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Weniger MA, Seifert M, Küppers R. B Cell Differentiation and the Origin and Pathogenesis of Human B Cell Lymphomas. Methods Mol Biol 2025; 2865:1-30. [PMID: 39424718 DOI: 10.1007/978-1-0716-4188-0_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2024]
Abstract
Immunoglobulin (IG) gene remodeling by V(D)J recombination plays a central role in the generation of normal B cells, and somatic hypermutation and class switching of IG genes are key processes during antigen-driven B cell differentiation in the germinal center reaction. However, errors of these processes are involved in the development of B cell lymphomas. IG locus-associated translocations of proto-oncogenes are a hallmark of many B cell malignancies. Additional transforming events include inactivating mutations in various tumor suppressor genes and also latent infection of B cells with viruses, such as Epstein-Barr virus. Most B cell lymphomas require B cell antigen receptor expression, and in several instances chronic antigenic stimulation plays a role in lymphoma development and/or sustaining tumor growth. Often, survival and proliferation signals provided by other cells in the microenvironment are a further critical factor in lymphoma development and pathophysiology. Most B cell malignancies derive from germinal center B cells, most likely due to the high proliferative activity of these B cells and aberrant mutations caused by their naturally active mutagenic processes.
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Affiliation(s)
- Marc A Weniger
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Essen, Germany
| | - Marc Seifert
- Department of Haematology, Oncology and Clinical Immunology, Heinrich Heine University, Medical School, Düsseldorf, Germany
| | - Ralf Küppers
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Essen, Germany.
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2
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Du L, Oksenych V, Wan H, Ye X, Dong J, Ye AY, Abolhassani H, Vlachiotis S, Zhang X, de la Rosa K, Hammarström L, van der Burg M, Alt FW, Pan-Hammarström Q. Orientation Regulation of Class-switch Recombination in Human B Cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 213:1093-1104. [PMID: 39248600 PMCID: PMC11457721 DOI: 10.4049/jimmunol.2300842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 08/16/2024] [Indexed: 09/10/2024]
Abstract
We developed a linear amplification-mediated high-throughput genome-wide translocation sequencing method to profile Ig class-switch recombination (CSR) in human B cells in an unbiased and quantitative manner. This enables us to characterize CSR junctions resulting from either deletional recombination or inversion for each Ig class/subclass. Our data showed that more than 90% of CSR junctions detected in peripheral blood in healthy control subjects were due to deletional recombination. We further identified two major CSR junction signatures/patterns in human B cells. Signature 1 consists of recombination junctions resulting from both IgG and IgA switching, with a dominance of Sµ-Sγ junctions (72%) and deletional recombination (87%). Signature 2 is contributed mainly by Sµ-Sα junctions (96%), and these junctions were almost all due to deletional recombination (99%) and were characterized by longer microhomologies. CSR junctions identified in healthy individuals can be assigned to both signatures but with a dominance of signature 1, whereas almost all CSR junctions found in patients with defects in DNA-PKcs or Artemis, two classical nonhomologous end joining (c-NHEJ) factors, align with signature 2. Thus, signature 1 may represent c-NHEJ activity during CSR, whereas signature 2 is associated with microhomology-mediated alternative end joining in the absence of the studied c-NHEJ factors. Our findings suggest that in human B cells, the efficiency of the c-NHEJ machinery and the features of switch regions are crucial for the regulation of CSR orientation. Finally, our high-throughput method can also be applied to study the mechanism of rare types of recombination, such as switching to IgD and locus suicide switching.
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Affiliation(s)
- Likun Du
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Valentyn Oksenych
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Hui Wan
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Xiaofei Ye
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Junchao Dong
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Adam Yongxin Ye
- Department of Genetics, Harvard Medical School, Boston, MA
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA
- Howard Hughes Medical Institute, Boston, MA
| | - Hassan Abolhassani
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Stelios Vlachiotis
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Xuefei Zhang
- Department of Genetics, Harvard Medical School, Boston, MA
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA
- Howard Hughes Medical Institute, Boston, MA
| | - Kathrin de la Rosa
- Department of Cancer and Immunology, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Lennart Hammarström
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Mirjam van der Burg
- Department of Pediatrics, Laboratory for Pediatric Immunology, Leiden University Medical Center, Leiden, the Netherlands
| | - Frederick W. Alt
- Department of Genetics, Harvard Medical School, Boston, MA
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA
- Howard Hughes Medical Institute, Boston, MA
| | - Qiang Pan-Hammarström
- Division of Immunology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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3
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Han X, Liu Z. Aberrant Somatic Hypermutation at Super-enhancer Drives B Cell Lymphoma Transformation. GENOMICS, PROTEOMICS & BIOINFORMATICS 2024; 22:qzae015. [PMID: 39424289 DOI: 10.1093/gpbjnl/qzae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/06/2024] [Indexed: 10/21/2024]
Affiliation(s)
- Xueshuai Han
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaoqi Liu
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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4
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Tambe A, MacCarthy T, Pavri R. Interpretable deep learning reveals the role of an E-box motif in suppressing somatic hypermutation of AGCT motifs within human immunoglobulin variable regions. Front Immunol 2024; 15:1407470. [PMID: 38863710 PMCID: PMC11165027 DOI: 10.3389/fimmu.2024.1407470] [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: 03/26/2024] [Accepted: 05/08/2024] [Indexed: 06/13/2024] Open
Abstract
Introduction Somatic hypermutation (SHM) of immunoglobulin variable (V) regions by activation induced deaminase (AID) is essential for robust, long-term humoral immunity against pathogen and vaccine antigens. AID mutates cytosines preferentially within WRCH motifs (where W=A or T, R=A or G and H=A, C or T). However, it has been consistently observed that the mutability of WRCH motifs varies substantially, with large variations in mutation frequency even between multiple occurrences of the same motif within a single V region. This has led to the notion that the immediate sequence context of WRCH motifs contributes to mutability. Recent studies have highlighted the potential role of local DNA sequence features in promoting mutagenesis of AGCT, a commonly mutated WRCH motif. Intriguingly, AGCT motifs closer to 5' ends of V regions, within the framework 1 (FW1) sub-region1, mutate less frequently, suggesting an SHM-suppressing sequence context. Methods Here, we systematically examined the basis of AGCT positional biases in human SHM datasets with DeepSHM, a machine-learning model designed to predict SHM patterns. This was combined with integrated gradients, an interpretability method, to interrogate the basis of DeepSHM predictions. Results DeepSHM predicted the observed positional differences in mutation frequencies at AGCT motifs with high accuracy. For the conserved, lowly mutating AGCT motifs in FW1, integrated gradients predicted a large negative contribution of 5'C and 3'G flanking residues, suggesting that a CAGCTG context in this location was suppressive for SHM. CAGCTG is the recognition motif for E-box transcription factors, including E2A, which has been implicated in SHM. Indeed, we found a strong, inverse relationship between E-box motif fidelity and mutation frequency. Moreover, E2A was found to associate with the V region locale in two human B cell lines. Finally, analysis of human SHM datasets revealed that naturally occurring mutations in the 3'G flanking residues, which effectively ablate the E-box motif, were associated with a significantly increased rate of AGCT mutation. Discussion Our results suggest an antagonistic relationship between mutation frequency and the binding of E-box factors like E2A at specific AGCT motif contexts and, therefore, highlight a new, suppressive mechanism regulating local SHM patterns in human V regions.
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Affiliation(s)
- Abhik Tambe
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, United States
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
- Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
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Mu Y, Chen Z, Plummer JB, Zelazowska MA, Dong Q, Krug LT, McBride KM. UNG-RPA interaction governs the choice between high-fidelity and mutagenic uracil repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591927. [PMID: 38746347 PMCID: PMC11092621 DOI: 10.1101/2024.04.30.591927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Mammalian Uracil DNA glycosylase (UNG) removes uracils and initiates high-fidelity base excision repair to maintain genomic stability. During B cell development, activation-induced cytidine deaminase (AID) creates uracils that UNG processes in an error-prone fashion to accomplish immunoglobulin (Ig) somatic hypermutation (SHM) or class switch recombination (CSR). The mechanism that governs high-fidelity versus mutagenic uracil repair is not understood. The B cell tropic gammaherpesvirus (GHV) encodes a functional homolog of UNG that can process AID induced genomic uracils. GHVUNG does not support hypermutation, suggesting intrinsic properties of UNG influence repair outcome. Noting the structural divergence between the UNGs, we define the RPA interacting motif as the determinant of mutation outcome. UNG or RPA mutants unable to interact with each other, only support high-fidelity repair. In B cells, transversions at the Ig variable region are abated while CSR is supported. Thus UNG-RPA governs the generation of mutations and has implications for locus specific mutagenesis in B cells and deamination associated mutational signatures in cancer.
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6
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Lauring MC, Basu U. Somatic hypermutation mechanisms during lymphomagenesis and transformation. Curr Opin Genet Dev 2024; 85:102165. [PMID: 38428317 DOI: 10.1016/j.gde.2024.102165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 03/03/2024]
Abstract
B cells undergoing physiologically programmed or aberrant genomic alterations provide an opportune system to study the causes and consequences of genome mutagenesis. Activated B cells in germinal centers express activation-induced cytidine deaminase (AID) to accomplish physiological somatic hypermutation (SHM) of their antibody-encoding genes. In attempting to diversify their immunoglobulin (Ig) heavy- and light-chain genes, several B-cell clones successfully optimize their antigen-binding affinities. However, SHM can sometimes occur at non-Ig loci, causing genetic alternations that lay the foundation for lymphomagenesis, particularly diffuse large B-cell lymphoma. Thus, SHM acts as a double-edged sword, bestowing superb humoral immunity at the potential risk of initiating disease. We refer to off-target, non-Ig AID mutations - that are often but not always associated with disease - as aberrant SHM (aSHM). A key challenge in understanding SHM and aSHM is determining how AID targets and mutates specific DNA sequences in the Ig loci to generate antibody diversity and non-Ig genes to initiate lymphomagenesis. Herein, we discuss some current advances regarding the regulation of AID's DNA mutagenesis activity in B cells.
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Affiliation(s)
- Max C Lauring
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York 10032, USA.
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York 10032, USA.
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7
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Leeman-Neill RJ, Bhagat G, Basu U. AID in non-Hodgkin B-cell lymphomas: The consequences of on- and off-target activity. Adv Immunol 2024; 161:127-164. [PMID: 38763700 DOI: 10.1016/bs.ai.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2024]
Abstract
Activation induced cytidine deaminase (AID) is a key element of the adaptive immune system, required for immunoglobulin isotype switching and affinity maturation of B-cells as they undergo the germinal center (GC) reaction in peripheral lymphoid tissue. The inherent DNA damaging activity of this enzyme can also have off-target effects in B-cells, producing lymphomagenic chromosomal translocations that are characteristic features of various classes of non-Hodgkin B-cell lymphoma (B-NHL), and generating oncogenic mutations, so-called aberrant somatic hypermutation (aSHM). Additionally, AID has been found to affect gene expression through demethylation as well as altered interactions between gene regulatory elements. These changes have been most thoroughly studied in B-NHL arising from GC B-cells. Here, we describe the most common classes of GC-derived B-NHL and explore the consequences of on- and off-target AID activity in B and plasma cell neoplasms. The relationships between AID expression, including effects of infection and other exposures/agents, mutagenic activity and lymphoma biology are also discussed.
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Affiliation(s)
- Rebecca J Leeman-Neill
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States; Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.
| | - Govind Bhagat
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
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8
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Malzl D, Peycheva M, Rahjouei A, Gnan S, Klein KN, Nazarova M, Schoeberl UE, Gilbert DM, Buonomo SCB, Di Virgilio M, Neumann T, Pavri R. RIF1 regulates early replication timing in murine B cells. Nat Commun 2023; 14:8049. [PMID: 38081811 PMCID: PMC10713614 DOI: 10.1038/s41467-023-43778-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
The mammalian DNA replication timing (RT) program is crucial for the proper functioning and integrity of the genome. The best-known mechanism for controlling RT is the suppression of late origins of replication in heterochromatin by RIF1. Here, we report that in antigen-activated, hypermutating murine B lymphocytes, RIF1 binds predominantly to early-replicating active chromatin and promotes early replication, but plays a minor role in regulating replication origin activity, gene expression and genome organization in B cells. Furthermore, we find that RIF1 functions in a complementary and non-epistatic manner with minichromosome maintenance (MCM) proteins to establish early RT signatures genome-wide and, specifically, to ensure the early replication of highly transcribed genes. These findings reveal additional layers of regulation within the B cell RT program, driven by the coordinated activity of RIF1 and MCM proteins.
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Affiliation(s)
- Daniel Malzl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090, Lazarettgasse 14, Vienna, Austria
| | - Mihaela Peycheva
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090, Lazarettgasse 14, Vienna, Austria
| | - Ali Rahjouei
- Max-Delbruck Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
| | - Stefano Gnan
- School of Biological Sciences, Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Kyle N Klein
- San Diego Biomedical Research Institute, San Diego, CA, 92121, USA
| | - Mariia Nazarova
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
| | - Ursula E Schoeberl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria
| | - David M Gilbert
- San Diego Biomedical Research Institute, San Diego, CA, 92121, USA
| | - Sara C B Buonomo
- School of Biological Sciences, Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Michela Di Virgilio
- Max-Delbruck Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria.
- Quantro Therapeutics, Vienna Biocenter, 1030, Vienna, Austria.
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030, Vienna, Austria.
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Gómez-Escolar C, Marina-Zárate E, Ramiro AR. Activation-induced deaminase expression defines mature B cell lymphoma in the mouse. Front Immunol 2023; 14:1268930. [PMID: 37809061 PMCID: PMC10558245 DOI: 10.3389/fimmu.2023.1268930] [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: 07/28/2023] [Accepted: 09/06/2023] [Indexed: 10/10/2023] Open
Abstract
Germinal centers (GCs) are the sites of secondary antibody diversification and underlie the mechanism of action of many vaccination strategies. Activation-induced deaminase (AID) triggers secondary antibody diversification through the introduction of somatic changes in immunoglobulin genes which lead to the generation of antibodies of higher affinity and more specialized effector functions. However, AID can also target other genomic regions, giving rise to mutations and chromosome translocations with oncogenic potential. Many human lymphomas originate from mature B cells that have undergone the GC reaction, such as the diffuse large B cell lymphoma, the follicular lymphoma and Burkitt lymphoma, and carry chromosome translocations. Mature B cell lymphomagenesis has been modeled in the mouse by the genetic introduction of chromosome translocations. Here, we present an in-depth characterization of one such model, λ-MYC mice. We found that young pre-tumor stage mice had a prominent block in early B cell differentiation that resulted in the generation of very aggressive tumors lacking surface B cell receptor (BCR) expression, indicating that a large fraction of tumors in λ-MYC mice arise from B cell precursors rather than from mature B cells. Further, we assessed the contribution of AID to B cell lymphomagenesis in λ-MYC mice by using a genetic tracer of historical AID expression. Only a fraction of tumors contained cells of GC origin as defined by AID expression. AID-experienced tumors associated with longer survival and resembled mature B cell lymphomas. Thus, AID expression defines Burkitt lymphomagenesis in λ-MYC mice.
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Affiliation(s)
| | | | - Almudena R. Ramiro
- B Lymphocyte Biology Lab, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
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10
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Canoy RJ, Shmakova A, Karpukhina A, Lomov N, Tiukacheva E, Kozhevnikova Y, André F, Germini D, Vassetzky Y. Specificity of cancer-related chromosomal translocations is linked to proximity after the DNA double-strand break and subsequent selection. NAR Cancer 2023; 5:zcad049. [PMID: 37750169 PMCID: PMC10518054 DOI: 10.1093/narcan/zcad049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/01/2023] [Accepted: 09/14/2023] [Indexed: 09/27/2023] Open
Abstract
Most cancer-related chromosomal translocations appear to be cell type specific. It is currently unknown why different chromosomal translocations occur in different cells. This can be due to either the occurrence of particular translocations in specific cell types or adaptive survival advantage conferred by translocations only in specific cells. We experimentally addressed this question by double-strand break (DSB) induction at MYC, IGH, AML and ETO loci in the same cell to generate chromosomal translocations in different cell lineages. Our results show that any translocation can potentially arise in any cell type. We have analyzed different factors that could affect the frequency of the translocations, and only the spatial proximity between gene loci after the DSB induction correlated with the resulting translocation frequency, supporting the 'breakage-first' model. Furthermore, upon long-term culture of cells with the generated chromosomal translocations, only oncogenic MYC-IGH and AML-ETO translocations persisted over a 60-day period. Overall, the results suggest that chromosomal translocation can be generated after DSB induction in any type of cell, but whether the cell with the translocation would persist in a cell population depends on the cell type-specific selective survival advantage that the chromosomal translocation confers to the cell.
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Affiliation(s)
- Reynand Jay Canoy
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, 1000 Manila, The Philippines
| | - Anna Shmakova
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
- Laboratory of Molecular Endocrinology, Institute of Experimental Cardiology, Federal State Budgetary Organization ‘National Cardiology Research Center’ of the Ministry of Health of the Russian Federation, 127994 Moscow, Russia
- Koltzov Institute of Developmental Biology, 117334 Moscow, Russia
| | - Anna Karpukhina
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
- Koltzov Institute of Developmental Biology, 117334 Moscow, Russia
| | - Nikolai Lomov
- Department of Molecular Biology, Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Eugenia Tiukacheva
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
- Koltzov Institute of Developmental Biology, 117334 Moscow, Russia
| | - Yana Kozhevnikova
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
| | - Franck André
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
| | - Diego Germini
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
| | - Yegor Vassetzky
- UMR 9018, CNRS, Univ. Paris-Sud, Université Paris Saclay, Institut Gustave Roussy, F-94805 Villejuif, France
- Koltzov Institute of Developmental Biology, 117334 Moscow, Russia
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11
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Bello A, Hirth G, Voigt S, Tepper S, Jungnickel B. Mechanism and regulation of secondary immunoglobulin diversification. Cell Cycle 2023; 22:2070-2087. [PMID: 37909747 PMCID: PMC10761156 DOI: 10.1080/15384101.2023.2275397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/20/2023] [Indexed: 11/03/2023] Open
Abstract
Secondary immunoglobulin diversification by somatic hypermutation and class switch recombination in B cells is instrumental for an adequate adaptive humoral immune response. These genetic events may, however, also introduce aberrations into other cellular genes and thereby cause B cell malignancies. While the basic mechanism of somatic hypermutation and class switch recombination is now well understood, their regulation and in particular the mechanism of their specific targeting to immunoglobulin genes is still rather mysterious. In this review, we summarize the current knowledge on the mechanism and regulation of secondary immunoglobulin diversification and discuss known mechanisms of physiological targeting to immunoglobulin genes and mistargeting to other cellular genes. We summarize open questions in the field and provide an outlook on future research.
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Affiliation(s)
- Amanda Bello
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Gianna Hirth
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Stefanie Voigt
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Sandra Tepper
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Berit Jungnickel
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
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12
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Wang Y, Zhang S, Yang X, Hwang JK, Zhan C, Lian C, Wang C, Gui T, Wang B, Xie X, Dai P, Zhang L, Tian Y, Zhang H, Han C, Cai Y, Hao Q, Ye X, Liu X, Liu J, Cao Z, Huang S, Song J, Pan-Hammarström Q, Zhao Y, Alt FW, Zheng X, Da LT, Yeap LS, Meng FL. Mesoscale DNA feature in antibody-coding sequence facilitates somatic hypermutation. Cell 2023; 186:2193-2207.e19. [PMID: 37098343 DOI: 10.1016/j.cell.2023.03.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 03/06/2023] [Accepted: 03/24/2023] [Indexed: 04/27/2023]
Abstract
Somatic hypermutation (SHM), initiated by activation-induced cytidine deaminase (AID), generates mutations in the antibody-coding sequence to allow affinity maturation. Why these mutations intrinsically focus on the three nonconsecutive complementarity-determining regions (CDRs) remains enigmatic. Here, we found that predisposition mutagenesis depends on the single-strand (ss) DNA substrate flexibility determined by the mesoscale sequence surrounding AID deaminase motifs. Mesoscale DNA sequences containing flexible pyrimidine-pyrimidine bases bind effectively to the positively charged surface patches of AID, resulting in preferential deamination activities. The CDR hypermutability is mimicable in in vitro deaminase assays and is evolutionarily conserved among species using SHM as a major diversification strategy. We demonstrated that mesoscale sequence alterations tune the in vivo mutability and promote mutations in an otherwise cold region in mice. Our results show a non-coding role of antibody-coding sequence in directing hypermutation, paving the way for the synthetic design of humanized animal models for optimal antibody discovery and explaining the AID mutagenesis pattern in lymphoma.
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Affiliation(s)
- Yanyan Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Senxin Zhang
- Department of Mathematics, Shanghai Normal University, Shanghai 200234, China
| | - Xinrui Yang
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Joyce K Hwang
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Chuanzong Zhan
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chaoyang Lian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chong Wang
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Tuantuan Gui
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Binbin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xia Xie
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Pengfei Dai
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Lu Zhang
- School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Ying Tian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huizhi Zhang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Chong Han
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Yanni Cai
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Qian Hao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaofei Ye
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, 141-83 Stockholm, Sweden; Kindstar Global Precision Medicine Institute, Wuhan 430000, China
| | - Xiaojing Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Jiaquan Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhiwei Cao
- School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shaohui Huang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; School of Biosciences, University of Chinese Academy of Sciences, Beijing 101499, China
| | - Jie Song
- Hangzhou Institute of Medicine, Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
| | - Qiang Pan-Hammarström
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, 141-83 Stockholm, Sweden; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Yaofeng Zhao
- State Key Laboratory of Farm Animal Biotech Breeding, China Agricultural University, Beijing 100193, China
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Xiaoqi Zheng
- Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin-Tai Da
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Leng-Siew Yeap
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Shanghai Huashen Institute of Microbes and Infections, Shanghai 200052, China.
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13
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Boehm T, Morimoto R, Trancoso I, Aleksandrova N. Genetic conflicts and the origin of self/nonself-discrimination in the vertebrate immune system. Trends Immunol 2023; 44:372-383. [PMID: 36941153 DOI: 10.1016/j.it.2023.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/23/2023] [Accepted: 02/26/2023] [Indexed: 03/22/2023]
Abstract
Genetic conflicts shape the genomes of prokaryotic and eukaryotic organisms. Here, we argue that some of the key evolutionary novelties of adaptive immune systems of vertebrates are descendants of prokaryotic toxin-antitoxin (TA) systems. Cytidine deaminases and RAG recombinase have evolved from genotoxic enzymes to programmable editors of host genomes, supporting the astounding discriminatory capability of variable lymphocyte receptors of jawless vertebrates, as well as immunoglobulins and T cell receptors of jawed vertebrates. The evolutionarily recent lymphoid lineage is uniquely sensitive to mutations of the DNA maintenance methylase, which is an orphaned distant relative of prokaryotic restriction-modification systems. We discuss how the emergence of adaptive immunity gave rise to higher order genetic conflicts between genetic parasites and their vertebrate host.
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Affiliation(s)
- Thomas Boehm
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Ryo Morimoto
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Inês Trancoso
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
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14
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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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15
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Crouch S, Painter D, Barrans SL, Roman E, Beer PA, Cooke SL, Glover P, Van Hoppe SJ, Webster N, Lacy SE, Ruiz C, Campbell PJ, Hodson DJ, Patmore R, Burton C, Smith A, Tooze RM. Molecular subclusters of follicular lymphoma: a report from the United Kingdom's Haematological Malignancy Research Network. Blood Adv 2022; 6:5716-5731. [PMID: 35363872 PMCID: PMC9619185 DOI: 10.1182/bloodadvances.2021005284] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 03/06/2022] [Indexed: 11/20/2022] Open
Abstract
Follicular lymphoma (FL) is morphologically and clinically diverse, with mutations in epigenetic regulators alongside t(14;18) identified as disease-initiating events. Identification of additional mutational entities confirms this cancer's heterogeneity, but whether mutational data can be resolved into mechanistically distinct subsets remains an open question. Targeted sequencing was applied to an unselected population-based FL cohort (n = 548) with full clinical follow-up (n = 538), which included 96 diffuse large B-cell lymphoma (DLBCL) transformations. We investigated whether molecular subclusters of FL can be identified and whether mutational data provide predictive information relating to transformation. DNA extracted from FL samples was sequenced with a 293-gene panel representing genes frequently mutated in DLBCL and FL. Three clusters were resolved using mutational data alone, independent of translocation status: FL_aSHM, with high burden of aberrant somatic hypermutation (aSHM) targets; FL_STAT6, with high STAT6 & CREBBP mutation and low aSHM; and FL_Com, with the absence of features of other subtypes and enriched KMT2D mutation. Analysis of mutation signatures demonstrated differential enrichment of predicted mutation signatures between subgroups and a dominant preference in the FL_aSHM subgroup for G(C>T)T and G(C>T)C transitions consistent with previously defined aSHM-like patterns. Of transformed cases with paired samples, 17 of 26 had evidence of branching evolution. Poorer overall survival (OS) in the aSHM group (P = .04) was associated with older age; however, overall tumor genetics provided limited information to predict individual patient risk. Our approach identifies 3 molecular subclusters of FL linked to differences in underlying mechanistic pathways. These clusters, which may be further resolved by the inclusion of translocation status and wider mutation profiles, have implications for understanding pathogenesis as well as improving treatment strategies in the future.
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Affiliation(s)
- Simon Crouch
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, United Kingdom
| | - Daniel Painter
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, United Kingdom
| | - Sharon L. Barrans
- Haematological Malignancy Diagnostic Service, St. James’s Institute of Oncology, Leeds, United Kingdom
| | - Eve Roman
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, United Kingdom
| | - Philip A. Beer
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Susanna L. Cooke
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Paul Glover
- Haematological Malignancy Diagnostic Service, St. James’s Institute of Oncology, Leeds, United Kingdom
| | - Suzan J.L. Van Hoppe
- Haematological Malignancy Diagnostic Service, St. James’s Institute of Oncology, Leeds, United Kingdom
| | - Nichola Webster
- Haematological Malignancy Diagnostic Service, St. James’s Institute of Oncology, Leeds, United Kingdom
| | - Stuart E. Lacy
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, United Kingdom
| | - Camilo Ruiz
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | | | - Daniel J. Hodson
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Russell Patmore
- Queen’s Centre for Oncology and Haematology, Castle Hill Hospital, Cottingham, United Kingdom
| | - Cathy Burton
- Haematological Malignancy Diagnostic Service, St. James’s Institute of Oncology, Leeds, United Kingdom
| | - Alexandra Smith
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, United Kingdom
| | - Reuben M. Tooze
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, United Kingdom
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16
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Soikkeli AI, Kyläniemi MK, Sihto H, Alinikula J. Oncogenic Merkel Cell Polyomavirus T Antigen Truncating Mutations are Mediated by APOBEC3 Activity in Merkel Cell Carcinoma. CANCER RESEARCH COMMUNICATIONS 2022; 2:1344-1354. [PMID: 36970060 PMCID: PMC10035372 DOI: 10.1158/2767-9764.crc-22-0211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/17/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
Merkel cell carcinoma (MCC) is an aggressive skin cancer, which is frequently caused by Merkel cell polyomavirus (MCPyV). Mutations of MCPyV tumor (T) antigens are major pathologic events of virus-positive (MCPyV+) MCCs, but their source is unclear. Activation-induced cytidine deaminase (AID)/APOBEC family cytidine deaminases contribute to antiviral immunity by mutating viral genomes and are potential carcinogenic mutators. We studied the contribution of AID/APOBEC cytidine deaminases to MCPyV large T (LT) truncation events. The MCPyV LT area in MCCs was enriched with cytosine-targeting mutations, and a strong APOBEC3 mutation signature was observed in MCC sequences. AICDA and APOBEC3 expression were detected in the Finnish MCC sample cohort, and LT expression correlated with APOBEC3H and APOBEC3G. Marginal but statistically significant somatic hypermutation targeting activity was detected in the MCPyV regulatory region. Our results suggest that APOBEC3 cytidine deaminases are a plausible cause of the LT truncating mutations in MCPyV+ MCC, while the role of AID in MCC carcinogenesis is unlikely.
Significance:
We uncover APOBEC3 mutation signature in MCPyV LT that reveals the likely cause of mutations underlying MCPyV+ MCC. We further reveal an expression pattern of APOBECs in a large Finnish MCC sample cohort. Thus, the findings presented here suggest a molecular mechanism underlying an aggressive carcinoma with poor prognosis.
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Affiliation(s)
- Anni I. Soikkeli
- 1Unit of Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland
- 2Turku Doctoral Programme of Molecular Medicine, University of Turku, Turku, Finland
| | - Minna K. Kyläniemi
- 3Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Harri Sihto
- 4Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Jukka Alinikula
- 1Unit of Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland
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17
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Heterologous expression of hAID in E. coli leads to the production of a splice isoform of AID: hAIDδC, a mystery to be explored. Protein Expr Purif 2022; 199:106149. [PMID: 35952962 DOI: 10.1016/j.pep.2022.106149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/21/2022]
Abstract
Activation-induced cytidine deaminase (AID) is a key player that initiates antibody diversification in activated B-cell. AID mediates somatic hypermutation (SHM) and class switch recombination (CSR) via the deamination of cytosine to uracil at the Ig locus, resulting in the production of high-affinity antibodies. AID is predominantly restricted to Ig genes, whereas off-targeting of AID leads to lymphocyte-related malignancies. Interestingly, apart from FL-AID other splice isoforms of AID are highly expressed in the lymphocyte malignancies. In our study, we found that the heterologous expression of hAID-FL in E. coli cells produced two induced bands of hAID as demonstrated by SDS-PAGE and western blotting. Remarkably, peptide mapping data predicted that one band is hAID-FL and the other is its splice isoform, hAIDδE4a. To get an insight into why E. coli cells expressed hAID-FL and hAID variant, we mutated the 5' and 3' splice site of a putative intron of hAID, but it failed to produce only hAID-FL. Incidentally, hAID expressed with fusion partners also displayed two bands, and peptide mapping data strongly suggest that besides hAID-FL, the lower band showed a significant number of amino acids missing towards the C-terminal domain (named as hAIDδC). Our results are the first report to show that expression of recombinant hAID alone or irrespective of solubilization tags in E. coli cells produced hAID-FL and hAIDδC. It will be fascinating to explore the potential mechanism underlying the expression of hAIDδC from recombinant hAID plasmid in E. coli cells.
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18
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Çakan E, Gunaydin G. Activation induced cytidine deaminase: An old friend with new faces. Front Immunol 2022; 13:965312. [PMID: 36405752 PMCID: PMC9670734 DOI: 10.3389/fimmu.2022.965312] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022] Open
Abstract
Activation induced cytidine deaminase (AID) protein is a member of APOBEC family. AID converts cytidine to uracil, which is a key step for somatic hypermutation (SHM) and class switch recombination (CSR). AID also plays critical roles in B cell precursor stages, removing polyreactive B cells from immune repertoire. Since the main function of AID is inducing point mutations, dysregulation can lead to increased mutation load, translocations, disturbed genomic integrity, and lymphomagenesis. As such, expression of AID as well as its function is controlled strictly at various molecular steps. Other members of the APOBEC family also play crucial roles during carcinogenesis. Considering all these functions, AID represents a bridge, linking chronic inflammation to carcinogenesis and immune deficiencies to autoimmune manifestations.
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Affiliation(s)
- Elif Çakan
- Hacettepe University School of Medicine, Sihhiye, Ankara, Turkey
| | - Gurcan Gunaydin
- Department of Basic Oncology, Hacettepe University Cancer Institute, Sihhiye, Ankara, Turkey
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19
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Peycheva M, Neumann T, Malzl D, Nazarova M, Schoeberl UE, Pavri R. DNA replication timing directly regulates the frequency of oncogenic chromosomal translocations. Science 2022; 377:eabj5502. [DOI: 10.1126/science.abj5502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Chromosomal translocations result from the joining of DNA double-strand breaks (DSBs) and frequently cause cancer. However, the steps linking DSB formation to DSB ligation remain undeciphered. We report that DNA replication timing (RT) directly regulates lymphomagenic
Myc
translocations during antibody maturation in B cells downstream of DSBs and independently of DSB frequency. Depletion of minichromosome maintenance complexes alters replication origin activity, decreases translocations, and deregulates global RT. Ablating a single origin at
Myc
causes an early-to-late RT switch, loss of translocations, and reduced proximity with the immunoglobulin heavy chain (
Igh
) gene, its major translocation partner. These phenotypes were reversed by restoring early RT. Disruption of early RT also reduced tumorigenic translocations in human leukemic cells. Thus, RT constitutes a general mechanism in translocation biogenesis linking DSB formation to DSB ligation.
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Affiliation(s)
- Mihaela Peycheva
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna Biocenter, 1030 Vienna, Austria
| | - Daniel Malzl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Mariia Nazarova
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Ursula E. Schoeberl
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter, 1030 Vienna, Austria
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20
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Hu H, Zhong T, Jiang S. H2AFX might be a prognostic biomarker for hepatocellular carcinoma. Cancer Rep (Hoboken) 2022; 6:e1684. [PMID: 35903980 PMCID: PMC9875689 DOI: 10.1002/cnr2.1684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND H2AFX can play a central role in DNA repair, replication, transcription regulation, and chromosomal stability. However, there is little research to explore the expression of H2AFX in cancers. Moreover, the correlation between the expression of H2AFX and tumor immunity, which affects the prognosis of hepatocellular carcinoma (HCC), is not clear. This article aimed to observe the correlation between H2AFX and tumor tissue infiltration biomarkers in HCC and its prognostic potential in HCC. METHOD Oncomine and TIMER database were used to assess the expression level of H2AFX mRNA, and GEPIA and Kaplan-Meier databases were used to evaluate its prognostic potential. The TIMER database analyzed the relationship between h2afx expression level and tumor immune cell infiltration markers in liver cancer tissues. RESULTS The results showed that H2AFX was overexpressed in tumor tissues than normal tissues in HCC via analysis, and its expression level was correlated with the survival rate of HCC. Moreover, the expression level of H2AFX was related to various immune biomarkers. These results show that overexpression of H2AFX would reflect the poor prognosis of HCC, and these would also reflect that the gene H2AFX can affect the infiltration of HCC immune cells and then play a role in regulating tumor immunity. CONCLUSION Our study showed that the gene H2AFX might be a potential poor prognostic biomarker in HCC and might be involved in the infiltration of HCC immune cells.
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Affiliation(s)
- Hailiang Hu
- Department of Blood TransfusionThe First Affiliated Hospital of Anhui Medical UniversityAnhuiChina
| | - Tao Zhong
- Department of Blood TransfusionThe First Affiliated Hospital of Anhui Medical UniversityAnhuiChina
| | - Suwei Jiang
- Department of Biological and Environmental EngineeringHefei UniversityHefeiAnhuiP. R. China
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21
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Leung W, Teater M, Durmaz C, Meydan C, Chivu AG, Chadburn A, Rice EJ, Muley A, Camarillo JM, Arivalagan J, Li Z, Flowers CR, Kelleher NL, Danko CG, Imielinski M, Dave SS, Armstrong SA, Mason CE, Melnick AM. SETD2 Haploinsufficiency Enhances Germinal Center-Associated AICDA Somatic Hypermutation to Drive B-cell Lymphomagenesis. Cancer Discov 2022; 12:1782-1803. [PMID: 35443279 PMCID: PMC9262862 DOI: 10.1158/2159-8290.cd-21-1514] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/08/2022] [Accepted: 04/18/2022] [Indexed: 01/26/2023]
Abstract
SETD2 is the sole histone methyltransferase responsible for H3K36me3, with roles in splicing, transcription initiation, and DNA damage response. Homozygous disruption of SETD2 yields a tumor suppressor effect in various cancers. However, SETD2 mutation is typically heterozygous in diffuse large B-cell lymphomas. Here we show that heterozygous Setd2 deficiency results in germinal center (GC) hyperplasia and increased competitive fitness, with reduced DNA damage checkpoint activity and apoptosis, resulting in accelerated lymphomagenesis. Impaired DNA damage sensing in Setd2-haploinsufficient germinal center B (GCB) and lymphoma cells associated with increased AICDA-induced somatic hypermutation, complex structural variants, and increased translocations including those activating MYC. DNA damage was selectively increased on the nontemplate strand, and H3K36me3 loss was associated with greater RNAPII processivity and mutational burden, suggesting that SETD2-mediated H3K36me3 is required for proper sensing of cytosine deamination. Hence, Setd2 haploinsufficiency delineates a novel GCB context-specific oncogenic pathway involving defective epigenetic surveillance of AICDA-mediated effects on transcribed genes. SIGNIFICANCE Our findings define a B cell-specific oncogenic effect of SETD2 heterozygous mutation, which unleashes AICDA mutagenesis of nontemplate strand DNA in the GC reaction, resulting in lymphomas with heavy mutational burden. GC-derived lymphomas did not tolerate SETD2 homozygous deletion, pointing to a novel context-specific therapeutic vulnerability. This article is highlighted in the In This Issue feature, p. 1599.
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Affiliation(s)
- Wilfred Leung
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York
- Department of Biomedical Sciences, Cornell University, Ithaca, New York
| | - Matt Teater
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York
| | - Ceyda Durmaz
- Graduate Program of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, New York
| | - Cem Meydan
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, New York
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York
- The WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, New York
| | - Alexandra G Chivu
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Amy Chadburn
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York
| | - Edward J Rice
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Ashlesha Muley
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York
| | - Jeannie M Camarillo
- Departments of Chemistry, Molecular Biosciences and the National Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois
| | - Jaison Arivalagan
- Departments of Chemistry, Molecular Biosciences and the National Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois
| | - Ziyi Li
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Christopher R Flowers
- Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Neil L Kelleher
- Departments of Chemistry, Molecular Biosciences and the National Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois
| | - Charles G Danko
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Marcin Imielinski
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York
- New York Genome Center, New York, New York
- Caryl and Israel Englander Institute for Precision Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, New York
| | - Sandeep S Dave
- Center for Genomic and Computational Biology and Department of Medicine, Duke University, Durham, North Carolina
| | - Scott A Armstrong
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, New York
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York
- The WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, New York
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York
| | - Ari M Melnick
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York
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22
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Bal E, Kumar R, Hadigol M, Holmes AB, Hilton LK, Loh JW, Dreval K, Wong JCH, Vlasevska S, Corinaldesi C, Soni RK, Basso K, Morin RD, Khiabanian H, Pasqualucci L, Dalla-Favera R. Super-enhancer hypermutation alters oncogene expression in B cell lymphoma. Nature 2022; 607:808-815. [PMID: 35794478 PMCID: PMC9583699 DOI: 10.1038/s41586-022-04906-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 05/25/2022] [Indexed: 12/16/2022]
Abstract
Diffuse large B cell lymphoma (DLBCL) is the most common B cell non-Hodgkin lymphoma and remains incurable in around 40% of patients. Efforts to sequence the coding genome identified several genes and pathways that are altered in this disease, including potential therapeutic targets1-5. However, the non-coding genome of DLBCL remains largely unexplored. Here we show that active super-enhancers are highly and specifically hypermutated in 92% of samples from individuals with DLBCL, display signatures of activation-induced cytidine deaminase activity, and are linked to genes that encode B cell developmental regulators and oncogenes. As evidence of oncogenic relevance, we show that the hypermutated super-enhancers linked to the BCL6, BCL2 and CXCR4 proto-oncogenes prevent the binding and transcriptional downregulation of the corresponding target gene by transcriptional repressors, including BLIMP1 (targeting BCL6) and the steroid receptor NR3C1 (targeting BCL2 and CXCR4). Genetic correction of selected mutations restored repressor DNA binding, downregulated target gene expression and led to the counter-selection of cells containing corrected alleles, indicating an oncogenic dependency on the super-enhancer mutations. This pervasive super-enhancer mutational mechanism reveals a major set of genetic lesions deregulating gene expression, which expands the involvement of known oncogenes in DLBCL pathogenesis and identifies new deregulated gene targets of therapeutic relevance.
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Affiliation(s)
- Elodie Bal
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
| | - Rahul Kumar
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India
| | - Mohammad Hadigol
- Center for Systems and Computational Biology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
| | - Antony B Holmes
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
| | - Laura K Hilton
- Centre for Lymphoid Cancer, BC Cancer Research Centre, Vancouver, British Columbia, Canada
| | - Jui Wan Loh
- Center for Systems and Computational Biology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
| | - Kostiantyn Dreval
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Jasper C H Wong
- Centre for Lymphoid Cancer, BC Cancer Research Centre, Vancouver, British Columbia, Canada
| | - Sofija Vlasevska
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
| | | | - Rajesh Kumar Soni
- Proteomics and Macromolecular Crystallography Shared Resource, Columbia University, New York, NY, USA
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA
| | - Katia Basso
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Ryan D Morin
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Genome Sciences Center, BC Cancer Research Institute, Vancouver, British Columbia, Canada
| | - Hossein Khiabanian
- Center for Systems and Computational Biology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
- Department of Pathology and Laboratory Medicine, Rutgers Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, USA
| | - Laura Pasqualucci
- Institute for Cancer Genetics, Columbia University, New York, NY, USA.
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA.
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
| | - Riccardo Dalla-Favera
- Institute for Cancer Genetics, Columbia University, New York, NY, USA.
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA.
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
- Department of Genetics & Development, Columbia University, New York, NY, USA.
- Department of Microbiology & Immunology, Columbia University, New York, NY, USA.
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23
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Tao J, Wang Q, Mendez-Dorantes C, Burns KH, Chiarle R. Frequency and mechanisms of LINE-1 retrotransposon insertions at CRISPR/Cas9 sites. Nat Commun 2022; 13:3685. [PMID: 35760782 PMCID: PMC9237045 DOI: 10.1038/s41467-022-31322-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 06/14/2022] [Indexed: 12/11/2022] Open
Abstract
CRISPR/Cas9-based genome editing has revolutionized experimental molecular biology and entered the clinical world for targeted gene therapy. Identifying DNA modifications occurring at CRISPR/Cas9 target sites is critical to determine efficiency and safety of editing tools. Here we show that insertions of LINE-1 (L1) retrotransposons can occur frequently at CRISPR/Cas9 editing sites. Together with PolyA-seq and an improved amplicon sequencing, we characterize more than 2500 de novo L1 insertions at multiple CRISPR/Cas9 editing sites in HEK293T, HeLa and U2OS cells. These L1 retrotransposition events exploit CRISPR/Cas9-induced DSB formation and require L1 RT activity. Importantly, de novo L1 insertions are rare during genome editing by prime editors (PE), cytidine or adenine base editors (CBE or ABE), consistent with their reduced DSB formation. These data demonstrate that insertions of retrotransposons might be a potential outcome of CRISPR/Cas9 genome editing and provide further evidence on the safety of different CRISPR-based editing tools.
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Affiliation(s)
- Jianli Tao
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
| | - Qi Wang
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | | | - Kathleen H Burns
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Roberto Chiarle
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, 10126, Italy.
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24
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Feng Y, Martin A. Mutagenic repair during antibody diversification: emerging insights. Trends Immunol 2022; 43:604-607. [PMID: 35701290 DOI: 10.1016/j.it.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 05/24/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
Abstract
Deoxyuracils (dUs) produced by activation-induced cytidine deaminase (AID) during antibody diversification are processed by base excision repair (BER) and mismatch repair (MMR) pathways that paradoxically expand this lesion within jawed vertebrate immunoglobulin (Ig) genes. We highlight new findings describing mechanisms that allow B cells to carry out mutagenic DNA repair, an essential process for antibody maturation with implications in cancer pathogenesis.
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Affiliation(s)
- Yuqing Feng
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Alberto Martin
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada.
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25
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Abstract
Activation-induced cytidine deaminase (AID) initiates somatic hypermutation of immunoglobulin (Ig) gene variable regions and class switch recombination (CSR) of Ig heavy chain constant regions. Two decades of intensive research has greatly expanded our knowledge of how AID functions in peripheral B cells to optimize antibody responses against infections, while maintaining tight regulation of AID to restrain its activity to protect B cell genomic integrity. The many exciting recent advances in the field include: 1) the first description of AID's molecular structure, 2) remarkable advances in high throughput approaches that precisely track AID targeting genome-wide, and 3) the discovery that the cohesion-mediate loop extrusion mechanism [initially discovered in V(D)J recombination studies] also governs AID-medicated CSR. These advances have significantly advanced our understanding of AID's biochemical properties in vitro and AID's function and regulation in vivo. This mini review will discuss these recent discoveries and outline the challenges and questions that remain to be addressed.
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26
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Neoantigens – the next frontier in precision immunotherapy for B-cell lymphoproliferative disorders. Blood Rev 2022; 56:100969. [DOI: 10.1016/j.blre.2022.100969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 12/20/2022]
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27
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Wu L, Shukla V, Yadavalli AD, Dinesh RK, Xu D, Rao A, Schatz DG. HMCES protects immunoglobulin genes specifically from deletions during somatic hypermutation. Genes Dev 2022; 36:433-450. [PMID: 35450882 PMCID: PMC9067407 DOI: 10.1101/gad.349438.122] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/29/2022] [Indexed: 01/07/2023]
Abstract
Somatic hypermutation (SHM) produces point mutations in immunoglobulin (Ig) genes in B cells when uracils created by the activation-induced deaminase are processed in a mutagenic manner by enzymes of the base excision repair (BER) and mismatch repair (MMR) pathways. Such uracil processing creates DNA strand breaks and is susceptible to the generation of deleterious deletions. Here, we demonstrate that the DNA repair factor HMCES strongly suppresses deletions without significantly affecting other parameters of SHM in mouse and human B cells, thereby facilitating the production of antigen-specific antibodies. The deletion-prone repair pathway suppressed by HMCES operates downstream from the uracil glycosylase UNG and is mediated by the combined action of BER factor APE2 and MMR factors MSH2, MSH6, and EXO1. HMCES's ability to shield against deletions during SHM requires its capacity to form covalent cross-links with abasic sites, in sharp contrast to its DNA end-joining role in class switch recombination but analogous to its genome-stabilizing role during DNA replication. Our findings lead to a novel model for the protection of Ig gene integrity during SHM in which abasic site cross-linking by HMCES intercedes at a critical juncture during processing of vulnerable gapped DNA intermediates by BER and MMR enzymes.
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Affiliation(s)
- Lizhen Wu
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA
| | - Vipul Shukla
- Division of Signaling and Gene Expression, La Jolla Institute for Immunology, La Jolla, California 92037, USA
| | | | - Ravi K Dinesh
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA
| | - Dijin Xu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Anjana Rao
- Division of Signaling and Gene Expression, La Jolla Institute for Immunology, La Jolla, California 92037, USA
- Department of Pharmacology, Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
- Consortium for Regenerative Medicine, La Jolla, California 92037, USA
| | - David G Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA
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28
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Dobson R, Wotherspoon A, Liu SA, Cucco F, Chen Z, Tang Y, Du M. Widespread in situ follicular neoplasia in patients who subsequently developed follicular lymphoma. J Pathol 2022; 256:369-377. [PMID: 34957565 PMCID: PMC9310836 DOI: 10.1002/path.5861] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 12/07/2021] [Accepted: 12/23/2021] [Indexed: 02/05/2023]
Abstract
In situ follicular neoplasia (ISFN) is usually an occasional incidental finding in lymph nodes by BCL2 immunohistochemistry, and its true scale is unknown. We have identified six cases of follicular lymphoma (FL) with a history of solid neoplasm 4-16 years ago, from which ISFN was identified widely in the surgically cleared lymph nodes (LNs). Using clone-specific PCR and BaseScope in situ hybridisation with primers or probes specific to the VDJ or BCL2-IGHJ junction sequence, we confirmed the clonal identity among different ISFNs and overt-FL in each of the four cases successfully investigated. Mutation analyses of overt-FL by targeted next-generation sequencing identified multiple potential pathogenic changes involving CREBBP, EZH2, KMT2D, TNFRS14, and STAT6. Further investigations of these mutations in paired ISFNs using Fluidigm PCR and Illumina sequencing showed the presence of the FL-associated mutations in early lesions for two of the six cases investigated (CREBBP and KMT2D in one case and STAT6 in the other), with one case displaying stepwise accumulation of its observed mutations. Remarkably, there were considerable divergences in BCL2 variants among different ISFN-involved lymph nodes in all four cases successfully investigated, indicating ongoing intraclonal diversification by somatic hypermutation machinery. Our findings demonstrate widespread distribution of ISFN lesions, further implicating their dynamic nature with the neoplastic cells undergoing active trafficking and clonal evolution. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Rachel Dobson
- Division of Cellular and Molecular Pathology, Department of PathologyUniversity of CambridgeCambridgeUK
| | | | - Shizhang Alexander Liu
- Division of Cellular and Molecular Pathology, Department of PathologyUniversity of CambridgeCambridgeUK
| | - Francesco Cucco
- Division of Cellular and Molecular Pathology, Department of PathologyUniversity of CambridgeCambridgeUK
| | - Zi Chen
- Division of Cellular and Molecular Pathology, Department of PathologyUniversity of CambridgeCambridgeUK
| | - Yuan Tang
- Division of Cellular and Molecular Pathology, Department of PathologyUniversity of CambridgeCambridgeUK
- Department of Pathology, West China HospitalSichuan UniversityChengduPR China
| | - Ming‐Qing Du
- Division of Cellular and Molecular Pathology, Department of PathologyUniversity of CambridgeCambridgeUK
- Department of Histopathology, Addenbrooke’s HospitalCambridge University Hospitals NHS Foundation TrustCambridgeUK
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29
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Liu D, Goodman MF, Pham P, Yu K, Hsieh CL, Lieber MR. The mRNA tether model for activation-induced deaminase and its relevance for Ig somatic hypermutation and class switch recombination. DNA Repair (Amst) 2022; 110:103271. [PMID: 34990960 PMCID: PMC8816865 DOI: 10.1016/j.dnarep.2021.103271] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/19/2021] [Accepted: 12/28/2021] [Indexed: 02/03/2023]
Abstract
Activation-induced deaminase (AID) only deaminates cytosine within single-stranded DNA. Transcription is known to increase AID deamination on duplex DNA substrates during transcription. Using a purified T7 RNA polymerase transcription system, we recently found that AID deamination of a duplex DNA substrate is reduced if RNase A is added during transcription. This finding prompted us to consider that the mRNA tail may contribute to AID action at the nearby transcribed strand (TS) or non-transcribed strand (NTS) of DNA, which are transiently single-stranded in the wake of RNA polymerase movement. Here, we used a purified system to test whether a single-stranded oligonucleotide (oligo) consisting of RNA in the 5' portion and DNA in the 3' portion (i.e., 5'RNA-DNA3', also termed an RNA-DNA fusion substrate) could be deaminated equally efficiently as the same sequence when it is entirely DNA. We found that AID acts on the RNA-DNA fusion substrate and the DNA-only substrate with similar efficiency. Based on this finding and our recent observation on the importance of the mRNA tail, we propose a model in which the proximity and length of the mRNA tail provide a critical site for AID loading to permit a high local collision frequency with the NTS and TS in the transient wake of the RNA polymerase. When the mRNA tail is not present, we know that AID action drops to levels equivalent to when there is no transcription at all. This mRNA tether model explains several local and global features of Ig somatic hypermutation and Ig class switch recombination, while integrating structural and functional features of AID.
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Affiliation(s)
- Di Liu
- Departments of Pathology, Biochemistry & Molecular Biology, and Molecular Microbiology & Immunology, and the Section of Molecular & Computational Biology in the Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA 90033
| | - Myron F. Goodman
- Department of Biological Sciences (Section of Molecular & Computational Biology), University of Southern California, Los Angeles, CA 90089
| | - Phuong Pham
- Department of Biological Sciences (Section of Molecular & Computational Biology), University of Southern California, Los Angeles, CA 90089
| | - Kefei Yu
- Microbiology and Molecular Genetics, Michigan State University, 5175 Biomedical Physical Sciences, East Lansing, MI 48824
| | - Chih-Lin Hsieh
- USC Norris Comprehensive Cancer Center, Department of Urology, University of Southern California and USC Keck School of Medicine, Los Angeles, CA 90033
| | - Michael R. Lieber
- Departments of Pathology, Biochemistry & Molecular Biology, and Molecular Microbiology & Immunology, and the Section of Molecular & Computational Biology in the Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA 90033,Corresponding author: M. Lieber, , ph. 323 865 0568
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30
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Tang C, Krantsevich A, MacCarthy T. Deep learning model of somatic hypermutation reveals importance of sequence context beyond hotspot targeting. iScience 2022; 25:103668. [PMID: 35036866 PMCID: PMC8749460 DOI: 10.1016/j.isci.2021.103668] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/08/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022] Open
Abstract
B cells undergo somatic hypermutation (SHM) of the Immunoglobulin (Ig) variable region to generate high-affinity antibodies. SHM relies on the activity of activation-induced deaminase (AID), which mutates C>U preferentially targeting WRC (W=A/T, R=A/G) hotspots. Downstream mutations at WA Polymerase η hotspots contribute further mutations. Computational models of SHM can describe the probability of mutations essential for vaccine responses. Previous studies using short subsequences (k-mers) failed to explain divergent mutability for the same k-mer. We developed the DeepSHM (Deep learning on SHM) model using k-mers of size 5-21, improving accuracy over previous models. Interpretation of DeepSHM identified an extended WWRCT motif with particularly high mutability. Increased mutability was further associated with lower surrounding G content. Our model also discovered a conserved AGYCTGGGGG (Y=C/T) motif within FW1 of IGHV3 family genes with unusually high T>G substitution rates. Thus, a wider sequence context increases predictive power and identifies features that drive mutational targeting.
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Affiliation(s)
- Catherine Tang
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Artem Krantsevich
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA
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31
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Lue JK, Downs-Canner S, Chaudhuri J. The role of B cells in the development, progression, and treatment of lymphomas and solid tumors. Adv Immunol 2022; 154:71-117. [PMID: 36038195 DOI: 10.1016/bs.ai.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
B cells are integral components of the mammalian immune response as they have the ability to generate antibodies against an almost infinite array of antigens. Over the past several decades, significant scientific progress has been made in understanding that this enormous B cell diversity contributes to pathogen clearance. However, our understanding of the humoral response to solid tumors and to tumor-specific antigens is unclear. In this review, we first discuss how B cells interact with other cells in the tumor microenvironment and influence the development and progression of various solid tumors. The ability of B lymphocytes to generate antibodies against a diverse repertoire of antigens and subsequently tailor the humoral immune response to specific pathogens relies on their ability to undergo genomic alterations during their development and differentiation. We will discuss key transforming events that lead to the development of B cell lymphomas. Overall, this review provides a foundation for innovative therapeutic interventions for both lymphoma and solid tumor malignancies.
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Affiliation(s)
- Jennifer K Lue
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States.
| | - Stephanie Downs-Canner
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States.
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States.
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32
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Tarsalainen A, Maman Y, Meng FL, Kyläniemi MK, Soikkeli A, Budzynska P, McDonald JJ, Šenigl F, Alt FW, Schatz DG, Alinikula J. Ig Enhancers Increase RNA Polymerase II Stalling at Somatic Hypermutation Target Sequences. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:143-154. [PMID: 34862258 PMCID: PMC8702490 DOI: 10.4049/jimmunol.2100923] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/20/2021] [Indexed: 01/03/2023]
Abstract
Somatic hypermutation (SHM) drives the genetic diversity of Ig genes in activated B cells and supports the generation of Abs with increased affinity for Ag. SHM is targeted to Ig genes by their enhancers (diversification activators [DIVACs]), but how the enhancers mediate this activity is unknown. We show using chicken DT40 B cells that highly active DIVACs increase the phosphorylation of RNA polymerase II (Pol II) and Pol II occupancy in the mutating gene with little or no accompanying increase in elongation-competent Pol II or production of full-length transcripts, indicating accumulation of stalled Pol II. DIVAC has similar effect also in human Ramos Burkitt lymphoma cells. The DIVAC-induced stalling is weakly associated with an increase in the detection of ssDNA bubbles in the mutating target gene. We did not find evidence for antisense transcription, or that DIVAC functions by altering levels of H3K27ac or the histone variant H3.3 in the mutating gene. These findings argue for a connection between Pol II stalling and cis-acting targeting elements in the context of SHM and thus define a mechanistic basis for locus-specific targeting of SHM in the genome. Our results suggest that DIVAC elements render the target gene a suitable platform for AID-mediated mutation without a requirement for increasing transcriptional output.
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Affiliation(s)
- Alina Tarsalainen
- Unit of Infections and Immunity, Institute of Biomedicine, University of Turku, 20520 Turku, Finland
| | - Yaakov Maman
- The Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
| | - Fei-Long Meng
- Department of Genetics, Harvard Medical School and Program in Cellular and Molecular Medicine, HHMI, Boston Children’s Hospital, Boston, MA 02115, USA.,Current address: State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Minna K. Kyläniemi
- Unit of Infections and Immunity, Institute of Biomedicine, University of Turku, 20520 Turku, Finland,Current address: Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Anni Soikkeli
- Unit of Infections and Immunity, Institute of Biomedicine, University of Turku, 20520 Turku, Finland
| | - Paulina Budzynska
- Unit of Infections and Immunity, Institute of Biomedicine, University of Turku, 20520 Turku, Finland
| | - Jessica J. McDonald
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA,Current address: The Annenberg Public Policy Center, Philadelphia, PA 19104-3806, USA
| | - Filip Šenigl
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Praha 4, Czech Republic
| | - Frederic W. Alt
- Department of Genetics, Harvard Medical School and Program in Cellular and Molecular Medicine, HHMI, Boston Children’s Hospital, Boston, MA 02115, USA
| | - David G. Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA,Correspondence should be addressed to and
| | - Jukka Alinikula
- Unit of Infections and Immunity, Institute of Biomedicine, University of Turku, 20520 Turku, Finland,Correspondence should be addressed to and
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33
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The role of HIRA-dependent H3.3 deposition and its modifications in the somatic hypermutation of immunoglobulin variable regions. Proc Natl Acad Sci U S A 2021; 118:2114743118. [PMID: 34873043 DOI: 10.1073/pnas.2114743118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2021] [Indexed: 12/17/2022] Open
Abstract
The H3.3 histone variant and its chaperone HIRA are involved in active transcription, but their detailed roles in regulating somatic hypermutation (SHM) of immunoglobulin variable regions in human B cells are not yet fully understood. In this study, we show that the knockout (KO) of HIRA significantly decreased SHM and changed the mutation pattern of the variable region of the immunoglobulin heavy chain (IgH) in the human Ramos B cell line without changing the levels of activation-induced deaminase and other major proteins known to be involved in SHM. Except for H3K79me2/3 and Spt5, many factors related to active transcription, including H3.3, were substantively decreased in HIRA KO cells, and this was accompanied by decreased nascent transcription in the IgH locus. The abundance of ZMYND11 that specifically binds to H3.3K36me3 on the IgH locus was also reduced in the HIRA KO. Somewhat surprisingly, HIRA loss increased the chromatin accessibility of the IgH V region locus. Furthermore, stable expression of ectopic H3.3G34V and H3.3G34R mutants that inhibit both the trimethylation of H3.3K36 and the recruitment of ZMYND11 significantly reduced SHM in Ramos cells, while the H3.3K79M did not. Consistent with the HIRA KO, the H3.3G34V mutant also decreased the occupancy of various elongation factors and of ZMYND11 on the IgH variable and downstream switching regions. Our results reveal an unrecognized role of HIRA and the H3.3K36me3 modification in SHM and extend our knowledge of how transcription-associated chromatin structure and accessibility contribute to SHM in human B cells.
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The optimal pH of AID is skewed from that of its catalytic pocket by DNA-binding residues and surface charge. Biochem J 2021; 479:39-55. [PMID: 34870314 DOI: 10.1042/bcj20210529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 11/17/2022]
Abstract
Activation-induced cytidine deaminase (AID) is a member of the apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) family of cytidine deaminases. AID mutates immunoglobulin loci to initiate secondary antibody diversification. The APOBEC3 (A3) sub-branch mutates viral pathogens in the cytosol and acidic endosomal compartments. Accordingly, AID functions optimally near neutral pH, while most A3s are acid-adapted (optimal pH 5.5-6.5). To gain a structural understanding for this pH disparity, we constructed high-resolution maps of AID catalytic activity vs pH. We found AID's optimal pH was 7.3 but it retained most (>70%) of the activity at pH 8. Probing of ssDNA-binding residues near the catalytic pocket, key for bending ssDNA into the pocket (e.g R25) yielded mutants with altered pH preference, corroborating previous findings that the equivalent residue in APOBEC3G (H216) underlies its acidic pH preference. AID from bony fish exhibited more basic optimal pH (pH 7.5-8.1) and several R25-equivalent mutants altered pH preference. Comparison of pH optima across the AID/APOBEC3 family revealed an inverse correlation between positive surface charge and overall catalysis. The paralogue with the most robust catalytic activity (APOBEC3A) has the lowest surface charge, most acidic pH preference, while the paralogue with the most lethargic catalytic rate (AID) has the most positive surface charge and highest optimal pH. We suggest one possible mechanism is through surface charge dictating an overall optimal pH that is different from the optimal pH of the catalytic pocket microenvironment. These findings illuminate an additional structural mechanism that regulates AID/APOBEC3 mutagenesis.
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35
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Feng Y, Li C, Stewart JA, Barbulescu P, Seija Desivo N, Álvarez-Quilón A, Pezo RC, Perera MLW, Chan K, Tong AHY, Mohamad-Ramshan R, Berru M, Nakib D, Li G, Kardar GA, Carlyle JR, Moffat J, Durocher D, Di Noia JM, Bhagwat AS, Martin A. FAM72A antagonizes UNG2 to promote mutagenic repair during antibody maturation. Nature 2021; 600:324-328. [PMID: 34819670 PMCID: PMC9425297 DOI: 10.1038/s41586-021-04144-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 10/14/2021] [Indexed: 11/09/2022]
Abstract
Activation-induced cytidine deaminase (AID) catalyses the deamination of deoxycytidines to deoxyuracils within immunoglobulin genes to induce somatic hypermutation and class-switch recombination1,2. AID-generated deoxyuracils are recognized and processed by subverted base-excision and mismatch repair pathways that ensure a mutagenic outcome in B cells3-6. However, why these DNA repair pathways do not accurately repair AID-induced lesions remains unknown. Here, using a genome-wide CRISPR screen, we show that FAM72A is a major determinant for the error-prone processing of deoxyuracils. Fam72a-deficient CH12F3-2 B cells and primary B cells from Fam72a-/- mice exhibit reduced class-switch recombination and somatic hypermutation frequencies at immunoglobulin and Bcl6 genes, and reduced genome-wide deoxyuracils. The somatic hypermutation spectrum in B cells from Fam72a-/- mice is opposite to that observed in mice deficient in uracil DNA glycosylase 2 (UNG2)7, which suggests that UNG2 is hyperactive in FAM72A-deficient cells. Indeed, FAM72A binds to UNG2, resulting in reduced levels of UNG2 protein in the G1 phase of the cell cycle, coinciding with peak AID activity. FAM72A therefore causes U·G mispairs to persist into S phase, leading to error-prone processing by mismatch repair. By disabling the DNA repair pathways that normally efficiently remove deoxyuracils from DNA, FAM72A enables AID to exert its full effects on antibody maturation. This work has implications in cancer, as the overexpression of FAM72A that is observed in many cancers8 could promote mutagenesis.
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Affiliation(s)
- Yuqing Feng
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Conglei Li
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- School of Medicine, The Chinese University of Hong Kong, Shenzhen, China
| | | | - Philip Barbulescu
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Noé Seija Desivo
- Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada
- Molecular Biology Programs, Department of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Alejandro Álvarez-Quilón
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Rossanna C Pezo
- Sunnybrook Health Sciences Center, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | - Katherine Chan
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Amy Hin Yan Tong
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | | | - Maribel Berru
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Diana Nakib
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Gavin Li
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Gholam Ali Kardar
- Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - James R Carlyle
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Jason Moffat
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Institute for Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Daniel Durocher
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Javier M Di Noia
- Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada
- Molecular Biology Programs, Department of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Ashok S Bhagwat
- Department of Chemistry, Wayne State University, Detroit, MI, USA
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Alberto Martin
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada.
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Dalloul I, Laffleur B, Dalloul Z, Wehbi B, Jouan F, Brauge B, Derouault P, Moreau J, Kracker S, Fischer A, Durandy A, Le Noir S, Cogné M. UnAIDed Class Switching in Activated B-Cells Reveals Intrinsic Features of a Self-Cleaving IgH Locus. Front Immunol 2021; 12:737427. [PMID: 34777346 PMCID: PMC8581400 DOI: 10.3389/fimmu.2021.737427] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Activation-induced deaminase (AID) is the major actor of immunoglobulin (Ig) gene diversification in germinal center B-cells. From its first description, it was considered as mandatory for class switch recombination (CSR), and this discovery initiated a long quest for all of the AID-interacting factors controlling its activity. The mechanisms focusing AID-mediated DNA lesions to given target sequences remain incompletely understood with regards the detailed characterization of optimal substrates in which cytidine deamination will lead to double strand breaks (DSBs) and chromosomal cleavage. In an effort to reconsider whether such CSR breaks absolutely require AID, we herein provide evidence, based on deep-sequencing approaches, showing that this dogma is not absolute in both human and mouse B lymphocytes. In activated B-cells from either AID-deficient mice or human AID-deficient patients, we report an intrinsic ability of the IgH locus to undergo "on-target" cleavage and subsequent synapsis of broken regions in conditions able to yield low-level CSR. DNA breaks occur in such conditions within the same repetitive S regions usually targeted by AID, but their repair follows a specific pathway with increased usage of microhomology-mediated repair. These data further demonstrate the role of AID machinery as not initiating de novo chromosomal cleavage but rather catalyzing a process which spontaneously initiates at low levels in an appropriately conformed IgH locus.
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Affiliation(s)
- Iman Dalloul
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1262, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 7276, Limoges University, Limoges, France
| | - Brice Laffleur
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 1236, Rennes1 University, Rennes, France
| | - Zeinab Dalloul
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1262, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 7276, Limoges University, Limoges, France
| | - Batoul Wehbi
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1262, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 7276, Limoges University, Limoges, France
| | - Florence Jouan
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 1236, Rennes1 University, Rennes, France
| | - Baptiste Brauge
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 1236, Rennes1 University, Rennes, France
| | - Paco Derouault
- Centre Hospitalier Universitaire (CHU) Dupuytren, Limoges, France
| | - Jeanne Moreau
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1262, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 7276, Limoges University, Limoges, France
| | - Sven Kracker
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1163, Laboratory of Human Lympho-hematopoiesis, Imagine Institute, Université de Paris, Paris, France
| | - Alain Fischer
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1163, Laboratory of Human Lympho-hematopoiesis, Imagine Institute, Université de Paris, Paris, France
| | - Anne Durandy
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1163, Laboratory of Human Lympho-hematopoiesis, Imagine Institute, Université de Paris, Paris, France
| | - Sandrine Le Noir
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1262, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 7276, Limoges University, Limoges, France
| | - Michel Cogné
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1262, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 7276, Limoges University, Limoges, France
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 1236, Rennes1 University, Rennes, France
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37
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Diffuse large B-cell lymphomas in adults with aberrant coexpression of CD10, BCL6, and MUM1 are enriched in IRF4 rearrangements. Blood Adv 2021; 6:2361-2372. [PMID: 34654055 PMCID: PMC9006278 DOI: 10.1182/bloodadvances.2021006034] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/16/2021] [Indexed: 12/01/2022] Open
Abstract
DLBCL in adults aberrantly coexpressing CD10, BCL6, and MUM1 is genetically heterogeneous and enriched in IRF4-rearranged cases. IRF4-rearranged DLBCL in adults share genetic features with LBCL-IRF4 in children but with higher genomic complexity and often ABC GEP.
Diffuse large B-cell lymphoma (DLBCL) with aberrant coexpression of CD10+BCL6+MUM1+ (DLBCL-AE), classified as germinal center B cell (GCB) type by the Hans algorithm (HA), was genetically characterized. To capture the complexity of DLBCL-AE, we used an integrated approach that included gene expression profiling (GEP), fluorescence in situ hybridization, targeted gene sequencing, and copy number (CN) arrays. According to GEP, 32/54 (59%) cases were classified as GCB-DLBCL, 16/54 (30%) as activated B-cell (ABC) DLBCL, and 6/54 (11%) as unclassifiable. The discrepancy between HA and GEP was 41%. Three genetic subgroups were identified. Group 1 included 13/50 (26%) cases without translocations and mainly showing and ABC/MCD molecular profile. Group 2 comprised 11/50 (22%) cases with IRF4 alterations (DLBCL-IRF4), frequent mutations in IRF4 (82%) and NF-κB pathway genes (MYD88, CARD11, and CD79B), and losses of 17p13.2. Five cases each were classified as GCB- or ABC-type. Group 3 included 26/50 (52%) cases with 1 or several translocations in BCL2/BCL6/MYC/IGH, and GCB/EZB molecular profile predominated. Two cases in this latter group showed complex BCL2/BCL6/IRF4 translocations. DLBCL-IRF4 in adults showed a similar copy number profile and shared recurrent CARD11 and CD79B mutations when compared with LBCL-IRF4 in the pediatric population. However, adult cases showed higher genetic complexity, higher mutational load with frequent MYD88 and KMT2D mutations, and more ABC GEP. IRF4 mutations were identified only in IRF4-rearranged cases, indicating its potential use in the diagnostic setting. In conclusion, DLBCL-AE is genetically heterogeneous and enriched in cases with IRF4 alterations. DLBCL-IRF4 in adults has many similarities to the pediatric counterpart.
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38
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Bloehdorn J, Braun A, Taylor-Weiner A, Jebaraj BMC, Robrecht S, Krzykalla J, Pan H, Giza A, Akylzhanova G, Holzmann K, Scheffold A, Johnston HE, Yeh RF, Klymenko T, Tausch E, Eichhorst B, Bullinger L, Fischer K, Weisser M, Robak T, Schneider C, Gribben J, Dahal LN, Carter MJ, Elemento O, Landau DA, Neuberg DS, Cragg MS, Benner A, Hallek M, Wu CJ, Döhner H, Stilgenbauer S, Mertens D. Multi-platform profiling characterizes molecular subgroups and resistance networks in chronic lymphocytic leukemia. Nat Commun 2021; 12:5395. [PMID: 34518531 PMCID: PMC8438057 DOI: 10.1038/s41467-021-25403-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 08/03/2021] [Indexed: 02/07/2023] Open
Abstract
Knowledge of the genomic landscape of chronic lymphocytic leukemia (CLL) grows increasingly detailed, providing challenges in contextualizing the accumulated information. To define the underlying networks, we here perform a multi-platform molecular characterization. We identify major subgroups characterized by genomic instability (GI) or activation of epithelial-mesenchymal-transition (EMT)-like programs, which subdivide into non-inflammatory and inflammatory subtypes. GI CLL exhibit disruption of genome integrity, DNA-damage response and are associated with mutagenesis mediated through activation-induced cytidine deaminase or defective mismatch repair. TP53 wild-type and mutated/deleted cases constitute a transcriptionally uniform entity in GI CLL and show similarly poor progression-free survival at relapse. EMT-like CLL exhibit high genomic stability, reduced benefit from the addition of rituximab and EMT-like differentiation is inhibited by induction of DNA damage. This work extends the perspective on CLL biology and risk categories in TP53 wild-type CLL. Furthermore, molecular targets identified within each subgroup provide opportunities for new treatment approaches.
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Affiliation(s)
| | - Andrejs Braun
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | | | | | - Sandra Robrecht
- Department I for Internal Medicine and Centre for Integrated Oncology, University of Cologne, Cologne, Germany
| | - Julia Krzykalla
- Division of Biostatistics, German Cancer Research Center, Heidelberg, Germany
| | - Heng Pan
- Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Adam Giza
- Department I for Internal Medicine and Centre for Integrated Oncology, University of Cologne, Cologne, Germany
| | - Gulnara Akylzhanova
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | | | - Annika Scheffold
- Department of Internal Medicine III, University of Ulm, Ulm, Germany
| | - Harvey E Johnston
- Centre for Cancer Immunology, Cancer Sciences, Faculty of Medicine, Cancer Research UK Centre and Experimental Cancer Medicine Centre, University of Southampton, Southampton, UK
| | - Ru-Fang Yeh
- Biostatistics, Genentech Inc., South San Francisco, CA, USA
| | - Tetyana Klymenko
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Eugen Tausch
- Department of Internal Medicine III, University of Ulm, Ulm, Germany
| | - Barbara Eichhorst
- Department I for Internal Medicine and Centre for Integrated Oncology, University of Cologne, Cologne, Germany
| | - Lars Bullinger
- Medical Clinic for Hematology, Oncology and Tumor Biology, Charité University Hospital, Berlin, Germany
| | - Kirsten Fischer
- Department I for Internal Medicine and Centre for Integrated Oncology, University of Cologne, Cologne, Germany
| | - Martin Weisser
- Roche Pharma Research and Early Development, Penzberg, Germany
| | - Tadeusz Robak
- Department of Hematology, Medical University of Lodz, Lodz, Poland
| | | | - John Gribben
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Lekh N Dahal
- Centre for Cancer Immunology, Cancer Sciences, Faculty of Medicine, Cancer Research UK Centre and Experimental Cancer Medicine Centre, University of Southampton, Southampton, UK
- Department of Pharmacology and Therapeutics, Faculty of Life and Health Sciences, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Mathew J Carter
- Centre for Cancer Immunology, Cancer Sciences, Faculty of Medicine, Cancer Research UK Centre and Experimental Cancer Medicine Centre, University of Southampton, Southampton, UK
| | - Olivier Elemento
- Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Dan A Landau
- Cancer Genomics and Evolutionary Dynamics, Weill Cornell Medicine, New York, NY, USA
- New York Genome Center, New York, NY, USA
| | - Donna S Neuberg
- Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Mark S Cragg
- Centre for Cancer Immunology, Cancer Sciences, Faculty of Medicine, Cancer Research UK Centre and Experimental Cancer Medicine Centre, University of Southampton, Southampton, UK
| | - Axel Benner
- Division of Biostatistics, German Cancer Research Center, Heidelberg, Germany
| | - Michael Hallek
- Department I for Internal Medicine and Centre for Integrated Oncology, University of Cologne, Cologne, Germany
| | - Catherine J Wu
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Internal Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Hartmut Döhner
- Department of Internal Medicine III, University of Ulm, Ulm, Germany
| | | | - Daniel Mertens
- Department of Internal Medicine III, University of Ulm, Ulm, Germany.
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
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39
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Ye X, Ren W, Liu D, Li X, Li W, Wang X, Meng FL, Yeap LS, Hou Y, Zhu S, Casellas R, Zhang H, Wu K, Pan-Hammarström Q. Genome-wide mutational signatures revealed distinct developmental paths for human B cell lymphomas. J Exp Med 2021; 218:211517. [PMID: 33136155 PMCID: PMC7608067 DOI: 10.1084/jem.20200573] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/31/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Both somatic hypermutation (SHM) and class switch recombination (CSR) are initiated by activation-induced cytidine deaminase (AID). Dysregulation of these processes has been linked to B cell lymphomagenesis. Here we performed an in-depth analysis of diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL) genomes. We characterized seven genomic mutational signatures, including two B cell tumor-specific signatures, one of which is novel and associated with aberrant SHM. We further identified two major mutational signatures (K1 and K2) of clustered mutations (kataegis) resulting from the activities of AID or error-prone DNA polymerase η, respectively. K1 was associated with the immunoglobulin (Ig) switch region mutations/translocations and the ABC subtype of DLBCL, whereas K2 was related to the Ig variable region mutations and the GCB subtype of DLBCL and FL. Similar patterns were also observed in chronic lymphocytic leukemia subtypes. Thus, alterations associated with aberrant CSR and SHM activities can be linked to distinct developmental paths for different subtypes of B cell lymphomas.
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Affiliation(s)
- Xiaofei Ye
- Department of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,BGI-Shenzhen, Shenzhen, China.,Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Weicheng Ren
- Department of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Dongbing Liu
- BGI-Shenzhen, Shenzhen, China.,Guangdong Provincial Key Laboratory of Human Disease Genomics, Shenzhen Key Laboratory of Genomics, Shenzhen, China
| | - Xiaobo Li
- BGI-Shenzhen, Shenzhen, China.,Guangdong Provincial Key Laboratory of Human Disease Genomics, Shenzhen Key Laboratory of Genomics, Shenzhen, China
| | - Wei Li
- Department of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Xianhuo Wang
- Department of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Leng-Siew Yeap
- Shanghai Institute of Immunology, State Key Laboratory of Oncogenes and Related Genes, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | | | | | - Rafael Casellas
- Genomics and Immunity, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD.,Center of Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Huilai Zhang
- Department of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Kui Wu
- BGI-Shenzhen, Shenzhen, China.,Guangdong Provincial Key Laboratory of Human Disease Genomics, Shenzhen Key Laboratory of Genomics, Shenzhen, China
| | - Qiang Pan-Hammarström
- Department of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
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40
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King JJ, Borzooee F, Im J, Asgharpour M, Ghorbani A, Diamond CP, Fifield H, Berghuis L, Larijani M. Structure-Based Design of First-Generation Small Molecule Inhibitors Targeting the Catalytic Pockets of AID, APOBEC3A, and APOBEC3B. ACS Pharmacol Transl Sci 2021; 4:1390-1407. [PMID: 34423273 PMCID: PMC8369683 DOI: 10.1021/acsptsci.1c00091] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 12/12/2022]
Abstract
![]()
Activation-induced
cytidine deaminase (AID) initiates antibody
diversification by mutating immunoglobulin loci in B lymphocytes.
AID and related APOBEC3 (A3) enzymes also induce genome-wide mutations
and lesions implicated in tumorigenesis and tumor progression. The
most prevalent mutation signatures across diverse tumor genomes are
attributable to the mistargeted mutagenic activities of AID/A3s. Thus,
inhibiting AID/A3s has been suggested to be of therapeutic benefit.
We previously used a computational-biochemical approach to gain insight
into the structure of AID’s catalytic pocket, which resulted
in the discovery of a novel type of regulatory catalytic pocket closure
that regulates AID/A3s that we termed the “Schrodinger’s
CATalytic pocket”. Our findings were subsequently confirmed
by direct structural studies. Here, we describe our search for small
molecules that target the catalytic pocket of AID. We identified small
molecules that inhibit purified AID, AID in cell extracts, and endogenous
AID of lymphoma cells. Analogue expansion yielded derivatives with
improved potencies. These were found to also inhibit A3A and A3B,
the two most tumorigenic siblings of AID. Two compounds exhibit low
micromolar IC50 inhibition of AID and A3A, exhibiting the
strongest potency for A3A. Docking suggests key interactions between
their warheads and residues lining the catalytic pockets of AID, A3A,
and A3B and between the tails and DNA-interacting residues on the
surface proximal to the catalytic pocket opening. Accordingly, mutants
of these residues decreased inhibition potency. The chemistry and
abundance of key stabilizing interactions between the small molecules
and residues within and immediately outside the catalytic pockets
are promising for therapeutic development.
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Affiliation(s)
- Justin J King
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Faezeh Borzooee
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Junbum Im
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada.,BC Cancer Research/Terry Fox Labs, University of British Columbia, Vancouver, British Columbia BC V5Z 1L3, Canada
| | - Mahdi Asgharpour
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Atefeh Ghorbani
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Cody P Diamond
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Heather Fifield
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Lesley Berghuis
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Mani Larijani
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
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41
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Böttcher K, Braunschmidt K, Hirth G, Schärich K, Klassert TE, Stock M, Sorgatz J, Fischer-Burkart S, Ullrich S, Frankenberger S, Kritsch D, Kosan C, Küppers R, Strobl LJ, Slevogt H, Zimber-Strobl U, Jungnickel B. Context-dependent regulation of immunoglobulin mutagenesis by p53. Mol Immunol 2021; 138:128-136. [PMID: 34392111 DOI: 10.1016/j.molimm.2021.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/22/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
p53 plays a major role in genome maintenance. In addition to multiple p53 functions in the control of DNA repair, a regulation of DNA damage bypass via translesion synthesis has been implied in vitro. Somatic hypermutation of immunoglobulin genes for affinity maturation of antibody responses is based on aberrant translesion polymerase action and must be subject to stringent control to prevent genetic alterations and lymphomagenesis. When studying the role of p53 in somatic hypermutation in vivo, we found altered translesion polymerase-mediated A:T mutagenesis in mice lacking p53 in all organs, but notably not in mice with B cell-specific p53 inactivation, implying that p53 functions in non-B cells may alter mutagenesis in B cells. During class switch recombination, when p53 prevents formation of chromosomal translocations, we in addition detected a B cell-intrinsic role for p53 in altering G:C and A:T mutagenesis. Thus, p53 regulates translesion polymerase activity and shows differential activity during somatic hypermutation versus class switch recombination in vivo. Finally, p53 inhibition leads to increased somatic hypermutation in human B lymphoma cells. We conclude that loss of p53 function may promote genetic instability via multiple routes during antibody diversification in vivo.
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Affiliation(s)
- Katrin Böttcher
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Kerstin Braunschmidt
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany; Institute of Clinical Molecular Biology, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.
| | - Gianna Hirth
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Karsten Schärich
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Tilman E Klassert
- Host Septomics, ZIK Septomics, Jena University Hospital, Jena, Germany.
| | - Magdalena Stock
- Host Septomics, ZIK Septomics, Jena University Hospital, Jena, Germany.
| | - Janine Sorgatz
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Sabine Fischer-Burkart
- Institute of Clinical Molecular Biology, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.
| | - Steffen Ullrich
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Samantha Frankenberger
- Institute of Clinical Molecular Biology, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Daniel Kritsch
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany; Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Christian Kosan
- Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Ralf Küppers
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Essen, Germany.
| | - Lothar J Strobl
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.
| | - Hortense Slevogt
- Host Septomics, ZIK Septomics, Jena University Hospital, Jena, Germany.
| | - Ursula Zimber-Strobl
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.
| | - Berit Jungnickel
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany; Institute of Clinical Molecular Biology, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.
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42
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Yin Y, Quinlan BD, Ou T, Guo Y, He W, Farzan M. In vitro affinity maturation of broader and more-potent variants of the HIV-1-neutralizing antibody CAP256-VRC26.25. Proc Natl Acad Sci U S A 2021; 118:e2106203118. [PMID: 34261793 PMCID: PMC8307357 DOI: 10.1073/pnas.2106203118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Three variable 2 (V2) loops of HIV-1 envelope glycoprotein (Env) trimer converge at the Env apex to form the epitope of an important classes of HIV-1 broadly neutralizing antibodies (bNAbs). These V2-glycan/apex antibodies are exceptionally potent but less broad (∼60 to 75%) than many other bNAbs. Their CDRH3 regions are typically long, acidic, and tyrosine sulfated. Tyrosine sulfation complicates efforts to improve these antibodies through techniques such as phage or yeast display. To improve the breadth of CAP256-VRC26.25 (VRC26.25), a very potent apex antibody, we adapted and extended a B cell display approach. Specifically, we used CRISPR/Cas12a to introduce VRC26.25 heavy- and light-chain genes into their respective loci in a B cell line, ensuring that each cell expresses a single VRC26.25 variant. We then diversified these loci through activation-induced cytidine deaminase-mediated hypermutation and homology-directed repair using randomized CDRH3 sequences as templates. Iterative sorting with soluble Env trimers and further randomization selected VRC26.25 variants with successively improving affinities. Three mutations in the CDRH3 region largely accounted for this improved affinity, and VRC26.25 modified with these mutations exhibited greater breadth and potency than the original antibody. Our data describe a broader and more-potent form of VRC26.25 as well as an approach useful for improving the breadth and potency of antibodies with functionally important posttranslational modifications.
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Affiliation(s)
- Yiming Yin
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL 33458
| | - Brian D Quinlan
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL 33458
| | - Tianling Ou
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL 33458
| | - Yan Guo
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL 33458
| | - Wenhui He
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL 33458
| | - Michael Farzan
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL 33458
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43
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Kasprzyk ME, Sura W, Dzikiewicz-Krawczyk A. Enhancing B-Cell Malignancies-On Repurposing Enhancer Activity towards Cancer. Cancers (Basel) 2021; 13:3270. [PMID: 34210001 PMCID: PMC8269369 DOI: 10.3390/cancers13133270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/24/2021] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
B-cell lymphomas and leukemias derive from B cells at various stages of maturation and are the 6th most common cancer-related cause of death. While the role of several oncogenes and tumor suppressors in the pathogenesis of B-cell neoplasms was established, recent research indicated the involvement of non-coding, regulatory sequences. Enhancers are DNA elements controlling gene expression in a cell type- and developmental stage-specific manner. They ensure proper differentiation and maturation of B cells, resulting in production of high affinity antibodies. However, the activity of enhancers can be redirected, setting B cells on the path towards cancer. In this review we discuss different mechanisms through which enhancers are exploited in malignant B cells, from the well-studied translocations juxtaposing oncogenes to immunoglobulin loci, through enhancer dysregulation by sequence variants and mutations, to enhancer hijacking by viruses. We also highlight the potential of therapeutic targeting of enhancers as a direction for future investigation.
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44
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Bello A, Jungnickel B. Impact of Chk1 dosage on somatic hypermutation in vivo. Immunol Cell Biol 2021; 99:879-893. [PMID: 34042197 DOI: 10.1111/imcb.12480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 04/19/2021] [Accepted: 05/24/2021] [Indexed: 12/14/2022]
Abstract
Checkpoint signaling in the context of a functional DNA damage response is crucial for the prevention of oncogenic transformation of cells. Our immune system, though, takes the risk of attenuated checkpoint responses during immunoglobulin diversification. B cells undergo continuous DNA damage and error-prone repair of their immunoglobulin genes during the process of somatic hypermutation. An accompanying attenuation of the DNA damage response via the ATR-Chk1 axis in B cells is believed to allow for a better DNA damage tolerance and for evasion of apoptosis, so as to ensure mutations to be passed on. We sought to determine whether the downregulation of Chk1 could also directly influence the process of hypermutation in vivo by altering the relative activity of error-prone DNA repair pathways. We analyzed the humoral response and the hypermutation process in mice whose B cells express reduced levels of the Chk1 protein. We found that Chk1 heterozygosity limits the accumulation of mutations in the immunoglobulin loci, likely by impacting on the survival of B cells as they accumulate DNA damage. Nevertheless, we unveiled an unanticipated role for Chk1 downregulation in favoring A/T mutagenesis at the antibody-variable regions during hypermutation. Even though immunoglobulin mutagenesis was found to be reduced, Chk1 signaling attenuation allows for sustained mutagenesis outside the immunoglobulin loci. Our study thus reveals that a proper Chk1 dosage is crucial for adequate somatic hypermutation in B cells.
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Affiliation(s)
- Amanda Bello
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Berit Jungnickel
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biological Sciences, Friedrich Schiller University, Jena, Germany
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45
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Oppezzo P, Navarrete M, Chiorazzi N. AID in Chronic Lymphocytic Leukemia: Induction and Action During Disease Progression. Front Oncol 2021; 11:634383. [PMID: 34041018 PMCID: PMC8141630 DOI: 10.3389/fonc.2021.634383] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/23/2021] [Indexed: 12/12/2022] Open
Abstract
The enzyme activation-induced cytidine deaminase (AID) initiates somatic hypermutation (SHM) and class switch recombination (CSR) of immunoglobulin (Ig) genes, critical actions for an effective adaptive immune response. However, in addition to the benefits generated by its physiological roles, AID is an etiological factor for the development of human and murine leukemias and lymphomas. This review highlights the pathological role of AID and the consequences of its actions on the development, progression, and therapeutic refractoriness of chronic lymphocytic leukemia (CLL) as a model disease for mature lymphoid malignancies. First, we summarize pertinent aspects of the expression and function of AID in normal B lymphocytes. Then, we assess putative causes for AID expression in leukemic cells emphasizing the role of an activated microenvironment. Thirdly, we discuss the role of AID in lymphomagenesis, in light of recent data obtained by NGS analyses on the genomic landscape of leukemia and lymphomas, concentrating on the frequency of AID signatures in these cancers and correlating previously described tumor-gene drivers with the presence of AID off-target mutations. Finally, we discuss how these changes could affect tumor suppressor and proto-oncogene targets and how they could be associated with disease progression. Collectively, we hope that these sections will help to better understand the complex paradox between the physiological role of AID in adaptive immunity and its potential causative activity in B-cell malignancies.
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Affiliation(s)
- Pablo Oppezzo
- Research Laboratory on Chronic Lymphocytic Leukemia, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | | | - Nicholas Chiorazzi
- The Karches Center for Oncology Research, The Feinstein Institutes for Medical Research, New York, NY, United States
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46
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Alvarez-Gonzalez J, Yasgar A, Maul RW, Rieffer AE, Crawford DJ, Salamango DJ, Dorjsuren D, Zakharov AV, Jansen DJ, Rai G, Marugan J, Simeonov A, Harris RS, Kohli RM, Gearhart PJ. Small Molecule Inhibitors of Activation-Induced Deaminase Decrease Class Switch Recombination in B Cells. ACS Pharmacol Transl Sci 2021; 4:1214-1226. [PMID: 34151211 DOI: 10.1021/acsptsci.1c00064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Indexed: 11/30/2022]
Abstract
Activation-induced deaminase (AID) not only mutates DNA within the immunoglobulin loci to generate antibody diversity, but it also promotes development of B cell lymphomas. To tame this mutagen, we performed a quantitative high-throughput screen of over 90 000 compounds to see if AID activity could be mitigated. The enzymatic activity was assessed in biochemical assays to detect cytosine deamination and in cellular assays to measure class switch recombination. Three compounds showed promise via inhibition of switching in a transformed B cell line and in murine splenic B cells. These compounds have similar chemical structures, which suggests a shared mechanism of action. Importantly, the inhibitors blocked AID, but not a related cytosine DNA deaminase, APOBEC3B. We further determined that AID was continually expressed for several days after B cell activation to induce switching. This first report of small molecules that inhibit AID can be used to gain regulatory control over base editors.
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Affiliation(s)
- Juan Alvarez-Gonzalez
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Adam Yasgar
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Robert W Maul
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Amanda E Rieffer
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Daniel J Crawford
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Daniel J Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Dorjbal Dorjsuren
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Alexey V Zakharov
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Daniel J Jansen
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Ganesha Rai
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Juan Marugan
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20816, United States
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Rahul M Kohli
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patricia J Gearhart
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
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47
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The dangers of déjà vu: memory B cells as the cells of origin of ABC-DLBCLs. Blood 2021; 136:2263-2274. [PMID: 32932517 DOI: 10.1182/blood.2020005857] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 08/27/2020] [Indexed: 02/06/2023] Open
Abstract
Activated B-cell (ABC)-diffuse large B-cell lymphomas (DLBCLs) are clinically aggressive and phenotypically complex malignancies, whose transformation mechanisms remain unclear. Partially differentiated antigen-secreting cells (plasmablasts) have long been regarded as cells-of-origin for these tumors, despite lack of definitive experimental evidence. Recent DLBCL reclassification based on mutational landscapes identified MCD/C5 tumors as specific ABC-DLBCLs with unfavorable clinical outcome, activating mutations in the signaling adaptors MYD88 and CD79B, and immune evasion through mutation of antigen-presenting genes. MCD/C5s manifest prominent extranodal dissemination and similarities with primary extranodal lymphomas (PENLs). In this regard, recent studies on TBL1XR1, a gene recurrently mutated in MCD/C5s and PENLs, suggest that aberrant memory B cells (MBs), and not plasmablasts, are the true cells-of-origin for these tumors. Moreover, transcriptional and phenotypic profiling suggests that MCD/C5s, as a class, represent bona fide MB tumors. Based on emerging findings we propose herein a generalized stepwise model for MCD/C5 and PENLs pathogenesis, whereby acquisition of founder mutations in activated B cells favors the development of aberrant MBs prone to avoid plasmacytic differentiation on recall and undergo systemic dissemination. Cyclic reactivation of these MBs through persistent antigen exposure favors their clonal expansion and accumulation of mutations, which further facilitate their activation. As a result, MB-like clonal precursors become trapped in an oscillatory state of semipermanent activation and phenotypic sway that facilitates ulterior transformation and accounts for the extranodal clinical presentation and biology of these tumors. In addition, we discuss diagnostic and therapeutic implications of a MB cell-of-origin for these lymphomas.
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48
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Repair of programmed DNA lesions in antibody class switch recombination: common and unique features. ACTA ACUST UNITED AC 2021; 2:115-125. [PMID: 33817557 PMCID: PMC7996122 DOI: 10.1007/s42764-021-00035-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/22/2021] [Accepted: 03/04/2021] [Indexed: 01/31/2023]
Abstract
The adaptive immune system can diversify the antigen receptors to eliminate various pathogens through programmed DNA lesions at antigen receptor genes. In immune diversification, general DNA repair machineries are applied to transform the programmed DNA lesions into gene mutation or recombination events with common and unique features. Here we focus on antibody class switch recombination (CSR), and review the initiation of base damages, the conversion of damaged base to DNA double-strand break, and the ligation of broken ends. With an emphasis on the unique features in CSR, we discuss recent advances in the understanding of DNA repair/replication coordination, and ERCC6L2-mediated deletional recombination. We further elaborate the application of CSR in end-joining, resection and translesion synthesis assays. In the time of the COVID-19 pandemic, we hope it help to understand the generation of therapeutic antibodies.
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49
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LUBAC accelerates B-cell lymphomagenesis by conferring resistance to genotoxic stress on B cells. Blood 2021; 136:684-697. [PMID: 32325488 DOI: 10.1182/blood.2019002654] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 03/30/2020] [Indexed: 02/07/2023] Open
Abstract
The linear ubiquitin chain assembly complex (LUBAC) is a key regulator of NF-κB signaling. Activating single-nucleotide polymorphisms of HOIP, the catalytic subunit of LUBAC, are enriched in patients with activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL), and expression of HOIP, which parallels LUBAC activity, is elevated in ABC-DLBCL samples. Thus, to clarify the precise roles of LUBAC in lymphomagenesis, we generated a mouse model with augmented expression of HOIP in B cells. Interestingly, augmented HOIP expression facilitated DLBCL-like B-cell lymphomagenesis driven by MYD88-activating mutation. The developed lymphoma cells partly shared somatic gene mutations with human DLBCLs, with increased frequency of a typical AID mutation pattern. In vitro analysis revealed that HOIP overexpression protected B cells from DNA damage-induced cell death through NF-κB activation, and analysis of the human DLBCL database showed that expression of HOIP positively correlated with gene signatures representing regulation of apoptosis signaling, as well as NF-κB signaling. These results indicate that HOIP facilitates lymphomagenesis by preventing cell death and augmenting NF-κB signaling, leading to accumulation of AID-mediated mutations. Furthermore, a natural compound that specifically inhibits LUBAC was shown to suppress the tumor growth in a mouse transplantation model. Collectively, our data indicate that LUBAC is crucially involved in B-cell lymphomagenesis through protection against DNA damage-induced cell death and is a suitable therapeutic target for B-cell lymphomas.
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50
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Safavi S, Larouche A, Zahn A, Patenaude AM, Domanska D, Dionne K, Rognes T, Dingler F, Kang SK, Liu Y, Johnson N, Hébert J, Verdun RE, Rada CA, Vega F, Nilsen H, Di Noia JM. The uracil-DNA glycosylase UNG protects the fitness of normal and cancer B cells expressing AID. NAR Cancer 2021; 2:zcaa019. [PMID: 33554121 PMCID: PMC7848951 DOI: 10.1093/narcan/zcaa019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022] Open
Abstract
In B lymphocytes, the uracil N-glycosylase (UNG) excises genomic uracils made by activation-induced deaminase (AID), thus underpinning antibody gene diversification and oncogenic chromosomal translocations, but also initiating faithful DNA repair. Ung−/− mice develop B-cell lymphoma (BCL). However, since UNG has anti- and pro-oncogenic activities, its tumor suppressor relevance is unclear. Moreover, how the constant DNA damage and repair caused by the AID and UNG interplay affects B-cell fitness and thereby the dynamics of cell populations in vivo is unknown. Here, we show that UNG specifically protects the fitness of germinal center B cells, which express AID, and not of any other B-cell subset, coincident with AID-induced telomere damage activating p53-dependent checkpoints. Consistent with AID expression being detrimental in UNG-deficient B cells, Ung−/− mice develop BCL originating from activated B cells but lose AID expression in the established tumor. Accordingly, we find that UNG is rarely lost in human BCL. The fitness preservation activity of UNG contingent to AID expression was confirmed in a B-cell leukemia model. Hence, UNG, typically considered a tumor suppressor, acquires tumor-enabling activity in cancer cell populations that express AID by protecting cell fitness.
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Affiliation(s)
- Shiva Safavi
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Ariane Larouche
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Astrid Zahn
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Anne-Marie Patenaude
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Diana Domanska
- Department of Informatics, University of Oslo, PO Box 1080, Blindern, 0316 Oslo, Norway
| | - Kiersten Dionne
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Torbjørn Rognes
- Department of Informatics, University of Oslo, PO Box 1080, Blindern, 0316 Oslo, Norway
| | - Felix Dingler
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Seong-Kwi Kang
- ITR Laboratories Canada, Inc., 19601 Clark Graham Ave, Baie-D'Urfe, QC H9X 3T1, Canada
| | - Yan Liu
- Section for Clinical Molecular Biology, Akershus University Hospital, PO 1000, 1478 Lørenskog, Norway
| | - Nathalie Johnson
- Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Josée Hébert
- Department of Medicine, Université de Montréal, C.P. 6128, Montreal, QC H3C 3J7, Canada
| | - Ramiro E Verdun
- Division of Hematology, Department of Medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL 33136, USA
| | | | - Francisco Vega
- Division of Hematology, Department of Medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL 33136, USA
| | - Hilde Nilsen
- Section for Clinical Molecular Biology, Akershus University Hospital, PO 1000, 1478 Lørenskog, Norway
| | - Javier M Di Noia
- Institut de Recherches Cliniques de Montréal, 110 Av des Pins Ouest, Montréal, QC H2W 1R7, Canada
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