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Reyes A, Ortiz G, Duarte LF, Fernández C, Hernández-Armengol R, Palacios PA, Prado Y, Andrade CA, Rodriguez-Guilarte L, Kalergis AM, Simon F, Carreño LJ, Riedel CA, Cáceres M, González PA. Contribution of viral and bacterial infections to senescence and immunosenescence. Front Cell Infect Microbiol 2023; 13:1229098. [PMID: 37753486 PMCID: PMC10518457 DOI: 10.3389/fcimb.2023.1229098] [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: 05/25/2023] [Accepted: 08/24/2023] [Indexed: 09/28/2023] Open
Abstract
Cellular senescence is a key biological process characterized by irreversible cell cycle arrest. The accumulation of senescent cells creates a pro-inflammatory environment that can negatively affect tissue functions and may promote the development of aging-related diseases. Typical biomarkers related to senescence include senescence-associated β-galactosidase activity, histone H2A.X phosphorylation at serine139 (γH2A.X), and senescence-associated heterochromatin foci (SAHF) with heterochromatin protein 1γ (HP-1γ protein) Moreover, immune cells undergoing senescence, which is known as immunosenescence, can affect innate and adaptative immune functions and may elicit detrimental effects over the host's susceptibility to infectious diseases. Although associations between senescence and pathogens have been reported, clear links between both, and the related molecular mechanisms involved remain to be determined. Furthermore, it remains to be determined whether infections effectively induce senescence, the impact of senescence and immunosenescence over infections, or if both events coincidently share common molecular markers, such as γH2A.X and p53. Here, we review and discuss the most recent reports that describe cellular hallmarks and biomarkers related to senescence in immune and non-immune cells in the context of infections, seeking to better understand their relationships. Related literature was searched in Pubmed and Google Scholar databases with search terms related to the sections and subsections of this review.
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Affiliation(s)
- Antonia Reyes
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gerardo Ortiz
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luisa F. Duarte
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Christian Fernández
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Rosario Hernández-Armengol
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Pablo A. Palacios
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Yolanda Prado
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Catalina A. Andrade
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Linmar Rodriguez-Guilarte
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Felipe Simon
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Leandro J. Carreño
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Claudia A. Riedel
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Mónica Cáceres
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Pablo A. González
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Sorrentino C, D'Antonio L, Ciummo SL, Fieni C, Landuzzi L, Ruzzi F, Vespa S, Lanuti P, Lotti LV, Lollini PL, Di Carlo E. CRISPR/Cas9-mediated deletion of Interleukin-30 suppresses IGF1 and CXCL5 and boosts SOCS3 reducing prostate cancer growth and mortality. J Hematol Oncol 2022; 15:145. [PMID: 36224639 PMCID: PMC9559017 DOI: 10.1186/s13045-022-01357-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/12/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Metastatic prostate cancer (PC) is a leading cause of cancer death in men worldwide. Targeting of the culprits of disease progression is an unmet need. Interleukin (IL)-30 promotes PC onset and development, but whether it can be a suitable therapeutic target remains to be investigated. Here, we shed light on the relationship between IL30 and canonical PC driver genes and explored the anti-tumor potential of CRISPR/Cas9-mediated deletion of IL30. METHODS PC cell production of, and response to, IL30 was tested by flow cytometry, immunoelectron microscopy, invasion and migration assays and PCR arrays. Syngeneic and xenograft models were used to investigate the effects of IL30, and its deletion by CRISPR/Cas9 genome editing, on tumor growth. Bioinformatics of transcriptional data and immunopathology of PC samples were used to assess the translational value of the experimental findings. RESULTS Human membrane-bound IL30 promoted PC cell proliferation, invasion and migration in association with STAT1/STAT3 phosphorylation, similarly to its murine, but secreted, counterpart. Both human and murine IL30 regulated PC driver and immunity genes and shared the upregulation of oncogenes, BCL2 and NFKB1, immunoregulatory mediators, IL1A, TNF, TLR4, PTGS2, PD-L1, STAT3, and chemokine receptors, CCR2, CCR4, CXCR5. In human PC cells, IL30 improved the release of IGF1 and CXCL5, which mediated, via autocrine loops, its potent proliferative effect. Deletion of IL30 dramatically downregulated BCL2, NFKB1, STAT3, IGF1 and CXCL5, whereas tumor suppressors, primarily SOCS3, were upregulated. Syngeneic and xenograft PC models demonstrated IL30's ability to boost cancer proliferation, vascularization and myeloid-derived cell infiltration, which were hindered, along with tumor growth and metastasis, by IL30 deletion, with improved host survival. RNA-Seq data from the PanCancer collection and immunohistochemistry of high-grade locally advanced PCs demonstrated an inverse association (chi-squared test, p = 0.0242) between IL30 and SOCS3 expression and a longer progression-free survival of patients with IL30NegSOCS3PosPC, when compared to patients with IL30PosSOCS3NegPC. CONCLUSIONS Membrane-anchored IL30 expressed by human PC cells shares a tumor progression programs with its murine homolog and, via juxtacrine signals, steers a complex network of PC driver and immunity genes promoting prostate oncogenesis. The efficacy of CRISPR/Cas9-mediated targeting of IL30 in curbing PC progression paves the way for its clinical use.
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Affiliation(s)
- Carlo Sorrentino
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Anatomic Pathology and Immuno-Oncology Unit, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Via L. Polacchi 11, 66100, Chieti, Italy
| | - Luigi D'Antonio
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Anatomic Pathology and Immuno-Oncology Unit, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Via L. Polacchi 11, 66100, Chieti, Italy
| | - Stefania Livia Ciummo
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Anatomic Pathology and Immuno-Oncology Unit, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Via L. Polacchi 11, 66100, Chieti, Italy
| | - Cristiano Fieni
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Anatomic Pathology and Immuno-Oncology Unit, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Via L. Polacchi 11, 66100, Chieti, Italy
| | - Lorena Landuzzi
- Laboratory of Experimental Oncology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Francesca Ruzzi
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Simone Vespa
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Paola Lanuti
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | | | - Pier Luigi Lollini
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Emma Di Carlo
- Department of Medicine and Sciences of Aging, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy. .,Anatomic Pathology and Immuno-Oncology Unit, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Via L. Polacchi 11, 66100, Chieti, Italy.
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Chen Y, Luo L, Deng L, Tian X, Chen S, Xu A, Yuan S. New Insights Into the Lineage-Specific Expansion and Functional Diversification of Lamprey AID/APOBEC Family. Front Immunol 2022; 13:822616. [PMID: 35359986 PMCID: PMC8962628 DOI: 10.3389/fimmu.2022.822616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/15/2022] [Indexed: 11/13/2022] Open
Abstract
The AID/APOBEC family which converts cytidine to uridine on RNA or DNA experienced dynamic expansion in primates in order to resist exogenous viruses and endogenous retrotransposons. Recently, expansion of AID/APOBEC-like homologs has also been observed in the extant jawless vertebrate lamprey. To reveal what causes such expansion and leads to the functional diversification of lamprey cytosine deaminases (CDAs), we reassessed the CDA genes in Lethenteron japonicum (Lj). We first confirmed the expansion of LjCDA1L1 (CDA1-like 1) genes and found the expression correlation of LjCDA2 and LjCDA1L2 with LjVLRs (variable lymphocyte receptors). Among up to 14 LjCDA1L1 proteins, LjCDA1L1_4a has an extremely high deamination activity on ssDNA and buDNA and, unexpectedly, on dsDNA. LjCDA1L1s can also restrict the infection of HSV-1 particles. Thus, the arms race between the host and pathogens along with the recruitment by VLR assembly may participate together to form a driving force in the expansion and diversification of the lamprey AID/APOBEC family.
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Affiliation(s)
- Yan Chen
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Lingjie Luo
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Lisi Deng
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiaoxue Tian
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shangwu Chen
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Anlong Xu
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
- *Correspondence: Shaochun Yuan, ; Anlong Xu,
| | - Shaochun Yuan
- Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Laboratory of Ocean Science and Engineering (Zhuhai), State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- *Correspondence: Shaochun Yuan, ; Anlong Xu,
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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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Lindsly S, Gupta M, Stansbury C, Rajapakse I. Understanding memory B cell selection. J Theor Biol 2021; 531:110905. [PMID: 34543633 DOI: 10.1016/j.jtbi.2021.110905] [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: 12/22/2020] [Revised: 09/12/2021] [Accepted: 09/14/2021] [Indexed: 11/18/2022]
Abstract
The mammalian adaptive immune system has evolved over millions of years to become an incredibly effective defense against foreign antigens. The adaptive immune system's humoral response creates plasma B cells and memory B cells, each with their own immunological objectives. The affinity maturation process is widely viewed as a heuristic to solve the global optimization problem of finding B cells with high affinity to the antigen. However, memory B cells appear to be purposely selected earlier in the affinity maturation process and have lower affinity. We propose that this memory B cell selection process may be an approximate solution to two optimization problems: optimizing for affinity to similar antigens in the future despite mutations or other minor differences, and optimizing to warm start the generation of plasma B cells in the future. We use simulations to provide evidence for our hypotheses, taking into account data showing that certain B cell mutations are more likely than others. Our findings are consistent with memory B cells having high-affinity to mutated antigens, but do not provide strong evidence that memory B cells will be more useful than selected naive B cells for seeding the secondary germinal centers.
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Affiliation(s)
- Stephen Lindsly
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, United States
| | - Maya Gupta
- Google Research, Mountain View, CA, United States.
| | - Cooper Stansbury
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, United States
| | - Indika Rajapakse
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, United States; Department of Mathematics, University of Michigan, Ann Arbor, United States.
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Ye Z, Shi Y, Lees-Miller SP, Tainer JA. Function and Molecular Mechanism of the DNA Damage Response in Immunity and Cancer Immunotherapy. Front Immunol 2021; 12:797880. [PMID: 34970273 PMCID: PMC8712645 DOI: 10.3389/fimmu.2021.797880] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/15/2021] [Indexed: 12/21/2022] Open
Abstract
The DNA damage response (DDR) is an organized network of multiple interwoven components evolved to repair damaged DNA and maintain genome fidelity. Conceptually the DDR includes damage sensors, transducer kinases, and effectors to maintain genomic stability and accurate transmission of genetic information. We have recently gained a substantially improved molecular and mechanistic understanding of how DDR components are interconnected to inflammatory and immune responses to stress. DDR shapes both innate and adaptive immune pathways: (i) in the context of innate immunity, DDR components mainly enhance cytosolic DNA sensing and its downstream STimulator of INterferon Genes (STING)-dependent signaling; (ii) in the context of adaptive immunity, the DDR is needed for the assembly and diversification of antigen receptor genes that is requisite for T and B lymphocyte development. Imbalances between DNA damage and repair impair tissue homeostasis and lead to replication and transcription stress, mutation accumulation, and even cell death. These impacts from DDR defects can then drive tumorigenesis, secretion of inflammatory cytokines, and aberrant immune responses. Yet, DDR deficiency or inhibition can also directly enhance innate immune responses. Furthermore, DDR defects plus the higher mutation load in tumor cells synergistically produce primarily tumor-specific neoantigens, which are powerfully targeted in cancer immunotherapy by employing immune checkpoint inhibitors to amplify immune responses. Thus, elucidating DDR-immune response interplay may provide critical connections for harnessing immunomodulatory effects plus targeted inhibition to improve efficacy of radiation and chemotherapies, of immune checkpoint blockade, and of combined therapeutic strategies.
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Affiliation(s)
- Zu Ye
- Department of Molecular and Cellular Oncology, and Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Yin Shi
- Department of Immunology, Zhejiang University School of Medicine, Hangzhou, China
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Charbonneau Cancer Institute, University of Calgary, Calgary, AB, Canada
| | - John A. Tainer
- Department of Molecular and Cellular Oncology, and Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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Unraveling the susceptibility of paracoccidioidomycosis: Insights towards the pathogen-immune interplay and immunogenetics. INFECTION GENETICS AND EVOLUTION 2020; 86:104586. [PMID: 33039601 DOI: 10.1016/j.meegid.2020.104586] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/27/2020] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis caused by Paracoccidioides spp. This disease comprises three clinical forms: symptomatic acute and chronic forms (PCM disease) and PCM infection, a latent form without clinical symptoms. PCM disease differs markedly according to severity, clinical manifestations, and host immune response. Fungal virulence factors and adhesion molecules are determinants for entry, latency, immune escape and invasion, and dissemination in the host. Neutrophils and macrophages play a paramount role in first-line defense against the fungus through the recognition of antigens by pattern recognition receptors (PRRs), activating their microbicidal machinery. Furthermore, the clinical outcome of the PCM is strongly associated with the variability of cytokines and immunoglobulins produced by T and B cells. While the mechanisms that mediate susceptibility or resistance to infection are dictated by the immune system, some genetic factors may alter gene expression and its final products and, hence, modulate how the organism responds to infection and injury. This review outlines the main findings relative to this topic, addressing the complexity of the immune response triggered by Paracoccidioides spp. infection from preclinical investigations to studies in humans. Here, we focus on mechanisms of fungal pathogenesis, the patterns of innate and adaptive immunity, and the genetic and molecular basis related to immune response and susceptibility to the development of the PCM and its clinical forms. Immunogenetic features such as HLA system, cytokines/cytokines receptors genes and other immune-related genes, and miRNAs are likewise discussed. Finally, we point out the occurrence of PCM in patients with primary immunodeficiencies and call attention to the research gaps and challenges faced by the PCM field.
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Che Z, Fan J, Zhou Z, Li Q, Ma Z, Hu Z, Wu Y, Jin Y, Su Y, Liang P, Li H. Activation-Induced Cytidine Deaminase Expression Facilitates the Malignant Phenotype and Epithelial-to-Mesenchymal Transition in Clear Cell Renal Cell Carcinoma. DNA Cell Biol 2020; 39:1299-1312. [PMID: 32551879 DOI: 10.1089/dna.2019.5119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Although advances have been made in the development of antiangiogenesis targeted therapy and surgery, metastatic clear cell renal cell carcinoma (ccRCC) is still incurable. Activation-induced cytidine deaminase (AID) is mainly expressed in a variety of germ and somatic cells, and induces somatic hypermutation and class-switch recombination, playing a vital role in antibody diversification. We confirmed that AID was expressed at a higher level in ccRCC tissues than in the corresponding nontumor renal tissues. We explored the impact of AID on ccRCC proliferation, invasion, and migration. In 769-p and 786-0 cells, expression of an AID-specific short hairpin RNA significantly reduced AID expression, which markedly inhibited tumor cell invasion, proliferation, and migration. Previous studies showed that AID is associated with Wnt ligand secretion mediator (WLS/GPR177), cyclin-dependent kinase 4 (CDK4), and stromal cell-derived factor-1 (SDF-1/CXCL12) regulation, which was further confirmed in human ccRCC tissues. Therefore, we studied the relationship between AID and these three molecules, and the impact of AID on epithelial-to-mesenchymal transition in ccRCC. WLS/GPR177, SDF-1/CXCL12, and CDK4 were sensitive to 5-azacytidine (a DNA demethylation agent), which reverted the inhibition of carcinogenesis caused by AID repression. In summary, AID is an oncogene that might induce tumorigenesis through DNA demethylation. Targeting AID may represent a novel therapeutic approach to treat metastatic ccRCC.
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Affiliation(s)
- Zhifei Che
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Jinfeng Fan
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Zhiyan Zhou
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Qi Li
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhe Ma
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Zhanhao Hu
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Yaoxi Wu
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Yingxia Jin
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yang Su
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Peiyu Liang
- Department of Urology, The First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Haoyong Li
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, China
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The prognostic importance of double-expressor subgroup and AID , UNG and mismatch repair protein expressions in diffuse large B-cell lymphomas. MARMARA MEDICAL JOURNAL 2020. [DOI: 10.5472/marumj.741651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Shi M, Tan L, Zhang Y, Meng C, Wang W, Sun Y, Song C, Liu W, Liao Y, Yu S, Ren T, Ding Z, Liu X, Qiu X, Ding C. Characterization and functional analysis of chicken APOBEC4. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 106:103631. [PMID: 31991164 DOI: 10.1016/j.dci.2020.103631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/21/2020] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The APOBEC proteins play significant roles in the innate and adaptive immune system, probably due to their deaminase activities. Because APOBEC1 (A1) and APOBEC3 (A3) are absent in the chicken genome, we were interested in determining whether chicken APOBEC4 (A4) possessed more complex functions than its mammalian homologs. In this study, chicken A4 (chA4) mRNA was identified and cloned for the first time. Based on bioinformatics analyses, the conserved zinc-coordinating motif (HXE … PC(X)2-6C) was identified on the surface of chA4 and contained highly conserved His97, Glu99, Pro130, Cys131 and Cys138 active sites. The highest expression levels of constitutive chA4 were detected in primary lymphocytes and bursa of Fabricius. Newcastle Disease (ND) is one of the most serious infectious diseases in birds, causing major economic losses to the poultry industry. In vitro, Newcastle Disease Virus (NDV) early infection induced significant increases in chA4 expression in the chicken B cell line, DT40, the macrophage cell line, HD11 and the CD4+ T cell line, MSB-1, but not the fibroblast cell line, DF-1. In vivo, the expression levels of chA4 were up-regulated in several tissues from NDV-infected chickens, especially the thymus, testicles, duodenum and kidney. The high level expression of exogenous chA4 displayed inhibitory effects on NDV and reduced viral RNA in infected cells. Taken together, these data demonstrate that chA4 is involved in the chicken immune system and may play important roles in host anti-viral responses.
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Affiliation(s)
- Mengyu Shi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Lei Tan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Yaodan Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Chunchun Meng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Wei Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Yingjie Sun
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Cuiping Song
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Weiwei Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Ying Liao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Tao Ren
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, People's Republic of China.
| | - Zhuang Ding
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Jilin University, Changchun, 130062, PR China.
| | - Xiufan Liu
- Key Laboratory of Animal Infectious Diseases, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, PR China.
| | - Xusheng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, PR China.
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11
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Chi X, Li Y, Qiu X. V(D)J recombination, somatic hypermutation and class switch recombination of immunoglobulins: mechanism and regulation. Immunology 2020; 160:233-247. [PMID: 32031242 DOI: 10.1111/imm.13176] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 12/30/2019] [Accepted: 01/08/2020] [Indexed: 02/06/2023] Open
Abstract
Immunoglobulins emerging from B lymphocytes and capable of recognizing almost all kinds of antigens owing to the extreme diversity of their antigen-binding portions, known as variable (V) regions, play an important role in immune responses. The exons encoding the V regions are known as V (variable), D (diversity), or J (joining) genes. V, D, J segments exist as multiple copy arrays on the chromosome. The recombination of the V(D)J gene is the key mechanism to produce antibody diversity. The recombinational process, including randomly choosing a pair of V, D, J segments, introducing double-strand breaks adjacent to each segment, deleting (or inverting in some cases) the intervening DNA and ligating the segments together, is defined as V(D)J recombination, which contributes to surprising immunoglobulin diversity in vertebrate immune systems. To enhance both the ability of immunoglobulins to recognize and bind to foreign antigens and the effector capacities of the expressed antibodies, naive B cells will undergo class switching recombination (CSR) and somatic hypermutation (SHM). However, the genetics mechanisms of V(D)J recombination, CSR and SHM are not clear. In this review, we summarize the major progress in mechanism studies of immunoglobulin V(D)J gene recombination and CSR as well as SHM, and their regulatory mechanisms.
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Affiliation(s)
- Xiying Chi
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China.,NHC Key Laboratory of Medical Immunology, Peking University, Beijing, China
| | - Yue Li
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China.,NHC Key Laboratory of Medical Immunology, Peking University, Beijing, China
| | - Xiaoyan Qiu
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, China.,NHC Key Laboratory of Medical Immunology, Peking University, Beijing, China
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12
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Tepper S, Mortusewicz O, Członka E, Bello A, Schmidt A, Jeschke J, Fischbach A, Pfeil I, Petersen-Mahrt SK, Mangerich A, Helleday T, Leonhardt H, Jungnickel B. Restriction of AID activity and somatic hypermutation by PARP-1. Nucleic Acids Res 2019; 47:7418-7429. [PMID: 31127309 PMCID: PMC6698665 DOI: 10.1093/nar/gkz466] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/13/2019] [Accepted: 05/16/2019] [Indexed: 12/20/2022] Open
Abstract
Affinity maturation of the humoral immune response depends on somatic hypermutation (SHM) of immunoglobulin (Ig) genes, which is initiated by targeted lesion introduction by activation-induced deaminase (AID), followed by error-prone DNA repair. Stringent regulation of this process is essential to prevent genetic instability, but no negative feedback control has been identified to date. Here we show that poly(ADP-ribose) polymerase-1 (PARP-1) is a key factor restricting AID activity during somatic hypermutation. Poly(ADP-ribose) (PAR) chains formed at DNA breaks trigger AID-PAR association, thus preventing excessive DNA damage induction at sites of AID action. Accordingly, AID activity and somatic hypermutation at the Ig variable region is decreased by PARP-1 activity. In addition, PARP-1 regulates DNA lesion processing by affecting strand biased A:T mutagenesis. Our study establishes a novel function of the ancestral genome maintenance factor PARP-1 as a critical local feedback regulator of both AID activity and DNA repair during Ig gene diversification.
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Affiliation(s)
- Sandra Tepper
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biology and Pharmacy, Friedrich Schiller University, 07745 Jena, Germany
| | - Oliver Mortusewicz
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany.,Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
| | - Ewelina Członka
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biology and Pharmacy, Friedrich Schiller University, 07745 Jena, Germany
| | - Amanda Bello
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biology and Pharmacy, Friedrich Schiller University, 07745 Jena, Germany
| | - Angelika Schmidt
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biology and Pharmacy, Friedrich Schiller University, 07745 Jena, Germany
| | - Julia Jeschke
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biology and Pharmacy, Friedrich Schiller University, 07745 Jena, Germany
| | - Arthur Fischbach
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Ines Pfeil
- Institute of Clinical Molecular Biology, Helmholtz Center Munich, German Research Center for Environmental Health, 81377 Munich, Germany
| | - Svend K Petersen-Mahrt
- DNA Editing in Immunity and Epigenetics, IFOM-Fondazione Instituto FIRC di Oncologia Molecolare, Milano, Italy
| | - Aswin Mangerich
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Thomas Helleday
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
| | - Heinrich Leonhardt
- Department of Biology II and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
| | - Berit Jungnickel
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biology and Pharmacy, Friedrich Schiller University, 07745 Jena, Germany.,Department of Biology, University of Konstanz, 78457 Konstanz, Germany
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13
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Mechanisms of Genomic Instability in Breast Cancer. Trends Mol Med 2019; 25:595-611. [DOI: 10.1016/j.molmed.2019.04.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/29/2019] [Accepted: 04/04/2019] [Indexed: 12/22/2022]
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14
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Tóth DM, Ocskó T, Balog A, Markovics A, Mikecz K, Kovács L, Jolly M, Bukiej AA, Ruthberg AD, Vida A, Block JA, Glant TT, Rauch TA. Amelioration of Autoimmune Arthritis in Mice Treated With the DNA Methyltransferase Inhibitor 5'-Azacytidine. Arthritis Rheumatol 2019; 71:1265-1275. [PMID: 30835944 DOI: 10.1002/art.40877] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/28/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Disease-associated, differentially hypermethylated regions have been reported in rheumatoid arthritis (RA), but no DNA methyltransferase inhibitors have been evaluated in either RA or any animal models of RA. The present study was conducted to evaluate the therapeutic potential of 5'-azacytidine (5'-azaC), a DNA methyltransferase inhibitor, and explore the cellular and gene regulatory networks involved in the context of autoimmune arthritis. METHODS A disease-associated genome-wide DNA methylation profile was explored by methylated CpG island recovery assay-chromatin immunoprecipitation (ChIP) in arthritic B cells. Mice with proteoglycan-induced arthritis (PGIA) were treated with 5'-azaC. The effect of 5'-azaC on the pathogenesis of PGIA was explored by measuring serum IgM and IgG1 antibody levels using enzyme-linked immunosorbent assay, investigating the efficiency of class-switch recombination (CSR) and Aicda gene expression using real-time quantitative polymerase chain reaction, monitoring germinal center (GC) formation by immunohistochemistry, and determining alterations in B cell subpopulations by flow cytometry. The 5'-azaC-induced regulation of the Aicda gene was explored using RNA interference, ChIP, and luciferase assays. RESULTS We explored arthritis-associated hypermethylated regions in mouse B cells and demonstrated that DNA demethylation had a beneficial effect on autoimmune arthritis. The 5'-azaC-mediated demethylation of the epigenetically inactivated Ahr gene resulted in suppressed expression of the Aicda gene, reduced CSR, and compromised GC formation. Ultimately, this process led to diminished IgG1 antibody production and amelioration of autoimmune arthritis in mice. CONCLUSION DNA hypermethylation plays a leading role in the pathogenesis of autoimmune arthritis and its targeted inhibition has therapeutic potential in arthritis management.
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Affiliation(s)
| | - Timea Ocskó
- Rush University Medical Center, Chicago, Illinois
| | - Attila Balog
- Albert Szent-Györgyi Clinical Center, Szeged, Hungary
| | | | | | - László Kovács
- Albert Szent-Györgyi Clinical Center, Szeged, Hungary
| | | | | | | | - András Vida
- Rush University Medical Center, Chicago, Illinois
| | - Joel A Block
- Rush University Medical Center, Chicago, Illinois
| | | | - Tibor A Rauch
- Rush University Medical Center, Chicago, Illinois, and University of Pécs, Pécs, Hungary
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15
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Knox JJ, Myles A, Cancro MP. T-bet + memory B cells: Generation, function, and fate. Immunol Rev 2019; 288:149-160. [PMID: 30874358 PMCID: PMC6626622 DOI: 10.1111/imr.12736] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 12/16/2022]
Abstract
B cells expressing the transcription factor T-bet have emerged as participants in a number of protective and pathogenic immune responses. T-bet+ B cells characteristically differentiate in response to combined Toll-like receptor and cytokine signaling, contribute to protective immunity against intracellular pathogens via IgG2a/c production and antibody-independent mechanisms, and are prone to produce autoantibodies. Despite recent advances, a number of questions remain regarding the basic biology of T-bet+ B cells and their functional niche within the immune system. Herein, we review the discovery and defining characteristics of the T-bet+ B cell subset in both mice and humans. We further discuss their origins, the basis for their persistence, and their potential fate in vivo. Evidence indicates that T-bet+ B cells represent a distinct, germinal center-derived memory population that may serve as an important therapeutic target for the improvement of humoral immunity and prevention of autoimmunity.
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Affiliation(s)
- James J. Knox
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - Arpita Myles
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - Michael P. Cancro
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
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16
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Abstract
Class switch recombination (CSR) generates isotype-switched antibodies with distinct effector functions essential for mediating effective humoral immunity. CSR is catalyzed by activation-induced deaminase (AID) that initiates DNA lesions in the evolutionarily conserved switch (S) regions at the immunoglobulin heavy chain (Igh) locus. AID-initiated DNA lesions are subsequently converted into DNA double stranded breaks (DSBs) in the S regions of Igh locus, repaired by non-homologous end-joining to effect CSR in mammalian B lymphocytes. While molecular mechanisms of CSR are well characterized, it remains less well understood how upstream signaling pathways regulate AID expression and CSR. B lymphocytes express multiple receptors including the B cell antigen receptor (BCR) and co-receptors (e.g., CD40). These receptors may share common signaling pathways or may use distinct signaling elements to regulate CSR. Here, we discuss how signals emanating from different receptors positively or negatively regulate AID expression and CSR.
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Affiliation(s)
- Zhangguo Chen
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
| | - Jing H Wang
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
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17
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Abstract
Activation-induced cytidine deaminase (AID) initiates somatic hypermutation (SHM) by converting deoxycytidines (dC) to deoxyuracils (dU) which then can induce other mutations, and plays a central role in introducing diversification of the antibody repertoire in B cells. Ectopic expression of AID in bacteria and non-B cells can also lead to frequent mutations in highly expressed genes. Taking advantage of this feature of AID, in recent years, systems coupling in vitro somatic hypermutation and mammalian cell surface display have been developed, with unique benefits in antibody discovery and optimization in vitro. Here, we provide a protocol for AID mediated in vitro protein evolution. A CHO cell clone bearing a single gene expression cassette has been constructed. The gene of an interested protein for in vitro evolution can be easily inserted into the cassette by dual recombinase-mediated cassette exchange (RMCE) and constantly expressed at high levels. Here, we matured an anti-TNFα antibody as an example. Firstly, we obtained a CHO cell clone highly displaying the antibody by dual RMCE. Then, the plasmid expressing AID is transfected into the CHO cells. After a few rounds of cell sorting-cell proliferation, mutant antibodies with improved features can be generated. This protocol can be applied for improving protein features based on displaying levels on cell surface and protein-protein interaction, and thus is able to enhance affinity, specificity, and stability besides others.
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18
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Grundström C, Kumar A, Priya A, Negi N, Grundström T. ETS1 and PAX5 transcription factors recruit AID to Igh DNA. Eur J Immunol 2018; 48:1687-1697. [PMID: 30089192 DOI: 10.1002/eji.201847625] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/12/2018] [Accepted: 08/07/2018] [Indexed: 01/25/2023]
Abstract
B lymphocytes optimize antibody responses by class switch recombination (CSR), which changes the expressed constant region exon of the immunoglobulin heavy chain (IgH), and by somatic hypermutation (SH) that introduces point mutations in the variable regions of the antibody genes. Activation-induced cytidine deaminase (AID) is the key mutagenic enzyme that initiates both these antibody diversification processes by deaminating cytosine to uracil. Here we asked the question if transcription factors can mediate the specific targeting of the antibody diversification by recruiting AID. We have recently reported that AID is together with the transcription factors E2A, PAX5 and IRF4 in a complex on key sequences of the Igh locus. Here we report that also ETS1 is together with AID in this complex on key sequences of the Igh locus in splenic B cells of mice. Furthermore, we show that both ETS1 and PAX5 can directly recruit AID to DNA sequences from the Igh locus with the specific binding site for the transcription factor. Taken together, our findings support the notion of a targeting mechanism for the selective diversification of antibody genes with limited genome wide mutagenesis by recruitment of AID by PAX5 and ETS1 in a transcription factor complex.
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Affiliation(s)
| | - Anjani Kumar
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Anshu Priya
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Neema Negi
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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19
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Recaldin T, Hobson PS, Mann EH, Ramadani F, Cousins DJ, Lavender P, Fear DJ. miR-29b directly targets activation-induced cytidine deaminase in human B cells and can limit its inappropriate expression in naïve B cells. Mol Immunol 2018; 101:419-428. [PMID: 30081328 DOI: 10.1016/j.molimm.2018.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/08/2018] [Accepted: 07/23/2018] [Indexed: 11/25/2022]
Abstract
Class-switch recombination (CSR) is an essential B cell process that alters the isotype of antibody produced by the B cell, tailoring the immune response to the nature of the invading pathogen. CSR requires the activity of the mutagenic enzyme AID (encoded by AICDA) to generate chromosomal lesions within the immunoglobulin genes that initiate the class switching recombination event. These AID-mediated mutations also participate in somatic-hypermutation of the immunoglobulin variable region, driving affinity maturation. As such, AID poses a significant oncogenic threat if it functions outside of the immunoglobulin locus. We found that expression of the microRNA, miR-29b, was repressed in B cells isolated from tonsil tissue, relative to circulating naïve B cells. Further investigation revealed that miR-29b was able to directly initiate the degradation of AID mRNA. Enforced overexpression of miR-29b in human B cells precipitated a reduction in overall AID protein and a corresponding diminution in CSR to IgE. Given miR-29b's ability to potently target AID, a mutagenic molecule that can initiate chromosomal translocations and "off-target" mutations, we propose that miR-29b acts to silence premature AID expression in naïve B cells, thus reducing the likelihood of inappropriate and potentially dangerous deamination activity.
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Affiliation(s)
- Timothy Recaldin
- School of Immunology & Microbial Sciences, King's College London, UK; Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK
| | - Philip S Hobson
- Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK
| | - Elizabeth H Mann
- Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK
| | - Faruk Ramadani
- Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK; School of Basic & Medical Biosciences, King's College London, UK
| | - David J Cousins
- Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK; Leicester Respiratory Biomedical Research Unit, Leicester University, UK
| | - Paul Lavender
- School of Immunology & Microbial Sciences, King's College London, UK; Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK
| | - David J Fear
- School of Immunology & Microbial Sciences, King's College London, UK; Medical Research Council and Asthma UK Centre, Allergic Mechanisms in Asthma, London, UK.
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20
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Kumar A, Priya A, Ahmed T, Grundström C, Negi N, Grundström T. Regulation of the DNA Repair Complex during Somatic Hypermutation and Class-Switch Recombination. THE JOURNAL OF IMMUNOLOGY 2018; 200:4146-4156. [PMID: 29728513 DOI: 10.4049/jimmunol.1701586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/11/2018] [Indexed: 02/06/2023]
Abstract
B lymphocytes optimize Ab responses by somatic hypermutation (SH), which introduces point mutations in the variable regions of the Ab genes and by class-switch recombination (CSR), which changes the expressed C region exon of the IgH. These Ab diversification processes are initiated by the deaminating enzyme activation-induced cytidine deaminase followed by many DNA repair enzymes, ultimately leading to deletions and a high mutation rate in the Ab genes, whereas DNA lesions made by activation-induced cytidine deaminase are repaired with low error rate on most other genes. This indicates an advanced regulation of DNA repair. In this study, we show that initiation of Ab diversification in B lymphocytes of mouse spleen leads to formation of a complex between many proteins in DNA repair. We show also that BCR activation, which signals the end of successful SH, reduces interactions between some proteins in the complex and increases other interactions in the complex with varying kinetics. Furthermore, we show increased localization of SH- and CSR-coupled proteins on switch regions of the Igh locus upon initiation of SH/CSR and differential changes in the localization upon BCR signaling, which terminates SH. These findings provide early evidence for a DNA repair complex or complexes that may be of functional significance for carrying out essential roles in SH and/or CSR in B cells.
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Affiliation(s)
- Anjani Kumar
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Anshu Priya
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Tanzeel Ahmed
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | | | - Neema Negi
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Thomas Grundström
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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21
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Haakenson JK, Huang R, Smider VV. Diversity in the Cow Ultralong CDR H3 Antibody Repertoire. Front Immunol 2018; 9:1262. [PMID: 29915599 PMCID: PMC5994613 DOI: 10.3389/fimmu.2018.01262] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 05/18/2018] [Indexed: 01/26/2023] Open
Abstract
Typical antibodies found in humans and mice usually have short CDR H3s and generally flat binding surfaces. However, cows possess a subset of antibodies with ultralong CDR H3s that can range up to 70 amino acids and form a unique “stalk and knob” structure, with the knob protruding far out of the antibody surface, where it has the potential to bind antigens with concave epitopes. Activation-induced cytidine deaminase (AID) has a proven role in diversifying antibody repertoires in humoral immunity, and it has been found to induce somatic hypermutation in bovine immunoglobulin genes both before and after contact with antigen. Due to limited use of variable and diversity genes in the V(D)J recombination events that produce ultralong CDR H3 antibodies in cows, the diversity in the bovine ultralong antibody repertoire has been proposed to rely on AID-induced mutations targeted to the IGHD8-2 gene that encodes the entire knob region. In this review, we discuss the genetics, structures, and diversity of bovine ultralong antibodies, as well as the role of AID in creating a diverse antibody repertoire.
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Affiliation(s)
- Jeremy K Haakenson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Ruiqi Huang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Vaughn V Smider
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
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22
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Tepper S, Jeschke J, Böttcher K, Schmidt A, Davari K, Müller P, Kremmer E, Hemmerich P, Pfeil I, Jungnickel B. PARP activation promotes nuclear AID accumulation in lymphoma cells. Oncotarget 2017; 7:13197-208. [PMID: 26921193 PMCID: PMC4914351 DOI: 10.18632/oncotarget.7603] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/12/2016] [Indexed: 12/20/2022] Open
Abstract
Activation-induced cytidine deaminase (AID) initiates immunoglobulin diversification in germinal center B cells by targeted introduction of DNA damage. As aberrant nuclear AID action contributes to the generation of B cell lymphoma, the protein's activity is tightly regulated, e.g. by nuclear/cytoplasmic shuttling and nuclear degradation. In the present study, we asked whether DNA damage may affect regulation of the AID protein. We show that exogenous DNA damage that mainly activates base excision repair leads to prevention of proteasomal degradation of AID and hence its nuclear accumulation. Inhibitor as well as knockout studies indicate that activation of poly (ADP-ribose) polymerase (PARP) by DNA damaging agents promotes both phenomena. These findings suggest that PARP inhibitors influence DNA damage dependent AID regulation, with interesting implications for the regulation of AID function and chemotherapy of lymphoma.
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Affiliation(s)
- Sandra Tepper
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany
| | - Julia Jeschke
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany.,Institute of Clinical and Molecular Biology, Helmholtz Center Munich, 81377 Munich, Germany
| | - Katrin Böttcher
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany
| | - Angelika Schmidt
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany
| | - Kathrin Davari
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany
| | - Peter Müller
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany
| | - Elisabeth Kremmer
- Institute of Molecular Immunology, Helmholtz Center Munich, 81377 Munich, Germany
| | - Peter Hemmerich
- Imaging Facility, Leibniz- Institute on Aging - Fritz Lipmann Institute, 07745 Jena, Germany
| | - Ines Pfeil
- Institute of Clinical and Molecular Biology, Helmholtz Center Munich, 81377 Munich, Germany
| | - Berit Jungnickel
- Department of Cell Biology, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich-Schiller University, 07745 Jena, Germany.,Institute of Clinical and Molecular Biology, Helmholtz Center Munich, 81377 Munich, Germany
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23
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Abdouni HS, King JJ, Ghorbani A, Fifield H, Berghuis L, Larijani M. DNA/RNA hybrid substrates modulate the catalytic activity of purified AID. Mol Immunol 2017; 93:94-106. [PMID: 29161581 DOI: 10.1016/j.molimm.2017.11.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/10/2017] [Accepted: 11/11/2017] [Indexed: 11/28/2022]
Abstract
Activation-induced cytidine deaminase (AID) converts cytidine to uridine at Immunoglobulin (Ig) loci, initiating somatic hypermutation and class switching of antibodies. In vitro, AID acts on single stranded DNA (ssDNA), but neither double-stranded DNA (dsDNA) oligonucleotides nor RNA, and it is believed that transcription is the in vivo generator of ssDNA targeted by AID. It is also known that the Ig loci, particularly the switch (S) regions targeted by AID are rich in transcription-generated DNA/RNA hybrids. Here, we examined the binding and catalytic behavior of purified AID on DNA/RNA hybrid substrates bearing either random sequences or GC-rich sequences simulating Ig S regions. If substrates were made up of a random sequence, AID preferred substrates composed entirely of DNA over DNA/RNA hybrids. In contrast, if substrates were composed of S region sequences, AID preferred to mutate DNA/RNA hybrids over substrates composed entirely of DNA. Accordingly, AID exhibited a significantly higher affinity for binding DNA/RNA hybrid substrates composed specifically of S region sequences, than any other substrates composed of DNA. Thus, in the absence of any other cellular processes or factors, AID itself favors binding and mutating DNA/RNA hybrids composed of S region sequences. AID:DNA/RNA complex formation and supporting mutational analyses suggest that recognition of DNA/RNA hybrids is an inherent structural property of AID.
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Affiliation(s)
- Hala S Abdouni
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, A1 B 3V6, Canada
| | - Justin J King
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, A1 B 3V6, Canada
| | - Atefeh Ghorbani
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, A1 B 3V6, Canada
| | - Heather Fifield
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, A1 B 3V6, Canada
| | - Lesley Berghuis
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, A1 B 3V6, Canada
| | - Mani Larijani
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, A1 B 3V6, Canada.
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24
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T-bet-expressing B cells during HIV and HCV infections. Cell Immunol 2017; 321:26-34. [PMID: 28739077 DOI: 10.1016/j.cellimm.2017.04.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
Abstract
T-bet-expressing B cells, first identified as perpetuators of autoimmunity, were recently shown to be critical for murine antiviral responses. While their role in human viral infections remains unclear, B cells expressing T-bet or demonstrating a related phenotype have been described in individuals chronically infected with HIV or HCV, suggesting these cells represent a component of human antiviral responses. In this review, we discuss the induction of T-bet in B cells following both HIV and HCV infections, the factors driving T-bet+ B cell expansions, T-bet's relationship to atypical memory B cells, and the consequences of T-bet induction. We propose potential antiviral roles for T-bet+ B cells and discuss whether this population poses any utility to the HIV and HCV immune responses.
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Abstract
Helicobacter pylori infection is the most important cause of human gastric cancer worldwide. Gastric cancer develops over a long time after H. pylori infection via stepwise accumulation of genetic alterations and positive selection of cells with growth advantages. H. pylori itself and the resultant chronic inflammation lead to the emergence of genetic alterations in gastric epithelial cells via increased susceptibility of these cells to DNA damage. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) in inflammatory and gastric epithelial cells, as well as the expression of cytidine deaminase in gastric epithelial cells, may link H. pylori-related inflammation and DNA damage. Recent comprehensive analyses of gastric cancer genomes provide clues for the possible molecular mechanisms of gastric carcinogenesis. In this chapter, we describe how genetic alterations emerge during gastric carcinogenesis related to H. pylori infection.
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26
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Knox JJ, Buggert M, Kardava L, Seaton KE, Eller MA, Canaday DH, Robb ML, Ostrowski MA, Deeks SG, Slifka MK, Tomaras GD, Moir S, Moody MA, Betts MR. T-bet+ B cells are induced by human viral infections and dominate the HIV gp140 response. JCI Insight 2017; 2:92943. [PMID: 28422752 DOI: 10.1172/jci.insight.92943] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/02/2017] [Indexed: 12/20/2022] Open
Abstract
Humoral immunity is critical for viral control, but the identity and mechanisms regulating human antiviral B cells are unclear. Here, we characterized human B cells expressing T-bet and analyzed their dynamics during viral infections. T-bet+ B cells demonstrated an activated phenotype, a distinct transcriptional profile, and were enriched for expression of the antiviral immunoglobulin isotypes IgG1 and IgG3. T-bet+ B cells expanded following yellow fever virus and vaccinia virus vaccinations and also during early acute HIV infection. Viremic HIV-infected individuals maintained a large T-bet+ B cell population during chronic infection that was associated with increased serum and cell-associated IgG1 and IgG3 expression. The HIV gp140-specific B cell response was dominated by T-bet-expressing memory B cells, and we observed a concomitant biasing of gp140-specific serum immunoglobulin to the IgG1 isotype. These findings suggest that T-bet induction promotes antiviral immunoglobulin isotype switching and development of a distinct T-bet+ B cell subset that is maintained by viremia and coordinates the HIV Env-specific humoral response.
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Affiliation(s)
- James J Knox
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Marcus Buggert
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Lela Kardava
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - Kelly E Seaton
- Duke Human Vaccine Institute; and Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael A Eller
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - David H Canaday
- Division of Infectious Disease, Case Western Reserve University School of Medicine, and Cleveland VA, Cleveland, Ohio, USA
| | - Merlin L Robb
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Mario A Ostrowski
- Departments of Immunology and Medicine, University of Toronto, Toronto, Ontario, Canada; Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Steven G Deeks
- Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Mark K Slifka
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Georgia D Tomaras
- Duke Human Vaccine Institute; and Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Susan Moir
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute; Department of Pediatrics; and Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael R Betts
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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27
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Cui L, Bi J, Yan D, Ye X, Zheng M, Yu G, Wan X. JSI-124 inhibits IgE production in an IgE B cell line. Biochem Biophys Res Commun 2017; 483:669-673. [PMID: 27988336 DOI: 10.1016/j.bbrc.2016.12.085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 12/12/2016] [Indexed: 11/30/2022]
Abstract
IgE is a key effector molecule in atopic diseases; however, the regulation mechanisms of IgE production in IgE B cells remain poorly understood. In the present study, we demonstrate that JSI-124 (cucurbitacin I), a selective STAT3 inhibitor, selectively inhibits production of IgE by a human IgE B cell line, CRL-8033 cells, while does not affect the IgG production by IgG B cell lines. In the aspect of molecular mechanism, we found that Igλ, but not Ighe, gene expression was suppressed by JSI-124. The above effects of JSI-124 were not mediated by affecting cellular proliferation or apoptosis. Furthermore, multiple B cell differentiation-related genes expression was not significantly affected by JSI-124. Taken together, we demonstrate a potential strategy of therapeutically suppressing IgE production without affecting IgG production in atopic patients.
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Affiliation(s)
- Lulu Cui
- Division of Immunology, School of Fundamental Medicine, Jinzhou Medical University, Jinzhou, 121000, China
| | - Jiacheng Bi
- Shenzhen Laboratory of Antibody Engineering, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Dehong Yan
- Shenzhen Laboratory of Antibody Engineering, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xiufeng Ye
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, 518035, China
| | - Mingxing Zheng
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, 518035, China
| | - Guang Yu
- Division of Immunology, School of Fundamental Medicine, Jinzhou Medical University, Jinzhou, 121000, China.
| | - Xiaochun Wan
- Shenzhen Laboratory of Antibody Engineering, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
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28
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Sapoznik S, Bahar-Shany K, Brand H, Pinto Y, Gabay O, Glick-Saar E, Dor C, Zadok O, Barshack I, Zundelevich A, Gal-Yam EN, Yung Y, Hourvitz A, Korach J, Beiner M, Jacob J, Levanon EY, Barak M, Aviel-Ronen S, Levanon K. Activation-Induced Cytidine Deaminase Links Ovulation-Induced Inflammation and Serous Carcinogenesis. Neoplasia 2016; 18:90-9. [PMID: 26936395 PMCID: PMC5005261 DOI: 10.1016/j.neo.2015.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 12/10/2015] [Accepted: 12/22/2015] [Indexed: 12/22/2022] Open
Abstract
In recent years, the notion that ovarian carcinoma results from ovulation-induced inflammation of the fallopian tube epithelial cells (FTECs) has gained evidence. However, the mechanistic pathway for this process has not been revealed yet. In the current study, we propose the mutator protein activation-induced cytidine deaminase (AID) as a link between ovulation-induced inflammation in FTECs and genotoxic damage leading to ovarian carcinogenesis. We show that AID, previously shown to be functional only in B lymphocytes, is expressed in FTECs under physiological conditions, and is induced in vitro upon ovulatory-like stimulation and in vivo in carcinoma-associated FTECs. We also report that AID activity results in epigenetic, genetic and genomic damage in FTECs. Overall, our data provides new insights into the etiology of ovarian carcinogenesis and may set the ground for innovative approaches aimed at prevention and early detection.
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Affiliation(s)
- Stav Sapoznik
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Keren Bahar-Shany
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Hadar Brand
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, 69978, Israel
| | - Yishay Pinto
- The Mina and Everard Goodman Faculty of Life Science, Bar Ilan University, Ramat-Gan, 52900, Israel
| | - Orshay Gabay
- The Mina and Everard Goodman Faculty of Life Science, Bar Ilan University, Ramat-Gan, 52900, Israel
| | - Efrat Glick-Saar
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Chen Dor
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Oranit Zadok
- Department of Pathology, Chaim Sheba Medical Center, Ramat-Gan 52621, Israel
| | - Iris Barshack
- Department of Pathology, Chaim Sheba Medical Center, Ramat-Gan 52621, Israel
| | - Adi Zundelevich
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Einav Nili Gal-Yam
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel; The Talpiot Medical Leadership Program, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Yuval Yung
- IVF Unit and Reproduction Lab, Department of Obstetrics and Gynecology, Chaim Sheba Medical Center, Ramat-Gan, 52621, Israel
| | - Ariel Hourvitz
- IVF Unit and Reproduction Lab, Department of Obstetrics and Gynecology, Chaim Sheba Medical Center, Ramat-Gan, 52621, Israel
| | - Jacob Korach
- Department of Gynecologic Oncology, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Mario Beiner
- Department of Gynecologic Oncology, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Jasmine Jacob
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Science, Bar Ilan University, Ramat-Gan, 52900, Israel
| | - Michal Barak
- The Mina and Everard Goodman Faculty of Life Science, Bar Ilan University, Ramat-Gan, 52900, Israel
| | - Sarit Aviel-Ronen
- Department of Pathology, Chaim Sheba Medical Center, Ramat-Gan 52621, Israel; The Talpiot Medical Leadership Program, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel
| | - Keren Levanon
- Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, 69978, Israel; The Talpiot Medical Leadership Program, Chaim Sheba Medical Center, Ramat Gan, 52621, Israel.
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29
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Hauser J, Grundström C, Kumar R, Grundström T. Regulated localization of an AID complex with E2A, PAX5 and IRF4 at the Igh locus. Mol Immunol 2016; 80:78-90. [DOI: 10.1016/j.molimm.2016.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 12/11/2022]
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Chen Z, Eder MD, Elos MT, Viboolsittiseri SS, Chen X, Wang JH. Interplay between Target Sequences and Repair Pathways Determines Distinct Outcomes of AID-Initiated Lesions. THE JOURNAL OF IMMUNOLOGY 2016; 196:2335-47. [PMID: 26810227 DOI: 10.4049/jimmunol.1502184] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/22/2015] [Indexed: 11/19/2022]
Abstract
Activation-induced deaminase (AID) functions by deaminating cytosines and causing U:G mismatches, a rate-limiting step of Ab gene diversification. However, precise mechanisms regulating AID deamination frequency remain incompletely understood. Moreover, it is not known whether different sequence contexts influence the preferential access of mismatch repair or uracil glycosylase (UNG) to AID-initiated U:G mismatches. In this study, we employed two knock-in models to directly compare the mutability of core Sμ and VDJ exon sequences and their ability to regulate AID deamination and subsequent repair process. We find that the switch (S) region is a much more efficient AID deamination target than the V region. Igh locus AID-initiated lesions are processed by error-free and error-prone repair. S region U:G mismatches are preferentially accessed by UNG, leading to more UNG-dependent deletions, enhanced by mismatch repair deficiency. V region mutation hotspots are largely determined by AID deamination. Recurrent and conserved S region motifs potentially function as spacers between AID deamination hotspots. We conclude that the pattern of mutation hotspots and DNA break generation is influenced by sequence-intrinsic properties, which regulate AID deamination and affect the preferential access of downstream repair. Our studies reveal an evolutionarily conserved role for substrate sequences in regulating Ab gene diversity and AID targeting specificity.
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Affiliation(s)
- Zhangguo Chen
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045; and Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Maxwell D Eder
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045; and
| | - Mihret T Elos
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045; and
| | - Sawanee S Viboolsittiseri
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045; and
| | - Xiaomi Chen
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045; and
| | - Jing H Wang
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045; and Department of Biomedical Research, National Jewish Health, Denver, CO 80206
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31
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Cannan WJ, Pederson DS. Mechanisms and Consequences of Double-Strand DNA Break Formation in Chromatin. J Cell Physiol 2016; 231:3-14. [PMID: 26040249 DOI: 10.1002/jcp.25048] [Citation(s) in RCA: 234] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 05/14/2015] [Indexed: 12/14/2022]
Abstract
All organisms suffer double-strand breaks (DSBs) in their DNA as a result of exposure to ionizing radiation. DSBs can also form when replication forks encounter DNA lesions or repair intermediates. The processing and repair of DSBs can lead to mutations, loss of heterozygosity, and chromosome rearrangements that result in cell death or cancer. The most common pathway used to repair DSBs in metazoans (non-homologous DNA end joining) is more commonly mutagenic than the alternative pathway (homologous recombination mediated repair). Thus, factors that influence the choice of pathways used DSB repair can affect an individual's mutation burden and risk of cancer. This review describes radiological, chemical, and biological mechanisms that generate DSBs, and discusses the impact of such variables as DSB etiology, cell type, cell cycle, and chromatin structure on the yield, distribution, and processing of DSBs. The final section focuses on nucleosome-specific mechanisms that influence DSB production, and the possible relationship between higher order chromosome coiling and chromosome shattering (chromothripsis).
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Affiliation(s)
- Wendy J Cannan
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont
| | - David S Pederson
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont
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32
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Chen Z, Elos MT, Viboolsittiseri SS, Gowan K, Leach SM, Rice M, Eder MD, Jones K, Wang JH. Combined deletion of Xrcc4 and Trp53 in mouse germinal center B cells leads to novel B cell lymphomas with clonal heterogeneity. J Hematol Oncol 2016; 9:2. [PMID: 26740101 PMCID: PMC4704435 DOI: 10.1186/s13045-015-0230-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/28/2015] [Indexed: 01/19/2023] Open
Abstract
Background Activated B lymphocytes harbor programmed DNA double-strand breaks (DSBs) initiated by activation-induced deaminase (AID) and repaired by non-homologous end-joining (NHEJ). While it has been proposed that these DSBs during secondary antibody gene diversification are the primary source of chromosomal translocations in germinal center (GC)-derived B cell lymphomas, this point has not been directly addressed due to the lack of proper mouse models. Methods In the current study, we establish a unique mouse model by specifically deleting a NHEJ gene, Xrcc4, and a cell cycle checkpoint gene, Trp53, in GC B cells, which results in the spontaneous development of B cell lymphomas that possess features of GC B cells. Results We show that these NHEJ deficient lymphomas harbor translocations frequently targeting immunoglobulin (Ig) loci. Furthermore, we found that Ig translocations were associated with distinct mechanisms, probably caused by AID- or RAG-induced DSBs. Intriguingly, the AID-associated Ig loci translocations target either c-myc or Pvt-1 locus whereas the partners of RAG-associated Ig translocations scattered randomly in the genome. Lastly, these NHEJ deficient lymphomas harbor complicated genomes including segmental translocations and exhibit a high level of ongoing DNA damage and clonal heterogeneity. Conclusions We propose that combined NHEJ and p53 defects may serve as an underlying mechanism for a high level of genomic complexity and clonal heterogeneity in cancers. Electronic supplementary material The online version of this article (doi:10.1186/s13045-015-0230-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhangguo Chen
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8333, Aurora, CO, 80045, USA.,Department of Biomedical Research, National Jewish Health, Denver, CO, 80206, USA
| | - Mihret T Elos
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8333, Aurora, CO, 80045, USA
| | - Sawanee S Viboolsittiseri
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8333, Aurora, CO, 80045, USA
| | - Katherine Gowan
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Sonia M Leach
- Department of Biomedical Research, National Jewish Health, Denver, CO, 80206, USA.,Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, CO, 80206, USA
| | - Michael Rice
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8333, Aurora, CO, 80045, USA
| | - Maxwell D Eder
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8333, Aurora, CO, 80045, USA
| | - Kenneth Jones
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Jing H Wang
- Department of Immunology and Microbiology, University of Colorado, Anschutz Medical Campus, 12800 E. 19th Ave, Mail Stop 8333, Aurora, CO, 80045, USA. .,Department of Biomedical Research, National Jewish Health, Denver, CO, 80206, USA.
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33
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Zan H, Casali P. Epigenetics of Peripheral B-Cell Differentiation and the Antibody Response. Front Immunol 2015; 6:631. [PMID: 26697022 PMCID: PMC4677338 DOI: 10.3389/fimmu.2015.00631] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/30/2015] [Indexed: 12/13/2022] Open
Abstract
Epigenetic modifications, such as histone post-translational modifications, DNA methylation, and alteration of gene expression by non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are heritable changes that are independent from the genomic DNA sequence. These regulate gene activities and, therefore, cellular functions. Epigenetic modifications act in concert with transcription factors and play critical roles in B cell development and differentiation, thereby modulating antibody responses to foreign- and self-antigens. Upon antigen encounter by mature B cells in the periphery, alterations of these lymphocytes epigenetic landscape are induced by the same stimuli that drive the antibody response. Such alterations instruct B cells to undergo immunoglobulin (Ig) class switch DNA recombination (CSR) and somatic hypermutation (SHM), as well as differentiation to memory B cells or long-lived plasma cells for the immune memory. Inducible histone modifications, together with DNA methylation and miRNAs modulate the transcriptome, particularly the expression of activation-induced cytidine deaminase, which is essential for CSR and SHM, and factors central to plasma cell differentiation, such as B lymphocyte-induced maturation protein-1. These inducible B cell-intrinsic epigenetic marks guide the maturation of antibody responses. Combinatorial histone modifications also function as histone codes to target CSR and, possibly, SHM machinery to the Ig loci by recruiting specific adaptors that can stabilize CSR/SHM factors. In addition, lncRNAs, such as recently reported lncRNA-CSR and an lncRNA generated through transcription of the S region that form G-quadruplex structures, are also important for CSR targeting. Epigenetic dysregulation in B cells, including the aberrant expression of non-coding RNAs and alterations of histone modifications and DNA methylation, can result in aberrant antibody responses to foreign antigens, such as those on microbial pathogens, and generation of pathogenic autoantibodies, IgE in allergic reactions, as well as B cell neoplasia. Epigenetic marks would be attractive targets for new therapeutics for autoimmune and allergic diseases, and B cell malignancies.
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Affiliation(s)
- Hong Zan
- Department of Microbiology and Immunology, University of Texas School of Medicine, UT Health Science Center , San Antonio, TX , USA
| | - Paolo Casali
- Department of Microbiology and Immunology, University of Texas School of Medicine, UT Health Science Center , San Antonio, TX , USA
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34
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Kasar S, Kim J, Improgo R, Tiao G, Polak P, Haradhvala N, Lawrence MS, Kiezun A, Fernandes SM, Bahl S, Sougnez C, Gabriel S, Lander ES, Kim HT, Getz G, Brown JR. Whole-genome sequencing reveals activation-induced cytidine deaminase signatures during indolent chronic lymphocytic leukaemia evolution. Nat Commun 2015; 6:8866. [PMID: 26638776 PMCID: PMC4686820 DOI: 10.1038/ncomms9866] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/08/2015] [Indexed: 12/17/2022] Open
Abstract
Patients with chromosome 13q deletion or normal cytogenetics represent the majority of chronic lymphocytic leukaemia (CLL) cases, yet have relatively few driver mutations. To better understand their genomic landscape, here we perform whole-genome sequencing on a cohort of patients enriched with these cytogenetic characteristics. Mutations in known CLL drivers are seen in only 33% of this cohort, and associated with normal cytogenetics and unmutated IGHV. The most commonly mutated gene in our cohort, IGLL5, shows a mutational pattern suggestive of activation-induced cytidine deaminase (AID) activity. Unsupervised analysis of mutational signatures demonstrates the activities of canonical AID (c-AID), leading to clustered mutations near active transcriptional start sites; non-canonical AID (nc-AID), leading to genome-wide non-clustered mutations, and an ageing signature responsible for most mutations. Using mutation clonality to infer time of onset, we find that while ageing and c-AID activities are ongoing, nc-AID-associated mutations likely occur earlier in tumour evolution. The oncogenic events driving indolent chronic lymphocytic leukaemia are relatively unknown. Here, the authors perform whole genome sequencing on 30 such tumours and identify recurrent mutations in IGLL5 and two activation induced cytidine deaminase signatures that are operative at different stages of CLL evolution.
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Affiliation(s)
- S Kasar
- Department of Medical Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - J Kim
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - R Improgo
- Department of Medical Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - G Tiao
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - P Polak
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - N Haradhvala
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - M S Lawrence
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - A Kiezun
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - S M Fernandes
- Department of Medical Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - S Bahl
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - C Sougnez
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - S Gabriel
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - E S Lander
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - H T Kim
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
| | - G Getz
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA.,Department of Pathology and Cancer Center, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.,Department of Pathology, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - J R Brown
- Department of Medical Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
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35
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Periyasamy M, Patel H, Lai CF, Nguyen VTM, Nevedomskaya E, Harrod A, Russell R, Remenyi J, Ochocka AM, Thomas RS, Fuller-Pace F, Győrffy B, Caldas C, Navaratnam N, Carroll JS, Zwart W, Coombes RC, Magnani L, Buluwela L, Ali S. APOBEC3B-Mediated Cytidine Deamination Is Required for Estrogen Receptor Action in Breast Cancer. Cell Rep 2015; 13:108-121. [PMID: 26411678 PMCID: PMC4597099 DOI: 10.1016/j.celrep.2015.08.066] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/16/2015] [Accepted: 08/24/2015] [Indexed: 02/07/2023] Open
Abstract
Estrogen receptor α (ERα) is the key transcriptional driver in a large proportion of breast cancers. We report that APOBEC3B (A3B) is required for regulation of gene expression by ER and acts by causing C-to-U deamination at ER binding regions. We show that these C-to-U changes lead to the generation of DNA strand breaks through activation of base excision repair (BER) and to repair by non-homologous end-joining (NHEJ) pathways. We provide evidence that transient cytidine deamination by A3B aids chromatin modification and remodelling at the regulatory regions of ER target genes that promotes their expression. A3B expression is associated with poor patient survival in ER+ breast cancer, reinforcing the physiological significance of A3B for ER action.
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Affiliation(s)
- Manikandan Periyasamy
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Hetal Patel
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Chun-Fui Lai
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Van T M Nguyen
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Ekaterina Nevedomskaya
- Department of Molecular Pathology, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Alison Harrod
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Roslin Russell
- Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | - Judit Remenyi
- Division of Cancer Research, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Anna Maria Ochocka
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Ross S Thomas
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Frances Fuller-Pace
- Division of Cancer Research, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Balázs Győrffy
- MTA TTK Lendület Cancer Biomarker Research Group, Second Department of Pediatrics, Semmelweis University and MTA-SE Pediatrics and Nephrology Research Group, Budapest 1085, Hungary
| | - Carlos Caldas
- Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | - Naveenan Navaratnam
- MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Jason S Carroll
- Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | - Wilbert Zwart
- Department of Molecular Pathology, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - R Charles Coombes
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Luca Magnani
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Laki Buluwela
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Simak Ali
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
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AID-associated DNA repair pathways regulate malignant transformation in a murine model of BCL6-driven diffuse large B-cell lymphoma. Blood 2015; 127:102-12. [PMID: 26385350 DOI: 10.1182/blood-2015-02-628164] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 09/08/2015] [Indexed: 12/27/2022] Open
Abstract
Somatic hypermutation and class-switch recombination of the immunoglobulin (Ig) genes occur in germinal center (GC) B cells and are initiated through deamination of cytidine to uracil by activation-induced cytidine deaminase (AID). Resulting uracil-guanine mismatches are processed by uracil DNA glycosylase (UNG)-mediated base-excision repair and MSH2-mediated mismatch repair (MMR) to yield mutations and DNA strand lesions. Although off-target AID activity also contributes to oncogenic point mutations and chromosome translocations associated with GC and post-GC B-cell lymphomas, the role of downstream AID-associated DNA repair pathways in the pathogenesis of lymphoma is unknown. Here, we show that simultaneous deficiency of UNG and MSH2 or MSH2 alone causes genomic instability and a shorter latency to the development of BCL6-driven diffuse large B-cell lymphoma (DLBCL) in a murine model. The additional development of several BCL6-independent malignancies in these mice underscores the critical role of MMR in maintaining general genomic stability. In contrast, absence of UNG alone is highly protective and prevents the development of BCL6-driven DLBCL. We further demonstrate that clonal and nonclonal mutations arise within non-Ig AID target genes in the combined absence of UNG and MSH2 and that DNA strand lesions arise in an UNG-dependent manner but are offset by MSH2. These findings lend insight into a complex interplay whereby potentially deleterious UNG activity and general genomic instability are opposed by the protective influence of MSH2, producing a net protective effect that promotes immune diversification while simultaneously attenuating malignant transformation of GC B cells.
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He X, Li J, Wu J, Zhang M, Gao P. Associations between activation-induced cytidine deaminase/apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like cytidine deaminase expression, hepatitis B virus (HBV) replication and HBV-associated liver disease (Review). Mol Med Rep 2015; 12:6405-14. [PMID: 26398702 PMCID: PMC4626158 DOI: 10.3892/mmr.2015.4312] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 08/25/2015] [Indexed: 12/12/2022] Open
Abstract
The hepatitis B virus (HBV) infection is a major risk factor in the development of chronic hepatitis (CH) and hepa-tocellular carcinoma (HCC). The activation-induced cytidine deaminase (AID)/apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) family of cytidine deaminases is significant in innate immunity, as it restricts numerous viruses, including HBV, through hypermutation-dependent and -independent mechanisms. It is important to induce covalently closed circular (ccc)DNA degradation by interferon-α without causing side effects in the infected host cell. Furthermore, organisms possess multiple mechanisms to regulate the expression of AID/APOBECs, control their enzymatic activity and restrict their access to DNA or RNA substrates. Therefore, the AID/APOBECs present promising targets for preventing and treating viral infections. In addition, gene polymorphisms of the AID/APOBEC family may alter host susceptibility to HBV acquisition and CH disease progression. Through G-to-A hypermutation, AID/APOBECs also edit HBV DNA and facilitate the mutation of HBV DNA, which may assist the virus to evolve and potentially escape from the immune responses. The AID/APOBEC family and their associated editing patterns may also exert oncogenic activity. Understanding the effects of cytidine deaminases in CH virus-induced hepatocarcinogenesis may aid with developing efficient prophylactic and therapeutic strategies against HCC.
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Affiliation(s)
- Xiuting He
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jie Li
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jing Wu
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Manli Zhang
- Department of Gastroenterology, The Second Branch of The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Pujun Gao
- Department of Hepatology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
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Stavnezer J, Schrader CE. IgH chain class switch recombination: mechanism and regulation. THE JOURNAL OF IMMUNOLOGY 2015; 193:5370-8. [PMID: 25411432 DOI: 10.4049/jimmunol.1401849] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
IgH class switching occurs rapidly after activation of mature naive B cells, resulting in a switch from expression of IgM and IgD to expression of IgG, IgE, or IgA; this switch improves the ability of Abs to remove the pathogen that induces the humoral immune response. Class switching occurs by a deletional recombination between two switch regions, each of which is associated with a H chain constant region gene. Class switch recombination (CSR) is instigated by activation-induced cytidine deaminase, which converts cytosines in switch regions to uracils. The uracils are subsequently removed by two DNA-repair pathways, resulting in mutations, single-strand DNA breaks, and the double-strand breaks required for CSR. We discuss several aspects of CSR, including how CSR is induced, CSR in B cell progenitors, the roles of transcription and chromosomal looping in CSR, and the roles of certain DNA-repair enzymes in CSR.
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Affiliation(s)
- Janet Stavnezer
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
| | - Carol E Schrader
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
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Pucella JN, Yen WF, Kim MV, van der Veeken J, Luo CT, Socci ND, Naito Y, Li MO, Iwai N, Chaudhuri J. miR-182 is largely dispensable for adaptive immunity: lack of correlation between expression and function. THE JOURNAL OF IMMUNOLOGY 2015; 194:2635-42. [PMID: 25672759 DOI: 10.4049/jimmunol.1402261] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
MicroRNA (miR)-mediated regulation of protein abundance is a pervasive mechanism of directing cellular processes. The well-studied and abundant miR-182 has previously been implicated in many aspects of T cell function, DNA repair, and cancer. In this study, we show that miR-182 is the most highly induced miR in B cells undergoing class-switch recombination. To elucidate the requirement of miR-182 in lymphocyte function, we extensively characterized mice with a targeted deletion of Mir182. We show that despite its dramatic induction, loss of miR-182 has minimal impact on B cell development, the ability of B cells to undergo class-switch recombination ex vivo and to undergo Ag-driven affinity maturation in vivo. Furthermore, in striking contrast to knockdown studies that demonstrated the requirement of miR-182 in T cell function, miR-182-deficient mice display no defect in T cell development and activation. Finally, we show that T cell-dependent immune response to experimental Listeria monocytogenes infection is intact in miR-182-deficient mice. We conclude that, contrary to previous studies, miR-182 does not play a significant role in all measured aspects of mouse adaptive immunity. This striking absence of a phenotype highlights the lack of correlation between expression pattern and functional requirement, underscores the limitations of using knockdown approaches to assess miR requirements, and suggests that miR networks may compensate for the chronic loss of specific miRs.
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Affiliation(s)
- Joseph N Pucella
- Immunology Program, Memorial Sloan Kettering Cancer Center, Gerstner Sloan Kettering Graduate School, New York, NY 10065
| | - Wei-Feng Yen
- Immunology Program, Memorial Sloan Kettering Cancer Center, Gerstner Sloan Kettering Graduate School, New York, NY 10065; Immunology and Microbial Pathogenesis Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY 10065
| | - Myoungjoo V Kim
- Immunology Program, Memorial Sloan Kettering Cancer Center, Gerstner Sloan Kettering Graduate School, New York, NY 10065; Immunology and Microbial Pathogenesis Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY 10065
| | - Joris van der Veeken
- Immunology Program, Memorial Sloan Kettering Cancer Center, Gerstner Sloan Kettering Graduate School, New York, NY 10065; Immunology and Microbial Pathogenesis Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY 10065
| | | | - Nicholas D Socci
- Bioinformatics Core, Memorial Sloan Kettering Cancer Center, New York, NY 10065; and
| | - Yukiko Naito
- Department of Genomic Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Ming O Li
- Immunology Program, Memorial Sloan Kettering Cancer Center, Gerstner Sloan Kettering Graduate School, New York, NY 10065; Immunology and Microbial Pathogenesis Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY 10065
| | - Naoharu Iwai
- Department of Genomic Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, Gerstner Sloan Kettering Graduate School, New York, NY 10065; Immunology and Microbial Pathogenesis Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY 10065;
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40
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Lycke N, Bemark M, Spencer J. Mucosal B Cell Differentiation and Regulation. Mucosal Immunol 2015. [DOI: 10.1016/b978-0-12-415847-4.00033-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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41
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Dahlberg CIM, He M, Visnes T, Torres ML, Cortizas EM, Verdun RE, Westerberg LS, Severinson E, Ström L. A novel mouse model for the hyper-IgM syndrome: a spontaneous activation-induced cytidine deaminase mutation leading to complete loss of Ig class switching and reduced somatic hypermutation. THE JOURNAL OF IMMUNOLOGY 2014; 193:4732-8. [PMID: 25252954 DOI: 10.4049/jimmunol.1401242] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We describe a spontaneously derived mouse line that completely failed to induce Ig class switching in vitro and in vivo. The mice inherited abolished IgG serum titers in a recessive manner caused by a spontaneous G → A transition mutation in codon 112 of the aicda gene, leading to an arginine to histidine replacement (AID(R112H)). Ig class switching was completely reconstituted by expressing wild-type AID. Mice homozygous for AID(R112H) had peripheral B cell hyperplasia and large germinal centers in the absence of Ag challenge. Immunization with SRBCs elicited an Ag-specific IgG1 response in wild-type mice, whereas AID(R112H) mice failed to produce IgG1 and had reduced somatic hypermutation. The phenotype recapitulates the human hyper-IgM (HIGM) syndrome that is caused by point mutations in the orthologous gene in humans, and the AID(R112H) mutation is frequently found in HIGM patients. The AID(R112H) mouse model for HIGM provides a powerful and more precise tool than conventional knockout strategies.
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Affiliation(s)
- Carin I M Dahlberg
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Minghui He
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Torkild Visnes
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden; and
| | - Magda Liz Torres
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Elena M Cortizas
- Division of Gerontology and Geriatric Medicine, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Ramiro E Verdun
- Division of Gerontology and Geriatric Medicine, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Lisa S Westerberg
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden;
| | - Eva Severinson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden;
| | - Lena Ström
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden; and
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42
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Retinoic acid acts as a selective human IgA switch factor. Hum Immunol 2014; 75:923-9. [DOI: 10.1016/j.humimm.2014.06.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 03/10/2014] [Accepted: 06/23/2014] [Indexed: 11/22/2022]
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43
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Ucher AJ, Ranjit S, Kadungure T, Linehan EK, Khair L, Xie E, Limauro J, Rauch KS, Schrader CE, Stavnezer J. Mismatch repair proteins and AID activity are required for the dominant negative function of C-terminally deleted AID in class switching. THE JOURNAL OF IMMUNOLOGY 2014; 193:1440-50. [PMID: 24973444 DOI: 10.4049/jimmunol.1400365] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Activation-induced cytidine deaminase (AID) is essential for class-switch recombination (CSR) and somatic hypermutation (SHM) of Ig genes. The AID C terminus is required for CSR, but not for S-region DNA double-strand breaks (DSBs) during CSR, and it is not required for SHM. AID lacking the C terminus (ΔAID) is a dominant negative (DN) mutant, because human patients heterozygous for this mutant fail to undergo CSR. In agreement, we show that ΔAID is a DN mutant when expressed in AID-sufficient mouse splenic B cells. To have DN function, ΔAID must have deaminase activity, suggesting that its ability to induce DSBs is important for the DN function. Supporting this hypothesis, Msh2-Msh6 have been shown to contribute to DSB formation in S regions, and we find in this study that Msh2 is required for the DN activity, because ΔAID is not a DN mutant in msh2(-/-) cells. Our results suggest that the DNA DSBs induced by ΔAID are unable to participate in CSR and might interfere with the ability of full-length AID to participate in CSR. We propose that ΔAID is impaired in its ability to recruit nonhomologous end joining repair factors, resulting in accumulation of DSBs that undergo aberrant resection. Supporting this hypothesis, we find that the S-S junctions induced by ΔAID have longer microhomologies than do those induced by full-length AID. In addition, our data suggest that AID binds Sμ regions in vivo as a monomer.
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Affiliation(s)
- Anna J Ucher
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Sanjay Ranjit
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Tatenda Kadungure
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Erin K Linehan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Lyne Khair
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Elaine Xie
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Jennifer Limauro
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Katherina S Rauch
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Carol E Schrader
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Janet Stavnezer
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
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44
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Chen Z, Wang JH. Generation and repair of AID-initiated DNA lesions in B lymphocytes. Front Med 2014; 8:201-16. [PMID: 24748462 PMCID: PMC4039616 DOI: 10.1007/s11684-014-0324-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 12/30/2013] [Indexed: 01/12/2023]
Abstract
Activation-induced deaminase (AID) initiates the secondary antibody diversification process in B lymphocytes. In mammalian B cells, this process includes somatic hypermutation (SHM) and class switch recombination (CSR), both of which require AID. AID induces U:G mismatch lesions in DNA that are subsequently converted into point mutations or DNA double stranded breaks during SHM/CSR. In a physiological context, AID targets immunoglobulin (Ig) loci to mediate SHM/CSR. However, recent studies reveal genome-wide access of AID to numerous non-Ig loci. Thus, AID poses a threat to the genome of B cells if AID-initiated DNA lesions cannot be properly repaired. In this review, we focus on the molecular mechanisms that regulate the specificity of AID targeting and the repair pathways responsible for processing AID-initiated DNA lesions.
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Affiliation(s)
- Zhangguo Chen
- Integrated Department of Immunology, University of Colorado Anschutz Medical Campus and National Jewish Health, Denver, CO 80206
| | - Jing H. Wang
- Integrated Department of Immunology, University of Colorado Anschutz Medical Campus and National Jewish Health, Denver, CO 80206
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45
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Matthews AJ, Zheng S, DiMenna LJ, Chaudhuri J. Regulation of immunoglobulin class-switch recombination: choreography of noncoding transcription, targeted DNA deamination, and long-range DNA repair. Adv Immunol 2014; 122:1-57. [PMID: 24507154 PMCID: PMC4150736 DOI: 10.1016/b978-0-12-800267-4.00001-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Upon encountering antigens, mature IgM-positive B lymphocytes undergo class-switch recombination (CSR) wherein exons encoding the default Cμ constant coding gene segment of the immunoglobulin (Ig) heavy-chain (Igh) locus are excised and replaced with a new constant gene segment (referred to as "Ch genes", e.g., Cγ, Cɛ, or Cα). The B cell thereby changes from expressing IgM to one producing IgG, IgE, or IgA, with each antibody isotype having a different effector function during an immune reaction. CSR is a DNA deletional-recombination reaction that proceeds through the generation of DNA double-strand breaks (DSBs) in repetitive switch (S) sequences preceding each Ch gene and is completed by end-joining between donor Sμ and acceptor S regions. CSR is a multistep reaction requiring transcription through S regions, the DNA cytidine deaminase AID, and the participation of several general DNA repair pathways including base excision repair, mismatch repair, and classical nonhomologous end-joining. In this review, we discuss our current understanding of how transcription through S regions generates substrates for AID-mediated deamination and how AID participates not only in the initiation of CSR but also in the conversion of deaminated residues into DSBs. Additionally, we review the multiple processes that regulate AID expression and facilitate its recruitment specifically to the Ig loci, and how deregulation of AID specificity leads to oncogenic translocations. Finally, we summarize recent data on the potential role of AID in the maintenance of the pluripotent stem cell state during epigenetic reprogramming.
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Affiliation(s)
- Allysia J Matthews
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, New York, USA
| | - Simin Zheng
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, New York, USA
| | - Lauren J DiMenna
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, New York, USA
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, New York, USA.
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46
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Abstract
In this review, I discuss the currently available experimental evidence concerning the molecular interactions of the activation-induced cytidine deaminase (AID) with transcription of its target genes. The basic question that underlies the transcription relationship is how the process of somatic hypermutation of Ig genes can be restricted to their variable (V) regions. This hallmark of SHM assures that high affinity antibodies can be created while the biological functions of their constant (C) region are undisturbed. I present a revised model of AID function in somatic hypermutation (SHM): In a B cell that produces AID protein and undergoes mutation of the V regions of the expressed Ig heavy and light chain genes, only some of the transcription complexes initiating at the active V-region promoters are associated with AID. When AID travels with the elongating RNA polymerase (pol), it attracts proteins that cause the pausing/stalling of pol and termination of transcription, followed by termination of SHM. This differential AID loading model would allow the mutating B cell to continue producing full-length Ig proteins that are required to avoid apoptosis by permitting the cell to assemble functional B cell receptors.
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Affiliation(s)
- Ursula Storb
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, USA.
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47
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Lam T, Thomas LM, White CA, Li G, Pone EJ, Xu Z, Casali P. Scaffold functions of 14-3-3 adaptors in B cell immunoglobulin class switch DNA recombination. PLoS One 2013; 8:e80414. [PMID: 24282540 PMCID: PMC3840166 DOI: 10.1371/journal.pone.0080414] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 10/02/2013] [Indexed: 12/22/2022] Open
Abstract
Class switch DNA recombination (CSR) of the immunoglobulin heavy chain (IgH) locus crucially diversifies antibody biological effector functions. CSR involves the induction of activation-induced cytidine deaminase (AID) expression and AID targeting to switch (S) regions by 14-3-3 adaptors. 14-3-3 adaptors specifically bind to 5'-AGCT-3' repeats, which make up for the core of all IgH locus S regions. They selectively target the upstream and downstream S regions that are set to undergo S-S DNA recombination. We hypothesized that 14-3-3 adaptors function as scaffolds to stabilize CSR enzymatic elements on S regions. Here we demonstrate that all seven 14-3-3β, 14-3-3ε, 14-3-3γ, 14-3-3η, 14-3-3σ, 14-3-3τ and 14-3-3ζ adaptors directly interacted with AID, PKA-Cα (catalytic subunit) and PKA-RIα (regulatory inhibitory subunit) and uracil DNA glycosylase (Ung). 14-3-3 adaptors, however, did not interact with AID C-terminal truncation mutant AIDΔ(180-198) or AIDF193A and AIDL196A point-mutants (which have been shown not to bind to S region DNA and fail to mediate CSR). 14-3-3 adaptors colocalized with AID and replication protein A (RPA) in B cells undergoing CSR. 14-3-3 and AID binding to S region DNA was disrupted by viral protein R (Vpr), an accessory protein of human immunodeficiency virus type-1 (HIV-1), which inhibited CSR without altering AID expression or germline IH-CH transcription. Accordingly, we demonstrated that 14-3-3 directly interact with Vpr, which in turn, also interact with AID, PKA-Cα and Ung. Altogether, our findings suggest that 14-3-3 adaptors play important scaffold functions and nucleate the assembly of multiple CSR factors on S regions. They also show that such assembly can be disrupted by a viral protein, thereby allowing us to hypothesize that small molecule compounds that specifically block 14-3-3 interactions with AID, PKA and/or Ung can be used to inhibit unwanted CSR.
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Affiliation(s)
- Tonika Lam
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
- Department of Microbiology and Immunology, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Lisa M. Thomas
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Clayton A. White
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Guideng Li
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Egest J. Pone
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
| | - Zhenming Xu
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
- Department of Microbiology and Immunology, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Paolo Casali
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California Irvine, Irvine, California, United States of America
- Department of Microbiology and Immunology, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
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48
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Combinatorial H3K9acS10ph histone modification in IgH locus S regions targets 14-3-3 adaptors and AID to specify antibody class-switch DNA recombination. Cell Rep 2013; 5:702-714. [PMID: 24209747 DOI: 10.1016/j.celrep.2013.09.031] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 06/11/2013] [Accepted: 09/23/2013] [Indexed: 01/14/2023] Open
Abstract
Class-switch DNA recombination (CSR) is central to the antibody response, in that it changes the immunoglobulin heavy chain (IgH) constant region, thereby diversifying biological effector functions of antibodies. The activation-induced cytidine deaminase (AID)-centered CSR machinery excises and rejoins DNA between an upstream (donor) and a downstream (acceptor) S region, which precede the respective constant region DNA. AID is stabilized on S regions by 14-3-3 adaptors. These adaptors display a high affinity for 5'-AGCT-3' repeats, which recur in all S regions. However, how 14-3-3, AID, and the CSR machinery target exclusively the donor and acceptor S regions is poorly understood. Here, we show that histone methyltransferases and acetyltransferases are induced by CD40 or Toll-like receptor signaling and catalyze H3K4me3 and H3K9ac/K14ac histone modifications, which are enriched in S regions but do not specify the S region targets of CSR. By contrast, the combinatorial H3K9acS10ph modification specifically marks the S regions set to recombine and directly recruits 14-3-3 adaptors for AID stabilization there. Inhibition of the enzymatic activity of GCN5 and PCAF histone acetyltransferases reduces H3K9acS10ph in S regions, 14-3-3 and AID stabilization, and CSR. Thus, H3K9acS10ph is a histone code that is "written" specifically in S regions and is "read" by 14-3-3 adaptors to target AID for CSR as an important biological outcome.
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Sun J, Keim CD, Wang J, Kazadi D, Oliver PM, Rabadan R, Basu U. E3-ubiquitin ligase Nedd4 determines the fate of AID-associated RNA polymerase II in B cells. Genes Dev 2013; 27:1821-33. [PMID: 23964096 PMCID: PMC3759698 DOI: 10.1101/gad.210211.112] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Programmed mutagenesis of the immunoglobulin locus of B lymphocytes during class switch recombination (CSR) and somatic hypermutation requires RNA polymerase II (polII) transcription complex-dependent targeting of the DNA mutator activation-induced cytidine deaminase (AID). AID deaminates cytidine residues on substrate sequences in the immunoglobulin (Ig) locus via a transcription-dependent mechanism, and this activity is stimulated by the RNA polII stalling cofactor Spt5 and the 11-subunit cellular noncoding RNA 3'-5' exonucleolytic processing complex RNA exosome. The mechanism by which the RNA exosome recognizes immunoglobulin locus RNA substrates to stimulate AID DNA deamination activity on its in vivo substrate sequences is an important question. Here we report that E3-ubiquitin ligase Nedd4 destabilizes AID-associated RNA polII by a ubiquitination event, leading to generation of 3' end free RNA exosome RNA substrates at the Ig locus and other AID target sequences genome-wide. We found that lack of Nedd4 activity in B cells leads to accumulation of RNA exosome substrates at AID target genes and defective CSR. Taken together, our study links noncoding RNA processing following RNA polII pausing with regulation of the mutator AID protein. Our study also identifies Nedd4 as a regulator of noncoding RNAs that are generated by stalled RNA polII genome-wide.
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Affiliation(s)
- Jianbo Sun
- Department of Microbiology and Immunology, Columbia University, New York, New York 10032, USA
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50
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Schrader CE, Linehan EK, Ucher AJ, Bertocci B, Stavnezer J. DNA polymerases β and λ do not directly affect Ig variable region somatic hypermutation although their absence reduces the frequency of mutations. DNA Repair (Amst) 2013; 12:1087-93. [PMID: 24084171 DOI: 10.1016/j.dnarep.2013.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/02/2013] [Accepted: 09/09/2013] [Indexed: 11/28/2022]
Abstract
During somatic hypermutation (SHM) of antibody variable (V) region genes, activation-induced cytidine deaminase (AID) converts dC to dU, and dUs can either be excised by uracil DNA glycosylase (UNG), by mismatch repair, or replicated over. If UNG excises the dU, the abasic site could be cleaved by AP-endonuclease (APE), introducing the single-strand DNA breaks (SSBs) required for generating mutations at A:T bp, which are known to depend upon mismatch repair and DNA Pol η. DNA Pol β or λ could instead repair the lesion correctly. To assess the involvement of Pols β and λ in SHM of antibody genes, we analyzed mutations in the VDJh4 3' flanking region in Peyer's patch germinal center (GC) B cells from polβ(-/-)polλ(-/-), polλ(-/-), and polβ(-/-) mice. We find that deficiency of either or both polymerases results in a modest but significant decrease in V region SHM, with Pol β having a greater effect, but there is no effect on mutation specificity, suggesting they have no direct role in SHM. Instead, the effect on SHM appears to be due to a role for these enzymes in GC B cell proliferation or viability. The results suggest that the BER pathway is not important during V region SHM for generating mutations at A:T bp. Furthermore, this implies that most of the SSBs required for Pol η to enter and create A:T mutations are likely generated during replication instead. These results contrast with the inhibitory effect of Pol β on mutations at the Ig Sμ locus, Sμ DSBs and class switch recombination (CSR) reported previously. We show here that B cells deficient in Pol λ or both Pol β and λ proliferate normally in culture and undergo slightly elevated CSR, as shown previously for Pol β-deficient B cells.
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Affiliation(s)
- Carol E Schrader
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, United States
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