151
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Sun C, Luecke S, Bodda C, Jønsson KL, Cai Y, Zhang BC, Jensen SB, Nordentoft I, Jensen JM, Jakobsen MR, Paludan SR. Cellular Requirements for Sensing and Elimination of Incoming HSV-1 DNA and Capsids. J Interferon Cytokine Res 2019; 39:191-204. [PMID: 30855198 DOI: 10.1089/jir.2018.0141] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Incoming viruses challenge the cell with diverse foreign molecules, which need to be sensed quickly to initiate immune responses and to remove the viral components. In this study, we investigate the cellular requirements for sensing and degradation of incoming viral DNA and capsids during herpes simplex virus type 1 (HSV-1) infections. Using click chemistry labeling of the viral genome, we found that HSV-1 DNA was released from a subset of capsids into the cytosol early in infection. By next-generation sequencing of cyclic GMP-AMP (cGAMP) synthase (cGAS)-bound DNA from HSV-1-infected cells, we show that HSV-1 DNA was bound by the cytosolic DNA sensor cGAS. Activation of cGAS enzymatic activity by viral DNA did not require proteasomal activity, indicating that viral DNA release into the cytosol is not proteasome-dependent. However, induction of interferon (IFN)-β expression was blocked by inhibition of the proteasome, suggesting a contribution of the proteasome to IFN-β induction through the cGAS-stimulator of interferon genes pathway. Viral DNA was cleared from the cytosol within few hours, in a manner dependent on TREX1 and a cGAS-dependent process. Capsid material in the cytoplasm was also degraded rapidly. This was partially blocked by treatment with a proteasome inhibitor. This treatment led to accumulation of DNA-containing viral capsids near the nucleus and reduced nuclear entry of viral DNA. Thus, cells infected with HSV-1 use a panel of mechanisms to eliminate viral DNA and capsids. This represents a barrier for establishment of infection and potentially enables the host to gear the IFN-β response to a level required for antiviral defense without causing immunopathology.
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Affiliation(s)
- Chenglong Sun
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
| | - Stefanie Luecke
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
| | | | - Kasper L Jønsson
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
| | - Yujia Cai
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
| | - Bao-Cun Zhang
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
| | - Søren B Jensen
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
| | - Iver Nordentoft
- 2 Department of Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Jacob M Jensen
- 3 Bioinformatics Research Center, Aarhus University, Aarhus, Denmark
| | | | - Søren R Paludan
- 1 Department of Biomedicine and Aarhus University, Aarhus, Denmark
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152
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cGAS activation causes lupus-like autoimmune disorders in a TREX1 mutant mouse model. J Autoimmun 2019; 100:84-94. [PMID: 30872080 DOI: 10.1016/j.jaut.2019.03.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 12/11/2022]
Abstract
TREX1 encodes a major cellular DNA exonuclease. Mutations of this gene in human cause cellular accumulation of DNA that triggers autoimmune diseases including Aicardi-Goutieres Syndrome (AGS) and systemic lupus erythematosus (SLE). We created a lupus mouse model by engineering a D18 N mutation in the Trex1 gene which inactivates the enzyme and has been found in human patients with lupus-like disorders. The Trex1D18N/D18N mice exhibited systemic inflammation that consistently recapitulates many characteristics of human AGS and SLE. Importantly, ablation of cGas gene in the Trex1D18N/D18N mice rescued the lethality and all detectable pathological phenotypes, including multi-organ inflammation, interferon stimulated gene induction, autoantibody production and aberrant T-cell activation. These results indicate that cGAS is a key mediator in the autoimmune disease associated with defective TREX1 function, providing additional insights into disease pathogenesis and guidance to the development of therapeutics for human systemic autoimmune disorders.
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153
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Pelzer N, Hoogeveen ES, Haan J, Bunnik R, Poot CC, van Zwet EW, Inderson A, Fogteloo AJ, Reinders MEJ, Middelkoop HAM, Kruit MC, van den Maagdenberg AMJM, Ferrari MD, Terwindt GM. Systemic features of retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations: a monogenic small vessel disease. J Intern Med 2019; 285:317-332. [PMID: 30411414 DOI: 10.1111/joim.12848] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is a small vessel disease caused by C-terminal truncating TREX1 mutations. The disease is typically characterized by vascular retinopathy and focal and global brain dysfunction. Systemic manifestations have also been reported but not yet systematically investigated. METHODS In a cross-sectional study, we compared the clinical characteristics of 33 TREX1 mutation carriers (MC+) from three Dutch RVCL-S families with those of 37 family members without TREX1 mutation (MC-). All participants were investigated using personal interviews, questionnaires, physical, neurological and neuropsychological examinations, blood and urine tests, and brain MRI. RESULTS In MC+, vascular retinopathy and Raynaud's phenomenon were the earliest symptoms presenting from age 20 onwards. Kidney disease became manifest from around age 35, followed by liver disease, anaemia, markers of inflammation and, in some MC+, migraine and subclinical hypothyroidism, all from age 40. Cerebral deficits usually started mildly around age 50, associated with white matter and intracerebral mass lesions, and becoming severe around age 60-65. CONCLUSIONS Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations is a rare, but likely underdiagnosed, systemic small vessel disease typically starting with vascular retinopathy, followed by multiple internal organ disease, progressive brain dysfunction, and ultimately premature death.
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Affiliation(s)
- N Pelzer
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - E S Hoogeveen
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - J Haan
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.,Department of Neurology, Alrijne Hospital, Leiderdorp, The Netherlands
| | - R Bunnik
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - C C Poot
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - E W van Zwet
- Department of Biomedical Data Sciences, Leiden University Medical Centre, Leiden, The Netherlands
| | - A Inderson
- Department of Gastroenterology-Hepatology, Leiden University Medical Centre, Leiden, The Netherlands
| | - A J Fogteloo
- Department of Internal Medicine (Acute Care), Leiden University Medical Centre, Leiden, The Netherlands
| | - M E J Reinders
- Department of Internal Medicine (Nephrology), Leiden University Medical Centre, Leiden, The Netherlands
| | - H A M Middelkoop
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.,Institute of Psychology, Health, Medical and Neuropsychology Unit, Leiden University, Leiden, The Netherlands
| | - M C Kruit
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - A M J M van den Maagdenberg
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.,Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - M D Ferrari
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - G M Terwindt
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
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154
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Dai J, Huang YJ, He X, Zhao M, Wang X, Liu ZS, Xue W, Cai H, Zhan XY, Huang SY, He K, Wang H, Wang N, Sang Z, Li T, Han QY, Mao J, Diao X, Song N, Chen Y, Li WH, Man JH, Li AL, Zhou T, Liu ZG, Zhang XM, Li T. Acetylation Blocks cGAS Activity and Inhibits Self-DNA-Induced Autoimmunity. Cell 2019; 176:1447-1460.e14. [PMID: 30799039 DOI: 10.1016/j.cell.2019.01.016] [Citation(s) in RCA: 199] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 11/27/2018] [Accepted: 01/04/2019] [Indexed: 12/30/2022]
Abstract
The presence of DNA in the cytoplasm is normally a sign of microbial infections and is quickly detected by cyclic GMP-AMP synthase (cGAS) to elicit anti-infection immune responses. However, chronic activation of cGAS by self-DNA leads to severe autoimmune diseases for which no effective treatment is available yet. Here we report that acetylation inhibits cGAS activation and that the enforced acetylation of cGAS by aspirin robustly suppresses self-DNA-induced autoimmunity. We find that cGAS acetylation on either Lys384, Lys394, or Lys414 contributes to keeping cGAS inactive. cGAS is deacetylated in response to DNA challenges. Importantly, we show that aspirin can directly acetylate cGAS and efficiently inhibit cGAS-mediated immune responses. Finally, we demonstrate that aspirin can effectively suppress self-DNA-induced autoimmunity in Aicardi-Goutières syndrome (AGS) patient cells and in an AGS mouse model. Thus, our study reveals that acetylation contributes to cGAS activity regulation and provides a potential therapy for treating DNA-mediated autoimmune diseases.
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Affiliation(s)
- Jiang Dai
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China; State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Yi-Jiao Huang
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Xinhua He
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Ming Zhao
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Xinzheng Wang
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Zhao-Shan Liu
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Wen Xue
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Hong Cai
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Xiao-Yan Zhan
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Shao-Yi Huang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China; State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Kun He
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Hongxia Wang
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Na Wang
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Zhihong Sang
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Tingting Li
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Qiu-Ying Han
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Jie Mao
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Xinwei Diao
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China; Department of Pathology, Xinqiao Hospital, 3(rd) Military Medical University, Chongqing 400037, China
| | - Nan Song
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Yuan Chen
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Wei-Hua Li
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Jiang-Hong Man
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Ai-Ling Li
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Tao Zhou
- State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China
| | - Zheng-Gang Liu
- Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Xue-Min Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China; State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China; Cancer Research Institute of Jilin University, the First Hospital of Jilin University, Changchun, Jilin Province 130021, China.
| | - Tao Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China; State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing 100850, China.
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155
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Broecker F, Moelling K. Evolution of Immune Systems From Viruses and Transposable Elements. Front Microbiol 2019; 10:51. [PMID: 30761103 PMCID: PMC6361761 DOI: 10.3389/fmicb.2019.00051] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022] Open
Abstract
Virus-derived sequences and transposable elements constitute a substantial portion of many cellular genomes. Recent insights reveal the intimate evolutionary relationship between these sequences and various cellular immune pathways. At the most basic level, superinfection exclusion may be considered a prototypical virus-mediated immune system that has been described in both prokaryotes and eukaryotes. More complex immune mechanisms fully or partially derived from mobile genetic elements include CRISPR-Cas of prokaryotes and the RAG1/2 system of vertebrates, which provide immunological memory of foreign genetic elements and generate antibody and T cell receptor diversity, respectively. In this review, we summarize the current knowledge on the contribution of mobile genetic elements to the evolution of cellular immune pathways. A picture is emerging in which the various cellular immune systems originate from and are spread by viruses and transposable elements. Immune systems likely evolved from simple superinfection exclusion to highly complex defense strategies.
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Affiliation(s)
- Felix Broecker
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Karin Moelling
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.,Max Planck Institute for Molecular Genetics, Berlin, Germany
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156
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Sase S, Takanohashi A, Vanderver A, Almad A. Astrocytes, an active player in Aicardi-Goutières syndrome. Brain Pathol 2019; 28:399-407. [PMID: 29740948 DOI: 10.1111/bpa.12600] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/02/2018] [Indexed: 01/10/2023] Open
Abstract
Aicardi-Goutières syndrome (AGS) is an early-onset, autoimmune and genetically heterogeneous disorder with severe neurologic injury. Molecular studies have established that autosomal recessive mutations in one of the following genes are causative: TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 and IFIH1/MDA5. The phenotypic presentation and pathophysiology of AGS is associated with over-production of the cytokine Interferon-alpha (IFN-α) and its downstream signaling, characterized as type I interferonopathy. Astrocytes are one of the major source of IFN in the central nervous system (CNS) and it is proposed that they could be key players in AGS pathology. Astrocytes are the most ubiquitous glial cell in the CNS and perform a number of crucial and complex functions ranging from formation of blood-brain barrier, maintaining ionic homeostasis, metabolic support to synapse formation and elimination in healthy CNS. Involvement of astrocytic dysfunction in neurological diseases-Alexander's disease, Epilepsy, Alzheimer's and amyotrophic lateral sclerosis (ALS)-has been well-established. It is now known that compromised astrocytic function can contribute to CNS abnormalities and severe neurodegeneration, nevertheless, its contribution in AGS is unclear. The current review discusses known molecular and cellular pathways for AGS mutations and how it stimulates IFN-α signaling. We shed light on how astrocytes might be key players in the phenotypic presentations of AGS and emphasize the cell-autonomous and non-cell-autonomous role of astrocytes. Understanding the contribution of astrocytes will help reveal mechanisms underlying interferonopathy and develop targeted astrocyte specific therapeutic treatments in AGS.
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Affiliation(s)
- Sunetra Sase
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Asako Takanohashi
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Akshata Almad
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
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157
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Prati B, da Silva Abjaude W, Termini L, Morale M, Herbster S, Longatto-Filho A, Nunes RAL, Córdoba Camacho LC, Rabelo-Santos SH, Zeferino LC, Aguayo F, Boccardo E. Three Prime Repair Exonuclease 1 (TREX1) expression correlates with cervical cancer cells growth in vitro and disease progression in vivo. Sci Rep 2019; 9:351. [PMID: 30674977 PMCID: PMC6344518 DOI: 10.1038/s41598-018-37064-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 10/17/2018] [Indexed: 12/17/2022] Open
Abstract
Alterations in specific DNA damage repair mechanisms in the presence of human papillomavirus (HPV) infection have been described in different experimental models. However, the global effect of HPV on the expression of genes involved in these pathways has not been analyzed in detail. In the present study, we compared the expression profile of 135 genes involved in DNA damage repair among primary human keratinocytes (PHK), HPV-positive (SiHa and HeLa) and HPV-negative (C33A) cervical cancer derived cell lines. We identified 9 genes which expression pattern distinguishes HPV-positive tumor cell lines from C33A. Moreover, we observed that Three Prime Repair Exonuclease 1 (TREX1) expression is upregulated exclusively in HPV-transformed cell lines and PHK expressing HPV16 E6 and E7 oncogenes. We demonstrated that TREX1 silencing greatly affects tumor cells clonogenic and anchorage independent growth potential. We showed that this effect is associated with p53 upregulation, accumulation of subG1 cells, and requires the expression of E7 from high-risk HPV types. Finally, we observed an increase in TREX1 levels in precancerous lesions, squamous carcinomas and adenocarcinomas clinical samples. Altogether, our results indicate that TREX1 upregulation is important for cervical tumor cells growth and may contribute with tumor establishment and progression.
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Affiliation(s)
- Bruna Prati
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1374, 05508-900, São Paulo, SP, Brazil
| | - Walason da Silva Abjaude
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1374, 05508-900, São Paulo, SP, Brazil
| | - Lara Termini
- Centro de Investigação Translacional em Oncologia (LIM24), Instituto do Câncer do Estado de São Paulo (ICESP), São Paulo, Brazil
| | - Mirian Morale
- Department of Biochemistry, Institute of Chemistry, USP, São Paulo, Brazil
| | - Suellen Herbster
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1374, 05508-900, São Paulo, SP, Brazil
| | - Adhemar Longatto-Filho
- Laboratory of Medical Investigation (LIM 14), Department of Pathology, School of Medicine, USP, Av. Dr. Arnaldo 455, São Paulo, 01246-903, Brazil.,Life and Health Sciences Research Institute, School of Health Sciences, ICVS/3B's - PT Government Associate Laboratory, University of Minho, Braga, Guimarães, Portugal.,Molecular Oncology Research Center, Barretos Cancer Hospital, Pio XII Foundation, Barretos, Rua Antenor Duarte Villela, 1331, Barretos, 14784-400, Brazil
| | - Rafaella Almeida Lima Nunes
- Centro de Investigação Translacional em Oncologia (LIM24), Instituto do Câncer do Estado de São Paulo (ICESP), São Paulo, Brazil
| | - Lizeth Carolina Córdoba Camacho
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1374, 05508-900, São Paulo, SP, Brazil.,Laboratório de Oncologia Experimental, Departamento de Radiologia, Faculdade de Medicina, USP, São Paulo, SP, Brazil.,Centro de Investigação Translacional em Oncologia, ICESP, São Paulo, SP, Brazil
| | | | - Luiz Carlos Zeferino
- School of Medical Sciences, State University of Campinas (UNICAMP), Rua Alexander Fleming 101, 13083-881, Campinas, SP, Brazil
| | - Francisco Aguayo
- Basic and Clinical Oncology Department, Faculty of Medicine, University of Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Enrique Boccardo
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1374, 05508-900, São Paulo, SP, Brazil.
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158
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Mechanistic link between DNA damage sensing, repairing and signaling factors and immune signaling. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 115:297-324. [PMID: 30798935 DOI: 10.1016/bs.apcsb.2018.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Previously, DNA damage sensing, repairing and signaling machineries were thought to mainly suppress genomic instability in response to genotoxic stress. Emerging evidence indicates a crosstalk between DNA repair machinery and the immune system. In this chapter, we attempt to decipher the molecular choreography of how factors, including ATM, BRCA1, DNA-PK, FANCA/D2, MRE11, MUS81, NBS1, RAD51 and TREX1, of multiple DNA metabolic processes are directly or indirectly involved in suppressing cytosolic DNA sensing pathway-mediated immune signaling. We provide systematic details showing how different DDR factors' roles in modulating immune signaling are not direct, but are rather a consequence of their inherent ability to sense, repair and signal in response to DNA damage. Unexpectedly, most DDR factors negatively impact the immune system; that is, the immune system shows defective signaling if there are defects in DNA repair pathways. Thus, in addition to their known DNA repair and replication functions, DDR factors help prevent erroneous activation of immune signaling. A more precise understanding of the mechanisms by which different DDR factors function in immune signaling can be exploited to redirect the immune system for both preventing and treating autoimmunity, cellular senescence and cancer in humans.
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159
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Peng X, Zhao J, Liu J, Li S. Advances in biomarkers of cerebral small vessel disease. JOURNAL OF NEURORESTORATOLOGY 2019. [DOI: 10.26599/jnr.2019.9040021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cerebral small vessel disease (CSVD) refers to a type of syndrome caused by lesions in perforating arteries, small veins, small arteries, or capillaries, resulting in clinical, imaging, or pathological alterations. The occurrence and development of CSVD are related to various cerebrovascular risk factors, such as metabolism and genetic factors. CSVD is diagnosed based on brain imaging biomarkers; however, biomarkers capable of predicting and diagnosing CSVD early in its progression have not been found. Exploring biomarkers closely related to disease progression is of great significance for early diagnosis, prognosis, prevention, and treatment of CSVD. This article examines the research progress of CSVD biomarkers, from inflammatory biomarkers, coagulation and fibrinolysis markers, biomarkers of endothelial dysfunction, biomarkers related to cerebrospinal fluid, and gene markers.
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160
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Takami T, Ohnishi N, Kurita Y, Iwamura S, Ohnishi M, Kusaba M, Mimura T, Sakamoto W. Organelle DNA degradation contributes to the efficient use of phosphate in seed plants. NATURE PLANTS 2018; 4:1044-1055. [PMID: 30420711 DOI: 10.1038/s41477-018-0291-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 09/27/2018] [Indexed: 06/09/2023]
Abstract
Mitochondria and chloroplasts (plastids) both harbour extranuclear DNA that originates from the ancestral endosymbiotic bacteria. These organelle DNAs (orgDNAs) encode limited genetic information but are highly abundant, with multiple copies in vegetative tissues, such as mature leaves. Abundant orgDNA constitutes a substantial pool of organic phosphate along with RNA in chloroplasts, which could potentially contribute to phosphate recycling when it is degraded and relocated. However, whether orgDNA is degraded nucleolytically in leaves remains unclear. In this study, we revealed the prevailing mechanism in which organelle exonuclease DPD1 degrades abundant orgDNA during leaf senescence. The DPD1 degradation system is conserved in seed plants and, more remarkably, we found that it was correlated with the efficient use of phosphate when plants were exposed to nutrient-deficient conditions. The loss of DPD1 compromised both the relocation of phosphorus to upper tissues and the response to phosphate starvation, resulting in reduced plant fitness. Our findings highlighted that DNA is also an internal phosphate-rich reservoir retained in organelles since their endosymbiotic origin.
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Affiliation(s)
- Tsuneaki Takami
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Norikazu Ohnishi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Yuko Kurita
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Shoko Iwamura
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Miwa Ohnishi
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Makoto Kusaba
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - Tetsuro Mimura
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan.
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161
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Rego SL, Harvey S, Simpson SR, Hemphill WO, McIver ZA, Grayson JM, Perrino FW. TREX1 D18N mice fail to process erythroblast DNA resulting in inflammation and dysfunctional erythropoiesis. Autoimmunity 2018; 51:333-344. [PMID: 30422000 DOI: 10.1080/08916934.2018.1522305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Anaemia is commonly observed in chronic inflammatory conditions, including systemic lupus erythematosus (SLE), where ∼50% of patients display clinical signs of anaemia. Mutation at the aspartate residue 18 of the three prime repair exonuclease 1 (TREX1) gene causes a monogenic form of cutaneous lupus in humans and the genetically precise TREX1 D18N mice recapitulate a lupus-like disease. TREX1 degrades single- and double-stranded DNA (dsDNA), and the link between failed DNA degradation by nucleases, including nucleoside-diphosphate kinases (NM23H1/H2) and Deoxyribonuclease II (DNase II), and anaemia prompted our studies to investigate whether TREX1 dysfunction contributes to anaemia. Utilizing the TREX1 D18N mice we demonstrate that (1) TREX1 mutant mice develop normocytic normochromic anaemia and (2) TREX1 exonuclease participates in the degradation of DNA originating from erythroblast nuclei during definitive erythropoiesis. Gene expression, hematocrit, hemoglobin, immunohistochemistry (IHC) and flow cytometry were used to quantify dysfunctional erythropoiesis. An altered response to induced anaemia in the TREX1 D18N mice was determined through IHC, flow cytometry, and interferon-stimulated gene (ISG) expression analysis of the liver, spleen and erythroblastic islands (EBIs). IHC, flow cytometry, and ISG expression studies were performed in vitro to determine the role of TREX1 in the degradation of erythroblast DNA within EBIs. The TREX1 D18N mice exhibit altered erythropoiesis including a 20% reduction in hematocrit, 10-20 fold increased erythropoietic gene expression levels in the spleen and phenotypic signs of normocytic normochromic anaemia. Anaemia in TREX1 D18N mice is accompanied by increased erythropoietin (Epo), normal hepcidin levels and the TREX1 D18N mice display an inappropriate response to anaemic challenge. Enhanced ISG expression results from failed processing and subsequent sensing of undegraded erythroblast DNA in EBIs. TREX1 participates in the degradation of erythroblast DNA in the EBI and TREX1 D18N mice exhibit a normocytic normochromic anaemia.
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Affiliation(s)
- Stephen L Rego
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Scott Harvey
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Sean R Simpson
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Wayne O Hemphill
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Zachariah A McIver
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jason M Grayson
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Fred W Perrino
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
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162
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Vijay N, Chande A. A hypothetical new role for single-stranded DNA binding proteins in the immune system. Immunobiology 2018; 223:671-676. [DOI: 10.1016/j.imbio.2018.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/25/2018] [Accepted: 07/05/2018] [Indexed: 12/21/2022]
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163
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Abstract
In mammals, cytosolic detection of nucleic acids is critical in initiating innate antiviral responses against invading pathogens (like bacteria, viruses, fungi and parasites). These programs are mediated by multiple cytosolic and endosomal sensors and adaptor molecules (c-GAS/STING axis and TLR9/MyD88 axis, respectively) and lead to the production of type I interferons (IFNs), pro-inflammatory cytokines, and chemokines. While the identity and role of multiple pattern recognition receptors (PRRs) have been elucidated, such immune surveillance systems must be tightly regulated to limit collateral damage and prevent aberrant responses to self- and non-self-nucleic acids. In this review, we discuss recent advances in our understanding of how cytosolic sensing of DNA is controlled during inflammatory immune responses.
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Affiliation(s)
- Takayuki Abe
- Department of Systems Biology, Columbia University, New York, NY, United States; Department of Microbiology and Immunology, Columbia University, New York, NY, United States
| | - Sagi D Shapira
- Department of Systems Biology, Columbia University, New York, NY, United States; Department of Microbiology and Immunology, Columbia University, New York, NY, United States.
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164
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Wang J, Dai M, Cui Y, Hou G, Deng J, Gao X, Liao Z, Liu Y, Meng Y, Wu L, Yao C, Wang Y, Qian J, Guo Q, Ding H, Qu B, Shen N. Association of Abnormal Elevations in IFIT3 With Overactive Cyclic GMP-AMP Synthase/Stimulator of Interferon Genes Signaling in Human Systemic Lupus Erythematosus Monocytes. Arthritis Rheumatol 2018; 70:2036-2045. [PMID: 29806091 DOI: 10.1002/art.40576] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 05/24/2018] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Increasing evidence indicates that the cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) signaling pathway has a critical pathogenic role in systemic lupus erythematosus (SLE). Expression levels of the interferon (IFN)-inducible gene IFIT3 are elevated in SLE patients. However, it is still not clear how IFIT3 contributes to the pathogenesis of SLE. This study was undertaken to investigate the activation of the cGAS/STING signaling pathway in human SLE monocytes, and to determine how elevated expression of IFIT3 could contribute to overactive cGAS/STING signaling in patients with SLE. METHODS Monocytes from SLE patients or healthy controls were examined for activity of the cGAS/STING signaling pathway and expression levels of IFIT3. Correlations between cGAS/STING signaling activity and SLE clinical features were analyzed. Gain- or loss-of-function experiments were used to determine the role of IFIT3 in cGAS/STING signaling. Coimmunoprecipitation assays were used to identify the interaction between IFIT3 and other proteins. RESULTS The cGAS/STING signaling pathway was found to have enhanced activity in monocytes from SLE patients compared to healthy controls, as indicated by the higher expression of IFNβ downstream. Levels of IFIT3 were significantly elevated in human SLE monocytes, and this was positively correlated with the activity of the cGAS/STING signaling pathway. In vitro, the expression of VACV70-induced IFNβ was reduced by knockdown of IFIT3, whereas overexpression of IFIT3 produced an opposite effect. Finally, IFIT3 was found to interact with both STING and TANK-binding kinase 1. CONCLUSION These findings suggest that IFIT3 is one of the genes that contributes to the overactive cGAS/STING signaling pathway in human SLE monocytes. IFIT3 may therefore serve as a novel therapeutic target for blocking the production of type I IFN and other proinflammatory cytokines by the cGAS/STING signaling pathway in patients with SLE.
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Affiliation(s)
- Jiehua Wang
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Min Dai
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yange Cui
- Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Guojun Hou
- Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jun Deng
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xin Gao
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhuojun Liao
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ya Liu
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yao Meng
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lingling Wu
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chao Yao
- Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yan Wang
- Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jie Qian
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qiang Guo
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huihua Ding
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Bo Qu
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Nan Shen
- Shanghai Institute of Rheumatology, and China-Australia Centre for Personalised Immunology, Renji Hospital, School of Medicine, and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
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165
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Kothari PH, Kolar GR, Jen JC, Hajj-Ali R, Bertram P, Schmidt RE, Atkinson JP. TREX1 is expressed by microglia in normal human brain and increases in regions affected by ischemia. Brain Pathol 2018; 28:806-821. [PMID: 30062819 PMCID: PMC6404532 DOI: 10.1111/bpa.12626] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 05/28/2018] [Indexed: 12/27/2022] Open
Abstract
Background Mutations in the three‐prime repair exonuclease 1 (TREX1) gene have been associated with neurological diseases, including Retinal Vasculopathy with Cerebral Leukoencephalopathy (RVCL). However, the endogenous expression of TREX1 in human brain has not been studied. Methods We produced a rabbit polyclonal antibody (pAb) to TREX1 to characterize TREX1 by Western blotting (WB) of cell lysates from normal controls and subjects carrying an RVCL frame‐shift mutation. Dual staining was performed to determine cell types expressing TREX1 in human brain tissue. TREX1 distribution in human brain was further evaluated by immunohistochemical analyses of formalin‐fixed, paraffin‐embedded samples from normal controls and patients with RVCL and ischemic stroke. Results After validating the specificity of our anti‐TREX1 rabbit pAb, WB analysis was utilized to detect the endogenous wild‐type and frame‐shift mutant of TREX1 in cell lysates. Dual staining in human brain tissues from patients with RVCL and normal controls localized TREX1 to a subset of microglia and macrophages. Quantification of immunohistochemical staining of the cerebral cortex revealed that TREX1+ microglia were primarily in the gray matter of normal controls (22.7 ± 5.1% and 5.5 ± 1.9% of Iba1+ microglia in gray and white matter, respectively) and commonly in association with the microvasculature. In contrast, in subjects with RVCL, the TREX1+ microglia were predominantly located in the white matter of normal appearing cerebral cortex (11.8 ± 3.1% and 38.9 ± 5.8% of Iba1+ microglia in gray and white matter, respectively). The number of TREX1+ microglia was increased in ischemic brain lesions in central nervous system of RVCL and stroke patients. Conclusions TREX1 is expressed by a subset of microglia in normal human brain, often in close proximity to the microvasculature, and increases in the setting of ischemic lesions. These findings suggest a role for TREX1+ microglia in vessel homeostasis and response to ischemic injury.
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Affiliation(s)
- Parul H Kothari
- Department of Biology and Biomedical Sciences Human & Statistical Genetics Program, Washington University School of Medicine, St. Louis, MO.,Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.,Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Grant R Kolar
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO.,Department of Pathology and Department of Ophthalmology, Saint Louis University School of Medicine, St. Louis, MO
| | - Joanna C Jen
- Departments of Neurology and Neurobiology, UCLA School of Medicine, Los Angeles, CA.,Departments of Neurology, Otolaryngology, Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Rula Hajj-Ali
- Center for Vasculitis Care and Research, Cleveland Clinic Lerner College of Medicine, Orthopaedic and Rheumatologic Institute, Cleveland, OH
| | - Paula Bertram
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
| | - Robert E Schmidt
- Department of Pathology and Immunology, Division of Neuropathology, Washington University School of Medicine, St. Louis, MO
| | - John P Atkinson
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
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166
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Coquel F, Neumayer C, Lin YL, Pasero P. SAMHD1 and the innate immune response to cytosolic DNA during DNA replication. Curr Opin Immunol 2018; 56:24-30. [PMID: 30292848 DOI: 10.1016/j.coi.2018.09.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 12/11/2022]
Abstract
Cytosolic DNA of endogenous or exogenous origin is sensed by the cGAS-STING pathway to activate innate immune responses. Besides microbial DNA, this pathway detects self-DNA in the cytoplasm of damaged or abnormal cells and plays a central role in antitumor immunity. The mechanism by which cytosolic DNA accumulates under genotoxic stress conditions is currently unclear, but recent studies on factors mutated in the Aicardi-Goutières syndrome cells, such as SAMHD1, RNase H2 and TREX1, are shedding new light on this key process. In particular, these studies indicate that the rupture of micronuclei and the release of ssDNA fragments during the processing of stalled replication forks and chromosome breaks represent potent inducers of the cGAS-STING pathway.
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Affiliation(s)
- Flavie Coquel
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue contre le Cancer, Montpellier France
| | - Christoph Neumayer
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue contre le Cancer, Montpellier France
| | - Yea-Lih Lin
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue contre le Cancer, Montpellier France.
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe Labellisée Ligue contre le Cancer, Montpellier France.
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167
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Matz KM, Guzman RM, Goodman AG. The Role of Nucleic Acid Sensing in Controlling Microbial and Autoimmune Disorders. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 345:35-136. [PMID: 30904196 DOI: 10.1016/bs.ircmb.2018.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Innate immunity, the first line of defense against invading pathogens, is an ancient form of host defense found in all animals, from sponges to humans. During infection, innate immune receptors recognize conserved molecular patterns, such as microbial surface molecules, metabolites produces during infection, or nucleic acids of the microbe's genome. When initiated, the innate immune response activates a host defense program that leads to the synthesis proteins capable of pathogen killing. In mammals, the induction of cytokines during the innate immune response leads to the recruitment of professional immune cells to the site of infection, leading to an adaptive immune response. While a fully functional innate immune response is crucial for a proper host response and curbing microbial infection, if the innate immune response is dysfunctional and is activated in the absence of infection, autoinflammation and autoimmune disorders can develop. Therefore, it follows that the innate immune response must be tightly controlled to avoid an autoimmune response from host-derived molecules, yet still unencumbered to respond to infection. In this review, we will focus on the innate immune response activated from cytosolic nucleic acids, derived from the microbe or host itself. We will depict how viruses and bacteria activate these nucleic acid sensing pathways and their mechanisms to inhibit the pathways. We will also describe the autoinflammatory and autoimmune disorders that develop when these pathways are hyperactive. Finally, we will discuss gaps in knowledge with regard to innate immune response failure and identify where further research is needed.
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Affiliation(s)
- Keesha M Matz
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - R Marena Guzman
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Alan G Goodman
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, United States; Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States.
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168
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Grandi N, Tramontano E. Human Endogenous Retroviruses Are Ancient Acquired Elements Still Shaping Innate Immune Responses. Front Immunol 2018; 9:2039. [PMID: 30250470 PMCID: PMC6139349 DOI: 10.3389/fimmu.2018.02039] [Citation(s) in RCA: 179] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/20/2018] [Indexed: 12/25/2022] Open
Abstract
About 8% of our genome is composed of sequences with viral origin, namely human Endogenous Retroviruses (HERVs). HERVs are relics of ancient infections that affected the primates' germ line along the last 100 million of years, and became stable elements at the interface between self and foreign DNA. Intriguingly, HERV co-evolution with the host led to the domestication of activities previously devoted to the retrovirus life cycle, providing novel cellular functions. For example, selected HERV envelope proteins have been coopted for pregnancy-related purposes, and proviral Long Terminal Repeats participate in the transcriptional regulation of various cellular genes. Given the HERV persistence in the host genome and its basal expression in most healthy tissues, it is reasonable that human defenses should prevent HERV-mediated immune activation. Despite this, HERVs and their products (including RNA, cytosolic DNA, and proteins) are still able to modulate and be influenced by the host immune system, fascinatingly suggesting a central role in the evolution and functioning of the human innate immunity. Indeed, HERV sequences had been major contributors in shaping and expanding the interferon network, dispersing inducible genes that have been occasionally domesticated in various mammalian lineages. Also the HERV integration within or near to genes encoding for critical immune factors has been shown to influence their activity, or to be responsible for their polymorphic variation in the human population, such as in the case of an HERV-K(HML10) provirus in the major histocompatibility complex region. In addition, HERV expressed products have been shown to modulate innate immunity effectors, being therefore often related on the one side to inflammatory and autoimmune disorders, while on the other side to the control of excessive immune activation through their immunosuppressive properties. Finally, HERVs have been proposed to establish a protective effect against exogenous infections. The present review summarizes the involvement of HERVs and their products in innate immune responses, describing how their intricate interplay with the first line of human defenses can actively contribute either to the host protection or to his damage, implying a subtle balance between the persistence of HERV expression and the maintenance of a basal immune alert.
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Affiliation(s)
- Nicole Grandi
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Enzo Tramontano
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.,Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cagliari, Italy
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169
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Vanpouille-Box C, Demaria S, Formenti SC, Galluzzi L. Cytosolic DNA Sensing in Organismal Tumor Control. Cancer Cell 2018; 34:361-378. [PMID: 30216189 DOI: 10.1016/j.ccell.2018.05.013] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/11/2018] [Accepted: 05/30/2018] [Indexed: 02/07/2023]
Abstract
Besides constituting a first layer of defense against microbial challenges, the detection of cytosolic DNA is fundamental for mammalian organisms to control malignant transformation and tumor progression. The accumulation of DNA in the cytoplasm can initiate the proliferative inactivation (via cellular senescence) or elimination (via regulated cell death) of neoplastic cell precursors. Moreover, cytosolic DNA sensing is intimately connected to the secretion of cytokines that support innate and adaptive antitumor immunity. Here, we discuss the molecular mechanisms whereby cytosolic DNA enables cell-intrinsic and -extrinsic oncosuppression, and their relevance for the development of novel therapeutic approaches that reinstate anticancer immunosurveillance.
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Affiliation(s)
- Claire Vanpouille-Box
- Department of Radiation Oncology, Weill Cornell Medical College, Stich Radiation Oncology, 525 East 68th Street, Box #169, New York, NY 10065, USA
| | - Sandra Demaria
- Department of Radiation Oncology, Weill Cornell Medical College, Stich Radiation Oncology, 525 East 68th Street, Box #169, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, New York, NY, USA; Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Silvia C Formenti
- Department of Radiation Oncology, Weill Cornell Medical College, Stich Radiation Oncology, 525 East 68th Street, Box #169, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, New York, NY, USA
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, Stich Radiation Oncology, 525 East 68th Street, Box #169, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, New York, NY, USA; Université Paris Descartes/Paris V, Paris, France.
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170
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Transposable element dysregulation in systemic lupus erythematosus and regulation by histone conformation and Hsp90. Clin Immunol 2018; 197:6-18. [PMID: 30149120 DOI: 10.1016/j.clim.2018.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 01/27/2023]
Abstract
Systemic lupus erythematosus (SLE) represents an autoimmune disease in which activation of the type I interferon pathway leads to dysregulation of tolerance and the generation of autoantibodies directed against nuclear constituents. The mechanisms driving the activation of the interferon pathway in SLE have been the subject of intense investigation but are still incompletely understood. Transposable elements represent an enormous source of RNA that could potentially stimulate the cell intrinsic RNA-recognition pathway, leading to upregulation of interferons. We used RNA-seq to define transposable element families and subfamilies in three cell types in SLE and found diverse effects on transposable element expression in the three cell types and even within a given family of transposable elements. When potential mechanisms were examined, we found that Hsp90 inhibition could drive increased expression of multiple type of transposable elements. Both direct inhibition and the delivery of a heat shock itself, which redirects heat shock regulators (including Hsp90) off of basal expression promoters and onto heat shock-responsive promoters, led to increased transposable element expression. This effect was amplified by the concurrent delivery of a histone deacetylase inhibitor. We conclude that transposable elements are dysregulated in SLE and there are tissue-specific effects and locus-specific effects. The magnitude of RNAs attributable to transposable elements makes their dysregulation of critical interest in SLE where transposable element RNA complexed with proteins has been shown to drive interferon expression.
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171
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Stam AH, Kothari PH, Shaikh A, Gschwendter A, Jen JC, Hodgkinson S, Hardy TA, Hayes M, Kempster PA, Kotschet KE, Bajema IM, van Duinen SG, Maat-Schieman MLC, de Jong PTVM, de Smet MD, de Wolff-Rouendaal D, Dijkman G, Pelzer N, Kolar GR, Schmidt RE, Lacey J, Joseph D, Fintak DR, Grand MG, Brunt EM, Liapis H, Hajj-Ali RA, Kruit MC, van Buchem MA, Dichgans M, Frants RR, van den Maagdenberg AMJM, Haan J, Baloh RW, Atkinson JP, Terwindt GM, Ferrari MD. Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations. Brain 2018; 139:2909-2922. [PMID: 27604306 DOI: 10.1093/brain/aww217] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 07/11/2016] [Indexed: 02/02/2023] Open
Affiliation(s)
- Anine H Stam
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Parul H Kothari
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Aisha Shaikh
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Andreas Gschwendter
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians Universität, D-81377 München, Germany
| | - Joanna C Jen
- Department of Neurology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Suzanne Hodgkinson
- Department of Neurology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia
| | - Todd A Hardy
- Department of Neurology, Concord Repatriation General Hospital, Concord, New South Wales 2139, Australia.,Brain and Mind Centre, University of Sydney, Australia
| | - Michael Hayes
- Department of Neurology, Concord Repatriation General Hospital, Concord, New South Wales 2139, Australia
| | - Peter A Kempster
- Neurosciences Department, Monash Medical Centre, Clayton, Victoria 3168, Australia
| | - Katya E Kotschet
- Neurosciences Department, Monash Medical Centre, Clayton, Victoria 3168, Australia
| | - Ingeborg M Bajema
- Department of Pathology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Sjoerd G van Duinen
- Department of Pathology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Paulus T V M de Jong
- Department of Ophthalmology, Academic Medical Centre, 1100 DD Amsterdam, The Netherlands.,Department of Retinal Signaling, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, 1000 GC Amsterdam, The Netherlands.,Department of Ophthalmology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Marc D de Smet
- Department of Ophthalmology, Academic Medical Centre, 1100 DD Amsterdam, The Netherlands
| | | | - Greet Dijkman
- Department of Ophthalmology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Nadine Pelzer
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Grant R Kolar
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - Robert E Schmidt
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - JoAnne Lacey
- West County Radiology Group, Mercy Hospital in St Louis, MO 63141, USA
| | - Daniel Joseph
- The Retina Institute, Department of Ophthalmology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - David R Fintak
- The Retina Institute, Department of Ophthalmology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - M Gilbert Grand
- The Retina Institute, Department of Ophthalmology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - Elizabeth M Brunt
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - Helen Liapis
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, 63110 USA
| | - Rula A Hajj-Ali
- Department of Rheumatic and Immunologic Disease, Cleveland Clinic, Cleveland, Ohio, 44195 USA
| | - Mark C Kruit
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Martin Dichgans
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians Universität, D-81377 München, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Rune R Frants
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Arn M J M van den Maagdenberg
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.,Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Joost Haan
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.,Department of Neurology, Alrijne Hospital, Leiderdorp, The Netherlands
| | - Robert W Baloh
- Department of Neurology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - John P Atkinson
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Gisela M Terwindt
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Michel D Ferrari
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
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172
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Martinez-Lopez A, Martin-Fernandez M, Buta S, Kim B, Bogunovic D, Diaz-Griffero F. SAMHD1 deficient human monocytes autonomously trigger type I interferon. Mol Immunol 2018; 101:450-460. [PMID: 30099227 DOI: 10.1016/j.molimm.2018.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 07/24/2018] [Accepted: 08/02/2018] [Indexed: 01/04/2023]
Abstract
Germline mutations in the human SAMHD1 gene cause the development of Aicardi-Goutières Syndrome (AGS), with a dominant feature being increased systemic type I interferon(IFN) production. Here we tested the state of type I IFN induction and response to, in SAMHD1 knockout (KO) human monocytic cells. SAMHD1 KO cells exhibited spontaneous transcription and translation of IFN-β and subsequent interferon-stimulated genes (ISGs) as compared to parental wild-type cells. This elevation of IFN-β and ISGs was abrogated via inhibition of the TBK1-IRF3 pathway in the SAMHD1 KO cells. In agreement, we found that SAMHD1 KO cells present high levels of phosphorylated TBK1 when compared to control cells. Moreover, addition of blocking antibody against type I IFN also reversed elevation of ISGs. These experiments suggested that SAMHD1 KO cells are persistently auto-stimulating the TBK1-IRF3 pathway, leading to an enhanced production of type I IFN and subsequent self-induction of ISGs.
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Affiliation(s)
- Alicia Martinez-Lopez
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Marta Martin-Fernandez
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Sofija Buta
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Baek Kim
- Department of Pediatrics, Emory University, Atlanta, GA 30322, United States
| | - Dusan Bogunovic
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
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173
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Lou H, Pickering MC. Extracellular DNA and autoimmune diseases. Cell Mol Immunol 2018; 15:746-755. [PMID: 29553134 PMCID: PMC6141478 DOI: 10.1038/cmi.2017.136] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 10/23/2017] [Accepted: 10/23/2017] [Indexed: 01/02/2023] Open
Abstract
Extracellular DNA is secreted from various sources including apoptotic cells, NETotic neutrophils and bacterial biofilms. Extracellular DNA can stimulate innate immune responses to induce type-I IFN production after being endocytosed. This process is central in antiviral responses but it also plays important role in the pathogenesis of a range of autoimmune diseases such as systemic lupus erythematosus. We discuss the recent advances in the understanding of the role of extracellular DNA, released from apoptotic and NETotic cells, in autoimmunity.
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Affiliation(s)
- Hantao Lou
- Molecular Immunology, Imperial College London, London, UK, W12 0NN.
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College London, London, UK, W12 0NN
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174
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Mujoo K, Hunt CR, Pandita RK, Ferrari M, Krishnan S, Cooke JP, Hahn S, Pandita TK. Harnessing and Optimizing the Interplay between Immunotherapy and Radiotherapy to Improve Survival Outcomes. Mol Cancer Res 2018; 16:1209-1214. [PMID: 29592896 PMCID: PMC6072560 DOI: 10.1158/1541-7786.mcr-17-0743] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/19/2018] [Accepted: 02/13/2018] [Indexed: 01/06/2023]
Abstract
In the past, radiotherapy was primarily used to control local disease, but recent technological advances in accurate, high-dose ionizing radiation (IR) delivery have not only increased local tumor control but in some cases reduced metastatic burden. These "off target" therapeutic effects of IR at nonirradiated tumor sites, also known as abscopal effects, are thought to be mediated by tumor antigen-primed T cells that travel to metastatic sites and promote tumor regression. Similarly, early indications reveal that IR in combination with immune checkpoint inhibitors, such as ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1), can provide superior therapeutic responses. These observations suggest that local radiotherapy results in altered gene expression, exposure of new antigens, or cell death that can interact with immunotherapy. As such, radiotherapy enhancement of immune responses offers a promising synergy with the potential for substantial clinical benefit. This review focuses on the biology that underlies the mechanisms for the interaction between radiation-induced tumor cell death and enhanced immunologic response. Mol Cancer Res; 16(8); 1209-14. ©2018 AACR.
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Affiliation(s)
- Kalpana Mujoo
- Department of Radiation Oncology, the Houston Methodist Research Institute, Weil Cornell Medical College, Houston, Texas.
| | - Clayton R Hunt
- Department of Radiation Oncology, the Houston Methodist Research Institute, Weil Cornell Medical College, Houston, Texas
| | - Raj K Pandita
- Department of Radiation Oncology, the Houston Methodist Research Institute, Weil Cornell Medical College, Houston, Texas
| | - Mauro Ferrari
- Department of Nanomedicine, the Houston Methodist Research Institute, Weil Cornell Medical College, Houston, Texas
| | - Sunil Krishnan
- Department of Radiation Oncology, the UT MD Anderson Cancer Center, Houston, Texas
| | - John P Cooke
- Department of Cardiovascular Sciences, the Houston Methodist Research Institute, Weil Cornell Medical College, Houston, Texas
| | - Stephen Hahn
- Department of Radiation Oncology, the UT MD Anderson Cancer Center, Houston, Texas
| | - Tej K Pandita
- Department of Radiation Oncology, the Houston Methodist Research Institute, Weil Cornell Medical College, Houston, Texas.
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175
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Faulkner GJ, Billon V. L1 retrotransposition in the soma: a field jumping ahead. Mob DNA 2018; 9:22. [PMID: 30002735 PMCID: PMC6035798 DOI: 10.1186/s13100-018-0128-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/27/2018] [Indexed: 12/13/2022] Open
Abstract
Retrotransposons are transposable elements (TEs) capable of "jumping" in germ, embryonic and tumor cells and, as is now clearly established, in the neuronal lineage. Mosaic TE insertions form part of a broader landscape of somatic genome variation and hold significant potential to generate phenotypic diversity, in the brain and elsewhere. At present, the LINE-1 (L1) retrotransposon family appears to be the most active autonomous TE in most mammals, based on experimental data obtained from disease-causing L1 mutations, engineered L1 reporter systems tested in cultured cells and transgenic rodents, and single-cell genomic analyses. However, the biological consequences of almost all somatic L1 insertions identified thus far remain unknown. In this review, we briefly summarize the current state-of-the-art in the field, including estimates of L1 retrotransposition rate in neurons. We bring forward the hypothesis that an extensive subset of retrotransposition-competent L1s may be de-repressed and mobile in the soma but largely inactive in the germline. We discuss recent reports of non-canonical L1-associated sequence variants in the brain and propose that the elevated L1 DNA content reported in several neurological disorders may predominantly comprise accumulated, unintegrated L1 nucleic acids, rather than somatic L1 insertions. Finally, we consider the main objectives and obstacles going forward in elucidating the biological impact of somatic retrotransposition.
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Affiliation(s)
- Geoffrey J. Faulkner
- Mater Research Institute – University of Queensland, TRI Building, Woolloongabba, QLD 4102 Australia
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD 4072 Australia
- Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072 Australia
| | - Victor Billon
- Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072 Australia
- Biology Department, École Normale Supérieure Paris-Saclay, 61 Avenue du Président Wilson, 94230 Cachan, France
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176
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Pasero P, Vindigni A. Nucleases Acting at Stalled Forks: How to Reboot the Replication Program with a Few Shortcuts. Annu Rev Genet 2018; 51:477-499. [PMID: 29178820 DOI: 10.1146/annurev-genet-120116-024745] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In a lifetime, a human being synthesizes approximately 2×1016 meters of DNA, a distance that corresponds to 130,000 times the distance between the Earth and the Sun. This daunting task is executed by thousands of replication forks, which progress along the chromosomes and frequently stall when they encounter DNA lesions, unusual DNA structures, RNA polymerases, or tightly-bound protein complexes. To complete DNA synthesis before the onset of mitosis, eukaryotic cells have evolved complex mechanisms to process and restart arrested forks through the coordinated action of multiple nucleases, topoisomerases, and helicases. In this review, we discuss recent advances in understanding the role and regulation of nucleases acting at stalled forks with a focus on the nucleolytic degradation of nascent DNA, a process commonly referred to as fork resection. We also discuss the effects of deregulated fork resection on genomic instability and on the unscheduled activation of the interferon response under replication stress conditions.
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Affiliation(s)
- Philippe Pasero
- Institute of Human Genetics, CNRS UMR9002, University of Montpellier, 34396 Montpellier, France;
| | - Alessandro Vindigni
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA;
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177
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Gulati A, Bale AE, Dykas DJ, Bia MJ, Danovitch GM, Moeckel GW, Somlo S, Dahl NK. TREX1 Mutation Causing Autosomal Dominant Thrombotic Microangiopathy and CKD-A Novel Presentation. Am J Kidney Dis 2018; 72:895-899. [PMID: 29941221 DOI: 10.1053/j.ajkd.2018.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 05/03/2018] [Indexed: 01/20/2023]
Abstract
Renal thrombotic microangiopathy (TMA) involves diverse causes and clinical presentations. Genetic determinants causing alternate pathway complement dysregulation underlie a substantial proportion of cases. In a significant proportion of TMAs, no defect in complement regulation is identified. Mutations in the major mammalian 3' DNA repair exonuclease 1 (TREX1) have been associated with autoimmune and cerebroretinal vasculopathy syndromes. Carboxy-terminal TREX1 mutations that result in only altered localization of the exonuclease protein with preserved catalytic function cause microangiopathy of the brain and retina, termed retinal vasculopathy and cerebral leukodystrophy (RVCL). Kidney involvement reported with RVCL usually accompanies significant brain and retinal microangiopathy. We present a pedigree with autosomal dominant renal TMA and chronic kidney disease found to have a carboxy-terminal frameshift TREX1 variant. Although symptomatic brain and retinal microangiopathy is known to associate with carboxy-terminal TREX1 mutations, this report describes a carboxy-terminal TREX1 frameshift variant causing predominant renal TMA. These findings underscore the clinical importance of recognizing TREX1 mutations as a cause of renal TMA. This case demonstrates the value of whole-exome sequencing in unsolved TMA.
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Affiliation(s)
- Ashima Gulati
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT.
| | - Allen E Bale
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Daniel J Dykas
- Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Margaret J Bia
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT
| | - Gabriel M Danovitch
- Division of Nephrology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Gilbert W Moeckel
- Department of Pathology, Yale University School of Medicine, New Haven, CT
| | - Stefan Somlo
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT; Department of Genetics, Yale University School of Medicine, New Haven, CT
| | - Neera K Dahl
- Department of Internal Medicine, Division of Nephrology, Yale University School of Medicine, New Haven, CT
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178
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Piras F, Riba M, Petrillo C, Lazarevic D, Cuccovillo I, Bartolaccini S, Stupka E, Gentner B, Cittaro D, Naldini L, Kajaste-Rudnitski A. Lentiviral vectors escape innate sensing but trigger p53 in human hematopoietic stem and progenitor cells. EMBO Mol Med 2018; 9:1198-1211. [PMID: 28667090 PMCID: PMC5582409 DOI: 10.15252/emmm.201707922] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Clinical application of lentiviral vector (LV)-based hematopoietic stem and progenitor cells (HSPC) gene therapy is rapidly becoming a reality. Nevertheless, LV-mediated signaling and its potential functional consequences on HSPC biology remain poorly understood. We unravel here a remarkably limited impact of LV on the HSPC transcriptional landscape. LV escaped innate immune sensing that instead led to robust IFN responses upon transduction with a gamma-retroviral vector. However, reverse-transcribed LV DNA did trigger p53 signaling, activated also by non-integrating Adeno-associated vector, ultimately leading to lower cell recovery ex vivo and engraftment in vivo These effects were more pronounced in the short-term repopulating cells while long-term HSC frequencies remained unaffected. Blocking LV-induced signaling partially rescued both apoptosis and engraftment, highlighting a novel strategy to further dampen the impact of ex vivo gene transfer on HSPC. Overall, our results shed light on viral vector sensing in HSPC and provide critical insight for the development of more stealth gene therapy strategies.
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Affiliation(s)
- Francesco Piras
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Michela Riba
- Center for Translational Genomics and Bioinformatics, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Carolina Petrillo
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Dejan Lazarevic
- Center for Translational Genomics and Bioinformatics, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Ivan Cuccovillo
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Sara Bartolaccini
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elia Stupka
- Center for Translational Genomics and Bioinformatics, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Bernhard Gentner
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Davide Cittaro
- Center for Translational Genomics and Bioinformatics, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Luigi Naldini
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Anna Kajaste-Rudnitski
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy
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179
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Lo MS. Insights Gained From the Study of Pediatric Systemic Lupus Erythematosus. Front Immunol 2018; 9:1278. [PMID: 29922296 PMCID: PMC5996073 DOI: 10.3389/fimmu.2018.01278] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/22/2018] [Indexed: 12/21/2022] Open
Abstract
The pathophysiology of systemic lupus erythematosus (SLE) has been intensely studied but remains incompletely defined. Currently, multiple mechanisms are known to contribute to the development of SLE. These include inadequate clearance of apoptotic debris, aberrant presentation of self nucleic antigens, loss of tolerance, and inappropriate activation of T and B cells. Genetic, hormonal, and environmental influences are also known to play a role. The study of lupus in children, in whom there is presumed to be greater genetic influence, has led to new understandings that are applicable to SLE pathophysiology as a whole. In particular, characterization of inherited disorders associated with excessive type I interferon production has elucidated specific mechanisms by which interferon is induced in SLE. In this review, we discuss several monogenic forms of lupus presenting in childhood and also review recent insights gained from cytokine and autoantibody profiling of pediatric SLE.
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Affiliation(s)
- Mindy S Lo
- Division of Immunology, Boston Children's Hospital, Boston, MA, United States.,Department of Pediatrics, Harvard Medical School, Boston, MA, United States
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180
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Abstract
Stress conditions such as UV irradiation, exposure to genotoxic agents, stalled DNA replication, and even tumors trigger the release of cytosolic genomic DNA (cgDNA). Classically, cgDNA induces interferon response via its binding to proteins such as STING. In this study, we found previously reported cgDNA (cg721) exists in the cytosol of the mouse cell lines, cultured under no stress conditions. The overexpression of cg721 suppressed the complementary RNA expression using strand selection and knockdown of DNA/RNA hybrid R-loop removing enzyme RNase H and three prime repair exonuclease 1 TREX1 increased the expression levels of cg721 and thus, inhibited the target Naa40 transcript, as well as protein expression, with a phenotypic effect. In addition, cgDNA was incorporated into extracellular vesicles (EVs), and the EV-derived cg721 inhibited gene expression of the acceptor cells. Thus, our findings suggest that cg721 functions as a natural antisense DNA and play a role in cell-to-cell gene regulation once it secreted outside the cell as EVs.
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181
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Suramin potently inhibits cGAMP synthase, cGAS, in THP1 cells to modulate IFN-β levels. Future Med Chem 2018; 10:1301-1317. [PMID: 29558821 DOI: 10.4155/fmc-2017-0322] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aim: Persistent activation of STING pathway is the basis for several autoimmune diseases. STING is activated by cGAMP, which is produced by cGAS in the presence of DNA. Results/methodology: HPLC-based medium throughput screening for inhibitors of cGAS identified suramin as a potent inhibitor. Unlike other reported cGAS inhibitors, which bind to the ATP/GTP binding site, suramin displaced the bound DNA from cGAS. Addition of suramin to THP1 cells reduced the levels of IFN-β mRNA and protein. Suramin did not inhibit lipopolysaccharide- or Pam3CSK4-induced IL-6 mRNA expression. Conclusion: Suramin inhibits STING pathway via the inhibition of cGAS enzymatic activity. Suramin or analogs thereof that displace DNA from cGAS could be used as anti-inflammatory drugs.
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182
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Shurtleff MJ, Itzhak DN, Hussmann JA, Schirle Oakdale NT, Costa EA, Jonikas M, Weibezahn J, Popova KD, Jan CH, Sinitcyn P, Vembar SS, Hernandez H, Cox J, Burlingame AL, Brodsky JL, Frost A, Borner GH, Weissman JS. The ER membrane protein complex interacts cotranslationally to enable biogenesis of multipass membrane proteins. eLife 2018; 7:37018. [PMID: 29809151 PMCID: PMC5995541 DOI: 10.7554/elife.37018] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/26/2018] [Indexed: 12/20/2022] Open
Abstract
The endoplasmic reticulum (ER) supports biosynthesis of proteins with diverse transmembrane domain (TMD) lengths and hydrophobicity. Features in transmembrane domains such as charged residues in ion channels are often functionally important, but could pose a challenge during cotranslational membrane insertion and folding. Our systematic proteomic approaches in both yeast and human cells revealed that the ER membrane protein complex (EMC) binds to and promotes the biogenesis of a range of multipass transmembrane proteins, with a particular enrichment for transporters. Proximity-specific ribosome profiling demonstrates that the EMC engages clients cotranslationally and immediately following clusters of TMDs enriched for charged residues. The EMC can remain associated after completion of translation, which both protects clients from premature degradation and allows recruitment of substrate-specific and general chaperones. Thus, the EMC broadly enables the biogenesis of multipass transmembrane proteins containing destabilizing features, thereby mitigating the trade-off between function and stability.
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Affiliation(s)
- Matthew J Shurtleff
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Daniel N Itzhak
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jeffrey A Hussmann
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Nicole T Schirle Oakdale
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Elizabeth A Costa
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Martin Jonikas
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Jimena Weibezahn
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Katerina D Popova
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Calvin H Jan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Pavel Sinitcyn
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Shruthi S Vembar
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, United States
| | - Hilda Hernandez
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Jürgen Cox
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, United States
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.,Chan Zuckerberg Biohub, San Francisco, United States
| | - Georg Hh Borner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
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183
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Monogenic systemic lupus erythematosus: insights in pathophysiology. Rheumatol Int 2018; 38:1763-1775. [DOI: 10.1007/s00296-018-4048-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 05/10/2018] [Indexed: 01/02/2023]
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184
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Liu ZS, Zhang ZY, Cai H, Zhao M, Mao J, Dai J, Xia T, Zhang XM, Li T. RINCK-mediated monoubiquitination of cGAS promotes antiviral innate immune responses. Cell Biosci 2018; 8:35. [PMID: 29760876 PMCID: PMC5944131 DOI: 10.1186/s13578-018-0233-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 05/04/2018] [Indexed: 12/19/2022] Open
Abstract
Background As an important danger signal, the presence of DNA in cytoplasm triggers potent immune responses. Cyclic GMP-AMP synthase (cGAS) is a recently characterized key sensor for cytoplasmic DNA. The engagement of cGAS with DNA leads to the synthesis of a second messenger, cyclic GMP-AMP (cGAMP), which binds and activates the downstream adaptor protein STING to promote type I interferon production. Although cGAS has been shown to play a pivotal role in innate immunity, the exact regulation of cGAS activation is not fully understood. Results We report that an E3 ubiquitin ligase, RING finger protein that interacts with C kinase (RINCK, also known as tripartite motif protein 41, TRIM41), is critical for cGAS activation by mediating the monoubiquitination of cGAS. Using CRISPR/Cas9, we generated RINCK-deletion cells and showed that the deficiency of RINCK resulted in dampened interferon production in response to cytosolic DNA. Consistently, the RINCK-deletion cells also exhibited insufficient interferon production upon herpes simplex virus 1, a DNA virus, infection. As a result, the viral load in RINCK-deficient cells was significantly higher than that in wild-type cells. We also found that RINCK deficiency inhibited the up-stream signaling of DNA-triggered interferon production pathway, which was reflected by the phosphorylation of the TANK-binding kinase 1 and the interferon regulatory factor 3. Interestingly, we found that RINCK binds to cGAS and promotes the monoubiquitination of cGAS, thereby positively regulating the cGAS-mediated cGAMP synthesis. Conclusions Our study reveals that monoubiquitination is an important regulation for cGAS activation and uncovers a critical role of RINCK in the cGAS-mediated innate immunity.
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Affiliation(s)
- Zhao-Shan Liu
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
| | - Zi-Yu Zhang
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
| | - Hong Cai
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
| | - Ming Zhao
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
| | - Jie Mao
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
| | - Jiang Dai
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China.,2State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing, 100850 China
| | - Tian Xia
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
| | - Xue-Min Zhang
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China.,2State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, National Center of Biomedical Analysis, 27 Tai-Ping Road, Beijing, 100850 China
| | - Tao Li
- 1State Key Laboratory of Proteomics, Institute of Basic Medical Sciences, National Center of Biomedical Analysis, 27 Tai-Ping Rd., Beijing, 100850 China
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185
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Structural basis for overhang excision and terminal unwinding of DNA duplexes by TREX1. PLoS Biol 2018; 16:e2005653. [PMID: 29734329 PMCID: PMC5957452 DOI: 10.1371/journal.pbio.2005653] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/17/2018] [Accepted: 04/03/2018] [Indexed: 01/12/2023] Open
Abstract
Three prime repair exonuclease 1 (TREX1) is an essential exonuclease in mammalian cells, and numerous in vivo and in vitro data evidenced its participation in immunity regulation and in genotoxicity remediation. In these very complicated cellular functions, the molecular mechanisms by which duplex DNA substrates are processed are mostly elusive because of the lack of structure information. Here, we report multiple crystal structures of TREX1 complexed with various substrates to provide the structure basis for overhang excision and terminal unwinding of DNA duplexes. The substrates were designed to mimic the intermediate structural DNAs involved in various repair pathways. The results showed that the Leu24-Pro25-Ser26 cluster of TREX1 served to cap the nonscissile 5′-end of the DNA for precise removal of the short 3′-overhang in L- and Y-structural DNA or to wedge into the double-stranded region for further digestion along the duplex. Biochemical assays were also conducted to demonstrate that TREX1 can indeed degrade double-stranded DNA (dsDNA) to a full extent. Overall, this study provided unprecedented knowledge at the molecular level on the enzymatic substrate processing involved in prevention of immune activation and in responses to genotoxic stresses. For example, Arg128, whose mutation in TREX1 was linked to a disease state, were shown to exhibit consistent interaction patterns with the nonscissile strand in all of the structures we solved. Such structure basis is expected to play an indispensable role in elucidating the functional activities of TREX1 at the cellular level and in vivo. Three prime repair exonuclease 1 (TREX1) was shown to participate in various cellular events such as DNA repair, immunity regulation, and viral infection. In addition to relating to autoimmune diseases, this exonuclease also acts as a potential protein target for anticancer or antiviral therapies. A key for such broad attendance of TREX1 is the activities of precise trimming of the 3′-overhang in a double-stranded (dsDNA) and breaking of the terminal base pairing of the duplex. Here, we designed a series of structural DNA substrates and activity assays to delineate the underlying mechanisms. The structures newly resolved in this work indicated that the Leu24-Pro25-Ser26 cluster of TREX1 is essential for the enzyme to carry out the aforementioned activities. Together, our results established an integrated structure view into the versatile exonuclease functions of TREX1 and illuminated the molecular origin for the unique catalytic properties of TREX1 in processing various DNA intermediates in DNA repair and in cytosolic immunity regulation.
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186
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Lumb JH, Li Q, Popov LM, Ding S, Keith MT, Merrill BD, Greenberg HB, Li JB, Carette JE. DDX6 Represses Aberrant Activation of Interferon-Stimulated Genes. Cell Rep 2018; 20:819-831. [PMID: 28746868 DOI: 10.1016/j.celrep.2017.06.085] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/30/2017] [Accepted: 06/28/2017] [Indexed: 12/31/2022] Open
Abstract
The innate immune system tightly regulates activation of interferon-stimulated genes (ISGs) to avoid inappropriate expression. Pathological ISG activation resulting from aberrant nucleic acid metabolism has been implicated in autoimmune disease; however, the mechanisms governing ISG suppression are unknown. Through a genome-wide genetic screen, we identified DEAD-box helicase 6 (DDX6) as a suppressor of ISGs. Genetic ablation of DDX6 induced global upregulation of ISGs and other immune genes. ISG upregulation proved cell intrinsic, imposing an antiviral state and making cells refractory to divergent families of RNA viruses. Epistatic analysis revealed that ISG activation could not be overcome by deletion of canonical RNA sensors. However, DDX6 deficiency was suppressed by disrupting LSM1, a core component of mRNA degradation machinery, suggesting that dysregulation of RNA processing underlies ISG activation in the DDX6 mutant. DDX6 is distinct among DExD/H helicases that regulate the antiviral response in its singular ability to negatively regulate immunity.
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Affiliation(s)
- Jennifer H Lumb
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Qin Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Lauren M Popov
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Siyuan Ding
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA; Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Palo Alto Veterans Institute of Research, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Marie T Keith
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Bryan D Merrill
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Harry B Greenberg
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA; Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Palo Alto Veterans Institute of Research, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA.
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187
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Tso CH, Lu MW. Transcriptome profiling analysis of grouper during nervous necrosis virus persistent infection. FISH & SHELLFISH IMMUNOLOGY 2018; 76:224-232. [PMID: 29510256 DOI: 10.1016/j.fsi.2018.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/28/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
Nervous necrosis virus (NNV) infection has been considered a serious disease in farmed grouper. Particularly, the persistent infection model conducts the grouper into a carrier state that continues to spread the virus through spawning. This particular model makes disease control more difficult in the aquaculture industry. In the present study, we used RNA-Seq, a high-throughput method based on next-generation sequencing, to profile the expression of genes during the period of NNV persistent infection. We evaluated the transcriptomic changes in the brain tissue of grouper. The inactivated-NNV vaccine was used as a comparison group. Based on the differentially expressed genes, highly immune cell active signaling and surface receptor expression were triggered during persistent infection. The interferon-induced response was also highly expressed in the infected brain tissue. However, critical negative regulatory factors of T-cells, such as PD-L1 and LAG3, were up-regulated. The present transcriptome study revealed a comprehensive view of the state of NNV persistent infection and provided insights into the state of impaired NNV clearance in the grouper.
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Affiliation(s)
- Chun-Hsi Tso
- Department of Aquaculture, National Taiwan Ocean University, Taiwan
| | - Ming-Wei Lu
- Department of Aquaculture, National Taiwan Ocean University, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Taiwan.
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188
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Abstract
PURPOSE OF REVIEW To review recent scientific advances and therapeutic approaches in the expanding field of type I interferonopathies. Type I interferonopathies represent a genetically and phenotypically heterogenous group of disorders of the innate immune system caused by constitutive activation of antiviral type I interferon (IFN). Clinically, type I interferonopathies are characterized by autoinflammation and varying degrees of autoimmunity or immunodeficiency. The elucidation of the underlying genetic causes has revealed novel cell-intrinsic mechanisms that protect the organism against inappropriate immune recognition of self nucleic acids by cytosolic nucleic acid sensors. The type I IFN system is subject to a tight and complex regulation. Disturbances of its checks and balances can spark an unwanted immune response causing uncontrolled type I IFN signaling. Novel mechanistic insight into pathways that control the type I IFN system is providing opportunities for targeted therapeutic approaches by repurposing drugs such as Janus kinase inhibitors or reverse transcriptase inhibitors.
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189
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SAMHD1 acts at stalled replication forks to prevent interferon induction. Nature 2018; 557:57-61. [PMID: 29670289 DOI: 10.1038/s41586-018-0050-1] [Citation(s) in RCA: 282] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 03/07/2018] [Indexed: 01/20/2023]
Abstract
SAMHD1 was previously characterized as a dNTPase that protects cells from viral infections. Mutations in SAMHD1 are implicated in cancer development and in a severe congenital inflammatory disease known as Aicardi-Goutières syndrome. The mechanism by which SAMHD1 protects against cancer and chronic inflammation is unknown. Here we show that SAMHD1 promotes degradation of nascent DNA at stalled replication forks in human cell lines by stimulating the exonuclease activity of MRE11. This function activates the ATR-CHK1 checkpoint and allows the forks to restart replication. In SAMHD1-depleted cells, single-stranded DNA fragments are released from stalled forks and accumulate in the cytosol, where they activate the cGAS-STING pathway to induce expression of pro-inflammatory type I interferons. SAMHD1 is thus an important player in the replication stress response, which prevents chronic inflammation by limiting the release of single-stranded DNA from stalled replication forks.
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190
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Li T, Chen ZJ. The cGAS-cGAMP-STING pathway connects DNA damage to inflammation, senescence, and cancer. J Exp Med 2018; 215:1287-1299. [PMID: 29622565 PMCID: PMC5940270 DOI: 10.1084/jem.20180139] [Citation(s) in RCA: 723] [Impact Index Per Article: 120.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/13/2018] [Accepted: 03/16/2018] [Indexed: 12/13/2022] Open
Abstract
The cGAS–cGAMP–STING pathway mediates immune and inflammatory responses to cytosolic DNA. This review summarizes recent findings on how genomic instability leads to cGAS activation and how this pathway critically connects DNA damage to autoinflammatory diseases, cellular senescence, and cancer. Detection of microbial DNA is an evolutionarily conserved mechanism that alerts the host immune system to mount a defense response to microbial infections. However, this detection mechanism also poses a challenge to the host as to how to distinguish foreign DNA from abundant self-DNA. Cyclic guanosine monophosphate (GMP)–adenosine monophosphate (AMP) synthase (cGAS) is a DNA sensor that triggers innate immune responses through production of the second messenger cyclic GMP-AMP (cGAMP), which binds and activates the adaptor protein STING. However, cGAS can be activated by double-stranded DNA irrespective of the sequence, including self-DNA. Although how cGAS is normally kept inactive in cells is still not well understood, recent research has provided strong evidence that genomic DNA damage leads to cGAS activation to stimulate inflammatory responses. This review summarizes recent findings on how genomic instability and DNA damage trigger cGAS activation and how cGAS serves as a link from DNA damage to inflammation, cellular senescence, and cancer.
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Affiliation(s)
- Tuo Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX .,Center for Inflammation Research, University of Texas Southwestern Medical Center, Dallas, TX
| | - Zhijian J Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX .,Center for Inflammation Research, University of Texas Southwestern Medical Center, Dallas, TX.,Howard Hughes Medical Institute, Chevy Chase, MD
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191
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Barbieri D, Elvira-Matelot E, Pelinski Y, Genève L, de Laval B, Yogarajah G, Pecquet C, Constantinescu SN, Porteu F. Thrombopoietin protects hematopoietic stem cells from retrotransposon-mediated damage by promoting an antiviral response. J Exp Med 2018; 215:1463-1480. [PMID: 29615469 PMCID: PMC5940259 DOI: 10.1084/jem.20170997] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 12/28/2017] [Accepted: 03/02/2018] [Indexed: 12/13/2022] Open
Abstract
Propagation of retrotransposons induces genomic instability. Their roles in HSCs remain poorly studied. Barbieri et al. show that retrotransposon expression and mobilization are involved in long-lasting HSC impairment upon irradiation. These effects are counteracted by the self-renewal cytokine THPO through induction of interferon-like response. Maintenance of genomic integrity is crucial for the preservation of hematopoietic stem cell (HSC) potential. Retrotransposons, spreading in the genome through an RNA intermediate, have been associated with loss of self-renewal, aging, and DNA damage. However, their role in HSCs has not been addressed. Here, we show that mouse HSCs express various retroelements (REs), including long interspersed element-1 (L1) recent family members that further increase upon irradiation. Using mice expressing an engineered human L1 retrotransposition reporter cassette and reverse transcription inhibitors, we demonstrate that L1 retransposition occurs in vivo and is involved in irradiation-induced persistent γH2AX foci and HSC loss of function. Thus, RE represents an important intrinsic HSC threat. Furthermore, we show that RE activity is restrained by thrombopoietin, a critical HSC maintenance factor, through its ability to promote a potent interferon-like, antiviral gene response in HSCs. This uncovers a novel mechanism allowing HSCs to minimize irradiation-induced injury and reinforces the links between DNA damage, REs, and antiviral immunity.
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Affiliation(s)
- Daniela Barbieri
- INSERM UMR1170, Villejuif, France.,Université Paris-Saclay, Paris, France.,Gustave Roussy Cancer Campus, Paris, France
| | - Emilie Elvira-Matelot
- INSERM UMR1170, Villejuif, France.,Université Paris-Saclay, Paris, France.,Gustave Roussy Cancer Campus, Paris, France
| | - Yanis Pelinski
- INSERM UMR1170, Villejuif, France.,Université Paris-Saclay, Paris, France.,Gustave Roussy Cancer Campus, Paris, France
| | - Laetitia Genève
- INSERM UMR1170, Villejuif, France.,Université Paris-Saclay, Paris, France.,Gustave Roussy Cancer Campus, Paris, France
| | - Bérengère de Laval
- Centre d'Immunologie Marseille-Luminy, Université Aix-Marseille, Institut National de la Santé et de la Recherche Médicale, U1104, Centre National de la Recherche Scientifique, UMR 7280
| | - Gayathri Yogarajah
- INSERM UMR1170, Villejuif, France.,Université Paris-Saclay, Paris, France.,Gustave Roussy Cancer Campus, Paris, France
| | - Christian Pecquet
- Ludwig Institute for Cancer Research, Brussels, Belgium.,SIGN Pole, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Stefan N Constantinescu
- Ludwig Institute for Cancer Research, Brussels, Belgium.,SIGN Pole, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Françoise Porteu
- INSERM UMR1170, Villejuif, France .,Université Paris-Saclay, Paris, France.,Gustave Roussy Cancer Campus, Paris, France
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192
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Abstract
HIV-1 sensors and their signaling features have been an ongoing topic of intense research over the last decade, as these mechanisms fail to establish protective immunity against HIV-1. Here, we discuss how HIV-1 infects dendritic cells (DCs) and which sensors play a role in recognizing viral DNA and RNA in these specialized immune cells. We will elaborate on the RNA helicase DDX3, which is crucial in translation initiation of HIV-1 mRNA, but also fulfills an important role as RNA sensor and inducer of antiviral immunity in DCs. As DDX3 is indispensable for HIV-1 replication, the virus cannot escape sensing by DDX3, which is an important aspect of its function. Last but not least, we will discuss how HIV-1 suppresses DDX3 sensing and how this impacts the viral load in HIV-1-infected individuals.
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Affiliation(s)
- Melissa Stunnenberg
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Teunis B H Geijtenbeek
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Sonja I Gringhuis
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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193
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Xia P, Wang S, Ye B, Du Y, Li C, Xiong Z, Qu Y, Fan Z. A Circular RNA Protects Dormant Hematopoietic Stem Cells from DNA Sensor cGAS-Mediated Exhaustion. Immunity 2018; 48:688-701.e7. [DOI: 10.1016/j.immuni.2018.03.016] [Citation(s) in RCA: 157] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/31/2017] [Accepted: 03/08/2018] [Indexed: 01/29/2023]
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194
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Louis C, Burns C, Wicks I. TANK-Binding Kinase 1-Dependent Responses in Health and Autoimmunity. Front Immunol 2018; 9:434. [PMID: 29559975 PMCID: PMC5845716 DOI: 10.3389/fimmu.2018.00434] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 02/19/2018] [Indexed: 01/05/2023] Open
Abstract
The pathogenesis of autoimmune diseases, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) is driven by genetic predisposition and environmental triggers that lead to dysregulated immune responses. These include the generation of pathogenic autoantibodies and aberrant production of inflammatory cytokines. Current therapies for RA and other autoimmune diseases reduce inflammation by targeting inflammatory mediators, most of which are innate response cytokines, resulting in generalized immunosuppression. Overall, this strategy has been very successful, but not all patients respond, responses can diminish over time and numerous side effects can occur. Therapies that target the germinal center (GC) reaction and/or antibody-secreting plasma cells (PC) potentially provide a novel approach. TANK-binding kinase 1 (TBK1) is an IKK-related serine/threonine kinase best characterized for its involvement in innate antiviral responses through the induction of type I interferons. TBK1 is also gaining attention for its roles in humoral immune responses. In this review, we discuss the role of TBK1 in immunological pathways involved in the development and maintenance of antibody responses, with particular emphasis on its potential relevance in the pathogenesis of humoral autoimmunity. First, we review the role of TBK1 in the induction of type I IFNs. Second, we highlight how TBK1 mediates inducible T cell co-stimulator signaling to the GC T follicular B helper population. Third, we discuss emerging evidence on the contribution of TBK1 to autophagic pathways and the potential implications for immune cell function. Finally, we discuss the therapeutic potential of TBK1 inhibition in autoimmunity.
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Affiliation(s)
- Cynthia Louis
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Chris Burns
- Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Ian Wicks
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Rheumatology Unit, Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia
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195
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Bartsch K, Knittler K, Borowski C, Rudnik S, Damme M, Aden K, Spehlmann ME, Frey N, Saftig P, Chalaris A, Rabe B. Absence of RNase H2 triggers generation of immunogenic micronuclei removed by autophagy. Hum Mol Genet 2018; 26:3960-3972. [PMID: 29016854 DOI: 10.1093/hmg/ddx283] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 07/13/2017] [Indexed: 12/16/2022] Open
Abstract
Hypomorphic mutations in the DNA repair enzyme RNase H2 cause the neuroinflammatory autoimmune disorder Aicardi-Goutières syndrome (AGS). Endogenous nucleic acids are believed to accumulate in patient cells and instigate pathogenic type I interferon expression. However, the underlying nucleic acid species amassing in the absence of RNase H2 has not been established yet. Here, we report that murine RNase H2 knockout cells accumulated cytosolic DNA aggregates virtually indistinguishable from micronuclei. RNase H2-dependent micronuclei were surrounded by nuclear lamina and most of them contained damaged DNA. Importantly, they induced expression of interferon-stimulated genes (ISGs) and co-localized with the nucleic acid sensor cGAS. Moreover, micronuclei associated with RNase H2 deficiency were cleared by autophagy. Consequently, induction of autophagy by pharmacological mTOR inhibition resulted in a significant reduction of cytosolic DNA and the accompanied interferon signature. Autophagy induction might therefore represent a viable therapeutic option for RNase H2-dependent disease. Endogenous retroelements have previously been proposed as a source of self-nucleic acids triggering inappropriate activation of the immune system in AGS. We used human RNase H2-knockout cells generated by CRISPR/Cas9 to investigate the impact of RNase H2 on retroelement propagation. Surprisingly, replication of LINE-1 and Alu elements was blunted in cells lacking RNase H2, establishing RNase H2 as essential host factor for the mobilisation of endogenous retrotransposons.
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Affiliation(s)
- Kareen Bartsch
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Katharina Knittler
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Christopher Borowski
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Sönke Rudnik
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Markus Damme
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Konrad Aden
- Institute of Clinical Molecular Biology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Martina E Spehlmann
- Clinic for Internal Medicine III, Cardiology and Angiology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Norbert Frey
- Clinic for Internal Medicine III, Cardiology and Angiology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Paul Saftig
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Athena Chalaris
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Björn Rabe
- Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
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196
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Hedrich CM, Smith EMD, Beresford MW. Juvenile-onset systemic lupus erythematosus (jSLE) - Pathophysiological concepts and treatment options. Best Pract Res Clin Rheumatol 2018; 31:488-504. [PMID: 29773269 DOI: 10.1016/j.berh.2018.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The systemic autoimmune/inflammatory condition systemic lupus erythematosus (SLE) manifests before the age of 16 years in 10-20% of all cases. Clinical courses are more severe, and organ complications are more common in patients with juvenile SLE. Varying gender distribution in different age groups and increasing severity with younger age and the presence of monogenic disease in early childhood indicate distinct differences in the pathophysiology of juvenile versus adult-onset SLE. Regardless of these differences, classification criteria and treatment options are identical. In this article, we discuss age-specific pathomechanisms of juvenile-onset SLE, which are currently available and as future treatment options, and propose reclassification of different forms of SLE along the inflammatory spectrum from autoinflammation to autoimmunity.
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Affiliation(s)
- Christian M Hedrich
- Department of Women's & Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK; Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, UK.
| | - Eve M D Smith
- Department of Women's & Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK; Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, UK
| | - Michael W Beresford
- Department of Women's & Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK; Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, UK
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197
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Abstract
The innate immune system is the first line of defense against invading pathogens. One important feature of innate immune recognition is self versus nonself discrimination. The selectivity for microbial ligands is achieved through substrate motif specificity, spatial compartmentalization, and functions of negative regulators. Loss-of-function mutations in negative regulators or gain-of-function mutations in drivers of innate immune signaling have been associated with autoimmune diseases such as lupus, rheumatoid arthritis, inflammatory vasculopathy, and a variety of interferonopathies. This review will focus on TREX1 and STING, which are opposing regulators of the cytosolic DNA-sensing pathway. Tremendous effort over the past decade among academic and clinical research groups has elucidated molecular mechanisms underlying immune diseases associated with TREX1 and STING dysfunction. We have also witnessed rapid therapeutic translation of the molecular findings. Several targeted treatment options or druggable candidates are now available for these once incurable diseases. With great enthusiasm from both academia and industry partners, we look forward to seeing the remaining scientific questions answered and, more importantly, the affected patients benefited from these discoveries.
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Affiliation(s)
- Nan Yan
- Department of Immunology, Department of Microbiology, University of Texas Southwestern Medical Center , Dallas, Texas
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198
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Suarez NA, Macia A, Muotri AR. LINE-1 retrotransposons in healthy and diseased human brain. Dev Neurobiol 2017; 78:434-455. [PMID: 29239145 DOI: 10.1002/dneu.22567] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 12/12/2022]
Abstract
Long interspersed element-1 (LINE-1 or L1) is a transposable element with the ability to self-mobilize throughout the human genome. The L1 elements found in the human brain is hypothesized to date back 56 million years ago and has survived evolution, currently accounting for 17% of the human genome. L1 retrotransposition has been theorized to contribute to somatic mosaicism. This review focuses on the presence of L1 in the healthy and diseased human brain, such as in autism spectrum disorders. Throughout this exploration, we will discuss the impact L1 has on neurological disorders that can occur throughout the human lifetime. With this, we hope to better understand the complex role of L1 in the human brain development and its implications to human cognition. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 434-455, 2018.
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Affiliation(s)
- Nicole A Suarez
- Department of Pediatrics/Rady Children's Hospital San Diego, University of California San Diego, La Jolla, California, 92093
| | - Angela Macia
- Department of Pediatrics/Rady Children's Hospital San Diego, University of California San Diego, La Jolla, California, 92093
| | - Alysson R Muotri
- Department of Pediatrics/Rady Children's Hospital San Diego, University of California San Diego, La Jolla, California, 92093
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199
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TREX1 is a checkpoint for innate immune sensing of DNA damage that fosters cancer immune resistance. Emerg Top Life Sci 2017; 1:509-515. [DOI: 10.1042/etls20170063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 12/19/2022]
Abstract
Genomic instability is a hallmark of neoplastic transformation that leads to the accumulation of mutations, and generates a state of replicative stress in neoplastic cells associated with dysregulated DNA damage repair (DDR) responses. The importance of increasing mutations in driving cancer progression is well established, whereas relatively little attention has been devoted to the DNA displaced to the cytosol of cancer cells, a byproduct of genomic instability and of the ensuing DDR response. The presence of DNA in the cytosol promotes the activation of viral defense pathways in all cells, leading to activation of innate and adaptive immune responses. In fact, the improper accumulation of cytosolic DNA in normal cells is known to drive severe autoimmune pathology. Thus, cancer cells must evade cytoplasmic DNA detection pathways to avoid immune-mediated destruction. The main sensor for cytoplasmic DNA is the cyclic GMP–AMP synthase, cGAS. Upon activation by cytosolic DNA, cGAS catalyzes the formation of the second messenger cGAMP, which activates STING (stimulator of IFN genes), leading to the production of type I interferon (IFN-I). IFN-I is a critical effector of cell-mediated antiviral and antitumor immunity, and its production by cancer cells can be subverted by several mechanisms. However, the key upstream regulator of cytosolic DNA-mediated immune stimulation is the DNA exonuclease 3′-repair exonuclease 1 (TREX1). Here, we will discuss evidence in support of a role of TREX1 as an immune checkpoint that, when up-regulated, hinders the development of antitumor immune responses.
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200
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Sidorova J. A game of substrates: replication fork remodeling and its roles in genome stability and chemo-resistance. Cell Stress 2017; 1:115-133. [PMID: 29355244 PMCID: PMC5771654 DOI: 10.15698/cst2017.12.114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
During the hours that human cells spend in the DNA synthesis (S) phase of the cell cycle, they may encounter adversities such as DNA damage or shortage of nucleotides. Under these stresses, replication forks in DNA may experience slowing, stalling, and breakage. Fork remodeling mechanisms, which stabilize slow or stalled replication forks and ensure their ability to continue or resume replication, protect cells from genomic instability and carcinogenesis. Fork remodeling includes DNA strand exchanges that result in annealing of newly synthesized strands (fork reversal), controlled DNA resection, and cleavage of DNA strands. Defects in major tumor suppressor genes BRCA1 and BRCA2, and a subset of the Fanconi Anemia genes have been shown to result in deregulation in fork remodeling, and most prominently, loss of kilobases of nascent DNA from stalled replication forks. This phenomenon has recently gained spotlight as a potential marker and mediator of chemo-sensitivity in cancer cells and, conversely, its suppression - as a hallmark of acquired chemo-resistance. Moreover, nascent strand degradation at forks is now known to also trigger innate immune response to self-DNA. An increasingly sophisticated molecular description of these events now points at a combination of unbalanced fork reversal and end-resection as a root cause, yet also reveals the multi-layered complexity and heterogeneity of the underlying processes in normal and cancer cells.
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Affiliation(s)
- Julia Sidorova
- Department of Pathology, University of Washington, Seattle, Washington, USA
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