1
|
Ferdoush J, Abdul Kadir R, Simay Kaplanoglu S, Osborn M. SARS-CoV-2 and UPS with potentials for therapeutic interventions. Gene 2024; 912:148377. [PMID: 38490508 DOI: 10.1016/j.gene.2024.148377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/09/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Abstract
The Ubiquitin proteasome system (UPS), an essential eukaryotic/host/cellular post-translational modification (PTM), plays a critical role in the regulation of diverse cellular functions including regulation of protein stability, immune signaling, antiviral activity, as well as virus replication. Although UPS regulation of viral proteins may be utilized by the host as a defense mechanism to invade viruses, viruses may have adapted to take advantage of the host UPS. This system can be manipulated by viruses such as the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) to stimulate various steps of the viral replication cycle and facilitate pathogenesis, thereby causing the respiratory disease COVID-19. Many SARS-CoV-2 encoded proteins including open reading frame 3a (ORF3a), ORF6, ORF7a, ORF9b, and ORF10 interact with the host's UPS machinery, influencing host immune signaling and apoptosis. Moreover, SARS-CoV-2 encoded papain-like protease (PLpro) interferes with the host UPS to facilitate viral replication and to evade the host's immune system. These alterations in SARS-CoV-2 infected cells have been revealed by various proteomic studies, suggesting potential targets for clinical treatment. To provide insight into the underlying causes of COVID-19 and suggest possible directions for therapeutic interventions, this paper reviews the intricate relationship between SARS-CoV-2 and UPS. Promising treatment strategies are also investigated in this paper including targeting PLpro with zinc-ejector drugs, as well as targeting viral non-structural protein (nsp12) via heat treatment associated ubiquitin-mediated proteasomal degradation to reduce viral pathogenesis.
Collapse
Affiliation(s)
- Jannatul Ferdoush
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga 615 McCallie Ave, Chattanooga, TN 37403, USA.
| | - Rizwaan Abdul Kadir
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga 615 McCallie Ave, Chattanooga, TN 37403, USA
| | - Selin Simay Kaplanoglu
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga 615 McCallie Ave, Chattanooga, TN 37403, USA
| | - Morgan Osborn
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga 615 McCallie Ave, Chattanooga, TN 37403, USA
| |
Collapse
|
2
|
Ramini D, Giuliani A, Kwiatkowska KM, Guescini M, Storci G, Mensà E, Recchioni R, Xumerle L, Zago E, Sabbatinelli J, Santi S, Garagnani P, Bonafè M, Olivieri F. Replicative senescence and high glucose induce the accrual of self-derived cytosolic nucleic acids in human endothelial cells. Cell Death Discov 2024; 10:184. [PMID: 38643201 PMCID: PMC11032409 DOI: 10.1038/s41420-024-01954-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/22/2024] Open
Abstract
Recent literature shows that loss of replicative ability and acquisition of a proinflammatory secretory phenotype in senescent cells is coupled with the build-in of nucleic acids in the cytoplasm. Its implication in human age-related diseases is under scrutiny. In human endothelial cells (ECs), we assessed the accumulation of intracellular nucleic acids during in vitro replicative senescence and after exposure to high glucose concentrations, which mimic an in vivo condition of hyperglycemia. We showed that exposure to high glucose induces senescent-like features in ECs, including telomere shortening and proinflammatory cytokine release, coupled with the accrual in the cytoplasm of telomeres, double-stranded DNA and RNA (dsDNA, dsRNA), as well as RNA:DNA hybrid molecules. Senescent ECs showed an activation of the dsRNA sensors RIG-I and MDA5 and of the DNA sensor TLR9, which was not paralleled by the involvement of the canonical (cGAS) and non-canonical (IFI16) activation of the STING pathway. Under high glucose conditions, only a sustained activation of TLR9 was observed. Notably, senescent cells exhibit increased proinflammatory cytokine (IL-1β, IL-6, IL-8) production without a detectable secretion of type I interferon (IFN), a phenomenon that can be explained, at least in part, by the accumulation of methyl-adenosine containing RNAs. At variance, exposure to exogenous nucleic acids enhances both IL-6 and IFN-β1 expression in senescent cells. This study highlights the accrual of cytoplasmic nucleic acids as a marker of senescence-related endothelial dysfunction, that may play a role in dysmetabolic age-related diseases.
Collapse
Affiliation(s)
- Deborah Ramini
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy
| | - Angelica Giuliani
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | | | - Michele Guescini
- Department of Biomolecular Science, University of Urbino Carlo Bo, Urbino, Italy
| | - Gianluca Storci
- IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy
| | - Emanuela Mensà
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | - Rina Recchioni
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy
| | | | | | - Jacopo Sabbatinelli
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy.
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy.
| | - Spartaco Santi
- CNR Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza" - Unit of Bologna, Bologna, Italy.
- IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Paolo Garagnani
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
- IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy
| | - Massimiliano Bonafè
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
- IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy
| | - Fabiola Olivieri
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| |
Collapse
|
3
|
Tomecki R, Drazkowska K, Kobylecki K, Tudek A. SKI complex: A multifaceted cytoplasmic RNA exosome cofactor in mRNA metabolism with links to disease, developmental processes, and antiviral responses. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1795. [PMID: 37384835 DOI: 10.1002/wrna.1795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 07/01/2023]
Abstract
RNA stability and quality control are integral parts of gene expression regulation. A key factor shaping eukaryotic transcriptomes, mainly via 3'-5' exoribonucleolytic trimming or degradation of diverse transcripts in nuclear and cytoplasmic compartments, is the RNA exosome. Precise exosome targeting to various RNA molecules requires strict collaboration with specialized auxiliary factors, which facilitate interactions with its substrates. The predominant class of cytoplasmic RNA targeted by the exosome are protein-coding transcripts, which are carefully scrutinized for errors during translation. Normal, functional mRNAs are turned over following protein synthesis by the exosome or by Xrn1 5'-3'-exonuclease, acting in concert with Dcp1/2 decapping complex. In turn, aberrant transcripts are eliminated by dedicated surveillance pathways, triggered whenever ribosome translocation is impaired. Cytoplasmic 3'-5' mRNA decay and surveillance are dependent on the tight cooperation between the exosome and its evolutionary conserved co-factor-the SKI (superkiller) complex (SKIc). Here, we summarize recent findings from structural, biochemical, and functional studies of SKIc roles in controlling cytoplasmic RNA metabolism, including links to various cellular processes. Mechanism of SKIc action is illuminated by presentation of its spatial structure and details of its interactions with exosome and ribosome. Furthermore, contribution of SKIc and exosome to various mRNA decay pathways, usually converging on recycling of ribosomal subunits, is delineated. A crucial physiological role of SKIc is emphasized by describing association between its dysfunction and devastating human disease-a trichohepatoenteric syndrome (THES). Eventually, we discuss SKIc functions in the regulation of antiviral defense systems, cell signaling and developmental transitions, emerging from interdisciplinary investigations. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Turnover and Surveillance > Regulation of RNA Stability RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
Collapse
Affiliation(s)
- Rafal Tomecki
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Karolina Drazkowska
- Laboratory of Epitranscriptomics, Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Kamil Kobylecki
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Tudek
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
4
|
Sikorska J, Hou Y, Chiurazzi P, Siu T, Baltus GA, Sheth P, McLaren D, Truong Q, Parish C, Wyss D. Characterization of RNA driven structural changes in full length RIG-I leading to its agonism or antagonism. Nucleic Acids Res 2023; 51:9356-9368. [PMID: 37486777 PMCID: PMC10516622 DOI: 10.1093/nar/gkad606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 06/30/2023] [Accepted: 07/20/2023] [Indexed: 07/26/2023] Open
Abstract
RIG-I (retinoic acid inducible gene-I) can sense subtle differences between endogenous and viral RNA in the cytoplasm, triggering an anti-viral immune response through induction of type I interferons (IFN) and other inflammatory mediators. Multiple crystal and cryo-EM structures of RIG-I suggested a mechanism in which the C-terminal domain (CTD) is responsible for the recognition of viral RNA with a 5'-triphoshate modification, while the CARD domains serve as a trigger for downstream signaling, leading to the induction of type I IFN. However, to date contradicting conclusions have been reached around the role of ATP in the mechanism of the CARD domains ejection from RIG-I's autoinhibited state. Here we present an application of NMR spectroscopy to investigate changes induced by the binding of 5'-triphosphate and 5'-OH dsRNA, both in the presence and absence of nucleotides, to full length RIG-I with all its methionine residues selectively labeled (Met-[ϵ-13CH3]). With this approach we were able to identify residues on the CTD, helicase domain, and CARDs that served as probes to sense RNA-induced conformational changes in those respective regions. Our results were analyzed in the context of either agonistic or antagonistic RNAs, by and large supporting a mechanism proposed by the Pyle Lab in which CARD release is primarily dependent on the RNA binding event.
Collapse
Affiliation(s)
| | - Yan Hou
- Merck & Co., Inc., Rahway, NJ, USA
| | | | - Tony Siu
- Merck & Co., Inc., Rahway, NJ, USA
| | | | | | | | | | | | | |
Collapse
|
5
|
Yuan J, Xu L, Bao HJ, Wang JL, Zhao Y, Chen S. Biological roles of A-to-I editing: implications in innate immunity, cell death, and cancer immunotherapy. J Exp Clin Cancer Res 2023; 42:149. [PMID: 37328893 DOI: 10.1186/s13046-023-02727-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/02/2023] [Indexed: 06/18/2023] Open
Abstract
Adenosine-to-inosine (A-to-I) editing, a key RNA modification widely found in eukaryotes, is catalyzed by adenosine deaminases acting on RNA (ADARs). Such RNA editing destabilizes endogenous dsRNAs, which are subsequently recognized by the sensors of innate immune and other proteins as autologous dsRNAs. This prevents the activation of innate immunity and type I interferon-mediated responses, thereby reducing the downstream cell death induced by the activation of the innate immune sensing system. ADARs-mediated editing can also occur in mRNAs and non-coding RNAs (ncRNAs) in different species. In mRNAs, A-to-I editing may lead to missense mutations and the selective splicing of coding regions. Meanwhile, in ncRNAs, A-to-I editing may affect targeting and disrupt ncRNAs maturation, leading to anomalous cell proliferation, invasion, and responses to immunotherapy. This review highlights the biological functions of A-to-I editing, its role in regulating innate immunity and cell death, and its potential molecular significance in tumorigenesis and cancer targeted therapy and immunotherapy.
Collapse
Affiliation(s)
- Jing Yuan
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangzhou City, Guangdong Province, 510150, P. R. China
| | - Li Xu
- Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, 110001, China
| | - Hai-Juan Bao
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangzhou City, Guangdong Province, 510150, P. R. China
| | - Jie-Lin Wang
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangzhou City, Guangdong Province, 510150, P. R. China
| | - Yang Zhao
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangzhou City, Guangdong Province, 510150, P. R. China.
| | - Shuo Chen
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangzhou City, Guangdong Province, 510150, P. R. China.
| |
Collapse
|
6
|
Wu L, Zhou L, An J, Shao X, Zhang H, Wang C, Zhao G, Chen S, Cui X, Zhang X, Yang F, Li X, Zhang X. Comprehensive profiling of extracellular vesicles in uveitis and scleritis enables biomarker discovery and mechanism exploration. J Transl Med 2023; 21:388. [PMID: 37322475 PMCID: PMC10273650 DOI: 10.1186/s12967-023-04228-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/25/2023] [Indexed: 06/17/2023] Open
Abstract
BACKGROUND Uveitis and posterior scleritis are sight-threatening diseases with undefined pathogenesis and accurate diagnosis remains challenging. METHODS Two plasma-derived extracellular vesicle (EV) subpopulations, small and large EVs, obtained from patients with ankylosing spondylitis-related uveitis, Behcet's disease uveitis, Vogt-Koyanagi-Harada syndrome, and posterior scleritis were subjected to proteomics analysis alongside plasma using SWATH-MS. A comprehensive bioinformatics analysis was performed on the proteomic profiles of sEVs, lEVs, and plasma. Candidate biomarkers were validated in a new cohort using ELISA. Pearson correlation analysis was performed to analyze the relationship between clinical parameters and proteomic data. Connectivity map database was used to predict therapeutic agents. RESULTS In total, 3,668 proteins were identified and over 3000 proteins were quantified from 278 samples. When comparing diseased group to healthy control, the proteomic profiles of the two EV subgroups were more correlated with disease than plasma. Comprehensive bioinformatics analysis highlighted potential pathogenic mechanisms for these diseases. Potential biomarker panels for four diseases were identified and validated. We found a negative correlation between plasma endothelin-converting enzyme 1 level and mean retinal thickness. Potential therapeutic drugs were proposed, and their targets were identified. CONCLUSIONS This study provides a proteomic landscape of plasma and EVs involved in ankylosing spondylitis-related uveitis, Behcet's disease uveitis, Vogt-Koyanagi-Harada syndrome, and posterior scleritis, offers insights into disease pathogenesis, identifies valuable biomarker candidates, and proposes promising therapeutic agents.
Collapse
Affiliation(s)
- Lingzi Wu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Lei Zhou
- Department of Applied Biology and Chemical Technology, School of Optometry, Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China
| | - Jinying An
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Xianfeng Shao
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Hui Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Chunxi Wang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | | | - Shuang Chen
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Xuexue Cui
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Xinyi Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Fuhua Yang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Xiaomin Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China.
| |
Collapse
|
7
|
Zheng J, Shi W, Yang Z, Chen J, Qi A, Yang Y, Deng Y, Yang D, Song N, Song B, Luo D. RIG-I-like receptors: Molecular mechanism of activation and signaling. Adv Immunol 2023; 158:1-74. [PMID: 37453753 DOI: 10.1016/bs.ai.2023.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
During RNA viral infection, RIG-I-like receptors (RLRs) recognize the intracellular pathogenic RNA species derived from viral replication and activate antiviral innate immune response by stimulating type 1 interferon expression. Three RLR members, namely, RIG-I, MDA5, and LGP2 are homologous and belong to a subgroup of superfamily 2 Helicase/ATPase that is preferably activated by double-stranded RNA. RLRs are significantly different in gene architecture, RNA ligand preference, activation, and molecular functions. As switchable macromolecular sensors, RLRs' activities are tightly regulated by RNA ligands, ATP, posttranslational modifications, and cellular cofactors. We provide a comprehensive review of the structure and function of the RLRs and summarize the molecular understanding of sensing and signaling events during the RLR activation process. The key roles RLR signaling play in both anti-infection and immune disease conditions highlight the therapeutic potential in targeting this important molecular pathway.
Collapse
Affiliation(s)
- Jie Zheng
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China; Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
| | - Wenjia Shi
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ziqun Yang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jin Chen
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ao Qi
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China; Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yulin Yang
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China; Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ying Deng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Dongyuan Yang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ning Song
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Bin Song
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
| |
Collapse
|
8
|
Nakahama T, Kawahara Y. The RNA-editing enzyme ADAR1: a regulatory hub that tunes multiple dsRNA-sensing pathways. Int Immunol 2023; 35:123-133. [PMID: 36469491 DOI: 10.1093/intimm/dxac056] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that catalyzes adenosine-to-inosine conversions in double-stranded RNAs (dsRNAs). In mammals, ADAR1 is composed of two isoforms: a nuclear short p110 isoform and a cytoplasmic long p150 isoform. Whereas both isoforms contain right-handed dsRNA-binding and deaminase domains, ADAR1 p150 harbors a Zα domain that binds to left-handed dsRNAs, termed Z-RNAs. Myeloma differentiation-associated gene 5 (MDA5) sensing of endogenous dsRNAs as non-self leads to the induction of type I interferon (IFN)-stimulated genes, but recent studies revealed that ADAR1 p150-mediated RNA editing, but not ADAR1 p110, prevents this MDA5-mediated sensing. ADAR1 p150-specific RNA-editing sites are present and at least a Zα domain-Z-RNA interaction is required for this specificity. Mutations in the ADAR1 gene cause Aicardi-Goutières syndrome (AGS), an infant encephalopathy with type I IFN overproduction. Insertion of a point mutation in the Zα domain of the Adar1 gene induces AGS-like encephalopathy in mice, which is rescued by concurrent deletion of MDA5. This finding indicates that impaired ADAR1 p150-mediated RNA-editing is a mechanism underlying AGS caused by an ADAR1 mutation. ADAR1 p150 also prevents ZBP1 sensing of endogenous Z-RNA, which leads to programmed cell death, via the Zα domain and its RNA-editing activity. Furthermore, ADAR1 prevents protein kinase R (PKR) sensing of endogenous right-handed dsRNAs, which leads to translational shutdown and growth arrest. Thus, ADAR1 acts as a regulatory hub that blocks sensing of endogenous dsRNAs as non-self by multiple sensor proteins, both in RNA editing-dependent and -independent manners, and is a potential therapeutic target for diseases, especially cancer.
Collapse
Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Integrated Frontier Research for Medical Science Division and RNA Frontier Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Integrated Frontier Research for Medical Science Division and RNA Frontier Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
| |
Collapse
|
9
|
Gillich N, Zhang Z, Binder M, Urban S, Bartenschlager R. Effect of variants in LGP2 on MDA5-mediated activation of interferon response and suppression of hepatitis D virus replication. J Hepatol 2023; 78:78-89. [PMID: 36152765 DOI: 10.1016/j.jhep.2022.08.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/11/2022] [Accepted: 08/30/2022] [Indexed: 02/01/2023]
Abstract
BACKGROUND & AIMS Retinoic acid inducible gene I (RIG-I)-like receptors (RLRs), including RIG-I, melanoma differentiation-associated protein 5 (MDA5), and laboratory of genetics and physiology 2 (LGP2), sense viral RNA to induce the antiviral interferon (IFN) response. LGP2, unable to activate the IFN response itself, modulates RIG-I and MDA5 signalling. HDV, a small RNA virus causing the most severe form of viral hepatitis, is sensed by MDA5. The mechanism underlying IFN induction and its effect on HDV replication is unclear. Here, we aimed to unveil the role of LGP2 and clinically relevant variants thereof in these processes. METHODS RLRs were depleted in HDV susceptible HepaRGNTCP cells and primary human hepatocytes. Cells were reconstituted to express different LGP2 versions. HDV and IFN markers were quantified in a time-resolved manner. Interaction studies among LGP2, MDA5, and RNA were performed by pull-down assays. RESULTS LGP2 is essential for the MDA5-mediated IFN response induced upon HDV infection. This induction requires both RNA binding and ATPase activities of LGP2. The IFN response only moderately reduced HDV replication in resting cells but profoundly suppressed cell division-mediated HDV spread. An LGP2 variant (Q425R), predominating in Africans who develop less severe chronic hepatitis D, mediated detectably higher basal and faster HDV-induced IFN response as well as stronger HDV suppression. Mechanistically, LGP2 RNA binding was a prerequisite for the formation of stable MDA5-RNA complexes. MDA5 binding to RNA was enhanced by the Q425R LGP2 variant. CONCLUSIONS LGP2 is essential to mount an antiviral IFN response induced by HDV and stabilises MDA5-RNA interaction required for downstream signalling. The natural Q425R LGP2 is a gain-of-function variant and might contribute to an attenuated course of hepatitis D. IMPACT AND IMPLICATIONS HDV is the causative pathogen of chronic hepatitis D, a severe form of viral hepatitis that can lead to cirrhosis and hepatocellular carcinoma. Upon infection, the human immune system senses HDV and mounts an antiviral interferon (IFN) response. Here, we demonstrate that the immune sensor LGP2 cooperates with MDA5 to mount an IFN response that represses HDV replication. We mapped LGP2 determinants required for IFN system activation and characterised several natural genetic variants of LGP2. One of them reported to predominate in sub-Saharan Africans can accelerate HDV-induced IFN responses, arguing that genetic determinants, possibly including LGP2, might contribute to slower disease progression in this population. Our results will hopefully prompt further studies on genetic variations in LGP2 and other components of the innate immune sensing system, including assessments of their possible impact on the course of viral infection.
Collapse
Affiliation(s)
- Nadine Gillich
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Division of Virus-Associated Carcinogenesis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Zhenfeng Zhang
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Marco Binder
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response," Division Virus-Associated Carcinogenesis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; German Center for Infection Research (DZIF) - Heidelberg Partner Site, Heidelberg, Germany.
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany; Division of Virus-Associated Carcinogenesis, German Cancer Research Center (DKFZ), Heidelberg, Germany; German Center for Infection Research (DZIF) - Heidelberg Partner Site, Heidelberg, Germany.
| |
Collapse
|
10
|
Farooq M, Khan AW, Ahmad B, Kim MS, Choi S. Therapeutic Targeting of Innate Immune Receptors Against SARS-CoV-2 Infection. Front Pharmacol 2022; 13:915565. [PMID: 35847031 PMCID: PMC9280161 DOI: 10.3389/fphar.2022.915565] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
The innate immune system is the first line of host's defense against invading pathogens. Multiple cellular sensors that detect viral components can induce innate antiviral immune responses. As a result, interferons and pro-inflammatory cytokines are produced which help in the elimination of invading viruses. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) belongs to Coronaviridae family, and has a single-stranded, positive-sense RNA genome. It can infect multiple hosts; in humans, it is responsible for the novel coronavirus disease 2019 (COVID-19). Successful, timely, and appropriate detection of SARS-CoV-2 can be very important for the early generation of the immune response. Several drugs that target the innate immune receptors as well as other signaling molecules generated during the innate immune response are currently being investigated in clinical trials. In this review, we summarized the current knowledge of the mechanisms underlying host sensing and innate immune responses against SARS-CoV-2 infection, as well as the role of innate immune receptors in terms of their therapeutic potential against SARS-CoV-2. Moreover, we discussed the drugs undergoing clinical trials and the FDA approved drugs against SARS-CoV-2. This review will help in understanding the interactions between SARS-CoV-2 and innate immune receptors and thus will point towards new dimensions for the development of new therapeutics, which can be beneficial in the current pandemic.
Collapse
Affiliation(s)
- Mariya Farooq
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
- S&K Therapeutics, Ajou University, Suwon, South Korea
| | - Abdul Waheed Khan
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Bilal Ahmad
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
- S&K Therapeutics, Ajou University, Suwon, South Korea
| | - Moon Suk Kim
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Sangdun Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
- S&K Therapeutics, Ajou University, Suwon, South Korea
| |
Collapse
|
11
|
Kano N, Ong GH, Ori D, Kawai T. Pathophysiological Role of Nucleic Acid-Sensing Pattern Recognition Receptors in Inflammatory Diseases. Front Cell Infect Microbiol 2022; 12:910654. [PMID: 35734577 PMCID: PMC9207338 DOI: 10.3389/fcimb.2022.910654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Pattern recognition receptors (PRRs) play critical roles in recognizing pathogen-derived nucleic acids and inducing innate immune responses, such as inflammation and type I interferon production. PRRs that recognize nucleic acids include members of endosomal Toll-like receptors, cytosolic retinoic acid inducible gene I-like receptors, cyclic GMP–AMP synthase, absent in melanoma 2-like receptors, and nucleotide binding oligomerization domain-like receptors. Aberrant recognition of self-derived nucleic acids by these PRRs or unexpected activation of downstream signaling pathways results in the constitutive production of type I interferons and inflammatory cytokines, which lead to the development of autoimmune or autoinflammatory diseases. In this review, we focus on the nucleic acid-sensing machinery and its pathophysiological roles in various inflammatory diseases.
Collapse
|
12
|
Breuer J, Barth P, Noe Y, Shalamova L, Goesmann A, Weber F, Rossbach O. What goes around comes around: Artificial circular RNAs bypass cellular antiviral responses. MOLECULAR THERAPY - NUCLEIC ACIDS 2022; 28:623-635. [PMID: 35497503 PMCID: PMC9042720 DOI: 10.1016/j.omtn.2022.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 04/21/2022] [Indexed: 12/14/2022]
Abstract
Natural circular RNAs have been found to sequester microRNAs and suppress their function. We have used this principle as a molecular tool and produced artificial circular RNA sponges in a cell-free system by in vitro transcription and ligation. Formerly, we were able to inhibit hepatitis C virus propagation by applying a circular RNA decoy strategy against microRNA-122, which is essential for the viral life cycle. In another proof-of-principle study, we used circular RNAs to sequester microRNA-21, an oncogenic and pro-proliferative microRNA. This strategy slowed tumor growth in a 3D cell culture model system, as well as in xenograft mice upon systemic delivery. In the wake of the global use of an in vitro transcribed RNA in coronavirus disease 2019 (COVID-19) vaccines, the question arose whether therapeutic circular RNAs trigger cellular antiviral defense mechanisms when delivered systemically. In this study, we present data on the cellular innate immune response as a consequence of liposome-based transfection of the circular RNA sponges we previously used to inhibit microRNA function. We find that circular RNAs produced by the presented methodology do not trigger the antiviral response and do not activate innate immune-signaling pathways.
Collapse
|
13
|
Abstract
In the past 20 years, the mRNA vaccine technology has evolved from the first proof of concept to the first licensed vaccine against emerging pandemics such as SARS-CoV-2. Two mRNA vaccines targeting SARS-CoV-2 have received emergency use authorization by US FDA, conditional marketing authorization by EMA, as well as multiple additional national regulatory authorities. The simple composition of an mRNA encoding the antigen formulated in a lipid nanoparticle enables a fast adaptation to new emerging pathogens. This can speed up vaccine development in pandemics from antigen and sequence selection to clinical trial to only a few months. mRNA vaccines are well tolerated and efficacious in animal models for multiple pathogens and will further contribute to the development of vaccines for other unaddressed diseases. Here, we give an overview of the mRNA vaccine design and factors for further optimization of this new promising technology and discuss current knowledge on the mode of action of mRNA vaccines interacting with the innate and adaptive immune system.
Collapse
|
14
|
Chang AY, Zhou YJ, Iyengar S, Pobiarzyn PW, Tishchenko P, Shah KM, Wheeler H, Wang YM, Loria PM, Loganzo F, Woo SR. Modulation of SF3B1 in the pre-mRNA spliceosome induces a RIG-I-dependent type I IFN response. J Biol Chem 2021; 297:101277. [PMID: 34619148 PMCID: PMC8559577 DOI: 10.1016/j.jbc.2021.101277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 09/22/2021] [Accepted: 09/30/2021] [Indexed: 12/14/2022] Open
Abstract
Nucleic acid-sensing pathways play critical roles in innate immune activation through the production of type I interferon (IFN-I) and proinflammatory cytokines. These factors are required for effective antitumor immune responses. Pharmacological modulators of the pre-mRNA spliceosome splicing factor 3b subunit 1 (SF3B1) are under clinical investigation as cancer cytotoxic agents. However, potential roles of these agents in aberrant RNA generation and subsequent RNA-sensing pathway activation have not been studied. In this study, we observed that SF3B1 pharmacological modulation using pladienolide B (Plad B) induces production of aberrant RNA species and robust IFN-I responses via engagement of the dsRNA sensor retinoic acid-inducible gene I (RIG-I) and downstream interferon regulatory factor 3. We found that Plad B synergized with canonical RIG-I agonism to induce the IFN-I response. In addition, Plad B induced NF-κB responses and secretion of proinflammatory cytokines and chemokines. Finally, we showed that cancer cells bearing the hotspot SF3B1K700E mutation, which leads to global aberrant splicing, had enhanced IFN-I response to canonical RIG-I agonism. Together, these results demonstrate that pharmacological modulation of SF3B1 in cancer cells can induce an enhanced IFN-I response dependent on RIG-I expression. The study suggests that spliceosome modulation may not only induce direct cancer cell cytotoxicity but also initiate an innate immune response via activation of RNA-sensing pathways.
Collapse
Affiliation(s)
- Aaron Y Chang
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA
| | - Yu Jerry Zhou
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA
| | - Sharanya Iyengar
- Emerging Science & Innovation, Pfizer Inc, Pearl River, New York, USA
| | - Piotr W Pobiarzyn
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA
| | - Pavel Tishchenko
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA
| | - Kesha M Shah
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA
| | - Heather Wheeler
- Medicine Design, Worldwide Research & Development, Pfizer Inc, Groton, Connecticut, USA
| | - Yue-Ming Wang
- Medicine Design, Worldwide Research & Development, Pfizer Inc, Groton, Connecticut, USA
| | - Paula M Loria
- Medicine Design, Worldwide Research & Development, Pfizer Inc, Groton, Connecticut, USA
| | - Frank Loganzo
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA
| | - Seng-Ryong Woo
- Oncology Research & Development, Pfizer Inc, Pearl River, New York, USA.
| |
Collapse
|
15
|
Nakahama T, Kawahara Y. Deciphering the Biological Significance of ADAR1-Z-RNA Interactions. Int J Mol Sci 2021; 22:ijms222111435. [PMID: 34768866 PMCID: PMC8584189 DOI: 10.3390/ijms222111435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 12/24/2022] Open
Abstract
Adenosine deaminase acting on RNA 1 (ADAR1) is an enzyme responsible for double-stranded RNA (dsRNA)-specific adenosine-to-inosine RNA editing, which is estimated to occur at over 100 million sites in humans. ADAR1 is composed of two isoforms transcribed from different promoters: p150 and N-terminal truncated p110. Deletion of ADAR1 p150 in mice activates melanoma differentiation-associated protein 5 (MDA5)-sensing pathway, which recognizes endogenous unedited RNA as non-self. In contrast, we have recently demonstrated that ADAR1 p110-mediated RNA editing does not contribute to this function, implying that a unique Z-DNA/RNA-binding domain α (Zα) in the N terminus of ADAR1 p150 provides specific RNA editing, which is critical for preventing MDA5 activation. In addition, a mutation in the Zα domain is identified in patients with Aicardi–Goutières syndrome (AGS), an inherited encephalopathy characterized by overproduction of type I interferon. Accordingly, we and other groups have recently demonstrated that Adar1 Zα-mutated mice show MDA5-dependent type I interferon responses. Furthermore, one such mutant mouse carrying a W197A point mutation in the Zα domain, which inhibits Z-RNA binding, manifests AGS-like encephalopathy. These findings collectively suggest that Z-RNA binding by ADAR1 p150 is essential for proper RNA editing at certain sites, preventing aberrant MDA5 activation.
Collapse
Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan;
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan;
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka 565-0871, Japan
- Correspondence: ; Tel.: +81-6-6879-3827
| |
Collapse
|
16
|
Li D, Wu M. Pattern recognition receptors in health and diseases. Signal Transduct Target Ther 2021; 6:291. [PMID: 34344870 PMCID: PMC8333067 DOI: 10.1038/s41392-021-00687-0] [Citation(s) in RCA: 580] [Impact Index Per Article: 193.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 05/23/2021] [Accepted: 06/22/2021] [Indexed: 02/07/2023] Open
Abstract
Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens, apoptotic host cells, and damaged senescent cells. PRRs bridge nonspecific immunity and specific immunity. Through the recognition and binding of ligands, PRRs can produce nonspecific anti-infection, antitumor, and other immunoprotective effects. Most PRRs in the innate immune system of vertebrates can be classified into the following five types based on protein domain homology: Toll-like receptors (TLRs), nucleotide oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), C-type lectin receptors (CLRs), and absent in melanoma-2 (AIM2)-like receptors (ALRs). PRRs are basically composed of ligand recognition domains, intermediate domains, and effector domains. PRRs recognize and bind their respective ligands and recruit adaptor molecules with the same structure through their effector domains, initiating downstream signaling pathways to exert effects. In recent years, the increased researches on the recognition and binding of PRRs and their ligands have greatly promoted the understanding of different PRRs signaling pathways and provided ideas for the treatment of immune-related diseases and even tumors. This review describes in detail the history, the structural characteristics, ligand recognition mechanism, the signaling pathway, the related disease, new drugs in clinical trials and clinical therapy of different types of PRRs, and discusses the significance of the research on pattern recognition mechanism for the treatment of PRR-related diseases.
Collapse
Affiliation(s)
- Danyang Li
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Minghua Wu
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, Hunan, China.
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China.
| |
Collapse
|
17
|
Abstract
Double-stranded RNA (dsRNA) is produced both by virus and host. Its recognition by the melanoma differentiation-associated gene 5 (MDA5) initiates type I interferon responses. How can a host distinguish self-transcripts from nonself to ensure that responses are targeted correctly? Here, I discuss a role for MDA5 helicase in inducing Z-RNA formation by Alu inverted repeat (AIR) elements. These retroelements have highly conserved sequences that favor Z-formation, creating a site for the dsRNA-specific deaminase enzyme ADAR1 to dock. The subsequent editing destabilizes the dsRNA, ending further interaction with MDA5 and terminating innate immune responses directed against self. By enabling self-recognition, Alu retrotransposons, once invaders, now are genetic elements that keep immune responses in check. I also discuss the possible but less characterized roles of the other helicases in modulating innate immune responses, focusing on DExH-box helicase 9 (DHX9) and Mov10 RISC complex RNA helicase (MOV10). DHX9 and MOV10 function differently from MDA5, but still use nucleic acid structure, rather than nucleotide sequence, to define self. Those genetic elements encoding the alternative conformations involved, referred to as flipons, enable helicases to dynamically shape a cell's repertoire of responses. In the case of MDA5, Alu flipons switch off the dsRNA-dependent responses against self. I suggest a number of genetic systems in which to study interactions between flipons and helicases further.
Collapse
Affiliation(s)
- Alan Herbert
- Discovery, InsideOutBio, Charlestown, Massachusetts, United States of America
| |
Collapse
|
18
|
Crooke PS, Tossberg JT, Porter KP, Aune TM. Reduced A-to-I editing of endogenous Alu RNAs in lung after SARS-CoV-2 infection. CURRENT RESEARCH IN IMMUNOLOGY 2021; 2:52-59. [PMID: 33969287 PMCID: PMC8084883 DOI: 10.1016/j.crimmu.2021.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 12/16/2022] Open
Abstract
Due to potential severity of disease caused by SARS-CoV-2 infection, it is critical to understand both mechanisms of viral pathogenesis as well as diversity of host responses to infection. Reduced A-to-I editing of endogenous double-stranded RNAs (dsRNAs), as a result of inactivating mutations in ADAR, produces one form of Aicardi-Goutières Syndrome, with an immune response similar to an anti-viral response. By analyzing whole genome RNA sequencing data, we find reduced levels of A-to-I editing of endogenous Alu RNAs in normal human lung cells after infection by SARS-CoV-2 as well as in lung biopsies from patients with SARS-CoV-2 infections. Unedited Alu RNAs, as seen after infection, induce IRF and NF-kB transcriptional responses and downstream target genes, while edited Alu RNAs as seen in the absence of infection, fail to activate these transcriptional responses. Thus, decreased A-to-I editing may represent an important host response to SARS-CoV-2 infection.
Collapse
Affiliation(s)
- Philip S Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN, 37212, USA
| | - John T Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37212, USA
| | - Krislyn P Porter
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37212, USA
| | - Thomas M Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37212, USA.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37212, USA
| |
Collapse
|
19
|
Crooke PS, Tossberg JT, Porter KP, Aune TM. Cutting Edge: Reduced Adenosine-to-Inosine Editing of Endogenous Alu RNAs in Severe COVID-19 Disease. THE JOURNAL OF IMMUNOLOGY 2021; 206:1691-1696. [PMID: 33782089 DOI: 10.4049/jimmunol.2001428] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/16/2021] [Indexed: 01/10/2023]
Abstract
Severe COVID-19 disease is associated with elevated inflammatory responses. One form of Aicardi-Goutières syndrome caused by inactivating mutations in ADAR results in reduced adenosine-to-inosine (A-to-I) editing of endogenous dsRNAs, induction of IFNs, IFN-stimulated genes, other inflammatory mediators, morbidity, and mortality. Alu elements, ∼10% of the human genome, are the most common A-to-I-editing sites. Using leukocyte whole-genome RNA-sequencing data, we found reduced A-to-I editing of Alu dsRNAs in patients with severe COVID-19 disease. Dendritic cells infected with COVID-19 also exhibit reduced A-to-I editing of Alu dsRNAs. Unedited Alu dsRNAs, but not edited Alu dsRNAs, are potent inducers of IRF and NF-κB transcriptional responses, IL6, IL8, and IFN-stimulated genes. Thus, decreased A-to-I editing that may lead to accumulation of unedited Alu dsRNAs and increased inflammatory responses is associated with severe COVID-19 disease.
Collapse
Affiliation(s)
- Philip S Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN 37212
| | - John T Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212; and
| | - Krislyn P Porter
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212; and
| | - Thomas M Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212; and .,Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN 37212
| |
Collapse
|
20
|
Khan MI, Nur SM, Adhami V, Mukhtar H. Epigenetic regulation of RNA sensors: Sentinels of immune response. Semin Cancer Biol 2021; 83:413-421. [PMID: 33484869 DOI: 10.1016/j.semcancer.2020.12.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/11/2022]
Abstract
Living host system possess mechanisms like innate immune system to combat against inflammation, stress singling, and cancer. These mechanisms are initiated by PAMP and DAMP mediated recognition by PRR. PRR is consist of variety of nucleic acid sensors like-RNA sensors. They play crucial role in identifying exogenous and endogenous RNA molecules, which subsequently mediate pro/inflammatory cytokine, IFN and ISGs response in traumatized or tumorigenic conditions. The sensors can sensitize wide range of nucleic acid particle in term of size and structure, while each category sensors belongs subclasses with differentially expressed in cell and distinguished functioning mechanisms. They are also able to make comparison between self and non-self-nucleic acid molecules through specific mechanisms. Besides exhibiting anti-inflammatory and anti-tumorigenic responses, RNA sensors cover the broad spectrum of response mechanisms. Transcriptionally RNA sensors undergo with tight epigenetic regulations. In this review study, we will be going to discuss about the details of RNA sensors, their functional mechanisms and epi-transactional regulations.
Collapse
Affiliation(s)
- Mohammad Imran Khan
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Suza Mohammad Nur
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Vaqar Adhami
- Department of Dermatology, School of Medicine and Public Health, University of Wisconsin, Madison, USA
| | - Hasan Mukhtar
- Department of Dermatology, School of Medicine and Public Health, University of Wisconsin, Madison, USA.
| |
Collapse
|
21
|
Abstract
The mRNA epitranscriptome imparts diversity to gene expression by installing chemical modifications. Advances in detection methods have identified chemical modifications in eukaryotic, bacterial, and viral messenger RNAs (mRNAs). The biological functions of modifications in mRNAs still remain to be understood. Chemical modifications are introduced in synthetic mRNAs meant for therapeutic applications to maximize expression from the synthetic mRNAs and to evade the host immune response. This overview provides a background of chemical modifications found in mRNAs, with an emphasis on pseudouridine and its known effects on the mRNA life cycle, its potential applications in synthetic mRNA, and the methods used to assess its effects on mRNA translation.
Collapse
Affiliation(s)
- Bijoyita Roy
- RNA and Genome Editing, New England Biolabs Inc, Ipswich, MA, USA.
| |
Collapse
|
22
|
Mao K, Breen P, Ruvkun G. Mitochondrial dysfunction induces RNA interference in C. elegans through a pathway homologous to the mammalian RIG-I antiviral response. PLoS Biol 2020; 18:e3000996. [PMID: 33264285 PMCID: PMC7735679 DOI: 10.1371/journal.pbio.3000996] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 12/14/2020] [Accepted: 11/09/2020] [Indexed: 12/27/2022] Open
Abstract
RNA interference (RNAi) is an antiviral pathway common to many eukaryotes that detects and cleaves foreign nucleic acids. In mammals, mitochondrially localized proteins such as mitochondrial antiviral signaling (MAVS), retinoic acid-inducible gene I (RIG-I), and melanoma differentiation-associated protein 5 (MDA5) mediate antiviral responses. Here, we report that mitochondrial dysfunction in Caenorhabditis elegans activates RNAi-directed silencing via induction of a pathway homologous to the mammalian RIG-I helicase viral response pathway. The induction of RNAi also requires the conserved RNA decapping enzyme EOL-1/DXO. The transcriptional induction of eol-1 requires DRH-1 as well as the mitochondrial unfolded protein response (UPRmt). Upon mitochondrial dysfunction, EOL-1 is concentrated into foci that depend on the transcription of mitochondrial RNAs that may form double-stranded RNA (dsRNA), as has been observed in mammalian antiviral responses. Enhanced RNAi triggered by mitochondrial dysfunction is necessary for the increase in longevity that is induced by mitochondrial dysfunction. Surveillance of mitochondrial dysfunction in the nematode Caenorhabditis elegans triggers the activation of an RNA interference pathway to mediate antiviral defense, in a manner homologous to the mammalian RIG-I helicase viral response pathway.
Collapse
Affiliation(s)
- Kai Mao
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Peter Breen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
23
|
Zhang Z, Urban S. Interplay between Hepatitis D Virus and the Interferon Response. Viruses 2020; 12:v12111334. [PMID: 33233762 PMCID: PMC7699955 DOI: 10.3390/v12111334] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/18/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis D (CHD) is the most severe form of viral hepatitis, with rapid progression of liver-related diseases and high rates of development of hepatocellular carcinoma. The causative agent, hepatitis D virus (HDV), contains a small (approximately 1.7 kb) highly self-pairing single-strand circular RNA genome that assembles with the HDV antigen to form a ribonucleoprotein (RNP) complex. HDV depends on hepatitis B virus (HBV) envelope proteins for envelopment and de novo hepatocyte entry; however, its intracellular RNA replication is autonomous. In addition, HDV can amplify HBV independently through cell division. Cellular innate immune responses, mainly interferon (IFN) response, are crucial for controlling invading viruses, while viruses counteract these responses to favor their propagation. In contrast to HBV, HDV activates profound IFN response through the melanoma differentiation antigen 5 (MDA5) pathway. This cellular response efficiently suppresses cell-division-mediated HDV spread and, to some extent, early stages of HDV de novo infection, but only marginally impairs RNA replication in resting hepatocytes. In this review, we summarize the current knowledge on HDV structure, replication, and persistence and subsequently focus on the interplay between HDV and IFN response, including IFN activation, sensing, antiviral effects, and viral countermeasures. Finally, we discuss crosstalk with HBV.
Collapse
Affiliation(s)
- Zhenfeng Zhang
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany;
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany;
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany
- Correspondence: ; Tel.: +49-6221-564-902
| |
Collapse
|
24
|
Tossberg JT, Heinrich RM, Farley VM, Crooke PS, Aune TM. Adenosine-to-Inosine RNA Editing of Alu Double-Stranded (ds)RNAs Is Markedly Decreased in Multiple Sclerosis and Unedited Alu dsRNAs Are Potent Activators of Proinflammatory Transcriptional Responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 205:2606-2617. [PMID: 33046502 PMCID: PMC7872017 DOI: 10.4049/jimmunol.2000384] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/14/2020] [Indexed: 12/27/2022]
Abstract
Sensors that detect dsRNA stimulate IFN responses as a defense against viral infection. IFN responses are also well documented in a variety of human autoimmune diseases, including relapsing-remitting multiple sclerosis (MS), in which increased IFN responses result from increased levels of double-stranded endogenous Alu RNAs. Mechanisms underlying increases in double-stranded Alu RNAs in MS are obscure. We find widespread loss of adenosine-to-inosine editing of Alu RNAs in MS. Unedited Alu RNAs are potent activators of both IFN and NF-κB responses via the dsRNA sensors, RIG-I, and TLR3. Minor editing of highly active Alu elements abrogates the ability to activate both transcriptional responses. Thus, adenosine-to-inosine editing may also represent an important defense against autoimmune diseases such as MS.
Collapse
Affiliation(s)
- John T Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212
| | - Rachel M Heinrich
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212
| | - Virginia M Farley
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212
| | - Philip S Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN 37212; and
| | - Thomas M Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212;
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37212
| |
Collapse
|
25
|
Espinosa-Riquer ZP, Segura-Villalobos D, Ramírez-Moreno IG, Pérez Rodríguez MJ, Lamas M, Gonzalez-Espinosa C. Signal Transduction Pathways Activated by Innate Immunity in Mast Cells: Translating Sensing of Changes into Specific Responses. Cells 2020; 9:E2411. [PMID: 33158024 PMCID: PMC7693401 DOI: 10.3390/cells9112411] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 12/17/2022] Open
Abstract
Mast cells (MCs) constitute an essential cell lineage that participates in innate and adaptive immune responses and whose phenotype and function are influenced by tissue-specific conditions. Their mechanisms of activation in type I hypersensitivity reactions have been the subject of multiple studies, but the signaling pathways behind their activation by innate immunity stimuli are not so well described. Here, we review the recent evidence regarding the main molecular elements and signaling pathways connecting the innate immune receptors and hypoxic microenvironment to cytokine synthesis and the secretion of soluble or exosome-contained mediators in this cell type. When known, the positive and negative control mechanisms of those pathways are presented, together with their possible implications for the understanding of mast cell-driven chronic inflammation. Finally, we discuss the relevance of the knowledge about signaling in this cell type in the recognition of MCs as central elements on innate immunity, whose remarkable plasticity converts them in sensors of micro-environmental discontinuities and controllers of tissue homeostasis.
Collapse
Affiliation(s)
| | | | | | | | | | - Claudia Gonzalez-Espinosa
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav), Unidad Sede Sur. Calzada de los Tenorios No. 235, Col. Granjas Coapa, Mexico City 14330, Mexico; (Z.P.E.-R.); (D.S.-V.); (I.G.R.-M.); (M.J.P.R.); (M.L.)
| |
Collapse
|
26
|
The noncoding small RNA SsrA is released by Vibrio fischeri and modulates critical host responses. PLoS Biol 2020; 18:e3000934. [PMID: 33141816 PMCID: PMC7665748 DOI: 10.1371/journal.pbio.3000934] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 11/13/2020] [Accepted: 09/22/2020] [Indexed: 01/13/2023] Open
Abstract
The regulatory noncoding small RNAs (sRNAs) of bacteria are key elements influencing gene expression; however, there has been little evidence that beneficial bacteria use these molecules to communicate with their animal hosts. We report here that the bacterial sRNA SsrA plays an essential role in the light-organ symbiosis between Vibrio fischeri and the squid Euprymna scolopes. The symbionts load SsrA into outer membrane vesicles, which are transported specifically into the epithelial cells surrounding the symbiont population in the light organ. Although an SsrA-deletion mutant (ΔssrA) colonized the host to a normal level after 24 h, it produced only 2/10 the luminescence per bacterium, and its persistence began to decline by 48 h. The host's response to colonization by the ΔssrA strain was also abnormal: the epithelial cells underwent premature swelling, and host robustness was reduced. Most notably, when colonized by the ΔssrA strain, the light organ differentially up-regulated 10 genes, including several encoding heightened immune-function or antimicrobial activities. This study reveals the potential for a bacterial symbiont's sRNAs not only to control its own activities but also to trigger critical responses promoting homeostasis in its host. In the absence of this communication, there are dramatic fitness consequences for both partners.
Collapse
|
27
|
Lefkopoulos S, Polyzou A, Derecka M, Bergo V, Clapes T, Cauchy P, Jerez-Longres C, Onishi-Seebacher M, Yin N, Martagon-Calderón NA, Potts KS, Klaeylé L, Liu F, Bowman TV, Jenuwein T, Mione MC, Trompouki E. Repetitive Elements Trigger RIG-I-like Receptor Signaling that Regulates the Emergence of Hematopoietic Stem and Progenitor Cells. Immunity 2020; 53:934-951.e9. [DOI: 10.1016/j.immuni.2020.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 06/23/2020] [Accepted: 09/30/2020] [Indexed: 02/06/2023]
|
28
|
Ma R, Ortiz Serrano TP, Davis J, Prigge AD, Ridge KM. The cGAS-STING pathway: The role of self-DNA sensing in inflammatory lung disease. FASEB J 2020; 34:13156-13170. [PMID: 32860267 PMCID: PMC8121456 DOI: 10.1096/fj.202001607r] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
Abstract
The presence of DNA in the cytosol is usually a sign of microbial infections, which alerts the host innate immune system to mount a defense response. Cyclic GMP-AMP synthase (cGAS) is a critical cytosolic DNA sensor that elicits robust innate immune responses through the production of the second messenger, cyclic GMP-AMP (cGAMP), which binds and activates stimulator of interferon genes (STING). However, cGAS binds to DNA irrespective of DNA sequence, therefore, self-DNA leaked from the nucleus or mitochondria can also serve as a cGAS ligand to activate this pathway and trigger extensive inflammatory responses. Dysregulation of the cGAS-STING pathway is responsible for a broad array of inflammatory and autoimmune diseases. Recently, evidence has shown that self-DNA release and cGAS-STING pathway over-activation can drive lung disease, making this pathway a promising therapeutic target for inflammatory lung disease. Here, we review recent advances on the cGAS-STING pathway governing self-DNA sensing, highlighting its role in pulmonary disease.
Collapse
Affiliation(s)
- Ruihua Ma
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Tatiana P Ortiz Serrano
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jennifer Davis
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Andrew D Prigge
- Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Karen M Ridge
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| |
Collapse
|
29
|
Stok JE, Vega Quiroz ME, van der Veen AG. Self RNA Sensing by RIG-I–like Receptors in Viral Infection and Sterile Inflammation. THE JOURNAL OF IMMUNOLOGY 2020; 205:883-891. [DOI: 10.4049/jimmunol.2000488] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 05/28/2020] [Indexed: 12/18/2022]
|
30
|
Nakahama T, Kawahara Y. Adenosine-to-inosine RNA editing in the immune system: friend or foe? Cell Mol Life Sci 2020; 77:2931-2948. [PMID: 31996954 PMCID: PMC11104962 DOI: 10.1007/s00018-020-03466-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/27/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
Our body expresses sensors to detect pathogens through the recognition of expressed molecules, including nucleic acids, lipids, and proteins, while immune tolerance prevents an overreaction with self and the development of autoimmune disease. Adenosine (A)-to-inosine (I) RNA editing, catalyzed by adenosine deaminases acting on RNA (ADARs), is a post-transcriptional modification that can potentially occur at over 100 million sites in the human genome, mainly in Alu repetitive elements that preferentially form a double-stranded RNA (dsRNA) structure. A-to-I conversion within dsRNA, which may induce a structural change, is required to escape from the host immune system, given that endogenous dsRNAs transcribed from Alu repetitive elements are potentially recognized by melanoma differentiation-associated protein 5 (MDA5) as non-self. Of note, loss-of-function mutations in the ADAR1 gene cause Aicardi-Goutières syndrome, a congenital autoimmune disease characterized by encephalopathy and a type I interferon (IFN) signature. However, the loss of ADAR1 in cancer cells with an IFN signature induces lethality via the activation of protein kinase R in addition to MDA5. This makes cells more sensitive to immunotherapy, highlighting the opposing immune status of autoimmune diseases (overreaction) and cancer (tolerance). In this review, we provide an overview of insights into two opposing aspects of RNA editing that functions as a modulator of the immune system in autoimmune diseases and cancer.
Collapse
Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
31
|
Liwinski T, Zheng D, Elinav E. The microbiome and cytosolic innate immune receptors. Immunol Rev 2020; 297:207-224. [PMID: 32658330 DOI: 10.1111/imr.12901] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 02/06/2023]
Abstract
The discovery of innate immune sensors (pattern recognition receptors, PRRs) has profoundly transformed the notion of innate immunity, in providing a mechanistic basis for host immune interactions with a wealth of environmental signals, leading to a variety of immune-mediated outcomes including instruction and activation of the adaptive immune arm. As part of this growing understanding of host-environmental cross talk, an intimate connection has been unveiled between innate immune sensors and signals perceived from the commensal microbiota, which may be regarded as a hub integrating a variety of environmental cues. Among cytosolic PRRs impacting on host homeostasis by interacting with the commensal microbiota are nucleotide-binding domain, leucine-rich repeat-containing protein receptors (NLRs), together with a number of cytosolic DNA sensors and the family of absent in melanoma (AIM)-like receptors (ALRs). NLR sensors have been a particular focus of research, and some NLRs have emerged as key orchestrators of inflammatory responses and host homeostasis. Some NLRs achieve this through the formation of cytoplasmic multiprotein complexes termed inflammasomes. More recently discovered PRRs include retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), cyclic GMP-AMP synthase (cGAS), and STING. In the present review, they summarize recent advancements in knowledge on structure and function of cytosolic PRRs and their roles in host-microbiota cross talk and immune surveillance. In addition, we discuss their relevance for human health and disease and future therapeutic applications involving modulation of their activation and signaling.
Collapse
Affiliation(s)
- Timur Liwinski
- Immunology Department, Weizmann Institute of Science, Rehovot, Israel.,1st Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Danping Zheng
- Immunology Department, Weizmann Institute of Science, Rehovot, Israel.,Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Eran Elinav
- Immunology Department, Weizmann Institute of Science, Rehovot, Israel.,Cancer-Microbiome Division Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| |
Collapse
|
32
|
Blum SI, Tse HM. Innate Viral Sensor MDA5 and Coxsackievirus Interplay in Type 1 Diabetes Development. Microorganisms 2020; 8:microorganisms8070993. [PMID: 32635205 PMCID: PMC7409145 DOI: 10.3390/microorganisms8070993] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 12/12/2022] Open
Abstract
Type 1 diabetes (T1D) is a polygenic autoimmune disease characterized by immune-mediated destruction of insulin-producing β-cells. The concordance rate for T1D in monozygotic twins is ≈30-50%, indicating that environmental factors also play a role in T1D development. Previous studies have demonstrated that enterovirus infections such as coxsackievirus type B (CVB) are associated with triggering T1D. Prior to autoantibody development in T1D, viral RNA and antibodies against CVB can be detected within the blood, stool, and pancreata. An innate pathogen recognition receptor, melanoma differentiation-associated protein 5 (MDA5), which is encoded by the IFIH1 gene, has been associated with T1D onset. It is unclear how single nucleotide polymorphisms in IFIH1 alter the structure and function of MDA5 that may lead to exacerbated antiviral responses contributing to increased T1D-susceptibility. Binding of viral dsRNA via MDA5 induces synthesis of antiviral proteins such as interferon-alpha and -beta (IFN-α/β). Viral infection and subsequent IFN-α/β synthesis can lead to ER stress within insulin-producing β-cells causing neo-epitope generation, activation of β-cell-specific autoreactive T cells, and β-cell destruction. Therefore, an interplay between genetics, enteroviral infections, and antiviral responses may be critical for T1D development.
Collapse
|
33
|
Schweinoch D, Bachmann P, Clausznitzer D, Binder M, Kaderali L. Mechanistic modeling explains the dsRNA length-dependent activation of the RIG-I mediated immune response. J Theor Biol 2020; 500:110336. [PMID: 32446742 DOI: 10.1016/j.jtbi.2020.110336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 12/25/2022]
Abstract
In cell-intrinsic antiviral immunity, cytoplasmic receptors such as retinoic acid-inducible gene I (RIG-I) detect viral double-stranded RNA (dsRNA) and trigger a signaling cascade activating the interferon (IFN) system. This leads to the transcription of hundreds of interferon-stimulated genes (ISGs) with a wide range of antiviral effects. This recognition of dsRNA not only has to be very specific to discriminate foreign from self but also highly sensitive to detect even very low numbers of pathogenic dsRNA molecules. Previous work indicated an influence of the dsRNA length on the binding behavior of RIG-I and its potential to elicit antiviral signaling. However, the molecular mechanisms behind the binding process are still under debate. We compare two hypothesized RIG-I binding mechanisms by translating them into mathematical models and analyzing their potential to describe published experimental data. The models consider the length of the dsRNA as well as known RIG-I binding motifs and describe RIG-I pathway activation after stimulation with dsRNA. We show that internal RIG-I binding sites in addition to cooperative RIG-I oligomerization are essential to describe the experimentally observed RIG-I binding behavior and immune response activation for different dsRNA lengths and concentrations. The combination of RIG-I binding to internal sites on the dsRNA and cooperative oligomerization compensates for a lack of high-affinity binding motifs and triggers a strong antiviral response for long dsRNAs. Model analysis reveals dsRNA length-dependency as a potential mechanism to discriminate between different types of dsRNAs: It allows for sensitive detection of small numbers of long dsRNAs, a typical by-product of viral replication, while ensuring tolerance against non-harming small dsRNAs.
Collapse
Affiliation(s)
- Darius Schweinoch
- University Medicine Greifswald, Institute of Bioinformatics and Center for Functional Genomics of Microbes (C_FunGene), Felix-Hausdorff-Str. 8, 17475 Greifswald, Germany
| | - Pia Bachmann
- University Medicine Greifswald, Institute of Bioinformatics and Center for Functional Genomics of Microbes (C_FunGene), Felix-Hausdorff-Str. 8, 17475 Greifswald, Germany
| | - Diana Clausznitzer
- Technische Universität Dresden, Faculty of Medicine Carl-Gustav Carus, Institute for Medical Informatics and Biometry, Dresden, Germany
| | - Marco Binder
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response", Division Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lars Kaderali
- University Medicine Greifswald, Institute of Bioinformatics and Center for Functional Genomics of Microbes (C_FunGene), Felix-Hausdorff-Str. 8, 17475 Greifswald, Germany.
| |
Collapse
|
34
|
RNA Signaling in Pulmonary Arterial Hypertension-A Double-Stranded Sword. Int J Mol Sci 2020; 21:ijms21093124. [PMID: 32354189 PMCID: PMC7247700 DOI: 10.3390/ijms21093124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 12/17/2022] Open
Abstract
Recognition of and response to pathogens and tissue injury is driven by the innate immune system via activation of pattern recognition receptors. One of the many patterns recognized is RNA and, while several receptors bind RNA, Toll-like receptor 3 (TLR3) is well placed for initial recognition of RNA molecules due to its localization within the endosome. There is a growing body of work describing a role for TLR3 in maintenance of vascular homeostasis. For example, TLR3 deficiency has been shown to play repair and remodeling roles in the systemic vasculature and in lung parenchyma. A hallmark of pulmonary arterial hypertension (PAH) is pulmonary vascular remodeling, yet drivers and triggers of this remodeling remain incompletely understood. Based on its role in the systemic vasculature, our group discovered reduced endothelial TLR3 expression in PAH and revealed a protective role for a TLR3 agonist in rodent models of pulmonary hypertension. This review will provide an overview of RNA signaling in the vasculature and how it relates to PAH pathobiology, including whether targeting double-stranded RNA signaling is a potential treatment option for PAH.
Collapse
|
35
|
Bankers L, Miller C, Liu G, Thongkittidilok C, Morrison J, Poeschla EM. Development of IFN-Stimulated Gene Expression from Embryogenesis through Adulthood, with and without Constitutive MDA5 Pathway Activation. THE JOURNAL OF IMMUNOLOGY 2020; 204:2791-2807. [PMID: 32277054 DOI: 10.4049/jimmunol.1901421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/26/2020] [Indexed: 11/19/2022]
Abstract
Pathogen-associated molecular patterns (e.g., dsRNA) activate expression of IFN-stimulated genes (ISGs), which protect hosts from infection. Although transient ISG upregulation is essential for effective innate immunity, constitutive activation typically causes harmful autoimmunity in mice and humans, often including severe developmental abnormalities. We have shown that transgenic mice expressing a picornavirus RNA-dependent RNA polymerase (RdRP) outside the viral context (RdRP mice) exhibit constitutive, MDA5-dependent, and quantitatively dramatic upregulation of many ISGs, which confers broad viral infection resistance. Remarkably, RdRP mice never develop autoinflammation, interferonopathy, or other discernible abnormalities. In this study, we used RNA sequencing and other methods to analyze ISG expression across five time points from fetal development to adulthood in wild-type and RdRP mice. In RdRP mice, the proportion of upregulated ISGs increased during development, with the most dramatic induction occurring 2 wk postnatally. The amplified ISG profile is then maintained lifelong. Molecular pathways and biological functions associated with innate immune and IFN signaling are only activated postnatally, suggesting constrained fetal responsiveness to innate immune stimuli. Biological functions supporting replication of viruses are only inhibited postnatally. We further determined that the RdRP is expressed at low levels and that blocking Ifnar1 reverses the amplified ISG transcriptome in adults. In conclusion, the upregulated ISG profile of RdRP mice is mostly triggered early postnatally, is maintained through adulthood, and requires ongoing type I IFN signaling to maintain it. The model provides opportunities to study the systems biology of innate immunity and to determine how sustained ISG upregulation can be compatible with robust health.
Collapse
Affiliation(s)
- Laura Bankers
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado Denver School of Medicine, Aurora, CO 80045
| | - Caitlin Miller
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado Denver School of Medicine, Aurora, CO 80045
| | - Guoqi Liu
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado Denver School of Medicine, Aurora, CO 80045
| | - Chommanart Thongkittidilok
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado Denver School of Medicine, Aurora, CO 80045
| | - James Morrison
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado Denver School of Medicine, Aurora, CO 80045
| | - Eric M Poeschla
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado Denver School of Medicine, Aurora, CO 80045
| |
Collapse
|
36
|
Elongin C Contributes to RNA Polymerase II Degradation by the Interferon Antagonist NSs of La Crosse Orthobunyavirus. J Virol 2020; 94:JVI.02134-19. [PMID: 31941775 PMCID: PMC7081911 DOI: 10.1128/jvi.02134-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 12/21/2022] Open
Abstract
The mosquito-borne La Crosse virus (LACV; genus Orthobunyavirus, family Peribunyaviridae, order Bunyavirales) is prevalent in the United States and can cause severe childhood meningoencephalitis. Its main virulence factor, the nonstructural protein NSs, is a strong inhibitor of the antiviral type I interferon (IFN) system. NSs acts by imposing a global host mRNA synthesis shutoff, mediated by NSs-driven proteasomal degradation of the RPB1 subunit of RNA polymerase II. Here, we show that RPB1 degradation commences as early as 1 h postinfection, and identify the E3 ubiquitin ligase subunit Elongin C (and its binding partners Elongins A and B) as an NSs cofactor involved in RPB1 degradation and in suppression of global as well as IFN-related mRNA synthesis. Mosquito-borne La Crosse virus (LACV; genus Orthobunyavirus, family Peribunyaviridae, order Bunyavirales) causes up to 100 annual cases of severe meningoencephalitis in children and young adults in the United States. A major virulence factor of LACV is the nonstructural protein NSs, which inhibits host cell mRNA synthesis to prevent the induction of antiviral type I interferons (IFN-α/β). To achieve this host transcriptional shutoff, LACV NSs drives the proteasomal degradation of RPB1, the large subunit of mammalian RNA polymerase II. Here, we show that NSs acts in a surprisingly rapid manner, as RPB1 degradation was commencing already at 1 h postinfection. The RPB1 degradation was partially dependent on the cellular E3 ubiquitin ligase subunit Elongin C. Consequently, removal of Elongin C, but also of the subunits Elongin A or B by siRNA transfection partially rescued general RNAP II transcription and IFN-beta mRNA synthesis from the blockade by NSs. In line with these results, LACV NSs was found to trigger the redistribution of Elongin C out of nucleolar speckles, which, however, is an epiphenomenon rather than part of the NSs mechanism. Our study also shows that the molecular phenotype of LACV NSs is different from RNA polymerase II inhibitors like α-amanitin or Rift Valley fever virus NSs, indicating that LACV is unique in involving the Elongin complex to shut off host transcription and IFN response. IMPORTANCE The mosquito-borne La Crosse virus (LACV; genus Orthobunyavirus, family Peribunyaviridae, order Bunyavirales) is prevalent in the United States and can cause severe childhood meningoencephalitis. Its main virulence factor, the nonstructural protein NSs, is a strong inhibitor of the antiviral type I interferon (IFN) system. NSs acts by imposing a global host mRNA synthesis shutoff, mediated by NSs-driven proteasomal degradation of the RPB1 subunit of RNA polymerase II. Here, we show that RPB1 degradation commences as early as 1 h postinfection, and identify the E3 ubiquitin ligase subunit Elongin C (and its binding partners Elongins A and B) as an NSs cofactor involved in RPB1 degradation and in suppression of global as well as IFN-related mRNA synthesis.
Collapse
|
37
|
Jackson NAC, Kester KE, Casimiro D, Gurunathan S, DeRosa F. The promise of mRNA vaccines: a biotech and industrial perspective. NPJ Vaccines 2020; 5:11. [PMID: 32047656 PMCID: PMC7000814 DOI: 10.1038/s41541-020-0159-8] [Citation(s) in RCA: 263] [Impact Index Per Article: 65.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/20/2019] [Indexed: 12/16/2022] Open
Abstract
mRNA technologies have the potential to transform areas of medicine, including the prophylaxis of infectious diseases. The advantages for vaccines range from the acceleration of immunogen discovery to rapid response and multiple disease target manufacturing. A greater understanding of quality attributes that dictate translation efficiency, as well as a comprehensive appreciation of the importance of mRNA delivery, are influencing a new era of investment in development activities. The application of translational sciences and growing early-phase clinical experience continue to inform candidate vaccine selection. Here we review the state of the art for the prevention of infectious diseases by using mRNA and pertinent topics to the biotechnology and pharmaceutical industries.
Collapse
Affiliation(s)
- Nicholas A. C. Jackson
- Coalition for Epidemic Preparedness Innovations (CEPI), Gibbs building, 215 Euston Road, Bloomsbury, London, NW1 2BE UK
| | - Kent E. Kester
- Sanofi Pasteur, 1 Discovery Dr, Swiftwater, PA 18370 USA
| | | | | | - Frank DeRosa
- Translate Bio, 29 Hartwell Ave, Lexington, MA 02421 USA
| |
Collapse
|
38
|
Maelfait J, Liverpool L, Rehwinkel J. Nucleic Acid Sensors and Programmed Cell Death. J Mol Biol 2020; 432:552-568. [PMID: 31786265 PMCID: PMC7322524 DOI: 10.1016/j.jmb.2019.11.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/15/2019] [Accepted: 11/15/2019] [Indexed: 02/07/2023]
Abstract
Nucleic acids derived from microorganisms are powerful triggers for innate immune responses. Proteins called RNA and DNA sensors detect foreign nucleic acids and, in mammalian cells, include RIG-I, cGAS, and AIM2. On binding to nucleic acids, these proteins initiate signaling cascades that activate host defense responses. An important aspect of this defense program is the production of cytokines such as type I interferons and IL-1β. Studies conducted over recent years have revealed that nucleic acid sensors also activate programmed cell death pathways as an innate immune response to infection. Indeed, RNA and DNA sensors induce apoptosis, pyroptosis, and necroptosis. Cell death via these pathways prevents replication of pathogens by eliminating the infected cell and additionally contributes to the release of cytokines and inflammatory mediators. Interestingly, recent evidence suggests that programmed cell death triggered by nucleic acid sensors plays an important role in a number of noninfectious pathologies. In addition to nonself DNA and RNA from microorganisms, nucleic acid sensors also recognize endogenous nucleic acids, for example when cells are damaged by genotoxic agents and in certain autoinflammatory diseases. This review article summarizes current knowledge on the links between nucleic acid sensing and cell death and explores important open questions for future studies in this area.
Collapse
Affiliation(s)
- Jonathan Maelfait
- VIB Center for Inflammation Research, 9052 Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.
| | - Layal Liverpool
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK.
| |
Collapse
|
39
|
The Caenorhabditis elegans RIG-I Homolog DRH-1 Mediates the Intracellular Pathogen Response upon Viral Infection. J Virol 2020; 94:JVI.01173-19. [PMID: 31619561 DOI: 10.1128/jvi.01173-19] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 10/04/2019] [Indexed: 02/07/2023] Open
Abstract
Mammalian retinoic acid-inducible gene I (RIG-I)-like receptors detect viral double-stranded RNA (dsRNA) and 5'-triphosphorylated RNA to activate the transcription of interferon genes and promote antiviral defense. The Caenorhabditis elegans RIG-I-like receptor DRH-1 promotes defense through antiviral RNA interference (RNAi), but less is known about its role in regulating transcription. Here, we describe a role for DRH-1 in directing a transcriptional response in C. elegans called the intracellular pathogen response (IPR), which is associated with increased pathogen resistance. The IPR includes a set of genes induced by diverse stimuli, including intracellular infection and proteotoxic stress. Previous work suggested that the proteotoxic stress caused by intracellular infections might be the common trigger of the IPR, but here, we demonstrate that different stimuli act through distinct pathways. Specifically, we demonstrate that DRH-1/RIG-I is required for inducing the IPR in response to Orsay virus infection but not in response to other triggers like microsporidian infection or proteotoxic stress. Furthermore, DRH-1 appears to be acting independently of its known role in RNAi. Interestingly, expression of the replication-competent Orsay virus RNA1 segment alone is sufficient to induce most of the IPR genes in a manner dependent on RNA-dependent RNA polymerase activity and on DRH-1. Altogether, these results suggest that DRH-1 is a pattern recognition receptor that detects viral replication products to activate the IPR stress/immune program in C. elegans IMPORTANCE C. elegans lacks homologs of most mammalian pattern recognition receptors, and how nematodes detect pathogens is poorly understood. We show that the C. elegans RIG-I homolog DRH-1 mediates the induction of the intracellular pathogen response (IPR), a novel transcriptional defense program, in response to infection by the natural C. elegans viral pathogen Orsay virus. DRH-1 appears to act as a pattern recognition receptor to induce the IPR transcriptional defense program by sensing the products of viral RNA-dependent RNA polymerase activity. Interestingly, this signaling role of DRH-1 is separable from its previously known role in antiviral RNAi. In addition, we show that there are multiple host pathways for inducing the IPR, shedding light on the regulation of this novel transcriptional immune response.
Collapse
|
40
|
Ren X, Linehan MM, Iwasaki A, Pyle AM. RIG-I Recognition of RNA Targets: The Influence of Terminal Base Pair Sequence and Overhangs on Affinity and Signaling. Cell Rep 2019; 29:3807-3815.e3. [PMID: 31851914 DOI: 10.1016/j.celrep.2019.11.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/24/2019] [Accepted: 11/13/2019] [Indexed: 12/25/2022] Open
Abstract
Within the complex environment of the human cell, the RIG-I innate immune receptor must detect the presence of double-stranded viral RNA molecules and differentiate them from a diversity of host RNA molecules. In an ongoing effort to understand the molecular basis for RIG-I target specificity, here, we evaluate the ability of this sensor to respond to triphosphorylated, double-stranded RNA molecules that contain all possible terminal base pairs and common mismatches. In addition, we test the response to duplexes with various types of 5' and 3' overhangs. We conducted quantitative measurements of RNA ligand affinity, then tested RNA variants for their ability to stimulate the RIG-I-dependent interferon response in cells and in whole animals. The resulting data provide insights into the design of RNA therapeutics that prevent RIG-I activation, and they provide valuable insights into the mechanisms of evasion by deadly pathogens such as the Ebola and Marburg viruses.
Collapse
Affiliation(s)
- Xiaoming Ren
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Melissa M Linehan
- Department of Immunobiology, Yale University, New Haven, CT 06520, USA
| | - Akiko Iwasaki
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Immunobiology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Anna Marie Pyle
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA.
| |
Collapse
|
41
|
Nguyen TA, Bieging-Rolett KT, Putoczki TL, Wicks IP, Attardi LD, Pang KC. SIDT2 RNA Transporter Promotes Lung and Gastrointestinal Tumor Development. iScience 2019; 20:14-24. [PMID: 31546103 PMCID: PMC6817685 DOI: 10.1016/j.isci.2019.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/20/2019] [Accepted: 09/05/2019] [Indexed: 02/07/2023] Open
Abstract
RNautophagy is a newly described type of selective autophagy whereby cellular RNAs are transported into lysosomes for degradation. This process involves the transmembrane protein SIDT2, which transports double-stranded RNA (dsRNA) across the endolysosomal membrane. We previously demonstrated that SIDT2 is a transcriptional target of p53, but its role in tumorigenesis, if any, is unclear. Unexpectedly, we show here that Sidt2−/− mice with concurrent oncogenic KrasG12D activation develop significantly fewer tumors than littermate controls in a mouse model of lung adenocarcinoma. Consistent with this observation, loss of SIDT2 also leads to enhanced survival and delayed tumor development in an Apcmin/+ mouse model of intestinal cancer. Within the intestine, Apcmin/+;Sidt2−/− mice display accumulation of dsRNA in association with increased phosphorylation of eIF2α and JNK as well as elevated rates of apoptosis. Taken together, our data demonstrate a role for SIDT2, and by extension RNautophagy, in promoting tumor development. Loss of the SIDT2 double-stranded RNA (dsRNA) transporter leads to accumulation of dsRNA in tissues is associated with increased apoptosis reduces tumor burden in mouse models of lung adenocarcinoma and intestinal cancer
Collapse
Affiliation(s)
- Tan A Nguyen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Kathryn T Bieging-Rolett
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Tracy L Putoczki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Ian P Wicks
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Laura D Attardi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Ken C Pang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Murdoch Children's Research Institute, Parkville, VIC, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia; Department of Psychiatry, University of Melbourne, Parkville, VIC, Australia.
| |
Collapse
|
42
|
Valdés López JF, Velilla PA, Urcuqui-Inchima S. Chikungunya Virus and Zika Virus, Two Different Viruses Examined with a Common Aim: Role of Pattern Recognition Receptors on the Inflammatory Response. J Interferon Cytokine Res 2019; 39:507-521. [DOI: 10.1089/jir.2019.0058] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
| | - Paula Andrea Velilla
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Medellín, Colombia
| | - Silvio Urcuqui-Inchima
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Medellín, Colombia
| |
Collapse
|
43
|
Schmidt N, Domingues P, Golebiowski F, Patzina C, Tatham MH, Hay RT, Hale BG. An influenza virus-triggered SUMO switch orchestrates co-opted endogenous retroviruses to stimulate host antiviral immunity. Proc Natl Acad Sci U S A 2019; 116:17399-17408. [PMID: 31391303 PMCID: PMC6717285 DOI: 10.1073/pnas.1907031116] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Dynamic small ubiquitin-like modifier (SUMO) linkages to diverse cellular protein groups are critical to orchestrate resolution of stresses such as genome damage, hypoxia, or proteotoxicity. Defense against pathogen insult (often reliant upon host recognition of "non-self" nucleic acids) is also modulated by SUMO, but the underlying mechanisms are incompletely understood. Here, we used quantitative SILAC-based proteomics to survey pan-viral host SUMOylation responses, creating a resource of almost 600 common and unique SUMO remodeling events that are mounted during influenza A and B virus infections, as well as during viral innate immune stimulation. Subsequent mechanistic profiling focused on a common infection-induced loss of the SUMO-modified form of TRIM28/KAP1, a host transcriptional repressor. By integrating knockout and reconstitution models with system-wide transcriptomics, we provide evidence that influenza virus-triggered loss of SUMO-modified TRIM28 leads to derepression of endogenous retroviral (ERV) elements, unmasking this cellular source of "self" double-stranded (ds)RNA. Consequently, loss of SUMO-modified TRIM28 potentiates canonical cytosolic dsRNA-activated IFN-mediated defenses that rely on RIG-I, MAVS, TBK1, and JAK1. Intriguingly, although wild-type influenza A virus robustly triggers this SUMO switch in TRIM28, the induction of IFN-stimulated genes is limited unless expression of the viral dsRNA-binding protein NS1 is abrogated. This may imply a viral strategy to antagonize such a host response by sequestration of induced immunostimulatory ERV dsRNAs. Overall, our data reveal that a key nuclear mechanism that normally prevents aberrant expression of ERV elements (ERVs) has been functionally co-opted via a stress-induced SUMO switch to augment antiviral immunity.
Collapse
Affiliation(s)
- Nora Schmidt
- Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland
| | - Patricia Domingues
- Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland
| | - Filip Golebiowski
- Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland
| | - Corinna Patzina
- Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland
| | - Michael H Tatham
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, DD1 5EH Dundee, United Kingdom
| | - Ronald T Hay
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, DD1 5EH Dundee, United Kingdom
| | - Benjamin G Hale
- Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland;
| |
Collapse
|
44
|
Hwang J, Kim K, Lee Y, Choi B. NMR Analysis of the Interaction between Cyclophilin A and RIG‐I. B KOREAN CHEM SOC 2019. [DOI: 10.1002/bkcs.11760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jihyun Hwang
- Department of ChemistryKorea Advanced Institute of Science and Technology Daejeon 34141 South Korea
| | - Ki‐Hun Kim
- Department of ChemistryKorea Advanced Institute of Science and Technology Daejeon 34141 South Korea
| | - Younghoon Lee
- Department of ChemistryKorea Advanced Institute of Science and Technology Daejeon 34141 South Korea
| | - Byong‐Seok Choi
- Department of ChemistryKorea Advanced Institute of Science and Technology Daejeon 34141 South Korea
| |
Collapse
|
45
|
Cadena C, Ahmad S, Xavier A, Willemsen J, Park S, Park JW, Oh SW, Fujita T, Hou F, Binder M, Hur S. Ubiquitin-Dependent and -Independent Roles of E3 Ligase RIPLET in Innate Immunity. Cell 2019; 177:1187-1200.e16. [PMID: 31006531 PMCID: PMC6525047 DOI: 10.1016/j.cell.2019.03.017] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/28/2019] [Accepted: 03/07/2019] [Indexed: 01/22/2023]
Abstract
The conventional view posits that E3 ligases function primarily through conjugating ubiquitin (Ub) to their substrate molecules. We report here that RIPLET, an essential E3 ligase in antiviral immunity, promotes the antiviral signaling activity of the viral RNA receptor RIG-I through both Ub-dependent and -independent manners. RIPLET uses its dimeric structure and a bivalent binding mode to preferentially recognize and ubiquitinate RIG-I pre-oligomerized on dsRNA. In addition, RIPLET can cross-bridge RIG-I filaments on longer dsRNAs, inducing aggregate-like RIG-I assemblies. The consequent receptor clustering synergizes with the Ub-dependent mechanism to amplify RIG-I-mediated antiviral signaling in an RNA-length dependent manner. These observations show the unexpected role of an E3 ligase as a co-receptor that directly participates in receptor oligomerization and ligand discrimination. It also highlights a previously unrecognized mechanism by which the innate immune system measures foreign nucleic acid length, a common criterion for self versus non-self nucleic acid discrimination.
Collapse
Affiliation(s)
- Cristhian Cadena
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA
| | - Sadeem Ahmad
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA
| | - Audrey Xavier
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA; Institute of Chemistry and Biochemistry, Free University of Berlin, Germany
| | - Joschka Willemsen
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response" (division F170), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Sehoon Park
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA
| | - Ji Woo Park
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA; Biology Department, Boston College, Chestnut Hill, MA, USA
| | - Seong-Wook Oh
- Laboratory of Molecular Genetics, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Takashi Fujita
- Laboratory of Molecular Genetics, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Fajian Hou
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China
| | - Marco Binder
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response" (division F170), German Cancer Research Center, 69120 Heidelberg, Germany
| | - Sun Hur
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA.
| |
Collapse
|
46
|
Flores-Romero H, García-Sáez AJ. MAVS-induced mitochondrial membrane remodeling. FEBS J 2019; 286:1540-1542. [PMID: 30957952 DOI: 10.1111/febs.14822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/26/2019] [Indexed: 12/25/2022]
Abstract
Mitochondrial membrane remodeling has been linked with several cellular processes including mitochondrial damage or apoptotic cell death and proceeds via yet poorly understood mechanisms. In this issue of The FEBS Journal, Hwang et al. used different forms of super resolution microscopy to study the formation of macromolecular complexes of mitochondrial antiviral signal protein (MAVS). They found that dsRNA stimulation correlates with MAVS-dependent changes in the morphology of mitochondria that require MAVS transmembrane domain.
Collapse
Affiliation(s)
- Hector Flores-Romero
- Interfaculty Institute of Biochemistry, Eberhard Karls University, Tübingen, Germany
| | - Ana J García-Sáez
- Interfaculty Institute of Biochemistry, Eberhard Karls University, Tübingen, Germany
| |
Collapse
|
47
|
Demeter T, Vaskovicova M, Malik R, Horvat F, Pasulka J, Svobodova E, Flemr M, Svoboda P. Main constraints for RNAi induced by expressed long dsRNA in mouse cells. Life Sci Alliance 2019; 2:2/1/e201800289. [PMID: 30808654 PMCID: PMC6391682 DOI: 10.26508/lsa.201800289] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/09/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022] Open
Abstract
A systematic survey of dsRNA expression in mouse fibroblasts and embryonic stem cells shows main constraints for RNAi. RNAi activity depends on the initial Dicer cleavage of dsRNA, having implications for the evolution of mammalian RNAi functions. RNAi is the sequence-specific mRNA degradation guided by siRNAs produced from long dsRNA by RNase Dicer. Proteins executing RNAi are present in mammalian cells but rather sustain the microRNA pathway. Aiming for a systematic analysis of mammalian RNAi, we report here that the main bottleneck for RNAi efficiency is the production of functional siRNAs, which integrates Dicer activity, dsRNA structure, and siRNA targeting efficiency. Unexpectedly, increased expression of Dicer cofactors TARBP2 or PACT reduces RNAi but not microRNA function. Elimination of protein kinase R, a key dsRNA sensor in the interferon response, had minimal positive effects on RNAi activity in fibroblasts. Without high Dicer activity, RNAi can still occur when the initial Dicer cleavage of the substrate yields an efficient siRNA. Efficient mammalian RNAi may use substrates with some features of microRNA precursors, merging both pathways even more than previously suggested. Although optimized endogenous Dicer substrates mimicking miRNA features could evolve for endogenous regulations, the same principles would make antiviral RNAi inefficient as viruses would adapt to avoid efficacy.
Collapse
Affiliation(s)
- Tomas Demeter
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Michaela Vaskovicova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Radek Malik
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Filip Horvat
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.,Bioinformatics Group, Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Josef Pasulka
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Eliska Svobodova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Matyas Flemr
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Petr Svoboda
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| |
Collapse
|
48
|
Hwang MS, Boulanger J, Howe JD, Albecka A, Pasche M, Mureşan L, Modis Y. MAVS polymers smaller than 80 nm induce mitochondrial membrane remodeling and interferon signaling. FEBS J 2019; 286:1543-1560. [PMID: 30715798 PMCID: PMC6513760 DOI: 10.1111/febs.14772] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/29/2018] [Accepted: 01/31/2019] [Indexed: 12/24/2022]
Abstract
Double‐stranded RNA (dsRNA) is a potent proinflammatory signature of viral infection and is sensed primarily by RIG‐I‐like receptors (RLRs). Oligomerization of RLRs following binding to cytosolic dsRNA activates and nucleates self‐assembly of the mitochondrial antiviral‐signaling protein (MAVS). In the current signaling model, the caspase recruitment domains of MAVS form helical fibrils that self‐propagate like prions to promote signaling complex assembly. However, there is no conclusive evidence that MAVS forms fibrils in cells or with the transmembrane anchor present. We show here with super‐resolution light microscopy that MAVS activation by dsRNA induces mitochondrial membrane remodeling. Quantitative image analysis at imaging resolutions as high as 32 nm shows that in the cellular context, MAVS signaling complexes and the fibrils within them are smaller than 80 nm. The transmembrane domain of MAVS is required for its membrane remodeling, interferon signaling, and proapoptotic activities. We conclude that membrane tethering of MAVS restrains its polymerization and contributes to mitochondrial remodeling and apoptosis upon dsRNA sensing.
Collapse
Affiliation(s)
- Ming-Shih Hwang
- Department of Medicine, University of Cambridge, MRC Laboratory of Molecular Biology, UK
| | | | | | - Anna Albecka
- Department of Medicine, University of Cambridge, MRC Laboratory of Molecular Biology, UK
| | | | - Leila Mureşan
- Cambridge Advanced Imaging Centre, University of Cambridge, UK.,Department of Physiology, Development and Neuroscience, University of Cambridge, UK
| | - Yorgo Modis
- Department of Medicine, University of Cambridge, MRC Laboratory of Molecular Biology, UK
| |
Collapse
|
49
|
Samuel CE. Adenosine deaminase acting on RNA (ADAR1), a suppressor of double-stranded RNA-triggered innate immune responses. J Biol Chem 2019; 294:1710-1720. [PMID: 30710018 PMCID: PMC6364763 DOI: 10.1074/jbc.tm118.004166] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Herbert "Herb" Tabor, who celebrated his 100th birthday this past year, served the Journal of Biological Chemistry as a member of the Editorial Board beginning in 1961, as an Associate Editor, and as Editor-in-Chief for 40 years, from 1971 until 2010. Among the many discoveries in biological chemistry during this period was the identification of RNA modification by C6 deamination of adenosine (A) to produce inosine (I) in double-stranded (ds) RNA. This posttranscriptional RNA modification by adenosine deamination, known as A-to-I RNA editing, diversifies the transcriptome and modulates the innate immune interferon response. A-to-I editing is catalyzed by a family of enzymes, adenosine deaminases acting on dsRNA (ADARs). The roles of A-to-I editing are varied and include effects on mRNA translation, pre-mRNA splicing, and micro-RNA silencing. Suppression of dsRNA-triggered induction and action of interferon, the cornerstone of innate immunity, has emerged as a key function of ADAR1 editing of self (cellular) and nonself (viral) dsRNAs. A-to-I modification of RNA is essential for the normal regulation of cellular processes. Dysregulation of A-to-I editing by ADAR1 can have profound consequences, ranging from effects on cell growth and development to autoimmune disorders.
Collapse
Affiliation(s)
- Charles E Samuel
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106.
| |
Collapse
|
50
|
Intracellular RNA Sensing in Mammalian Cells: Role in Stress Response and Cancer Therapies. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 344:31-89. [DOI: 10.1016/bs.ircmb.2018.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|