexed: 01/18/2023] Open
Abstract
Enhancer and super-enhancers are master regulators of cell fate. While they act at long-distances on adjacent genes, it is unclear whether they also act on one another. The immunoglobulin heavy chain (IgH) locus is unique in carrying two super-enhancers at both ends of the constant gene cluster: the 5'Eμ super-enhancer promotes VDJ recombination during the earliest steps of B-cell ontogeny while the 3' regulatory region (3'RR) is essential for late differentiation. Since they carry functional synergies in mature B-cells and physically interact during IgH locus DNA looping, we investigated if they were independent engines of locus remodelling or if their function was more intimately intermingled, their optimal activation then requiring physical contact with each other. Analysis of chromatin marks, enhancer RNA transcription and accessibility in Eμ- and 3'RR-deficient mice show, in mature activated B-cells, an unilateral dependence of this pair of enhancers: while the 3'RR acts in autonomy, Eμ in contrast likely falls under control of the 3'RR.
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Affiliation(s)
- A Saintamand
- CNRS UMR 7276, CRIBL, Université de Limoges, Limoges, France. .,INSERM U1236, Université Rennes 1, Rennes, France.
| | | | - M Marquet
- CNRS UMR 7276, CRIBL, Université de Limoges, Limoges, France
| | - N Ghazzaui
- CNRS UMR 7276, CRIBL, Université de Limoges, Limoges, France
| | - V Magnone
- CNRS et Université de Nice Sophia Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 6097, Sophia, Antipolis, France
| | - E Pinaud
- CNRS UMR 7276, CRIBL, Université de Limoges, Limoges, France
| | - M Cogné
- CNRS UMR 7276, CRIBL, Université de Limoges, Limoges, France
| | - Y Denizot
- CNRS UMR 7276, CRIBL, Université de Limoges, Limoges, France.
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20
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Saintamand A, Rouaud P, Garot A, Saad F, Carrion C, Oblet C, Cogné M, Pinaud E, Denizot Y. The IgH 3' regulatory region governs μ chain transcription in mature B lymphocytes and the B cell fate. Oncotarget 2016; 6:4845-52. [PMID: 25742787 PMCID: PMC4467119 DOI: 10.18632/oncotarget.3010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 12/21/2014] [Indexed: 12/11/2022] Open
Abstract
We report that the IgH 3' regulatory region (3'RR) has no role on μ chain transcription and pre-BCR expression in B cell progenitors. In contrast, analysis of heterozygous IgH aΔ3'RR/bwt mice indicated that the 3'RR controls μ chain transcripts in mature splenocytes and impacts membrane IgM density without obvious effect on BCR signals (colocalisation with lipid rafts and phosphorylation of Erk and Akt after BCR crosslinking). Deletion of the 3'RR modulates the B cell fate to less marginal zone B cells. In conclusion, the 3'RR is dispensable for pre-BCR expression and necessary for optimal commitments toward the marginal zone B cell fate. These results reinforce the concept of a dual regulation of the IgH locus transcription and accessibility by 5' elements at immature B cell stages, and by the 3'RR as early as the resting mature B cell stage and then along further activation and differentiation.
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Affiliation(s)
| | | | | | | | | | | | - Michel Cogné
- CNRS, CRIBL, UMR 7276, Limoges, France.,Université de Limoges, CRIBL, UMR 7276, Limoges, France.,Institut Universitaire de France, Paris, France
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21
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Saintamand A, Vincent-Fabert C, Garot A, Rouaud P, Oruc Z, Magnone V, Cogné M, Denizot Y. Deciphering the importance of the palindromic architecture of the immunoglobulin heavy-chain 3' regulatory region. Nat Commun 2016; 7:10730. [PMID: 26883548 PMCID: PMC4757795 DOI: 10.1038/ncomms10730] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 01/15/2016] [Indexed: 01/16/2023] Open
Abstract
The IgH 3' regulatory region (3'RR) controls class switch recombination (CSR) and somatic hypermutation (SHM) in B cells. The mouse 3'RR contains four enhancer elements with hs1,2 flanked by inverted repeated sequences and the centre of a 25-kb palindrome bounded by two hs3 enhancer inverted copies (hs3a and hs3b). hs4 lies downstream of the palindrome. In mammals, evolution maintained this unique palindromic arrangement, suggesting that it is functionally significant. Here we report that deconstructing the palindromic IgH 3'RR strongly affects its function even when enhancers are preserved. CSR and IgH transcription appear to be poorly dependent on the 3'RR architecture and it is more or less preserved, provided 3'RR enhancers are present. By contrast, a ‘palindromic effect' significantly lowers VH germline transcription, AID recruitment and SHM. In conclusion, this work indicates that the IgH 3'RR does not simply pile up enhancer units but also optimally exposes them into a functional architecture of crucial importance. The IgH 3' regulatory region contains an evolutionarily conserved palindromic sequence flanking important enhancer elements. Here the authors show that the palindrome is required for generating antibody diversity.
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Affiliation(s)
| | | | - Armand Garot
- Université de Limoges, CRIBL, UMR CNRS 7276, Limoges 87025, France
| | - Pauline Rouaud
- Université de Limoges, CRIBL, UMR CNRS 7276, Limoges 87025, France
| | - Zeliha Oruc
- Université de Limoges, CRIBL, UMR CNRS 7276, Limoges 87025, France
| | - Virginie Magnone
- CNRS et Université de Nice Sophia Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 6097, Sophia Antipolis 06560, France
| | - Michel Cogné
- Université de Limoges, CRIBL, UMR CNRS 7276, Limoges 87025, France.,Institut Universitaire de France, Paris 75231, France
| | - Yves Denizot
- Université de Limoges, CRIBL, UMR CNRS 7276, Limoges 87025, France
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22
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Sequential activation and distinct functions for distal and proximal modules within the IgH 3' regulatory region. Proc Natl Acad Sci U S A 2016; 113:1618-23. [PMID: 26831080 DOI: 10.1073/pnas.1514090113] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
As a master regulator of functional Ig heavy chain (IgH) expression, the IgH 3' regulatory region (3'RR) controls multiple transcription events at various stages of B-cell ontogeny, from newly formed B cells until the ultimate plasma cell stage. The IgH 3'RR plays a pivotal role in early B-cell receptor expression, germ-line transcription preceding class switch recombination, interactions between targeted switch (S) regions, variable region transcription before somatic hypermutation, and antibody heavy chain production, but the functional ranking of its different elements is still inaccurate, especially that of its evolutionarily conserved quasi-palindromic structure. By comparing relevant previous knockout (KO) mouse models (3'RR KO and hs3b-4 KO) to a novel mutant devoid of the 3'RR quasi-palindromic region (3'PAL KO), we pinpointed common features and differences that specify two distinct regulatory entities acting sequentially during B-cell ontogeny. Independently of exogenous antigens, the 3'RR distal part, including hs4, fine-tuned B-cell receptor expression in newly formed and naïve B-cell subsets. At mature stages, the 3'RR portion including the quasi-palindrome dictated antigen-dependent locus remodeling (global somatic hypermutation and class switch recombination to major isotypes) in activated B cells and antibody production in plasma cells.
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23
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Proudhon C, Hao B, Raviram R, Chaumeil J, Skok JA. Long-Range Regulation of V(D)J Recombination. Adv Immunol 2015; 128:123-82. [PMID: 26477367 DOI: 10.1016/bs.ai.2015.07.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Given their essential role in adaptive immunity, antigen receptor loci have been the focus of analysis for many years and are among a handful of the most well-studied genes in the genome. Their investigation led initially to a detailed knowledge of linear structure and characterization of regulatory elements that confer control of their rearrangement and expression. However, advances in DNA FISH and imaging combined with new molecular approaches that interrogate chromosome conformation have led to a growing appreciation that linear structure is only one aspect of gene regulation and in more recent years, the focus has switched to analyzing the impact of locus conformation and nuclear organization on control of recombination. Despite decades of work and intense effort from numerous labs, we are still left with an incomplete picture of how the assembly of antigen receptor loci is regulated. This chapter summarizes our advances to date and points to areas that need further investigation.
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Affiliation(s)
- Charlotte Proudhon
- Department of Pathology, New York University School of Medicine, New York, USA
| | - Bingtao Hao
- Department of Pathology, New York University School of Medicine, New York, USA
| | - Ramya Raviram
- Department of Pathology, New York University School of Medicine, New York, USA
| | - Julie Chaumeil
- Institut Curie, CNRS UMR3215, INSERM U934, Paris, France
| | - Jane A Skok
- Department of Pathology, New York University School of Medicine, New York, USA.
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24
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Tartey S, Matsushita K, Imamura T, Wakabayashi A, Ori D, Mino T, Takeuchi O. Essential Function for the Nuclear Protein Akirin2 in B Cell Activation and Humoral Immune Responses. THE JOURNAL OF IMMUNOLOGY 2015; 195:519-27. [DOI: 10.4049/jimmunol.1500373] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/07/2015] [Indexed: 02/06/2023]
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25
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Saintamand A, Rouaud P, Saad F, Rios G, Cogné M, Denizot Y. Elucidation of IgH 3′ region regulatory role during class switch recombination via germline deletion. Nat Commun 2015; 6:7084. [DOI: 10.1038/ncomms8084] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/01/2015] [Indexed: 02/06/2023] Open
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