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Yin Y, Yang Z, Sun Y, Yang Y, Zhang X, Zhao X, Tian W, Qiu Y, Yin Y, You F, Lu D. RNA-binding protein PTENα blocks RIG-I activation to prevent viral inflammation. Nat Chem Biol 2024; 20:1317-1328. [PMID: 38773328 DOI: 10.1038/s41589-024-01621-5] [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: 12/02/2022] [Accepted: 04/15/2024] [Indexed: 05/23/2024]
Abstract
A timely inflammatory response is crucial for early viral defense, but uncontrolled inflammation harms the host. Retinoic acid-inducible gene I (RIG-I) has a pivotal role in detecting RNA viruses, yet the regulatory mechanisms governing its sensitivity remain elusive. Here we identify PTENα, an N-terminally extended form of PTEN, as an RNA-binding protein with a preference for the CAUC(G/U)UCAU motif. Using both in vivo and in vitro viral infection assays, we demonstrated that PTENα restricted the host innate immune response, relying on its RNA-binding capacity and phosphatase activity. Mechanistically, PTENα directly bound to viral RNA and enzymatically converted its 5'-triphosphate to 5'-monophosphate, thereby reducing RIG-I sensitivity. Physiologically, brain-intrinsic PTENα exerted protective effects against viral inflammation, while peripheral PTENα restricted host antiviral immunity and, to some extent, promoted viral replication. Collectively, our findings underscore the significance of PTENα in modulating viral RNA- and RIG-I-mediated immune recognition, offering potential therapeutic implications for infectious diseases.
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Affiliation(s)
- Yue Yin
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Zeliang Yang
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Yizhe Sun
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Ying Yang
- Department of Blood Transfusion, Peking University People's Hospital, Beijing, P.R. China
| | - Xin Zhang
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Xuyang Zhao
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Wenyu Tian
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Yaruo Qiu
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China
| | - Yuxin Yin
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China.
| | - Fuping You
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China.
| | - Dan Lu
- Institute of Systems Biomedicine, Department of Immunology, Department of Pathology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, P.R. China.
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Szymanik KH, Hancks DC, Sullivan CS. Viral piracy of host RNA phosphatase DUSP11 by avipoxviruses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.06.606876. [PMID: 39211142 PMCID: PMC11361023 DOI: 10.1101/2024.08.06.606876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Proper recognition of viral pathogens is an essential part of the innate immune response. A common viral replicative intermediate and chemical signal that cells use to identify pathogens is the presence of a triphosphorylated 5' end (5'ppp) RNA, which activates the cytosolic RNA sensor RIG-I and initiates downstream antiviral signaling. While 5'pppRNA generated by viral RNA-dependent RNA polymerases (RdRps) can be a potent activator of the immune response, endogenous RNA polymerase III (RNAPIII) transcripts can retain the 5'pppRNA generated during transcription and induce a RIG-I-mediated immune response. We have previously shown that host RNA triphosphatase dual-specificity phosphatase 11 (DUSP11) can act on both host and viral RNAs, altering their levels and reducing their ability to induce RIG-I activation. Our previous work explored how artificially altered DUSP11 can impact immune activation, prompting further exploration into natural contexts of altered DUSP11. Here, we have identified viral DUSP11 homologs (vDUSP11s) present in some avipoxviruses. Consistent with the known functions of endogenous DUSP11, we have shown that expression of vDUSP11s: 1) reduces levels of endogenous RNAPIII transcripts, 2) reduces a cell's sensitivity to 5'pppRNA-mediated immune activation, and 3) restores virus infection defects seen in the absence of DUSP11. Our results identify a virus-relevant context where DUSP11 activity has been co-opted to alter RNA metabolism and influence the outcome of infection.
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Liu Y, Wang K, Gong X, Qu W, Xiao Y, Sun H, Kang J, Sheng J, Wu F, Dai F. Schisandra chinensis inhibits the entry of BoHV-1 by blocking PI3K-Akt pathway and enhances the m6A methylation of gD to inhibit the entry of progeny virus. Front Microbiol 2024; 15:1444414. [PMID: 39104584 PMCID: PMC11298802 DOI: 10.3389/fmicb.2024.1444414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Accepted: 07/11/2024] [Indexed: 08/07/2024] Open
Abstract
Schisandra chinensis, a traditional Chinese medicine known for its antitussive and sedative effects, has shown promise in preventing various viral infections. Bovine herpesvirus-1 (BoHV-1) is an enveloped DNA virus that causes respiratory disease in cattle, leading to significant economic losses in the industry. Because the lack of previous reports on Schisandra chinensis resisting BoHV-1 infection, this study aimed to investigate the specific mechanisms involved. Results from TCID50, qPCR, IFA, and western blot analyses demonstrated that Schisandra chinensis could inhibit BoHV-1 entry into MDBK cells, primarily through its extract Methylgomisin O (Meth O). The specific mechanism involved Meth O blocking BoHV-1 entry into cells via clathrin- and caveolin-mediated endocytosis by suppressing the activation of PI3K-Akt signaling pathway. Additionally, findings from TCID50, qPCR, co-immunoprecipitation and western blot assays revealed that Schisandra chinensis blocked BoHV-1 gD transcription through enhancing m6A methylation of gD after virus entry, thereby hindering gD protein expression and preventing progeny virus entry into cells and ultimately inhibiting BoHV-1 replication. Overall, these results suggest that Schisandra chinensis can resist BoHV-1 infection by targeting the PI3K-Akt signaling pathway and inhibiting gD transcription.
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Affiliation(s)
- Yang Liu
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
| | - Kang Wang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
| | - Xiao Gong
- Qingdao YeBio Bio-Engineering Co., Ltd., Qingdao, China
| | - Weijie Qu
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
| | - Yangyang Xiao
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
- College of Animal Science and Technology, Shihezi University, Xinjiang, China
| | - Hongtao Sun
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
| | - Jingli Kang
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
| | - Jinliang Sheng
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
- College of Animal Science and Technology, Shihezi University, Xinjiang, China
| | - Faxing Wu
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, China
| | - Feiyan Dai
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
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Landau LM, Chaudhary N, Tien YC, Rogozinska M, Joshi S, Yao C, Crowley J, Hullahalli K, Campbell IW, Waldor MK, Haigis M, Kagan JC. pLxIS-containing domains are biochemically flexible regulators of interferons and metabolism. Mol Cell 2024; 84:2436-2454.e10. [PMID: 38925114 PMCID: PMC11282577 DOI: 10.1016/j.molcel.2024.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/28/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
Signal transduction proteins containing a pLxIS motif induce interferon (IFN) responses central to antiviral immunity. Apart from their established roles in activating the IFN regulator factor (IRF) transcription factors, the existence of additional pathways and functions associated with the pLxIS motif is unknown. Using a synthetic biology-based platform, we identified two orphan pLxIS-containing proteins that stimulate IFN responses independent of all known pattern-recognition receptor pathways. We further uncovered a diversity of pLxIS signaling mechanisms, where the pLxIS motif represents one component of a multi-motif signaling entity, which has variable functions in activating IRF3, the TRAF6 ubiquitin ligase, IκB kinases, mitogen-activated protein kinases, and metabolic activities. The most diverse pLxIS signaling mechanisms were associated with the highest antiviral activities in human cells. The flexibility of domains that regulate IFN signaling may explain their prevalence in nature.
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Affiliation(s)
- Lauren M Landau
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Neha Chaudhary
- Cambridge Research Center, AbbVie, Inc., Cambridge, MA, USA
| | - Yun Chen Tien
- Cambridge Research Center, AbbVie, Inc., Cambridge, MA, USA
| | | | - Shakchhi Joshi
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Conghui Yao
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Joseph Crowley
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Karthik Hullahalli
- Division of Infectious Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ian W Campbell
- Division of Infectious Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Marcia Haigis
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
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Parthasarathy S, Saenjamsai P, Hao H, Ferkul A, Pfannenstiel JJ, Suder EL, Bejan DS, Chen Y, Schwarting N, Aikawa M, Muhlberger E, Orozco RC, Sullivan CS, Cohen MS, Davido DJ, Hume AJ, Fehr AR. PARP14 is pro- and anti-viral host factor that promotes IFN production and affects the replication of multiple viruses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591186. [PMID: 38712082 PMCID: PMC11071520 DOI: 10.1101/2024.04.26.591186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
PARP14 is a 203 kDa multi-domain protein that is primarily known as an ADP-ribosyltransferase, and is involved in a variety of cellular functions including DNA damage, microglial activation, inflammation, and cancer progression. In addition, PARP14 is upregulated by interferon (IFN), indicating a role in the antiviral response. Furthermore, PARP14 has evolved under positive selection, again indicating that it is involved in host-pathogen conflict. We found that PARP14 is required for increased IFN-I production in response to coronavirus infection lacking ADP-ribosylhydrolase (ARH) activity and poly(I:C), however, whether it has direct antiviral function remains unclear. Here we demonstrate that the catalytic activity of PARP14 enhances IFN-I and IFN-III responses and restricts ARH-deficient murine hepatitis virus (MHV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. To determine if PARP14's antiviral functions extended beyond CoVs, we tested the ability of herpes simplex virus 1 (HSV-1) and several negative-sense RNA viruses, including vesicular stomatitis virus (VSV), Ebola virus (EBOV), and Nipah virus (NiV), to infect A549 PARP14 knockout (KO) cells. HSV-1 had increased replication in PARP14 KO cells, indicating that PARP14 restricts HSV-1 replication. In contrast, PARP14 was critical for the efficient infection of VSV, EBOV, and NiV, with EBOV infectivity at less than 1% of WT cells. A PARP14 active site inhibitor had no impact on HSV-1 or EBOV infection, indicating that its effect on these viruses was independent of its catalytic activity. These data demonstrate that PARP14 promotes IFN production and has both pro- and anti-viral functions targeting multiple viruses.
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Affiliation(s)
| | - Pradtahna Saenjamsai
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | - Hongping Hao
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | - Anna Ferkul
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | | | - Ellen L. Suder
- Department of Microbiology, Boston University School of Medicine, Boston, MA, 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, 02118, USA
- Center for Emerging Infectious Diseases Policy & Research, Boston University, Boston, MA, 02118, USA
| | - Daniel S. Bejan
- Department of Chemical Physiology and Biochemistry, Oregon Health Sciences University, Portland, OR, 97239, USA
| | - Yating Chen
- Department of Molecular Biosciences, University of Texas, Austin, TX, 78712, USA
| | - Nancy Schwarting
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | - Masanori Aikawa
- Center for Excellence in Vascular Biology (P.K.J., M.A., E.A.), Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Center for Interdisciplinary Cardiovascular Sciences (M.A., E.A.), Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Channing Division of Network Medicine (M.A.), Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Elke Muhlberger
- Department of Microbiology, Boston University School of Medicine, Boston, MA, 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, 02118, USA
- Center for Emerging Infectious Diseases Policy & Research, Boston University, Boston, MA, 02118, USA
| | - Robin C. Orozco
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | | | - Michael S. Cohen
- Department of Chemical Physiology and Biochemistry, Oregon Health Sciences University, Portland, OR, 97239, USA
| | - David J. Davido
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | - Adam J. Hume
- Department of Microbiology, Boston University School of Medicine, Boston, MA, 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, 02118, USA
- Center for Emerging Infectious Diseases Policy & Research, Boston University, Boston, MA, 02118, USA
| | - Anthony R. Fehr
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
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Avila-Bonilla RG, Macias S. The molecular language of RNA 5' ends: guardians of RNA identity and immunity. RNA (NEW YORK, N.Y.) 2024; 30:327-336. [PMID: 38325897 PMCID: PMC10946433 DOI: 10.1261/rna.079942.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
RNA caps are deposited at the 5' end of RNA polymerase II transcripts. This modification regulates several steps of gene expression, in addition to marking transcripts as self to enable the innate immune system to distinguish them from uncapped foreign RNAs, including those derived from viruses. Specialized immune sensors, such as RIG-I and IFITs, trigger antiviral responses upon recognition of uncapped cytoplasmic transcripts. Interestingly, uncapped transcripts can also be produced by mammalian hosts. For instance, 5'-triphosphate RNAs are generated by RNA polymerase III transcription, including tRNAs, Alu RNAs, or vault RNAs. These RNAs have emerged as key players of innate immunity, as they can be recognized by the antiviral sensors. Mechanisms that regulate the presence of 5'-triphosphates, such as 5'-end dephosphorylation or RNA editing, prevent immune recognition of endogenous RNAs and excessive inflammation. Here, we provide a comprehensive overview of the complexity of RNA cap structures and 5'-triphosphate RNAs, highlighting their roles in transcript identity, immune surveillance, and disease.
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Affiliation(s)
- Rodolfo Gamaliel Avila-Bonilla
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, United Kingdom
| | - Sara Macias
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, United Kingdom
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Avila-Bonilla RG, Martínez-Montero JP. Crosstalk between vault RNAs and innate immunity. Mol Biol Rep 2024; 51:387. [PMID: 38443657 PMCID: PMC10914904 DOI: 10.1007/s11033-024-09305-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/31/2024] [Indexed: 03/07/2024]
Abstract
PURPOSE Vault (vt) RNAs are noncoding (nc) RNAs transcribed by RNA polymerase III (RNA Pol III) with 5'-triphosphate (5'-PPP) termini that play significant roles and are recognized by innate immune sensors, including retinoic acid-inducible protein 1 (RIG-I). In addition, vtRNAs adopt secondary structures that can be targets of interferon-inducible protein kinase R (PKR) and the oligoadenylate synthetase (OAS)/RNase L system, both of which are important for activating antiviral defenses. However, changes in the expression of vtRNAs have been associated with pathological processes that activate proinflammatory pathways, which influence cellular events such as differentiation, aging, autophagy, apoptosis, and drug resistance in cancer cells. RESULTS In this review, we summarized the biology of vtRNAs and focused on their interactions with the innate immune system. These findings provide insights into the diverse roles of vtRNAs and their correlation with various cellular processes to improve our understanding of their biological functions.
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Affiliation(s)
- Rodolfo Gamaliel Avila-Bonilla
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Genética y Biología Molecular, Av. IPN 2508, 07360, Mexico City, Mexico.
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8
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Liu Y, Cui J, Kang J, Wang Z, Xu X, Wu F. Bovine herpesvirus-1 gE protein inhibits IFN-β production to enhance replication by promoting MAVS ubiquitination and interfering with the interaction between IRF3 and CBP/p300. Vet Microbiol 2023; 287:109899. [PMID: 37931576 DOI: 10.1016/j.vetmic.2023.109899] [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: 09/07/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 11/08/2023]
Abstract
Bovine herpesvirus-1 (BoHV-1) can infect all breeds of cattle and cause respiratory and genital tract diseases. In the process of viral infection, viruses can use their own proteins to suppress the innate immunity of the host and promote its replication; however, the mechanism by which BoHV-1 evades the innate immune response is not fully understood. In this study, we found that rabbits inoculated with the live gene deletion vaccine BoHV-1-△gI/gE/TK generated higher interferon-β (IFN-β) production in the serum, liver, lung and kidney than rabbits inoculated with wt BoHV-1, which led to milder lesions in the lung and kidney. We performed gene deletion and ectopic expression experiments on viral proteins and found that gE was the major protein that inhibited IFN-β expression. Further studies showed that MAVS and IRF3 were the targets of gE, and the specific mechanism was that gE inhibited IFN-β production by promoting MAVS ubiquitination and interfering with the interaction between IRF3 and CBP/p300. These results suggest a new way of BoHV-1 inhibition of IFN-β production to evade the host innate immunity.
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Affiliation(s)
- Yang Liu
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, Shandong 266032, China; College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Jin Cui
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, Shandong 266032, China
| | - Jingli Kang
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, Shandong 266032, China
| | - Zhiliang Wang
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, Shandong 266032, China
| | - Xingang Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Faxing Wu
- Key Laboratory of Animal Biosafety Risk Prevention and Control of Ministry of Agriculture and Rural Affairs (South), China Animal Health and Epidemiology Center, Qingdao, Shandong 266032, China.
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9
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Naesens L, Haerynck F, Gack MU. The RNA polymerase III-RIG-I axis in antiviral immunity and inflammation. Trends Immunol 2023; 44:435-449. [PMID: 37149405 PMCID: PMC10461603 DOI: 10.1016/j.it.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/29/2023] [Accepted: 04/03/2023] [Indexed: 05/08/2023]
Abstract
Nucleic acid sensors survey subcellular compartments for atypical or mislocalized RNA or DNA, ultimately triggering innate immune responses. Retinoic acid-inducible gene-I (RIG-I) is part of the family of cytoplasmic RNA receptors that can detect viruses. A growing literature demonstrates that mammalian RNA polymerase III (Pol III) transcribes certain viral or cellular DNA sequences into immunostimulatory RIG-I ligands, which elicits antiviral or inflammatory responses. Dysregulation of the Pol III-RIG-I sensing axis can lead to human diseases including severe viral infection outcomes, autoimmunity, and tumor progression. Here, we summarize the newly emerging role of viral and host-derived Pol III transcripts in immunity and also highlight recent advances in understanding how mammalian cells prevent unwanted immune activation by these RNAs to maintain homeostasis.
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Affiliation(s)
- Leslie Naesens
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium; Primary Immunodeficiency Research Lab, Center for Primary Immunodeficiency, Jeffrey Modell Diagnosis and Research Center, Ghent University Hospital, Ghent, Belgium
| | - Filomeen Haerynck
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium; Primary Immunodeficiency Research Lab, Center for Primary Immunodeficiency, Jeffrey Modell Diagnosis and Research Center, Ghent University Hospital, Ghent, Belgium
| | - Michaela U Gack
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA.
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10
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Corbet GA, Burke JM, Parker R. Nucleic acid-protein condensates in innate immune signaling. EMBO J 2023; 42:e111870. [PMID: 36178199 PMCID: PMC10068312 DOI: 10.15252/embj.2022111870] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/24/2022] [Accepted: 09/19/2022] [Indexed: 11/09/2022] Open
Abstract
The presence of foreign nucleic acids in the cytosol is a marker of infection. Cells have sensors, also known as pattern recognition receptors (PRRs), in the cytosol that detect foreign nucleic acid and initiate an innate immune response. Recent studies have reported the condensation of multiple PRRs including PKR, NLRP6, and cGAS, with their nucleic acid activators into discrete nucleoprotein assemblies. Nucleic acid-protein condensates form due to multivalent interactions and can create high local concentrations of components. The formation of PRR-containing condensates may alter the magnitude or timing of PRR activation. In addition, unique condensates form following RNase L activation or during paracrine signaling from virally infected cells that may play roles in antiviral defense. These observations suggest that condensate formation may be a conserved mechanism that cells use to regulate activation of the innate immune response and open an avenue for further investigation into the composition and function of these condensates. Here we review the nucleic acid-protein granules that are implicated in the innate immune response, discuss general consequences of condensate formation and signal transduction, as well as what outstanding questions remain.
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Affiliation(s)
- Giulia A Corbet
- Department of BiochemistryUniversity of ColoradoBoulderCOUSA
| | - James M Burke
- Department of BiochemistryUniversity of ColoradoBoulderCOUSA
- Present address:
Department of Molecular MedicineUniversity of Florida Scripps Biomedical ResearchJupiterFLUSA
| | - Roy Parker
- Department of BiochemistryUniversity of ColoradoBoulderCOUSA
- Howard Hughes Medical InstituteChevy ChaseMDUSA
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11
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Jiang Y, Zhang H, Wang J, Chen J, Guo Z, Liu Y, Hua H. Exploiting RIG-I-like receptor pathway for cancer immunotherapy. J Hematol Oncol 2023; 16:8. [PMID: 36755342 PMCID: PMC9906624 DOI: 10.1186/s13045-023-01405-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/30/2023] [Indexed: 02/10/2023] Open
Abstract
RIG-I-like receptors (RLRs) are intracellular pattern recognition receptors that detect viral or bacterial infection and induce host innate immune responses. The RLRs family comprises retinoic acid-inducible gene 1 (RIG-I), melanoma differentiation-associated gene 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2) that have distinctive features. These receptors not only recognize RNA intermediates from viruses and bacteria, but also interact with endogenous RNA such as the mislocalized mitochondrial RNA, the aberrantly reactivated repetitive or transposable elements in the human genome. Evasion of RLRs-mediated immune response may lead to sustained infection, defective host immunity and carcinogenesis. Therapeutic targeting RLRs may not only provoke anti-infection effects, but also induce anticancer immunity or sensitize "immune-cold" tumors to immune checkpoint blockade. In this review, we summarize the current knowledge of RLRs signaling and discuss the rationale for therapeutic targeting RLRs in cancer. We describe how RLRs can be activated by synthetic RNA, oncolytic viruses, viral mimicry and radio-chemotherapy, and how the RNA agonists of RLRs can be systemically delivered in vivo. The integration of RLRs agonism with RNA interference or CAR-T cells provides new dimensions that complement cancer immunotherapy. Moreover, we update the progress of recent clinical trials for cancer therapy involving RLRs activation and immune modulation. Further studies of the mechanisms underlying RLRs signaling will shed new light on the development of cancer therapeutics. Manipulation of RLRs signaling represents an opportunity for clinically relevant cancer therapy. Addressing the challenges in this field will help develop future generations of cancer immunotherapy.
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Affiliation(s)
- Yangfu Jiang
- Laboratory of Oncogene, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Hongying Zhang
- Laboratory of Oncogene, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Jiao Wang
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Jinzhu Chen
- Laboratory of Oncogene, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Zeyu Guo
- Laboratory of Oncogene, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yongliang Liu
- Laboratory of Oncogene, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Hui Hua
- Laboratory of Stem Cell Biology, West China Hospital, Sichuan University, Chengdu, 610041, China.
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12
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Wang W, Pyle AM. The RIG-I receptor adopts two different conformations for distinguishing host from viral RNA ligands. Mol Cell 2022; 82:4131-4144.e6. [DOI: 10.1016/j.molcel.2022.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 08/09/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
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13
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Vabret N, Najburg V, Solovyov A, Gopal R, McClain C, Šulc P, Balan S, Rahou Y, Beauclair G, Chazal M, Varet H, Legendre R, Sismeiro O, Sanchez David RY, Chauveau L, Jouvenet N, Markowitz M, van der Werf S, Schwartz O, Tangy F, Bhardwaj N, Greenbaum BD, Komarova AV. Y RNAs are conserved endogenous RIG-I ligands across RNA virus infection and are targeted by HIV-1. iScience 2022; 25:104599. [PMID: 35789859 PMCID: PMC9250025 DOI: 10.1016/j.isci.2022.104599] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/01/2022] [Accepted: 06/07/2022] [Indexed: 11/18/2022] Open
Abstract
Pattern recognition receptors (PRRs) protect against microbial invasion by detecting specific molecular patterns found in pathogens and initiating an immune response. Although microbial-derived PRR ligands have been extensively characterized, the contribution and relevance of endogenous ligands to PRR activation remains overlooked. Here, we characterize the landscape of endogenous ligands that engage RIG-I-like receptors (RLRs) upon infection by different RNA viruses. In each infection, several RNAs transcribed by RNA polymerase III (Pol3) specifically engaged RLRs, particularly the family of Y RNAs. Sensing of Y RNAs was dependent on their mimicking of viral secondary structure and their 5'-triphosphate extremity. Further, we found that HIV-1 triggered a VPR-dependent downregulation of RNA triphosphatase DUSP11 in vitro and in vivo, inducing a transcriptome-wide change of cellular RNA 5'-triphosphorylation that licenses Y RNA immunogenicity. Overall, our work uncovers the contribution of endogenous RNAs to antiviral immunity and demonstrates the importance of this pathway in HIV-1 infection.
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Affiliation(s)
- Nicolas Vabret
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Valérie Najburg
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Alexander Solovyov
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ramya Gopal
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Christopher McClain
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Petr Šulc
- Center for Molecular Design and Biomimetics at the Biodesign Institute and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Sreekumar Balan
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yannis Rahou
- Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Guillaume Beauclair
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Maxime Chazal
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Hugo Varet
- Transcriptome and EpiGenome Platform, BioMics, Center of Innovation and Technological Research, Institut Pasteur, Université de Paris, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
- Hub Informatique et Biostatistique, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI, USR 3756 IP-CNRS), Institut Pasteur, Université de Paris, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Rachel Legendre
- Transcriptome and EpiGenome Platform, BioMics, Center of Innovation and Technological Research, Institut Pasteur, Université de Paris, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
- Hub Informatique et Biostatistique, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI, USR 3756 IP-CNRS), Institut Pasteur, Université de Paris, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Odile Sismeiro
- Transcriptome and EpiGenome Platform, BioMics, Center of Innovation and Technological Research, Institut Pasteur, Université de Paris, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Raul Y. Sanchez David
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Lise Chauveau
- Virus & Immunity Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Nolwenn Jouvenet
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Martin Markowitz
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, NY, USA
| | - Sylvie van der Werf
- Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Olivier Schwartz
- Virus & Immunity Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Frédéric Tangy
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
| | - Nina Bhardwaj
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Extra-mural Member, Parker Institute of Cancer Immunotherapy, USA
| | - Benjamin D. Greenbaum
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Physiology, Biophysics, & Systems Biology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Anastassia V. Komarova
- Viral Genomics and Vaccination Unit, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
- Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, Université de Paris, CNRS UMR-3569, 75015 Paris, France
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14
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Chen YG, Hur S. Cellular origins of dsRNA, their recognition and consequences. Nat Rev Mol Cell Biol 2022; 23:286-301. [PMID: 34815573 PMCID: PMC8969093 DOI: 10.1038/s41580-021-00430-1] [Citation(s) in RCA: 143] [Impact Index Per Article: 71.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2021] [Indexed: 01/02/2023]
Abstract
Double-stranded RNA (dsRNA) is associated with most viral infections - it either constitutes the viral genome (in the case of dsRNA viruses) or is generated in host cells during viral replication. Hence, nearly all organisms have the capability of recognizing dsRNA and mounting a response, the primary aim of which is to mitigate the potential infection. In vertebrates, a set of innate immune receptors for dsRNA induce a multitude of cell-intrinsic and cell-extrinsic immune responses upon dsRNA recognition. Notably, recent studies showed that vertebrate cells can accumulate self-derived dsRNAs or dsRNA-like species upon dysregulation of several cellular processes, activating the very same immune pathways as in infected cells. On the one hand, such aberrant immune activation in the absence of infection can lead to pathogenesis of immune disorders, such as Aicardi-Goutières syndrome. On the other hand, the same innate immune reaction can be induced in a controlled setting for a therapeutic benefit, as occurs in immunotherapies. In this Review, we describe mechanisms by which immunostimulatory dsRNAs are generated in mammalian cells, either by viruses or by the host cells, and how cells respond to them, with the focus on recent developments regarding the role of cellular dsRNAs in immune modulation.
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Affiliation(s)
- Y Grace Chen
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.
| | - Sun Hur
- Harvard Medical School & Boston Children's Hospital, Boston, MA, USA.
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15
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van Gent M, Chiang JJ, Muppala S, Chiang C, Azab W, Kattenhorn L, Knipe DM, Osterrieder N, Gack MU. The US3 Kinase of Herpes Simplex Virus Phosphorylates the RNA Sensor RIG-I To Suppress Innate Immunity. J Virol 2022; 96:e0151021. [PMID: 34935440 PMCID: PMC8865413 DOI: 10.1128/jvi.01510-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/10/2021] [Indexed: 11/20/2022] Open
Abstract
Recent studies have demonstrated that the signaling activity of the cytosolic pathogen sensor retinoic acid-inducible gene-I (RIG-I) is modulated by a variety of posttranslational modifications (PTMs) to fine-tune the antiviral type I interferon (IFN) response. Whereas K63-linked ubiquitination of the RIG-I caspase activation and recruitment domains (CARDs) catalyzed by TRIM25 or other E3 ligases activates RIG-I, phosphorylation of RIG-I at S8 and T170 represses RIG-I signal transduction by preventing the TRIM25-RIG-I interaction and subsequent RIG-I ubiquitination. While strategies to suppress RIG-I signaling by interfering with its K63-polyubiquitin-dependent activation have been identified for several viruses, evasion mechanisms that directly promote RIG-I phosphorylation to escape antiviral immunity are unknown. Here, we show that the serine/threonine (Ser/Thr) kinase US3 of herpes simplex virus 1 (HSV-1) binds to RIG-I and phosphorylates RIG-I specifically at S8. US3-mediated phosphorylation suppressed TRIM25-mediated RIG-I ubiquitination, RIG-I-MAVS binding, and type I IFN induction. We constructed a mutant HSV-1 encoding a catalytically-inactive US3 protein (K220A) and found that, in contrast to the parental virus, the US3 mutant HSV-1 was unable to phosphorylate RIG-I at S8 and elicited higher levels of type I IFNs, IFN-stimulated genes (ISGs), and proinflammatory cytokines in a RIG-I-dependent manner. Finally, we show that this RIG-I evasion mechanism is conserved among the alphaherpesvirus US3 kinase family. Collectively, our study reveals a novel immune evasion mechanism of herpesviruses in which their US3 kinases phosphorylate the sensor RIG-I to keep it in the signaling-repressed state. IMPORTANCE Herpes simplex virus 1 (HSV-1) establishes lifelong latency in the majority of the human population worldwide. HSV-1 occasionally reactivates to produce infectious virus and to facilitate dissemination. While often remaining subclinical, both primary infection and reactivation occasionally cause debilitating eye diseases, which can lead to blindness, as well as life-threatening encephalitis and newborn infections. To identify new therapeutic targets for HSV-1-induced diseases, it is important to understand the HSV-1-host interactions that may influence infection outcome and disease. Our work uncovered direct phosphorylation of the pathogen sensor RIG-I by alphaherpesvirus-encoded kinases as a novel viral immune escape strategy and also underscores the importance of RNA sensors in surveilling DNA virus infection.
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Affiliation(s)
- Michiel van Gent
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, Florida, USA
- Department of Microbiology, The University of Chicago, Chicago, Illinois, USA
| | - Jessica J. Chiang
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Santoshi Muppala
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, Florida, USA
| | - Cindy Chiang
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, Florida, USA
- Department of Microbiology, The University of Chicago, Chicago, Illinois, USA
| | - Walid Azab
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Berlin, Germany
| | - Lisa Kattenhorn
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
| | - David M. Knipe
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Nikolaus Osterrieder
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Berlin, Germany
| | - Michaela U. Gack
- Florida Research and Innovation Center, Cleveland Clinic, Port Saint Lucie, Florida, USA
- Department of Microbiology, The University of Chicago, Chicago, Illinois, USA
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16
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Shao L, Yu X, Han Q, Zhang X, Lu N, Zhang C. Enhancing anti-tumor efficacy and immune memory by combining 3p-GPC-3 siRNA treatment with PD-1 blockade in hepatocellular carcinoma. Oncoimmunology 2022; 11:2010894. [PMID: 36524206 PMCID: PMC9746623 DOI: 10.1080/2162402x.2021.2010894] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is associated with a high mortality rate and presents a major challenge for human health. Activation of multiple oncogenes has been reported to be strongly associated with the progression of HCC. Moreover, the immunosuppressive tumor microenvironment (TME) and the host immune system are also implicated in the development of malignant HCC tumors. Glypican-3 (GPC-3), a proteoglycan involved in the regulation of cell proliferation and apoptosis, is aberrantly expressed in HCC. We synthesized a short 5'-triphosphate (3p) RNA targeting GPC-3, 3p-GPC-3 siRNA, and found that it effectively inhibited subcutaneous HCC growth by raising type I IFN levels in tumor cells and serum and promoting tumor cell apoptosis. Moreover, 3p-GPC-3 siRNA was able to enhance the activation of CD4+ T cells, CD8+ T cells, and natural killer (NK) cells while reducing the proportion of regulatory T cells (Tregs) in the TME. Most intriguingly, a blocking anti-PD-1 antibody improved the anti-tumor effect of 3p-GPC-3 siRNA, predominantly by activating the immune response, reversing immune exhaustion, and improving immune memory. Our study suggests that the combination of 3p-GPC-3 siRNA administration and PD-1 blockade may represent a promising therapeutic strategy for HCC.
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Affiliation(s)
- Liwei Shao
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Xin Yu
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China,College of Life Sciences, Ludong University, Yantai, Shandong, China
| | - Qiuju Han
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Xinke Zhang
- Department of Pharmacology, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Nan Lu
- Institute of Diagnostics, School of Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Cai Zhang
- Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China,CONTACT Cai Zhang , Institute of Immunopharmaceutical Sciences, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012Shandong, China
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17
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NUDT2 initiates viral RNA degradation by removal of 5'-phosphates. Nat Commun 2021; 12:6918. [PMID: 34824277 PMCID: PMC8616924 DOI: 10.1038/s41467-021-27239-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 11/08/2021] [Indexed: 12/22/2022] Open
Abstract
While viral replication processes are largely understood, comparably little is known on cellular mechanisms degrading viral RNA. Some viral RNAs bear a 5′-triphosphate (PPP-) group that impairs degradation by the canonical 5′-3′ degradation pathway. Here we show that the Nudix hydrolase 2 (NUDT2) trims viral PPP-RNA into monophosphorylated (P)-RNA, which serves as a substrate for the 5′-3′ exonuclease XRN1. NUDT2 removes 5′-phosphates from PPP-RNA in an RNA sequence- and overhang-independent manner and its ablation in cells increases growth of PPP-RNA viruses, suggesting an involvement in antiviral immunity. NUDT2 is highly homologous to bacterial RNA pyrophosphatase H (RppH), a protein involved in the metabolism of bacterial mRNA, which is 5′-tri- or diphosphorylated. Our results show a conserved function between bacterial RppH and mammalian NUDT2, indicating that the function may have adapted from a protein responsible for RNA turnover in bacteria into a protein involved in the immune defense in mammals. RNA of some viruses is protected from degradation by a 5′ triphosphate group. Here the authors identify nudix hydrolase 2 (NUDT2) as novel antiviral defense protein that dephosphorylates viral RNA and thereby enables its degradation.
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18
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Thoresen D, Wang W, Galls D, Guo R, Xu L, Pyle AM. The molecular mechanism of RIG-I activation and signaling. Immunol Rev 2021; 304:154-168. [PMID: 34514601 PMCID: PMC9293153 DOI: 10.1111/imr.13022] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022]
Abstract
RIG‐I is our first line of defense against RNA viruses, serving as a pattern recognition receptor that identifies molecular features common among dsRNA and ssRNA viral pathogens. RIG‐I is maintained in an inactive conformation as it samples the cellular space for pathogenic RNAs. Upon encounter with the triphosphorylated terminus of blunt‐ended viral RNA duplexes, the receptor changes conformation and releases a pair of signaling domains (CARDs) that are selectively modified and interact with an adapter protein (MAVS), thereby triggering a signaling cascade that stimulates transcription of interferons. Here, we describe the structural determinants for specific RIG‐I activation by viral RNA, and we describe the strategies by which RIG‐I remains inactivated in the presence of host RNAs. From the initial RNA triggering event to the final stages of interferon expression, we describe the experimental evidence underpinning our working knowledge of RIG‐I signaling. We draw parallels with behavior of related proteins MDA5 and LGP2, describing evolutionary implications of their collective surveillance of the cell. We conclude by describing the cell biology and immunological investigations that will be needed to accurately describe the role of RIG‐I in innate immunity and to provide the necessary foundation for pharmacological manipulation of this important receptor.
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Affiliation(s)
- Daniel Thoresen
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Wenshuai Wang
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Drew Galls
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Rong Guo
- Chemistry, Yale University, New Haven, CT, USA
| | - Ling Xu
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Anna Marie Pyle
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.,Chemistry, Yale University, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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19
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Affiliation(s)
- Joon H. Choi
- Department of Molecular Biosciences, LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, United States of America
| | - Christopher S. Sullivan
- Department of Molecular Biosciences, LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
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