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Wan Q, Tavakoli L, Wang TY, Tucker AJ, Zhou R, Liu Q, Feng S, Choi D, He Z, Gack MU, Zhao J. Hijacking of nucleotide biosynthesis and deamidation-mediated glycolysis by an oncogenic herpesvirus. Nat Commun 2024; 15:1442. [PMID: 38365882 PMCID: PMC10873312 DOI: 10.1038/s41467-024-45852-5] [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: 06/21/2023] [Accepted: 02/05/2024] [Indexed: 02/18/2024] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS) and multiple types of B cell malignancies. Emerging evidence demonstrates that KSHV reprograms host-cell central carbon metabolic pathways, which contributes to viral persistence and tumorigenesis. However, the mechanisms underlying KSHV-mediated metabolic reprogramming remain poorly understood. Carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase (CAD) is a key enzyme of the de novo pyrimidine synthesis, and was recently identified to deamidate the NF-κB subunit RelA to promote aerobic glycolysis and cell proliferation. Here we report that KSHV infection exploits CAD for nucleotide synthesis and glycolysis. Mechanistically, KSHV vCyclin binds to and hijacks cyclin-dependent kinase CDK6 to phosphorylate Ser-1900 on CAD, thereby activating CAD-mediated pyrimidine synthesis and RelA-deamidation-mediated glycolytic reprogramming. Correspondingly, genetic depletion or pharmacological inhibition of CDK6 and CAD potently impeded KSHV lytic replication and thwarted tumorigenesis of primary effusion lymphoma (PEL) cells in vitro and in vivo. Altogether, our work defines a viral metabolic reprogramming mechanism underpinning KSHV oncogenesis, which may spur the development of new strategies to treat KSHV-associated malignancies and other diseases.
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Affiliation(s)
- Quanyuan Wan
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA
| | - Leah Tavakoli
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA
| | - Ting-Yu Wang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
- Proteome Exploration Laboratory, Beckman Institute, California Institute of Technology, Pasadena, CA, USA
| | - Andrew J Tucker
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA
| | - Ruiting Zhou
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA
| | - Qizhi Liu
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
- State Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, Hunan, China
| | - Shu Feng
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
- Department of Diabetes & Cancer Metabolism, Beckman Research Institute of City of Hope, Duarte, CA, USA
| | - Dongwon Choi
- Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Zhiheng He
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Michaela U Gack
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA
| | - Jun Zhao
- Florida Research and Innovation Center, Cleveland Clinic, Port St. Lucie, FL, USA.
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Kesika P, Thangaleela S, Sisubalan N, Radha A, Sivamaruthi BS, Chaiyasut C. The Role of the Nuclear Factor-Kappa B (NF-κB) Pathway in SARS-CoV-2 Infection. Pathogens 2024; 13:164. [PMID: 38392902 PMCID: PMC10892479 DOI: 10.3390/pathogens13020164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/01/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
COVID-19 is a global health threat caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is associated with a significant increase in morbidity and mortality. The present review discusses nuclear factor-kappa B (NF-κB) activation and its potential therapeutical role in treating COVID-19. COVID-19 pathogenesis, the major NF-κB pathways, and the involvement of NF-κB in SARS-CoV-2 have been detailed. Specifically, NF-κB activation and its impact on managing COVID-19 has been discussed. As a central player in the immune and inflammatory responses, modulating NF-κB activation could offer a strategic avenue for managing SARS-CoV-2 infection. Understanding the NF-κB pathway's role could aid in developing treatments against SARS-CoV-2. Further investigations into the intricacies of NF-κB activation are required to reveal effective therapeutic strategies for managing and combating the SARS-CoV-2 infection and COVID-19.
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Affiliation(s)
- Periyanaina Kesika
- Office of Research Administration, Chiang Mai University, Chiang Mai 50200, Thailand; (P.K.); (N.S.)
- Innovation Center for Holistic Health, Nutraceuticals, and Cosmeceuticals, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Subramanian Thangaleela
- Institute of Biotechnology, Department of Medical Biotechnology and Integrative Physiology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, Tamil Nadu, India
| | - Natarajan Sisubalan
- Office of Research Administration, Chiang Mai University, Chiang Mai 50200, Thailand; (P.K.); (N.S.)
- Innovation Center for Holistic Health, Nutraceuticals, and Cosmeceuticals, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Arumugam Radha
- Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | | | - Chaiyavat Chaiyasut
- Innovation Center for Holistic Health, Nutraceuticals, and Cosmeceuticals, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand
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He Y, Liu J, Miao Y, Liu M, Wu H, Xiao J, Feng H. Black carp LGP2 suppresses RIG-I mediated IFN signaling during the antiviral innate immunity. FISH & SHELLFISH IMMUNOLOGY 2023; 143:109208. [PMID: 37944680 DOI: 10.1016/j.fsi.2023.109208] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/17/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
Laboratory of genetics and physiology 2 (LGP2), a member of retinoic acid-inducible gene (RIG)-I-like receptors (RLRs), has been reported to play different roles in IFN signaling in both mammals and teleost fish. In our previous study, black carp (Mylopharyngodon piceus) LGP2 (bcLGP2) has been characterized to positively regulate melanoma differentiation-associated gene 5 (MDA5). In this study, knockdown of bcLGP2 decreased the expression of host genes, including bcIFNb, bcPKR, bcMx1, and bcViperin, and also attenuated the antiviral capability of host cells. The relationship between bcLGP2 and black carp RIG-Ib (bcRIG-Ib) has been explored. Dual-luciferase reporter assay and qRT-PCR assay indicated that bcLGP2 dampened bcRIG-Ib induced transcription of type I interferons (IFNs) and interferon-stimulated genes (ISGs), including PKR, ISG15, and Viperin. Consistently, the plaque assay identified that bcLGP2 attenuated bcRIG-Ib mediated antiviral ability against spring viremia of carp virus (SVCV). Co-immunoprecipitation assay identified the interaction between bcLGP2 and bcRIG-Ib, as well as bcLGP2 and bcRIG-Ib-CARD. And bcRIG-Ib-CARD mediated antiviral ability was also attenuated by bcLGP2. Truncation mutation analysis showed DExD/H-box Helicase domain of bcLGP2 possessed a similar inhibitory effect on bcRIG-Ib to that of bcLGP2, while the C-terminus repressor domain (CTD) presented little impact on bcRIG-Ib. Furthermore, bcLGP2 enhanced the K48-linked ubiquitination of bcRIG-Ib, promoting proteasome-dependent degradation of bcRIG-Ib. Thus, our data supported the conclusion that bcLGP2 interacted with and induced degradation of bcRIG-Ib through proteasome, leading to the dampened antiviral signaling mediated by bcRIG-Ib.
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Affiliation(s)
- Yixuan He
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Ji Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China; College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, China
| | - Yujia Miao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Meiling Liu
- College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, China
| | - Hui Wu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Jun Xiao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Hao Feng
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China.
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4
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The infection of murine gammaherpesvirus-68 delays the early embryonic development of zebrafish. REPRODUCTION AND BREEDING 2023. [DOI: 10.1016/j.repbre.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2023] Open
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5
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Lytic Replication and Reactivation from B Cells Is Not Required for Establishing or Maintaining Gammaherpesvirus Latency In Vivo. J Virol 2022; 96:e0069022. [PMID: 35647668 PMCID: PMC9215232 DOI: 10.1128/jvi.00690-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gammaherpesviruses (GHVs) are lymphotropic tumor viruses with a biphasic infectious cycle. Lytic replication at the primary site of infection is necessary for GHVs to spread throughout the host and establish latency in distal sites. Dissemination is mediated by infected B cells that traffic hematogenously from draining lymph nodes to peripheral lymphoid organs, such as the spleen. B cells serve as the major reservoir for viral latency, and it is hypothesized that periodic reactivation from latently infected B cells contributes to maintaining long-term chronic infection. While fundamentally important to an understanding of GHV biology, aspects of B cell infection in latency establishment and maintenance are incompletely defined, especially roles for lytic replication and reactivation in this cell type. To address this knowledge gap and overcome limitations of replication-defective viruses, we generated a recombinant murine gammaherpesvirus 68 (MHV68) in which ORF50, the gene that encodes the essential immediate-early replication and transcription activator protein (RTA), was flanked by loxP sites to enable conditional ablation of lytic replication by ORF50 deletion in cells that express Cre recombinase. Following infection of mice that encode Cre in B cells with this virus, splenomegaly and viral reactivation from splenocytes were significantly reduced; however, the number of latently infected splenocytes was equivalent to WT MHV68. Despite ORF50 deletion, MHV68 latency was maintained over time in spleens of mice at levels approximating WT, reactivation-competent MHV68. Treatment of infected mice with lipopolysaccharide (LPS), which promotes B cell activation and MHV68 reactivation ex vivo, yielded equivalent increases in the number of latently infected cells for both ORF50-deleted and WT MHV68, even when mice were simultaneously treated with the antiviral drug cidofovir to prevent reactivation. Together, these data demonstrate that productive viral replication in B cells is not required for MHV68 latency establishment and support the hypothesis that B cell proliferation facilitates latency maintenance in vivo in the absence of reactivation. IMPORTANCE Gammaherpesviruses establish lifelong chronic infections in cells of the immune system and place infected hosts at risk for developing lymphomas and other diseases. It is hypothesized that gammaherpesviruses must initiate acute infection in these cells to establish and maintain long-term infection, but this has not been directly tested. We report here the use of a viral genetic system that allows for cell-type-specific deletion of a viral gene that is essential for replication and reactivation. We employ this system in an in vivo model to reveal that viral replication is not required to initiate or maintain infection within B cells.
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Chen Y, Zhao M, Fan X, Zhu P, Jiang Z, Li F, Yuan W, You S, Chen J, Li Y, Shi Y, Zhu X, Ye X, Li F, Zhuang J, Li Y, Jiang Z, Wang Y, Wu X. Engagement of gcFKBP5/TRAF2 by spring viremia of carp virus to promote host cell apoptosis for supporting viral replication in grass carp. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 127:104291. [PMID: 34710469 DOI: 10.1016/j.dci.2021.104291] [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: 07/30/2021] [Revised: 10/07/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Spring viremia of carp virus (SVCV) causes severe morbidity and mortality in grass carp (Ctenopharyngodon idellus) in Europe, America and several Asian countries. We found that FKBP5 (FK506-binding protein 5) is an SVCV infection response factor; however, its role in the innate immune mechanism caused by SVCV infection remains unknown. This study cloned gcFKBP5 (grass carp FKBP5) and made its mimic protein structure for function discussion. We found that gcFKBP5 expression in the primary innate immune organs of grass carp, including intestine, liver and spleen, was highly upregulated by SVCV in 24 h, with a similar result in fish cells by poly(I:C) treatment. gcFKBP overexpression aggravates viral damage to cells and increases viral replication. Furthermore, SVCV engages gcFKBP5 interacting with TRAF2 (tumour necrosis factor receptor-associated factor 2) to promote host cell apoptosis for supporting viral replication. The enhanced viral replication seems not to be due to the repression of IFN and other antiviral factors as expected. For the first time, these data show the pivotal role of gcFKBP5 in the innate immune response of grass carp to SVCV infection.
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Affiliation(s)
- Yu Chen
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Mengjing Zhao
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Xiongwei Fan
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Ping Zhu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Zhaobiao Jiang
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Faxiang Li
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Wuzhou Yuan
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Shiqi You
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Jimei Chen
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Yunxuan Li
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Yan Shi
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Xiaolan Zhu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Xiangli Ye
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Fang Li
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Jian Zhuang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510100, China
| | - Yongqing Li
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Zhigang Jiang
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China.
| | - Yuequn Wang
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China.
| | - Xiushan Wu
- State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China.
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Huang H, Zhao J, Wang TY, Zhang S, Zhou Y, Rao Y, Qin C, Liu Y, Chen Y, Xia Z, Feng P. Species-Specific Deamidation of RIG-I Reveals Collaborative Action between Viral and Cellular Deamidases in HSV-1 Lytic Replication. mBio 2021; 12:e00115-21. [PMID: 33785613 PMCID: PMC8092204 DOI: 10.1128/mbio.00115-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 02/23/2021] [Indexed: 12/17/2022] Open
Abstract
Retinoic acid-inducible gene I (RIG-I) is a sensor that recognizes cytosolic double-stranded RNA derived from microbes to induce host immune response. Viruses, such as herpesviruses, deploy diverse mechanisms to derail RIG-I-dependent innate immune defense. In this study, we discovered that mouse RIG-I is intrinsically resistant to deamidation and evasion by herpes simplex virus 1 (HSV-1). Comparative studies involving human and mouse RIG-I indicate that N495 of human RIG-I dictates species-specific deamidation by HSV-1 UL37. Remarkably, deamidation of the other site, N549, hinges on that of N495, and it is catalyzed by cellular phosphoribosylpyrophosphate amidotransferase (PPAT). Specifically, deamidation of N495 enables RIG-I to interact with PPAT, leading to subsequent deamidation of N549. Collaboration between UL37 and PPAT is required for HSV-1 to evade RIG-I-mediated antiviral immune response. This work identifies an immune regulatory role of PPAT in innate host defense and establishes a sequential deamidation event catalyzed by distinct deamidases in immune evasion.IMPORTANCE Herpesviruses are ubiquitous pathogens in human and establish lifelong persistence despite host immunity. The ability to evade host immune response is pivotal for viral persistence and pathogenesis. In this study, we investigated the evasion, mediated by deamidation, of species-specific RIG-I by herpes simplex virus 1 (HSV-1). Our findings uncovered a collaborative and sequential action between viral deamidase UL37 and a cellular glutamine amidotransferase, phosphoribosylpyrophosphate amidotransferase (PPAT), to inactivate RIG-I and mute antiviral gene expression. PPAT catalyzes the rate-limiting step of the de novo purine synthesis pathway. This work describes a new function of cellular metabolic enzymes in host defense and viral immune evasion.
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Affiliation(s)
- Huichao Huang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
- Department of Oncology, NHC Key Laboratory of Cancer Proteomics, XiangYa Hospital, Central South University, Changsha, Hunan, China
| | - Jun Zhao
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
| | - Ting-Yu Wang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
| | - Shu Zhang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
| | - Yuzheng Zhou
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
- Department of Cell Biology, Hunan Key Laboratory of Animal Models for Human Diseases, Hunan Key Laboratory of Medical Genetics and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Youliang Rao
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
| | - Chao Qin
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
| | - Yongzhen Liu
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
| | - Yongheng Chen
- Department of Oncology, NHC Key Laboratory of Cancer Proteomics, XiangYa Hospital, Central South University, Changsha, Hunan, China
| | - Zanxian Xia
- Department of Cell Biology, Hunan Key Laboratory of Animal Models for Human Diseases, Hunan Key Laboratory of Medical Genetics and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Pinghui Feng
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA
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8
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Abstract
Viral infection can dramatically change the gene expression landscape of the host cell, yet little is known regarding changes in noncoding gene transcription by RNA polymerase III (RNAPIII). Among these are transfer RNAs (tRNAs), which are fundamental in protein translation, yet whose gene regulatory features remain largely undefined in mammalian cells. Transfer RNAs (tRNAs) are transcribed by RNA polymerase III (RNAPIII) and play a central role in decoding our genome, yet their expression and noncanonical function remain understudied. Many DNA tumor viruses enhance the activity of RNAPIII, yet whether infection alters tRNA expression is largely unknown. Here, we present the first genome-wide analysis of how viral infection alters the tRNAome. Using a tRNA-specific sequencing method (DM-tRNA-seq), we find that the murine gammaherpesvirus MHV68 induces global changes in premature tRNA (pre-tRNA) expression, with 14% of tRNA genes upregulated more than 3-fold, indicating that differential tRNA gene induction is a characteristic of DNA virus infection. Elevated pre-tRNA expression corresponds to increased RNAPIII occupancy for the subset of tRNA genes tested; additionally, posttranscriptional mechanisms contribute to the accumulation of pre-tRNA species. We find increased abundance of tRNA fragments derived from pre-tRNAs upregulated by viral infection, suggesting that noncanonical tRNA cleavage is also affected. Furthermore, pre-tRNA accumulation, but not RNAPIII recruitment, requires gammaherpesvirus-induced degradation of host mRNAs by the virally encoded mRNA endonuclease muSOX. We hypothesize that depletion of pre-tRNA maturation or turnover machinery contributes to robust accumulation of full-length pre-tRNAs in infected cells. Collectively, these findings reveal pervasive changes to tRNA expression during DNA virus infection and highlight the potential of using viruses to explore tRNA biology.
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Zhang LN, Li MJ, Shang YH, Zhao FF, Huang HC, Lao FX. Independent and Correlated Role of Apolipoprotein E ɛ4 Genotype and Herpes Simplex Virus Type 1 in Alzheimer's Disease. J Alzheimers Dis 2020; 77:15-31. [PMID: 32804091 DOI: 10.3233/jad-200607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The ɛ4 allele of the Apolipoprotein E (APOE) gene in individuals infected by Herpes simplex virus type 1 (HSV-1) has been demonstrated to be a risk factor in Alzheimer's disease (AD). APOE-ɛ4 reduces the levels of neuronal cholesterol, interferes with the transportation of cholesterol, impairs repair of synapses, decreases the clearance of neurotoxic peptide amyloid-β (Aβ), and promotes the deposition of amyloid plaque, and eventually may cause development of AD. HSV-1 enters host cells and can infect the olfactory system, trigeminal ganglia, entorhinal cortex, and hippocampus, and may cause AD-like pathological changes. The lifecycle of HSV-1 goes through a long latent phase. HSV-1 induces neurotropic cytokine expression with pro-inflammatory action and inhibits antiviral cytokine production in AD. It should be noted that interferons display antiviral activity in HSV-1-infected AD patients. Reactivated HSV-1 is associated with infectious burden in cognitive decline and AD. Finally, HSV-1 DNA has been confirmed as present in human brains and is associated with APOEɛ4 in AD. HSV-1 and APOEɛ4 increase the risk of AD and relate to abnormal autophagy, higher concentrations of HSV-1 DNA in AD, and formation of Aβ plaques and neurofibrillary tangles.
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Affiliation(s)
- Li-Na Zhang
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, P.R. China.,Institute of Functional Factors and Brain Science, Beijing Union University, Beijing, P.R. China.,College of Biochemical Engineering, Beijing Union University, Beijing, P.R. China
| | - Meng-Jie Li
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, P.R. China.,Institute of Functional Factors and Brain Science, Beijing Union University, Beijing, P.R. China.,College of Biochemical Engineering, Beijing Union University, Beijing, P.R. China
| | - Ying-Hui Shang
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, P.R. China.,Institute of Functional Factors and Brain Science, Beijing Union University, Beijing, P.R. China.,College of Biochemical Engineering, Beijing Union University, Beijing, P.R. China
| | - Fan-Fan Zhao
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, P.R. China.,Institute of Functional Factors and Brain Science, Beijing Union University, Beijing, P.R. China.,College of Biochemical Engineering, Beijing Union University, Beijing, P.R. China
| | - Han-Chang Huang
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, P.R. China.,Institute of Functional Factors and Brain Science, Beijing Union University, Beijing, P.R. China.,College of Biochemical Engineering, Beijing Union University, Beijing, P.R. China
| | - Feng-Xue Lao
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing, P.R. China.,Institute of Functional Factors and Brain Science, Beijing Union University, Beijing, P.R. China.,College of Biochemical Engineering, Beijing Union University, Beijing, P.R. China
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10
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Conserved Herpesvirus Kinase ORF36 Activates B2 Retrotransposons during Murine Gammaherpesvirus Infection. J Virol 2020; 94:JVI.00262-20. [PMID: 32404524 DOI: 10.1128/jvi.00262-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022] Open
Abstract
Short interspersed nuclear elements (SINEs) are RNA polymerase III (RNAPIII)-transcribed, retrotransposable noncoding RNA (ncRNA) elements ubiquitously spread throughout mammalian genomes. While normally silenced in healthy somatic tissue, SINEs can be induced during infection with DNA viruses, including the model murine gammaherpesvirus 68 (MHV68). Here, we explored the mechanisms underlying MHV68 activation of SINE ncRNAs. We demonstrate that lytic MHV68 infection of B cells, macrophages, and fibroblasts leads to robust activation of the B2 family of SINEs in a cell-autonomous manner. B2 ncRNA induction requires neither host innate immune signaling factors nor involvement of the RNAPIII master regulator Maf1. However, we identified MHV68 ORF36, the conserved herpesviral kinase, as playing a key role in B2 induction during lytic infection. SINE activation is linked to ORF36 kinase activity and can also be induced by inhibition of histone deacetylases 1 and 2 (HCAC 1/2), which is one of the known ORF36 functions. Collectively, our data suggest that ORF36-mediated changes in chromatin modification contribute to B2 activation during MHV68 infection and that this activity is conserved in other herpesviral protein kinase homologs.IMPORTANCE Viral infection dramatically changes the levels of many types of RNA in a cell. In particular, certain oncogenic viruses activate expression of repetitive genes called retrotransposons, which are normally silenced due to their ability to copy and spread throughout the genome. Here, we established that infection with the gammaherpesvirus MHV68 leads to a dramatic induction of a class of noncoding retrotransposons called B2 SINEs in multiple cell types. We then explored how MHV68 activates B2 SINEs, revealing a role for the conserved herpesviral protein kinase ORF36. Both ORF36 kinase-dependent and kinase-independent functions contribute to B2 induction, perhaps through ORF36 targeting of proteins involved in controlling the accessibility of chromatin surrounding SINE loci. Understanding the features underlying induction of these elements following MHV68 infection should provide insight into core elements of SINE regulation, as well as disregulation of SINE elements associated with disease.
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Deamidation Shunts RelA from Mediating Inflammation to Aerobic Glycolysis. Cell Metab 2020; 31:937-955.e7. [PMID: 32325032 PMCID: PMC7257911 DOI: 10.1016/j.cmet.2020.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 01/15/2020] [Accepted: 04/02/2020] [Indexed: 12/11/2022]
Abstract
Cell proliferation and inflammation are two metabolically demanding biological processes. How these competing processes are selectively executed in the same cell remains unknown. Here, we report that the enzyme carbamoyl-phosphate synthetase, aspartyl transcarbamoylase, and dihydroorotase (CAD) deamidates the RelA subunit of NF-κB in cancer cells to promote aerobic glycolysis and fuel cell proliferation in tumorigenesis. This post-translational modification switches RelA function from mediating the expression of NF-κB-responsive genes to that of glycolytic enzymes, thus shunting the cell's inflammatory response to aerobic glycolysis. Further, we profiled diverse human cancer cell lines and found that high CAD expression and a subset of RELA mutations correlated with RelA deamidation. And by use of inhibitors of key glycolytic enzymes, we validated the pivotal role of RelA deamidation in tumorigenesis of cancer cell lines. This work illuminates a mechanism by which protein deamidation selectively specifies gene expression and consequent biological processes.
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12
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López-Rodríguez DM, Kirillov V, Krug LT, Mesri EA, Andreansky S. A role of hypoxia-inducible factor 1 alpha in Murine Gammaherpesvirus 68 (MHV68) lytic replication and reactivation from latency. PLoS Pathog 2019; 15:e1008192. [PMID: 31809522 PMCID: PMC6975554 DOI: 10.1371/journal.ppat.1008192] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 01/22/2020] [Accepted: 11/05/2019] [Indexed: 12/15/2022] Open
Abstract
The hypoxia-inducible factor 1 alpha (HIF1α) protein and the hypoxic microenvironment are critical for infection and pathogenesis by the oncogenic gammaherpesviruses (γHV), Kaposi sarcoma herpes virus (KSHV) and Epstein-Barr virus (EBV). However, understanding the role of HIF1α during the virus life cycle and its biological relevance in the context of host has been challenging due to the lack of animal models for human γHV. To study the role of HIF1α, we employed the murine gammaherpesvirus 68 (MHV68), a rodent pathogen that readily infects laboratory mice. We show that MHV68 infection induces HIF1α protein and HIF1α-responsive gene expression in permissive cells. siRNA silencing or drug-inhibition of HIF1α reduce virus production due to a global downregulation of viral gene expression. Most notable was the marked decrease in many viral genes bearing hypoxia-responsive elements (HREs) such as the viral G-Protein Coupled Receptor (vGPCR), which is known to activate HIF1α transcriptional activity during KSHV infection. We found that the promoter of MHV68 ORF74 is responsive to HIF1α and MHV-68 RTA. Moreover, Intranasal infection of HIF1αLoxP/LoxP mice with MHV68 expressing Cre- recombinase impaired virus expansion during early acute infection and affected lytic reactivation in the splenocytes explanted from mice. Low oxygen concentrations accelerated lytic reactivation and enhanced virus production in MHV68 infected splenocytes. Thus, we conclude that HIF1α plays a critical role in promoting virus replication and reactivation from latency by impacting viral gene expression. Our results highlight the importance of the mutual interactions of the oxygen-sensing machinery and gammaherpesviruses in viral replication and pathogenesis.
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Affiliation(s)
- Darlah M. López-Rodríguez
- Department of Microbiology and Immunology and Miami Center for AIDS Research, Miami, Florida, United States of America
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Varvara Kirillov
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Laurie T. Krug
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
- IV and AIDS Malignancy Branch, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Enrique A. Mesri
- Department of Microbiology and Immunology and Miami Center for AIDS Research, Miami, Florida, United States of America
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Samita Andreansky
- Department of Microbiology and Immunology and Miami Center for AIDS Research, Miami, Florida, United States of America
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Florida
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13
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Epstein-Barr Virus and Innate Immunity: Friends or Foes? Microorganisms 2019; 7:microorganisms7060183. [PMID: 31238570 PMCID: PMC6617214 DOI: 10.3390/microorganisms7060183] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 06/20/2019] [Accepted: 06/22/2019] [Indexed: 12/16/2022] Open
Abstract
Epstein–Barr virus (EBV) successfully persists in the vast majority of adults but causes lymphoid and epithelial malignancies in a small fraction of latently infected individuals. Innate immunity is the first-line antiviral defense, which EBV has to evade in favor of its own replication and infection. EBV uses multiple strategies to perturb innate immune signaling pathways activated by Toll-like, RIG-I-like, NOD-like, and AIM2-like receptors as well as cyclic GMP-AMP synthase. EBV also counteracts interferon production and signaling, including TBK1-IRF3 and JAK-STAT pathways. However, activation of innate immunity also triggers pro-inflammatory response and proteolytic cleavage of caspases, both of which exhibit proviral activity under some circumstances. Pathogenic inflammation also contributes to EBV oncogenesis. EBV activates NFκB signaling and induces pro-inflammatory cytokines. Through differential modulation of the proviral and antiviral roles of caspases and other host factors at different stages of infection, EBV usurps cellular programs for death and inflammation to its own benefits. The outcome of EBV infection is governed by a delicate interplay between innate immunity and EBV. A better understanding of this interplay will instruct prevention and intervention of EBV-associated cancers.
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14
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Liu Q, Rao Y, Tian M, Zhang S, Feng P. Modulation of Innate Immune Signaling Pathways by Herpesviruses. Viruses 2019; 11:E572. [PMID: 31234396 PMCID: PMC6630988 DOI: 10.3390/v11060572] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 06/16/2019] [Accepted: 06/18/2019] [Indexed: 12/25/2022] Open
Abstract
Herpesviruses can be detected by pattern recognition receptors (PRRs), which then activate downstream adaptors, kinases and transcription factors (TFs) to induce the expression of interferons (IFNs) and inflammatory cytokines. IFNs further activate the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, inducing the expression of interferon-stimulated genes (ISGs). These signaling events constitute host innate immunity to defeat herpesvirus infection and replication. A hallmark of all herpesviruses is their ability to establish persistent infection in the presence of active immune response. To achieve this, herpesviruses have evolved multiple strategies to suppress or exploit host innate immune signaling pathways to facilitate their infection. This review summarizes the key host innate immune components and their regulation by herpesviruses during infection. Also we highlight unanswered questions and research gaps for future perspectives.
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Affiliation(s)
- Qizhi Liu
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, 925 W 34th Street, Los Angeles, CA 90089, USA.
| | - Youliang Rao
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, 925 W 34th Street, Los Angeles, CA 90089, USA.
| | - Mao Tian
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, 925 W 34th Street, Los Angeles, CA 90089, USA.
| | - Shu Zhang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, 925 W 34th Street, Los Angeles, CA 90089, USA.
| | - Pinghui Feng
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, 925 W 34th Street, Los Angeles, CA 90089, USA.
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15
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Zhang J, Zhao J, Xu S, Li J, He S, Zeng Y, Xie L, Xie N, Liu T, Lee K, Seo GJ, Chen L, Stabell AC, Xia Z, Sawyer SL, Jung J, Huang C, Feng P. Species-Specific Deamidation of cGAS by Herpes Simplex Virus UL37 Protein Facilitates Viral Replication. Cell Host Microbe 2018; 24:234-248.e5. [PMID: 30092200 PMCID: PMC6094942 DOI: 10.1016/j.chom.2018.07.004] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/26/2018] [Accepted: 06/26/2018] [Indexed: 02/05/2023]
Abstract
Herpes simplex virus 1 (HSV-1) establishes infections in humans and mice, but some non-human primates exhibit resistance via unknown mechanisms. Innate immune recognition pathways are highly conserved but are pivotal in determining susceptibility to DNA virus infections. We report that variation of a single amino acid residue in the innate immune sensor cGAS determines species-specific inactivation by HSV-1. The HSV-1 UL37 tegument protein deamidates human and mouse cGAS. Deamidation impairs the ability of cGAS to catalyze cGAMP synthesis, which activates innate immunity. HSV-1 with deamidase-deficient UL37 promotes robust antiviral responses and is attenuated in mice in a cGAS- and STING-dependent manner. Mutational analyses identified a single asparagine in human and mouse cGAS that is not conserved in many non-human primates. This residue underpins UL37-mediated cGAS deamidation and species permissiveness of HSV-1. Thus, HSV-1 mediates cGAS deamidation for immune evasion and exploits species sequence variation to disarm host defenses.
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Affiliation(s)
- Junjie Zhang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jun Zhao
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Simin Xu
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Junhua Li
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Shanping He
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; School of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Yi Zeng
- Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Linshen Xie
- The Fourth West China Hospital, Sichuan University, Chengdu, China
| | - Na Xie
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| | - Ting Liu
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Katie Lee
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Gil Ju Seo
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Lin Chen
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Alex C Stabell
- BioFrontiers Institute and Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Zanxian Xia
- School of Life Sciences, Central South University, Changsha, Hunan 410008, China
| | - Sara L Sawyer
- BioFrontiers Institute and Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Jae Jung
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Canhua Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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16
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Shen Y, Wang S, Sun F, Zheng G, Wu T, Du Y, Zhang S, Qian J, Sun R. Inhibition of murine herpesvirus-68 replication by IFN-gamma in macrophages is counteracted by the induction of SOCS1 expression. PLoS Pathog 2018; 14:e1007202. [PMID: 30075008 PMCID: PMC6093694 DOI: 10.1371/journal.ppat.1007202] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/15/2018] [Accepted: 07/08/2018] [Indexed: 01/20/2023] Open
Abstract
Gamma interferon (IFN-γ) is known to negatively regulate murine gammaherpesvirus-68 (MHV-68 or γHV-68) replication. This process involves the suppression of the viral gene replication and transcription activator (RTA) promoter, as well as activation of signal transducers and activators of transcription (STAT1). Notably, this effect is gradually attenuated during MHV-68 infection of bone marrow-derived macrophages (BMMs), which raised the possibility that the virus may utilize a mechanism that counteracts the antiviral effect of IFN-γ. By identifying the cellular factors that negatively regulate JAK-STAT1 signaling, we revealed that the infection of BMMs by MHV-68 induces the expression of suppressor of cytokine signaling 1 (SOCS1) and that depletion of SOCS1 restores the inhibitory effect of IFN-γ on virus replication. Moreover, we demonstrated that the expression of SOCS1 was induced as a result of the Toll-like receptor 3 (TLR3) mediated activation of the NF-κB signaling cascade. In conclusion, we report that TLR3-TRAF-NF-κB signaling pathway play a role in the induction of SOCS1 that counteracts the antiviral effect of IFN-γ during MHV-68 infection. This process is cell type-specific: it is functional in macrophages, but not in epithelial cells or fibroblasts. Our study reveals a mechanism that balances the immune responses and the escape of a gamma-herpesvirus in some antigen-presenting cells.
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Affiliation(s)
- Yong Shen
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Saisai Wang
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Fangfang Sun
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Gang Zheng
- Department of Cardiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Tingting Wu
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Yushen Du
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Suzhan Zhang
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
| | - Jing Qian
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, P. R. China
| | - Ren Sun
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- Research Center of Infection and Immunity, ZJU-UCLA Joint Center for Medical Education and Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, P. R. China
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
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17
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Van Skike ND, Minkah NK, Hogan CH, Wu G, Benziger PT, Oldenburg DG, Kara M, Kim-Holzapfel DM, White DW, Tibbetts SA, French JB, Krug LT. Viral FGARAT ORF75A promotes early events in lytic infection and gammaherpesvirus pathogenesis in mice. PLoS Pathog 2018; 14:e1006843. [PMID: 29390024 PMCID: PMC5811070 DOI: 10.1371/journal.ppat.1006843] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 02/13/2018] [Accepted: 12/27/2017] [Indexed: 12/19/2022] Open
Abstract
Gammaherpesviruses encode proteins with homology to the cellular purine metabolic enzyme formyl-glycinamide-phosphoribosyl-amidotransferase (FGARAT), but the role of these viral FGARATs (vFGARATs) in the pathogenesis of a natural host has not been investigated. We report a novel role for the ORF75A vFGARAT of murine gammaherpesvirus 68 (MHV68) in infectious virion production and colonization of mice. MHV68 mutants with premature stop codons in orf75A exhibited a log reduction in acute replication in the lungs after intranasal infection, which preceded a defect in colonization of multiple host reservoirs including the mediastinal lymph nodes, peripheral blood mononuclear cells, and the spleen. Intraperitoneal infection rescued splenic latency, but not reactivation. The 75A.stop virus also exhibited defective replication in primary fibroblast and macrophage cells. Viruses produced in the absence of ORF75A were characterized by an increase in the ratio of particles to PFU. In the next round of infection this led to the alteration of early events in lytic replication including the deposition of the ORF75C tegument protein, the accelerated kinetics of viral gene expression, and induction of TNFα release and cell death. Infecting cells to deliver equivalent genomes revealed that ORF75A was required for initiating early events in infection. In contrast with the numerous phenotypes observed in the absence of ORF75A, ORF75B was dispensable for replication and pathogenesis. These studies reveal that murine rhadinovirus vFGARAT family members ORF75A and ORF75C have evolved to perform divergent functions that promote replication and colonization of the host. Gammaherpesviruses are infectious agents that cause cancer. The study of viral genes unique to this subfamily may offer insight into the strategies that these viruses use to persist in the host and drive disease. The vFGARATs are a family of viral proteins found only in gammaherpesviruses, and are critical for replication in cell culture. Here we report that a rhadinovirus of rodents requires a previously uncharacterized vFGARAT family member, ORF75A, to support viral growth and persistence in mice. In addition, viruses lacking ORF75A are defective in the production of infectious viral particles. Thus, duplications and functional divergence of the various vFGARATs in the rhadinovirus lineage have likely been driven by selective pressures to disseminate within and colonize the host. Identification of the shared host processes that are targeted by the diverse family of vFGARATs may reveal novel targets for therapeutic agents to prevent life-long infections by these oncogenic viruses.
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Affiliation(s)
- Nick D. Van Skike
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Nana K. Minkah
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Chad H. Hogan
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
- Graduate Program of Genetics, Stony Brook University, Stony Brook, New York, United States of America
| | - Gary Wu
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Peter T. Benziger
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | | | - Mehmet Kara
- Department of Molecular Genetics and Microbiology and UF Shands Cancer Center, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Deborah M. Kim-Holzapfel
- Departments of Chemistry and of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, United States of America
| | - Douglas W. White
- Gundersen Health System, La Crosse, Wisconsin, United States of America
| | - Scott A. Tibbetts
- Department of Molecular Genetics and Microbiology and UF Shands Cancer Center, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Jarrod B. French
- Departments of Chemistry and of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, United States of America
| | - Laurie T. Krug
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
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18
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Dunker W, Zhao Y, Song Y, Karijolich J. Recognizing the SINEs of Infection: Regulation of Retrotransposon Expression and Modulation of Host Cell Processes. Viruses 2017; 9:v9120386. [PMID: 29258254 PMCID: PMC5744160 DOI: 10.3390/v9120386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/12/2017] [Accepted: 12/17/2017] [Indexed: 12/16/2022] Open
Abstract
Short interspersed elements (SINEs) are a family of retrotransposons evolutionarily derived from cellular RNA polymerase III transcripts. Over evolutionary time, SINEs have expanded throughout the human genome and today comprise ~11% of total chromosomal DNA. While generally transcriptionally silent in healthy somatic cells, SINE expression increases during a variety of types of stresses, including DNA virus infection. The relevance of SINE expression to viral infection was largely unexplored, however, recent years have seen great progress towards defining the impact of SINE expression on viral replication and host gene expression. Here we review the origin and diversity of SINE elements and their transcriptional control, with an emphasis on how their expression impacts host cell biology during viral infection.
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Affiliation(s)
- William Dunker
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA.
| | - Yang Zhao
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA.
| | - Yu Song
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA.
- College of Pharmacy, Xinxiang Medical University, Xingxiang 453000, China.
| | - John Karijolich
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA.
- Vanderbilt-Ingram Cancer Center, Nashville, TN 37232-2363, USA.
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19
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Abstract
Our genomes are dominated by repetitive elements. The majority of these elements derive from retrotransposons, which expand throughout the genome through a process of reverse transcription and integration. Short interspersed nuclear elements, or SINEs, are an abundant class of retrotransposons that are transcribed by RNA polymerase III, thus generating exclusively noncoding RNA (ncRNA) that must hijack the machinery required for their transposition. SINE loci are generally transcriptionally repressed in somatic cells but can be robustly induced upon infection with multiple DNA viruses. Recent research has focused on the gene expression and signaling events that are modulated by SINE ncRNAs, particularly during gammaherpesvirus infection. Here, we review the biology of these SINE ncRNAs, explore how DNA virus infection may lead to their induction, and describe how novel gene regulatory and immune-related functions of these ncRNAs may impact the viral life cycle.
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20
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Karijolich J, Zhao Y, Alla R, Glaunsinger B. Genome-wide mapping of infection-induced SINE RNAs reveals a role in selective mRNA export. Nucleic Acids Res 2017; 45:6194-6208. [PMID: 28334904 PMCID: PMC5449642 DOI: 10.1093/nar/gkx180] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 03/08/2017] [Indexed: 12/11/2022] Open
Abstract
Short interspersed nuclear elements (SINEs) are retrotransposons evolutionarily derived from endogenous RNA Polymerase III RNAs. Though SINE elements have undergone exaptation into gene regulatory elements, how transcribed SINE RNA impacts transcriptional and post-transcriptional regulation is largely unknown. This is partly due to a lack of information regarding which of the loci have transcriptional potential. Here, we present an approach (short interspersed nuclear element sequencing, SINE-seq), which selectively profiles RNA Polymerase III-derived SINE RNA, thereby identifying transcriptionally active SINE loci. Applying SINE-seq to monitor murine B2 SINE expression during a gammaherpesvirus infection revealed transcription from 28 270 SINE loci, with ∼50% of active SINE elements residing within annotated RNA Polymerase II loci. Furthermore, B2 RNA can form intermolecular RNA–RNA interactions with complementary mRNAs, leading to nuclear retention of the targeted mRNA via a mechanism involving p54nrb. These findings illuminate a pathway for the selective regulation of mRNA export during stress via retrotransposon activation.
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Affiliation(s)
- John Karijolich
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3370, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3370, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232-2363, USA
| | - Yang Zhao
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232-2363, USA
| | - Ravi Alla
- California Institute for Quantitative Biology, University of California, Berkeley, CA 94720-3370, USA
| | - Britt Glaunsinger
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3370, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3370, USA.,California Institute for Quantitative Biology, University of California, Berkeley, CA 94720-3370, USA
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Xiao J, Yan C, Zhou W, Li J, Wu H, Chen T, Feng H. CARD and TM of MAVS of black carp play the key role in its self-association and antiviral ability. FISH & SHELLFISH IMMUNOLOGY 2017; 63:261-269. [PMID: 28232279 DOI: 10.1016/j.fsi.2017.02.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 06/06/2023]
Abstract
Mitochondrial antiviral signaling protein (MAVS) is an adaptor protein of the innate immune system of higher vertebrate. In this paper, the transcription profile of black carp MAVS (bcMAVS) in host cells in response to spring viremia of carp virus (SVCV) and grass carp reovirus (GCRV) infection was identified. EPC cells expressing bcMAVS possessed obviously enhanced antiviral activity against both SVCV and GCRV. Immunofluorescence (IF) staining data demonstrated that bcMAVS molecules were redistributed and formed aggregates on the mitochondria of EPC cells after virus infection. Co-immunoprecipitation (co-IP) assay in HEK293T cells demonstrated that bcMAVS proteins bound to each other, which suggested that this fish protein owned self-association in vivo. IF assay identified that the transmembrane (TM) domain of bcMAVS was crucial for its mitochondrial localization. Co-IP assays among bcMAVS mutants demonstrated that both N-terminal caspase recruitment domain (CARD) and TM domain were indispensible for dimerization of bcMAVS. It was interesting that Truncated-bcMAVS possessed much enhanced interferon-inducing activity and antiviral ability than wild type bcMAVS, which only contains CARD and TM. All the data generated in this study support the idea that oligomerization of bcMAVS on mitochondrion is crucial for the antiviral ability of bcMAVS, which is depend on both CARD and TM domain of this fish MAVS orthologue.
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Affiliation(s)
- Jun Xiao
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Chuanzhe Yan
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Wei Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Jun Li
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Hui Wu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Tiansheng Chen
- College of Fisheries, Huazhong Agricultural University, Wuhan 410081, China
| | - Hao Feng
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; College of Life Science, Hunan Normal University, Changsha 410081, China.
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22
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Santana AL, Oldenburg DG, Kirillov V, Malik L, Dong Q, Sinayev R, Marcu KB, White DW, Krug LT. RTA Occupancy of the Origin of Lytic Replication during Murine Gammaherpesvirus 68 Reactivation from B Cell Latency. Pathogens 2017; 6:pathogens6010009. [PMID: 28212352 PMCID: PMC5371897 DOI: 10.3390/pathogens6010009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 02/10/2017] [Indexed: 02/06/2023] Open
Abstract
RTA, the viral Replication and Transcription Activator, is essential for rhadinovirus lytic gene expression upon de novo infection and reactivation from latency. Lipopolysaccharide (LPS)/toll-like receptor (TLR)4 engagement enhances rhadinovirus reactivation. We developed two new systems to examine the interaction of RTA with host NF-kappaB (NF-κB) signaling during murine gammaherpesvirus 68 (MHV68) infection: a latent B cell line (HE-RIT) inducible for RTA-Flag expression and virus reactivation; and a recombinant virus (MHV68-RTA-Bio) that enabled in vivo biotinylation of RTA in BirA transgenic mice. LPS acted as a second stimulus to drive virus reactivation from latency in the context of induced expression of RTA-Flag. ORF6, the gene encoding the single-stranded DNA binding protein, was one of many viral genes that were directly responsive to RTA induction; expression was further increased upon treatment with LPS. However, NF-κB sites in the promoter of ORF6 did not influence RTA transactivation in response to LPS in HE-RIT cells. We found no evidence for RTA occupancy of the minimal RTA-responsive region of the ORF6 promoter, yet RTA was found to complex with a portion of the right origin of lytic replication (oriLyt-R) that contains predicted RTA recognition elements. RTA occupancy of select regions of the MHV-68 genome was also evaluated in our novel in vivo RTA biotinylation system. Streptavidin isolation of RTA-Bio confirmed complex formation with oriLyt-R in LPS-treated primary splenocytes from BirA mice infected with MHV68 RTA-Bio. We demonstrate the utility of reactivation-inducible B cells coupled with in vivo RTA biotinylation for mechanistic investigations of the interplay of host signaling with RTA.
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Affiliation(s)
- Alexis L Santana
- The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY 10016, USA.
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA.
| | | | - Varvara Kirillov
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Laraib Malik
- Department of Computer Science, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Qiwen Dong
- Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Roman Sinayev
- Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Kenneth B Marcu
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA.
- Biomedical Research Foundation Academy of Athens (BRFAA), Athens 115 27, Greece.
- Biochemistry and Cell Biology Dept., Stony Brook University, Stony Brook, NY 11794, USA.
- Department of Pathology, Health Sciences Center, Stony Brook University, Stony Brook, NY 11794, USA.
| | | | - Laurie T Krug
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA.
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Zhao J, Zeng Y, Xu S, Chen J, Shen G, Yu C, Knipe D, Yuan W, Peng J, Xu W, Zhang C, Xia Z, Feng P. A Viral Deamidase Targets the Helicase Domain of RIG-I to Block RNA-Induced Activation. Cell Host Microbe 2016; 20:770-784. [PMID: 27866900 DOI: 10.1016/j.chom.2016.10.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/08/2016] [Accepted: 10/07/2016] [Indexed: 12/31/2022]
Abstract
RIG-I detects double-stranded RNA (dsRNA) to trigger antiviral cytokine production. Protein deamidation is emerging as a post-translational modification that chiefly regulates protein function. We report here that UL37 of herpes simplex virus 1 (HSV-1) is a protein deamidase that targets RIG-I to block RNA-induced activation. Mass spectrometry analysis identified two asparagine residues in the helicase 2i domain of RIG-I that were deamidated upon UL37 expression or HSV-1 infection. Deamidation rendered RIG-I unable to sense viral dsRNA, thus blocking its ability to trigger antiviral immune responses and restrict viral replication. Purified full-length UL37 and its carboxyl-terminal fragment were sufficient to deamidate RIG-I in vitro. Uncoupling RIG-I deamidation from HSV-1 infection, by engineering deamidation-resistant RIG-I or introducing deamidase-deficient UL37 into the HSV-1 genome, restored RIG-I activation and antiviral immune signaling. Our work identifies a viral deamidase and extends the paradigm of deamidation-mediated suppression of innate immunity by microbial pathogens.
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Affiliation(s)
- Jun Zhao
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Street, Los Angeles, CA 90033, USA
| | - Yi Zeng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Street, Los Angeles, CA 90033, USA
| | - Simin Xu
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Street, Los Angeles, CA 90033, USA
| | - Jie Chen
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Street, Los Angeles, CA 90033, USA; Division of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Guobo Shen
- Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Caiqun Yu
- Department of Chemistry, Dornsife College of Arts, Letters, and Sciences, University of Southern California, LJS 369, 840 Downey Way, Los Angeles, CA 90089, USA
| | - David Knipe
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Weiming Yuan
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Street, Los Angeles, CA 90033, USA
| | - Jian Peng
- Division of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Wenqing Xu
- Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Chao Zhang
- Department of Chemistry, Dornsife College of Arts, Letters, and Sciences, University of Southern California, LJS 369, 840 Downey Way, Los Angeles, CA 90089, USA
| | - Zanxian Xia
- State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan 410008, China
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Street, Los Angeles, CA 90033, USA.
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24
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Cieniewicz B, Santana AL, Minkah N, Krug LT. Interplay of Murine Gammaherpesvirus 68 with NF-kappaB Signaling of the Host. Front Microbiol 2016; 7:1202. [PMID: 27582728 PMCID: PMC4987367 DOI: 10.3389/fmicb.2016.01202] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/19/2016] [Indexed: 11/13/2022] Open
Abstract
Herpesviruses establish a chronic infection in the host characterized by intervals of lytic replication, quiescent latency, and reactivation from latency. Murine gammaherpesvirus 68 (MHV68) naturally infects small rodents and has genetic and biologic parallels with the human gammaherpesviruses (gHVs), Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus. The murine gammaherpesvirus model pathogen system provides a platform to apply cutting-edge approaches to dissect the interplay of gammaherpesvirus and host determinants that enable colonization of the host, and that shape the latent or lytic fate of an infected cell. This knowledge is critical for the development of novel therapeutic interventions against the oncogenic gHVs. The nuclear factor kappa B (NF-κB) signaling pathway is well-known for its role in the promotion of inflammation and many aspects of B cell biology. Here, we review key aspects of the virus lifecycle in the host, with an emphasis on the route that the virus takes to gain access to the B cell latency reservoir. We highlight how the murine gammaherpesvirus requires components of the NF-κB signaling pathway to promote replication, latency establishment, and maintenance of latency. These studies emphasize the complexity of gammaherpesvirus interactions with NF-κB signaling components that direct innate and adaptive immune responses of the host. Importantly, multiple facets of NF-κB signaling have been identified that might be targeted to reduce the burden of gammaherpesvirus-associated diseases.
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Affiliation(s)
- Brandon Cieniewicz
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook NY, USA
| | - Alexis L Santana
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook NY, USA
| | - Nana Minkah
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook NY, USA
| | - Laurie T Krug
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook NY, USA
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25
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Zhang J, Feng H, Zhao J, Feldman ER, Chen SY, Yuan W, Huang C, Akbari O, Tibbetts SA, Feng P. IκB Kinase ε Is an NFATc1 Kinase that Inhibits T Cell Immune Response. Cell Rep 2016; 16:405-418. [PMID: 27346349 DOI: 10.1016/j.celrep.2016.05.083] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/11/2016] [Accepted: 05/19/2016] [Indexed: 02/05/2023] Open
Abstract
Activation of nuclear factor of activated T cells (NFAT) is crucial for immune responses. IKKε is an IκB kinase (IKK)-related kinase, and the function of IKKε remains obscure in T cells, despite its abundant expression. We report that IKKε inhibits NFAT activation and T cell responses by promoting NFATc1 phosphorylation. During T cell activation, IKKε was transiently activated to phosphorylate NFATc1. Loss of IKKε elevated T cell antitumor and antiviral immunity and, therefore, reduced tumor development and persistent viral infection. IKKε was activated in CD8(+) T cells of mice bearing melanoma or persistently infected with a model herpesvirus. These results collectively show that IKKε promotes NFATc1 phosphorylation and inhibits T cell responses, identifying IKKε as a crucial negative regulator of T cell activation and a potential target for immunotherapy.
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Affiliation(s)
- Junjie Zhang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Hao Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA; Key Laboratory of Protein Chemistry and Developmental Biology of Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, P.R. China
| | - Jun Zhao
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Emily R Feldman
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Si-Yi Chen
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Weiming Yuan
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Canhua Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and Collaborative Innovation Center for Biotherapy, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Omid Akbari
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Scott A Tibbetts
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA.
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26
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Lopušná K, Benkóczka T, Lupták J, Matúšková R, Lukáčiková Ľ, Ovečková I, Režuchová I. Murine gammaherpesvirus targets type I IFN receptor but not type III IFN receptor early in infection. Cytokine 2016; 83:158-170. [PMID: 27152708 DOI: 10.1016/j.cyto.2016.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 02/07/2023]
Abstract
The innate immune response represents a primary line of defense against invading viral pathogens. Since epithelial cells are the primary site of gammaherpesvirus replication during infection in vivo and there are no information on activity of IFN-III signaling against gammaherpesviruses in this cell type, in present study, we evaluated the expression profile and virus-host interactions in mouse mammary epithelial cell (NMuMG) infected with three strains of murine gammaherpesvirus, MHV-68, MHV-72 and MHV-4556. Studying three strains of murine gammaherpesvirus, which differ in nucleotide sequence of some structural and non-structural genes, allowed us to compare the strain-dependent interactions with host organism. Our results clearly demonstrate that: (i) MHV-68, MHV-72 and MHV-4556 differentially interact with intracellular signaling and dysregulate IFN signal transduction; (ii) MHV-68, MHV-72 and MHV-4556 degrade type I IFN receptor in very early stages of infection (2-4hpi), but not type III IFN receptor; (iii) type III IFN signaling might play a key role in antiviral defense of epithelial cells in early stages of murine gammaherpesvirus replication; (iv) NMuMG cells are an appropriate model for study of not only type I IFN signaling, but also type III IFN signaling pathway. These findings are important for better understanding of individual virus-host interactions in lytic as well as in persistent gammaherpesvirus replication and help us to elucidate IFN-III function in early events of virus infection.
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Affiliation(s)
- Katarína Lopušná
- Institute of Virology, Biomedical Research Center of Slovak Academy of Sciences, Bratislava 845 05, Slovak Republic
| | - Tímea Benkóczka
- Institute of Virology, Biomedical Research Center of Slovak Academy of Sciences, Bratislava 845 05, Slovak Republic
| | - Jakub Lupták
- School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Radka Matúšková
- Institute of Virology, Biomedical Research Center of Slovak Academy of Sciences, Bratislava 845 05, Slovak Republic
| | - Ľubomíra Lukáčiková
- Institute of Virology, Biomedical Research Center of Slovak Academy of Sciences, Bratislava 845 05, Slovak Republic
| | - Ingrid Ovečková
- Institute of Virology, Biomedical Research Center of Slovak Academy of Sciences, Bratislava 845 05, Slovak Republic
| | - Ingeborg Režuchová
- Institute of Virology, Biomedical Research Center of Slovak Academy of Sciences, Bratislava 845 05, Slovak Republic.
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27
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Abstract
Protein deamidation has been considered a nonenzymatic process associated with protein functional decay or "aging." Recent studies implicate protein deamidation in regulating signal transduction in fundamental biological processes, such as innate immune responses. Work investigating gammaherpesviruses and bacterial pathogens indicates that microbial pathogens deploy deamidases or enzyme-deficient homologues (pseudoenzymes) to induce deamidation of key signaling components and evade host immune responses. Here, we review studies on protein deamidation in innate immune signaling and present several imminent questions concerning the roles of protein deamidation in infection and immunity.
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28
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Jha HC, Banerjee S, Robertson ES. The Role of Gammaherpesviruses in Cancer Pathogenesis. Pathogens 2016; 5:pathogens5010018. [PMID: 26861404 PMCID: PMC4810139 DOI: 10.3390/pathogens5010018] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 01/27/2016] [Indexed: 12/15/2022] Open
Abstract
Worldwide, one fifth of cancers in the population are associated with viral infections. Among them, gammaherpesvirus, specifically HHV4 (EBV) and HHV8 (KSHV), are two oncogenic viral agents associated with a large number of human malignancies. In this review, we summarize the current understanding of the molecular mechanisms related to EBV and KSHV infection and their ability to induce cellular transformation. We describe their strategies for manipulating major cellular systems through the utilization of cell cycle, apoptosis, immune modulation, epigenetic modification, and altered signal transduction pathways, including NF-kB, Notch, Wnt, MAPK, TLR, etc. We also discuss the important EBV latent antigens, namely EBNA1, EBNA2, EBNA3’s and LMP’s, which are important for targeting these major cellular pathways. KSHV infection progresses through the engagement of the activities of the major latent proteins LANA, v-FLIP and v-Cyclin, and the lytic replication and transcription activator (RTA). This review is a current, comprehensive approach that describes an in-depth understanding of gammaherpes viral encoded gene manipulation of the host system through targeting important biological processes in viral-associated cancers.
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Affiliation(s)
- Hem Chandra Jha
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Shuvomoy Banerjee
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Erle S Robertson
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
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29
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Zhao J, He S, Minassian A, Li J, Feng P. Recent advances on viral manipulation of NF-κB signaling pathway. Curr Opin Virol 2015; 15:103-11. [PMID: 26385424 PMCID: PMC4688235 DOI: 10.1016/j.coviro.2015.08.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/09/2015] [Accepted: 08/26/2015] [Indexed: 12/18/2022]
Abstract
NF-κB transcription factors regulate the expression of hundreds of genes primarily involved in immune responses. Signaling events leading to NF-κB activation constitute a major antiviral immune pathway. To replicate and persist within their hosts, viruses have evolved diverse strategies to evade and exploit cellular NF-κB immune signaling cascades for their benefit. We summarize recent studies concerning viral manipulation of the NF-κB signaling pathway downstream of pattern recognition receptors. Signal transduction mediated by pattern recognition receptors is a research frontier for both infectious disease and innate immunology.
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Affiliation(s)
- Jun Zhao
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, United States
| | - Shanping He
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, United States
| | - Arlet Minassian
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, United States
| | - Junhua Li
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, United States
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, United States.
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30
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Karijolich J, Abernathy E, Glaunsinger BA. Infection-Induced Retrotransposon-Derived Noncoding RNAs Enhance Herpesviral Gene Expression via the NF-κB Pathway. PLoS Pathog 2015; 11:e1005260. [PMID: 26584434 PMCID: PMC4652899 DOI: 10.1371/journal.ppat.1005260] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/13/2015] [Indexed: 02/07/2023] Open
Abstract
Short interspersed nuclear elements (SINEs) are highly abundant, RNA polymerase III-transcribed noncoding retrotransposons that are silenced in somatic cells but activated during certain stresses including viral infection. How these induced SINE RNAs impact the host-pathogen interaction is unknown. Here we reveal that during murine gammaherpesvirus 68 (MHV68) infection, rapidly induced SINE RNAs activate the antiviral NF-κB signaling pathway through both mitochondrial antiviral-signaling protein (MAVS)-dependent and independent mechanisms. However, SINE RNA-based signaling is hijacked by the virus to enhance viral gene expression and replication. B2 RNA expression stimulates IKKβ-dependent phosphorylation of the major viral lytic cycle transactivator protein RTA, thereby enhancing its activity and increasing progeny virion production. Collectively, these findings suggest that SINE RNAs participate in the innate pathogen response mechanism, but that herpesviruses have evolved to co-opt retrotransposon activation for viral benefit. Short interspersed nuclear elements (SINEs) are noncoding mobile genetic elements that are present at ~106 copies per mammalian genome, roughly comprising 10% of mammalian genomic real estate. SINEs are typically transcriptionally silenced, though in some cases viral infection can promote their expression, yet to an unknown functional outcome. Thus, SINE elements represent the largest class of infection-inducible noncoding RNAs that are functionally uncharacterized. Here, we reveal that SINE RNAs play a critical role in the host-pathogen interaction in that they are required for efficient murine gammaherpesvirus 68 (MHV68) replication and gene expression. We demonstrate that SINE RNAs, both exogenously expressed and infection-induced, are robust activators of the IKKβ kinase, a key signaling molecule in the innate immune response. Activation of the IKKβ kinase by SINE RNA is mediated through both MAVS-dependent and independent mechanisms. Moreover, we demonstrate the activation of the IKKβ via SINE RNA is required to drive the phosphorylation of MHV68 RTA, the main viral transcriptional activator, which enhances its transcriptional activating property. Collectively, we reveal the first example of a role for SINE RNAs in the host-pathogen interaction and identify them as a key immune signaling molecule early during infection. Though SINE RNAs activate the innate immune response, MHV68 has co-opted SINE-mediate innate immune activation to enhance the viral lifecycle.
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Affiliation(s)
- John Karijolich
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Emma Abernathy
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Britt A. Glaunsinger
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, California, United States of America
- * E-mail:
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31
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Qu Y, Zhou M, Peng L, Li J, Yan J, Yang P, Feng H. Molecular cloning and characterization of IKKε gene from black carp Mylopharyngodon piceus. FISH & SHELLFISH IMMUNOLOGY 2015; 47:122-129. [PMID: 26332502 DOI: 10.1016/j.fsi.2015.08.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/22/2015] [Accepted: 08/26/2015] [Indexed: 06/05/2023]
Abstract
IKKε is an IκB kinase functioning in NF-κB signal pathway in the innate immune system of higher vertebrates. To exploit the function of IKKε of black carp (bcIKKε) in its antiviral innate immunity, the IKKε gene has been cloned from the RNA isolated from the spleen of black carp. The full-length cDNA of bcIKKε is 2537 bp, which encodes the peptide of 723 amino acids. bcIKKε contains a S-Tkc domain, a PKc domain and a UBL-TBK1-like domain and bcIKKε shares the highest amino acid sequence similarity with that of grass carp. bcIKKε was constitutively transcribed in the selected tissues of black carp including gill, kidney, heart, intestine, liver, muscle, skin and spleen; and the mRNA level of bcIKKε in these tissues varied right after SVCV or GCRV infection. bcIKKε had been well expressed in HEK293T cells and western blot assay determined that this fish kinase was around 80 KDa. The immunofluorescence assay of both NH3T3 cells and EPC cells demonstrated that bcIKKε was located in the cytosolic part of the cell. Report assay result showed that overexpression of bcIKKε in EPC cells activated the expression of both zebrafish IFN and EPC IFN. All our data suggest that bcIKKε is a novel fish kinase functioning in the innate antiviral immune response of black carp.
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Affiliation(s)
- Yixiao Qu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Man Zhou
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Linzhi Peng
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Jun Li
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Jun Yan
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Peilin Yang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Hao Feng
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China.
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Li J, Zhou M, Peng L, Sun W, Yang P, Yan J, Feng H. Identification and characterization of IKKε gene from grass carp Ctenopharyngodon idella. FISH & SHELLFISH IMMUNOLOGY 2015; 47:255-263. [PMID: 26370541 DOI: 10.1016/j.fsi.2015.09.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/01/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
IKKε is an IKK-related kinase implicated in antiviral immune response in higher vertebrates. To elucidate the function of IKKε in teleost fish, grass carp IKKε (gcIKKε) has been cloned and characterized in this paper. The full-length cDNA of gcIKKε is composed of 2529 nucleotides and encodes a polypeptide of 723 amino acids. The mRNA transcription of gcIKKε was constitutively detected in all the selected tissues and the gcIKKε mRNA level increased at 36 h after GCRV infection. Western blot data of both HEK293T cells and EPC cells demonstrated that gcIKKε was around 80 KDa; and immunofluorescence staining data of both NIH3T3 cells and EPC cells determined gcIKKε was a cytosolic protein. The mRNA level of gcIKKε in CIK cells was increased more than 150 times right after poly(I:C) treatment and PMA treatment triggered gcIKKε mRNA transcription in CIK cells more than 100 times. Over-expression of gcIKKε in EPC cells activated the promoter activity of both zebrafish IFN and fathead minnow IFN. gcIKKε mRNA transcription level in CIK cells was increased from 48 h post GCRV infection with different MOIs. All the data support the idea that gcIKKε is a novel teleost IκB kinase recruited in the IFN-mediated antiviral immunity of grass carp.
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Affiliation(s)
- Jun Li
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Man Zhou
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Lingzhi Peng
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Wenzheng Sun
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Peilin Yang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Jun Yan
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Hao Feng
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha 410081, China.
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Minassian A, Zhang J, He S, Zhao J, Zandi E, Saito T, Liang C, Feng P. An Internally Translated MAVS Variant Exposes Its Amino-terminal TRAF-Binding Motifs to Deregulate Interferon Induction. PLoS Pathog 2015. [PMID: 26221961 PMCID: PMC4519330 DOI: 10.1371/journal.ppat.1005060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Activation of pattern recognition receptors and proper regulation of downstream signaling are crucial for host innate immune response. Upon infection, the NF-κB and interferon regulatory factors (IRF) are often simultaneously activated to defeat invading pathogens. Mechanisms concerning differential activation of NF-κB and IRF are not well understood. Here we report that a MAVS variant inhibits interferon (IFN) induction, while enabling NF-κB activation. Employing herpesviral proteins that selectively activate NF-κB signaling, we discovered that a MAVS variant of ~50 kDa, thus designated MAVS50, was produced from internal translation initiation. MAVS50 preferentially interacts with TRAF2 and TRAF6, and activates NF-κB. By contrast, MAVS50 inhibits the IRF activation and suppresses IFN induction. Biochemical analysis showed that MAVS50, exposing a degenerate TRAF-binding motif within its N-terminus, effectively competed with full-length MAVS for recruiting TRAF2 and TRAF6. Ablation of the TRAF-binding motif of MAVS50 impaired its inhibitory effect on IRF activation and IFN induction. These results collectively identify a new means by which signaling events is differentially regulated via exposing key internally embedded interaction motifs, implying a more ubiquitous regulatory role of truncated proteins arose from internal translation and other related mechanisms. Host innate immune signaling plays critical roles in defeating pathogen infection. In response to viral infection, cellular signaling events cumulate in the activation of NF-κB and interferon regulatory factors. How these two signaling ramifications are differentially regulated remains an open question. Here we report an internally translated MAVS variant deregulates IRF activation via exposing N-terminal TRAF-binding motifs. As such, the short form of MAVS efficiently competes for binding to TRAF2 and TRAF6 against full-length MAVS, thereby sequestering key adaptors from the signaling cascades mediated by full-length MAVS. Our study uncovers a delicate regulatory mechanism of truncated proteins bearing key protein-interacting motifs that is enabled by internal translation initiation and potentially other relevant means.
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Affiliation(s)
- Arlet Minassian
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Junjie Zhang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Shanping He
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jun Zhao
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Ebrahim Zandi
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Takeshi Saito
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Chengyu Liang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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He S, Zhao J, Song S, He X, Minassian A, Zhou Y, Zhang J, Brulois K, Wang Y, Cabo J, Zandi E, Liang C, Jung JU, Zhang X, Feng P. Viral pseudo-enzymes activate RIG-I via deamidation to evade cytokine production. Mol Cell 2015; 58:134-46. [PMID: 25752576 PMCID: PMC4385502 DOI: 10.1016/j.molcel.2015.01.036] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/22/2014] [Accepted: 01/26/2015] [Indexed: 12/21/2022]
Abstract
RIG-I is a pattern recognition receptor that senses viral RNA and is crucial for host innate immune defense. Here, we describe a mechanism of RIG-I activation through amidotransferase-mediated deamidation. We show that viral homologs of phosphoribosylformylglycinamidine synthetase (PFAS), although lacking intrinsic enzyme activity, recruit cellular PFAS to deamidate and activate RIG-I. Accordingly, depletion and biochemical inhibition of PFAS impair RIG-I deamidation and concomitant activation. Purified PFAS and viral homolog thereof deamidate RIG-I in vitro. Ultimately, herpesvirus hijacks activated RIG-I to avoid antiviral cytokine production; loss of RIG-I or inhibition of RIG-I deamidation results in elevated cytokine production. Together, these findings demonstrate a surprising mechanism of RIG-I activation that is mediated by an enzyme.
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Affiliation(s)
- Shanping He
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Jun Zhao
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Shanshan Song
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Xiaojing He
- Department of Pharmacology, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75039, USA
| | - Arlet Minassian
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Yu Zhou
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Junjie Zhang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Kevin Brulois
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Yuqi Wang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Jackson Cabo
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Ebrahim Zandi
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Chengyu Liang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Jae U Jung
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA
| | - Xuewu Zhang
- Department of Pharmacology, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75039, USA
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA.
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Zhou W, Zhou J, Lv Y, Qu Y, Chi M, Li J, Feng H. Identification and characterization of MAVS from black carp Mylopharyngodon piceus. FISH & SHELLFISH IMMUNOLOGY 2015; 43:460-468. [PMID: 25655327 DOI: 10.1016/j.fsi.2015.01.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/14/2015] [Accepted: 01/22/2015] [Indexed: 06/04/2023]
Abstract
MAVS (mitochondria antiviral signaling protein) plays an important role in the host cellular innate immune response against microbial pathogens. In this study, MAVS has been cloned and characterized from black carp (Mylopharyngodon piceus). The full-length cDNA of black carp MAVS (bcMAVS) consists of 2352 nucleotides and the predicted bcMAVS protein contains 579 amino acids. Structural analysis showed that bcMAVS is composed of functional domains including an N-terminal CARD, a central proline-rich domain, a putative TRAF2-binding motif and a C-terminal TM domain, which is similar to mammalian MAVS. bcMAVS is constitutively transcribed in all the selected tissues including gill, kidney, heart, intestine, liver, muscle, skin and spleen; bcMAVS mRNA level in intestine, liver, muscle increased but decreased in spleen right after GCRV or SVCV infection. Multiple bands of bcMAVS were detected in western blot when it was expressed in tissue culture, which is similar to mammalian MAVS. Immunofluorescence assay determined that bcMAVS is a mitochondria protein and luciferase reporter assay demonstrated that bcMAVS could induce zebrafish IFN and EPC IFN expression in tissue culture. Data generated in this manuscript has built a solid foundation for further elucidating the function of bcMAVS in the innate immune system of black carp.
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Affiliation(s)
- Wei Zhou
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Jujun Zhou
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Ying Lv
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Yixiao Qu
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Mengdie Chi
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Jun Li
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China
| | - Hao Feng
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education of China, College of Life Science, Hunan Normal University, Changsha, 410081, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan, 430072, China.
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Zhang J, He S, Wang Y, Brulois K, Lan K, Jung JU, Feng P. Herpesviral G protein-coupled receptors activate NFAT to induce tumor formation via inhibiting the SERCA calcium ATPase. PLoS Pathog 2015; 11:e1004768. [PMID: 25811856 PMCID: PMC4374719 DOI: 10.1371/journal.ppat.1004768] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/27/2015] [Indexed: 11/24/2022] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest family of proteins that transmit signal to regulate an array of fundamental biological processes. Viruses deploy diverse tactics to hijack and harness intracellular signaling events induced by GPCR. Herpesviruses encode multiple GPCR homologues that are implicated in viral pathogenesis. Cellular GPCRs are primarily regulated by their cognate ligands, while herpesviral GPCRs constitutively activate downstream signaling cascades, including the nuclear factor of activated T cells (NFAT) pathway. However, the roles of NFAT activation and mechanism thereof in viral GPCR tumorigenesis remain unknown. Here we report that GPCRs of human Kaposi’s sarcoma-associated herpesvirus (kGPCR) and cytomegalovirus (US28) shortcut NFAT activation by inhibiting the sarcoplasmic reticulum calcium ATPase (SERCA), which is necessary for viral GPCR tumorigenesis. Biochemical approaches, entailing pharmacological inhibitors and protein purification, demonstrate that viral GPCRs target SERCA2 to increase cytosolic calcium concentration. As such, NFAT activation induced by vGPCRs was exceedingly sensitive to cyclosporine A that targets calcineurin, but resistant to inhibition upstream of ER calcium release. Gene expression profiling identified a signature of NFAT activation in endothelial cells expressing viral GPCRs. The expression of NFAT-dependent genes was up-regulated in tumors derived from tva-kGPCR mouse and human KS. Employing recombinant kGPCR-deficient KSHV, we showed that kGPCR was critical for NFAT-dependent gene expression in KSHV lytic replication. Finally, cyclosporine A treatment diminished NFAT-dependent gene expression and tumor formation induced by viral GPCRs. These findings reveal essential roles of NFAT activation in viral GPCR tumorigenesis and a mechanism of “constitutive” NFAT activation by viral GPCRs. G protein-coupled receptors (GPCRs) constitute the largest family of proteins that transmit signal across plasma membrane. Herpesviral GPCRs (vGPCRs) activate diverse signaling cascades and are implicated in viral pathogenesis (e.g., tumor development). In contrast to cellular GPCRs that are chiefly regulated via cognate ligand-association, vGPCRs are constitutively active independent of ligand-binding. vGPCRs provide useful tools to dissect signal transduction from plasma membrane receptors to nuclear transcription factors. To probe the activation of nuclear factor of T cells (NFAT), we demonstrate that vGPCRs target the ER calcium ATPase to increase cytosolic calcium concentration and activate NFAT. Inhibition of NFAT activation impairs tumor formation induced by vGPCRs, implying the antitumor therapeutic potential via disabling NFAT activation.
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Affiliation(s)
- Junjie Zhang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Shanping He
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Yi Wang
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kevin Brulois
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Ke Lan
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, P.R. China
| | - Jae U. Jung
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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Interplay between Kaposi's sarcoma-associated herpesvirus and the innate immune system. Cytokine Growth Factor Rev 2014; 25:597-609. [PMID: 25037686 DOI: 10.1016/j.cytogfr.2014.06.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 06/16/2014] [Indexed: 02/04/2023]
Abstract
Understanding of the innate immune response to viral infections is rapidly progressing, especially with regards to the detection of DNA viruses. Kaposi's sarcoma-associated herpesvirus (KSHV) is a large dsDNA virus that is responsible for three human diseases: Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. The major target cells of KSHV (B cells and endothelial cells) express a wide range of pattern recognition receptors (PRRs) and play a central role in mobilizing inflammatory responses. On the other hand, KSHV encodes an array of immune evasion genes, including several pirated host genes, which interfere with multiple aspects of the immune response. This review summarizes current understanding of innate immune recognition of KSHV and the role of immune evasion genes that shape the antiviral and inflammatory responses.
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The gammaherpesviruses Kaposi's sarcoma-associated herpesvirus and murine gammaherpesvirus 68 modulate the Toll-like receptor-induced proinflammatory cytokine response. J Virol 2014; 88:9245-59. [PMID: 24899179 DOI: 10.1128/jvi.00841-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The human pathogen Kaposi's sarcoma-associated herpesvirus (KSHV), the etiological agent of Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease, establishes lifelong latency upon infection. Murine gammaherpesvirus 68 (MHV68) is a well-established model for KSHV. Toll-like receptors (TLRs) play a crucial role for the innate immune response to pathogens. Although KSHV and MHV68 are detected by TLRs, studies suggest they modulate TLR4 and TLR9 signaling, respectively. In this study, we show that in bone marrow-derived macrophages (BMDMs), MHV68 did not induce a detectable proinflammatory cytokine response. Furthermore, MHV68 abrogated the response to TLR2, -4, -7, and -9 agonists in BMDMs. Similarly to observations with MHV68, infection with KSHV efficiently inhibited TLR2 signaling in THP-1 monocytes. Using a KSHV open reading frame (ORF) library, we found that K4.2, ORF21, ORF31, and the replication and transcription activator protein (RTA)/ORF50 inhibited TLR2-dependent nuclear factor kappa B (NF-κB) activation in HEK293 TLR2-yellow fluorescent protein (YFP)- and Flag-TLR2-transfected HEK293T cells. Of the identified ORFs, RTA/ORF50 strongly downregulated TLR2 and TLR4 signaling by reducing TLR2 and TLR4 protein expression. Confocal microscopy revealed that TLR2 and TLR4 were no longer localized to the plasma membrane in cells expressing RTA/ORF50. In this study, we have shown that the gammaherpesviruses MHV68 and KSHV efficiently downmodulate TLR signaling in macrophages and have identified a novel function of RTA/ORF50 in modulation of the innate immune response. IMPORTANCE The Toll-like receptors (TLRs) are an important class of pattern recognition receptors of the innate immune system. They induce a potent proinflammatory cytokine response upon detection of a variety of pathogens. In this study, we found that the gammaherpesviruses murine gammaherpesvirus 68 (MHV68) and Kaposi's sarcoma-associated herpesvirus (KSHV) efficiently inhibit the TLR-mediated innate immune response. We further identified the KSHV-encoded replication and transcription activator protein (RTA) as a novel modulator of TLR signaling. Our data suggest that the gammaherpesviruses MHV68 and KSHV prevent activation of the innate immune response by targeting TLR signaling.
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Zhang J, Zhu L, Feng P. Dissecting innate immune signaling in viral evasion of cytokine production. J Vis Exp 2014. [PMID: 24637875 DOI: 10.3791/51078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
In response to a viral infection, the host innate immune response is activated to up-regulate gene expression and production of antiviral cytokines. Conversely, viruses have evolved intricate strategies to evade and exploit host immune signaling for survival and propagation. Viral immune evasion, entailing host defense and viral evasion, provides one of the most fascinating and dynamic interfaces to discern the host-virus interaction. These studies advance our understanding in innate immune regulation and pave our way to develop novel antiviral therapies. Murine γHV68 is a natural pathogen of murine rodents. γHV68 infection of mice provides a tractable small animal model to examine the antiviral response to human KSHV and EBV of which perturbation of in vivo virus-host interactions is not applicable. Here we describe a protocol to determine the antiviral cytokine production. This protocol can be adapted to other viruses and signaling pathways. Recently, we have discovered that γHV68 hijacks MAVS and IKKβ, key innate immune signaling components downstream of the cytosolic RIG-I and MDA5, to abrogate NFΚB activation and antiviral cytokine production. Specifically, γHV68 infection activates IKKβ and that activated IKKβ phosphorylates RelA to accelerate RelA degradation. As such, γHV68 efficiently uncouples NFΚB activation from its upstream activated IKKβ, negating antiviral cytokine gene expression. This study elucidates an intricate strategy whereby the upstream innate immune activation is intercepted by a viral pathogen to nullify the immediate downstream transcriptional activation and evade antiviral cytokine production.
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Affiliation(s)
- Junjie Zhang
- Department of Microbiology and Immunology, Keck School of Medicine, University of Southern California
| | - Lining Zhu
- Department of Microbiology and Immunology, Keck School of Medicine, University of Southern California
| | - Pinghui Feng
- Department of Microbiology and Immunology, Keck School of Medicine, University of Southern California;
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40
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Toll-like receptor activation and expression in bovine alpha-herpesvirus infections. Res Vet Sci 2014; 96:196-203. [DOI: 10.1016/j.rvsc.2013.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/07/2013] [Accepted: 11/30/2013] [Indexed: 01/19/2023]
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NF-κB activation coordinated by IKKβ and IKKε enables latent infection of Kaposi's sarcoma-associated herpesvirus. J Virol 2013; 88:444-55. [PMID: 24155403 DOI: 10.1128/jvi.01716-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
All herpesviruses share a remarkable propensity to establish latent infection. Human Kaposi's sarcoma-associated herpesvirus (KSHV) effectively enters latency after de novo infection, suggesting that KSHV has evolved with strategies to facilitate latent infection. NF-κB activation is imperative for latent infection of gammaherpesviruses. However, how NF-κB is activated during de novo herpesvirus infection is not fully understood. Here, we report that KSHV infection activates the inhibitor of κB kinase β (IKKβ) and the IKK-related kinase epsilon (IKKε) to enable host NF-κB activation and KSHV latent infection. Specifically, KSHV infection activated IKKβ and IKKε that were crucial for latent infection. Knockdown of IKKβ and IKKε caused aberrant lytic gene expression and impaired KSHV latent infection. Biochemical and genetic experiments identified RelA as a key player downstream of IKKβ and IKKε. Remarkably, IKKβ and IKKε were essential for phosphorylation of S(536) and S(468) of RelA, respectively. Phosphorylation of RelA S(536) was required for phosphorylation of S(468), which activated NF-κB and promoted KSHV latent infection. Expression of the phosphorylation-resistant RelA S(536)A increased KSHV lytic gene expression and impaired latent infection. Our findings uncover a scheme wherein NF-κB activation is coordinated by IKKβ and IKKε, which sequentially phosphorylate RelA in a site-specific manner to enable latent infection after KSHV de novo infection.
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Meyer F, Ehlers E, Steadman A, Waterbury T, Cao M, Zhang L. TLR-TRIF pathway enhances the expression of KSHV replication and transcription activator. J Biol Chem 2013; 288:20435-42. [PMID: 23723066 PMCID: PMC3711309 DOI: 10.1074/jbc.m113.487421] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Indexed: 11/06/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is a human γ-herpesvirus. KSHV replication and transcription activator (RTA) is necessary and sufficient for KSHV reactivation from latency. Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns, act through adaptors, and initiate innate and adaptive immune responses against pathogens. Toll/interleukin-1-receptor domain containing adaptor protein inducing interferon-β (TRIF) is an adaptor associated with TLR3 and TLR4 signaling, and is closely related to antiviral signaling to activate type I interferon (IFN) production. We previously found that KSHV RTA degrades TRIF indirectly and blocks TLR3 pathways. In this report, we find that TRIF, as well as TLR3 activation, enhances KSHV RTA protein expression. The C-terminal region of the RTA is involved in the responding TRIF-mediated enhancement. The degradation of TRIF and the enhancement of RTA expression are using two different pathways. The enhancement by TLR-TRIF is at least partially via promoting translational efficiency of RTA mRNA. Finally, the receptor-interacting protein 1 (RIP1) may be involved in TRIF-mediated enhancement of RTA expression, but not in the RTA-mediated degradation of TRIF. Therefore, the activation of TLR-TRIF pathway enhances KSHV RTA protein expression, and KSHV RTA in turn degrades TRIF to block innate immunity. The putative KSHV-TLR-adaptor-interacting loop may be a critical element to evade and usurp host innate immunity in KSHV life-cycle.
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Affiliation(s)
| | | | | | | | | | - Luwen Zhang
- From the School of Biological Sciences and
- the Nebraska Center for Virology, University of Nebraska, Lincoln, Nebraska 68583
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43
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Feng P, Moses A, Früh K. Evasion of adaptive and innate immune response mechanisms by γ-herpesviruses. Curr Opin Virol 2013; 3:285-95. [PMID: 23735334 DOI: 10.1016/j.coviro.2013.05.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/01/2013] [Accepted: 05/14/2013] [Indexed: 01/05/2023]
Abstract
γ-Herpesviral immune evasion mechanisms are optimized to support the acute, lytic and the longterm, latent phase of infection. During acute infection, specific immune modulatory proteins limit, but also exploit, the antiviral activities of cell intrinsic innate immune responses as well as those of innate and adaptive immune cells. During latent infection, a restricted gene expression program limits immune targeting and cis-acting mechanisms to reduce the antigen presentation as well as antigenicity of latency-associated proteins. Here, we will review recent progress in our understanding of γ-herpesviral immune evasion strategies.
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Affiliation(s)
- Pinghui Feng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
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NF-κB activation by equine arteritis virus is MyD88 dependent and promotes viral replication. Arch Virol 2012; 158:701-5. [PMID: 23151818 PMCID: PMC7086945 DOI: 10.1007/s00705-012-1515-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 09/14/2012] [Indexed: 10/27/2022]
Abstract
NF-κB, a family of transcription factors involved in different cell functions and immune responses is targeted by viruses. The mechanism of NF-κB signalling and its role in replication of EAV have not been investigated. We demonstrate that EAV infection in BHK-21 cells activates NF-κB, and this activation was found to be mediated through the MyD88 pathway. Infection of IKKβ(-/-) murine embryo fibroblasts (MEFs), which are deficient in NF-κB signalling, resulted in lower virus titre, less cytopathic effect, and reduced expression of viral proteins. These findings implicate the MyD88 pathway in EAV-induced NF-κB activation and suggest that NF-κB activation is essential for efficient replication of EAV.
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Denard B, Seemann J, Chen Q, Gay A, Huang H, Chen Y, Ye J. The membrane-bound transcription factor CREB3L1 is activated in response to virus infection to inhibit proliferation of virus-infected cells. Cell Host Microbe 2011; 10:65-74. [PMID: 21767813 DOI: 10.1016/j.chom.2011.06.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 05/02/2011] [Accepted: 06/06/2011] [Indexed: 01/22/2023]
Abstract
CREB3L1/OASIS is a cellular transcription factor synthesized as a membrane-bound precursor and activated by regulated intramembrane proteolysis in response to stimuli like ER stress. Comparing gene expression between Huh7 subclones that are permissive for hepatitis C virus (HCV) replication versus the nonpermissive parental Huh7 cells, we identified CREB3L1 as a host factor that inhibits proliferation of virus-infected cells. Upon infection with diverse DNA and RNA viruses, including murine γ-herpesvirus 68, HCV, West Nile virus (WNV), and Sendai virus, CREB3L1 was proteolytically cleaved, allowing its NH(2) terminus to enter the nucleus and induce multiple genes encoding inhibitors of the cell cycle to block cell proliferation. Consistent with this, we observed a necessity for CREB3L1 expression to be silenced in proliferating cells that harbor replicons of HCV or WNV. Our results indicate that CREB3L1 may play an important role in limiting virus spread by inhibiting proliferation of virus-infected cells.
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Affiliation(s)
- Bray Denard
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Murine gammaherpesvirus 68 evades host cytokine production via replication transactivator-induced RelA degradation. J Virol 2011; 86:1930-41. [PMID: 22130545 DOI: 10.1128/jvi.06127-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cytokines play crucial roles in curtailing the propagation and spread of pathogens within the host. As obligate pathogens, gammaherpesviruses have evolved a plethora of mechanisms to evade host immune responses. We have previously shown that murine gammaherpesvirus 68 (γHV68) induces the degradation of RelA, an essential subunit of the transcriptionally active NF-κB dimer, to evade cytokine production. Here, we report that the immediately early gene product of γHV68, replication transactivator (RTA), functions as a ubiquitin E3 ligase to promote RelA degradation and abrogate cytokine production. A targeted genomic screen identified that RTA, out of 24 candidates, induces RelA degradation and abolishes NF-κB activation. Biochemical analyses indicated that RTA interacts with RelA and promotes RelA ubiquitination, thereby facilitating RelA degradation. Mutations within a conserved cysteine/histidine-rich, putative E3 ligase domain impaired the ability of RTA to induce RelA ubiquitination and degradation. Moreover, infection by recombinant γHV68 carrying mutations that diminish the E3 ligase activity of RTA resulted in more robust NF-κB activation and cytokine induction than did infection by wild-type γHV68. These findings support the conclusion that γHV68 subverts early NF-κB activation and cytokine production through RTA-induced RelA degradation, uncovering a key function of RTA that antagonizes the intrinsic cytokine production during gammaherpesvirus infection.
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Dong X, Feng P. Murine gamma herpesvirus 68 hijacks MAVS and IKKβ to abrogate NFκB activation and antiviral cytokine production. PLoS Pathog 2011; 7:e1002336. [PMID: 22110409 PMCID: PMC3213086 DOI: 10.1371/journal.ppat.1002336] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 09/11/2011] [Indexed: 12/25/2022] Open
Abstract
Upon viral infection, mitochondrial antiviral signaling (MAVS) protein serves as a key adaptor to promote cytokine production. We report here that murine gamma herpesvirus 68 (γHV68), a model virus for oncogenic human gamma herpesviruses, subverts cytokine production via the MAVS adaptor. During early infection, γHV68 hijacks MAVS and IKKβ to induce the site-specific phosphorylation of RelA, a crucial subunit of the transcriptionally active NFκB dimer, which primes RelA for the proteasome-mediated degradation. As such, γHV68 efficiently abrogated NFκB activation and cytokine gene expression. Conversely, uncoupling RelA degradation from γHV68 infection promoted NFκB activation and elevated cytokine production. Loss of MAVS increased cytokine production and immune cell infiltration in the lungs of γHV68-infected mice. Moreover, exogenous expression of the phosphorylation- and degradation-resistant RelA variant restored γHV68-induced cytokine production. Our findings uncover an intricate strategy whereby signaling via the upstream MAVS adaptor is intercepted by a pathogen to nullify the immediate downstream effector, RelA, of the innate immune pathway. Innate immunity represents the first line of defense against invading pathogens chiefly through anti-viral cytokines. The mitochondrial antiviral signaling (MAVS)-dependent innate immune pathways are critical for inflammatory cytokine production. Deficiency in essential innate immune components, such as MAVS, severely impairs cytokine production and host defense that are enabled by the master transcription factor, NFκB. Here we show that murine gamma herpesvirus 68 (γHV68), a model herpesvirus for human Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus, hijacks MAVS and IKKβ to abrogate NFκB activation and cytokine production. Uncoupling RelA degradation from γHV68 infection restored NFκB-dependent cytokine gene expression and elevated cytokine production. Thus, our results demonstrate that upstream innate immune activation can be harnessed by pathogens to inactivate the downstream effector and subvert cytokine production.
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Affiliation(s)
- Xiaonan Dong
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Pinghui Feng
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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Dong X, Feng P. Dissecting host-virus interaction in lytic replication of a model herpesvirus. J Vis Exp 2011:3140. [PMID: 22006158 PMCID: PMC3227218 DOI: 10.3791/3140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In response to viral infection, a host develops various defensive responses, such as activating innate immune signaling pathways that lead to antiviral cytokine production. In order to colonize the host, viruses are obligate to evade host antiviral responses and manipulate signaling pathways. Unraveling the host-virus interaction will shed light on the development of novel therapeutic strategies against viral infection. Murine γHV68 is closely related to human oncogenic Kaposi's sarcoma-associated herpesvirus and Epsten-Barr virus. γHV68 infection in laboratory mice provides a tractable small animal model to examine the entire course of host responses and viral infection in vivo, which are not available for human herpesviruses. In this protocol, we present a panel of methods for phenotypic characterization and molecular dissection of host signaling components in γHV68 lytic replication both in vivo and ex vivo. The availability of genetically modified mouse strains permits the interrogation of the roles of host signaling pathways during γHV68 acute infection in vivo. Additionally, mouse embryonic fibroblasts (MEFs) isolated from these deficient mouse strains can be used to further dissect roles of these molecules during γHV68 lytic replication ex vivo. Using virological and molecular biology assays, we can pinpoint the molecular mechanism of host-virus interactions and identify host and viral genes essential for viral lytic replication. Finally, a bacterial artificial chromosome (BAC) system facilitates the introduction of mutations into the viral factor(s) that specifically interrupt the host-virus interaction. Recombinant γHV68 carrying these mutations can be used to recapitulate the phenotypes of γHV68 lytic replication in MEFs deficient in key host signaling components. This protocol offers an excellent strategy to interrogate host-pathogen interaction at multiple levels of intervention in vivo and ex vivo. Recently, we have discovered that γHV68 usurps an innate immune signaling pathway to promote viral lytic replication. Specifically, γHV68 de novo infection activates the immune kinase IKKβ and activated IKKβ phosphorylates the master viral transcription factor, replication and transactivator (RTA), to promote viral transcriptional activation. In doing so, γHV68 efficiently couples its transcriptional activation to host innate immune activation, thereby facilitating viral transcription and lytic replication. This study provides an excellent example that can be applied to other viruses to interrogate host-virus interaction.
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Affiliation(s)
- Xiaonan Dong
- Center for Autophagy Research, Department of Internal Medicine, UT Southwestern Medical Center, USA
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Abstract
Endoplasmic reticulum (ER) stress triggers a homeostatic cellular response in mammalian cells to ensure efficient folding, sorting, and processing of client proteins. In lytic-permissive lymphoblastoid cell lines (LCLs), pulse exposure to the chemical ER-stress inducer thapsigargin (TG) followed by recovery resulted in the activation of the EBV immediate-early (BRLF1, BZLF1), early (BMRF1), and late (gp350) genes, gp350 surface expression, and virus release. The protein phosphatase 1 a (PP1a)-specific phosphatase inhibitor Salubrinal (SAL) synergized with TG to induce EBV lytic genes; however, TG treatment alone was sufficient to activate EBV lytic replication. SAL showed ER-stress-dependent and -independent antiviral effects, preventing virus release in human LCLs and abrogating gp350 expression in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated B95-8 cells. TG resulted in sustained BCL6 but not BLIMP1 or CD138 expression, which is consistent with maintenance of a germinal center B-cell, rather than plasma-cell, phenotype. Microarray analysis identified candidate genes governing lytic replication in LCLs undergoing ER stress.
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Wang C, Liu X, Wei B. Mitochondrion: an emerging platform critical for host antiviral signaling. Expert Opin Ther Targets 2011; 15:647-65. [PMID: 21476879 DOI: 10.1517/14728222.2011.561321] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Toll-like receptors (TLRs) and cytoplasmic retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) are the two major receptor systems for detecting RNA viruses. RLRs play essential roles within the cytosol of various cell types. The signaling pathways converge at the mitochondrial antiviral signalling protein (MAVS) on the outer membrane of mitochondria. Recent research has surprisingly shown that many mitochondrial intrinsic factors play novel functions in RLR signaling, conferring a new perspective of therapeutic drug design to inhibit viral infection. AREAS COVERED This review covers the literature of the past 6 years and summarizes the components, regulation and mechanisms of RLR signaling, highlighting the function and regulation of mitochondrial proteins, such as MAVS and translocase of outer membrane (Tom)70 in this process. The authors attempt to delineate the complicated cross-talk among subcellular organelles in the context of intracellular antiviral signaling. EXPERT OPINION It is imperative to elucidate the specific roles and mechanisms of post-translational modifications in MAVS signaling. The sub-cellular dynamics of regulatory proteins should be correlated with their multiple functions. Animal models are needed to further probe the integration of mitochondria with innate immunity evolutionarily; they will be instrumental for identifying novel antiviral targets and, ultimately, for developing specific clinical drugs.
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Affiliation(s)
- Chen Wang
- Shanghai Institutes for Biological Sciences-Institute of Biochemistry and Cell Biology, Shanghai, China.
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