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Dutta S, Ganguly A, Ghosh Roy S. An Overview of the Unfolded Protein Response (UPR) and Autophagy Pathways in Human Viral Oncogenesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2024; 386:81-131. [PMID: 38782502 DOI: 10.1016/bs.ircmb.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Autophagy and Unfolded Protein Response (UPR) can be regarded as the safe keepers of cells exposed to intense stress. Autophagy maintains cellular homeostasis, ensuring the removal of foreign particles and misfolded macromolecules from the cytoplasm and facilitating the return of the building blocks into the system. On the other hand, UPR serves as a shock response to prolonged stress, especially Endoplasmic Reticulum Stress (ERS), which also includes the accumulation of misfolded proteins in the ER. Since one of the many effects of viral infection on the host cell machinery is the hijacking of the host translational system, which leaves in its wake a plethora of misfolded proteins in the ER, it is perhaps not surprising that UPR and autophagy are common occurrences in infected cells, tissues, and patient samples. In this book chapter, we try to emphasize how UPR, and autophagy are significant in infections caused by six major oncolytic viruses-Epstein-Barr (EBV), Human Papilloma Virus (HPV), Human Immunodeficiency Virus (HIV), Human Herpesvirus-8 (HHV-8), Human T-cell Lymphotropic Virus (HTLV-1), and Hepatitis B Virus (HBV). Here, we document how whole-virus infection or overexpression of individual viral proteins in vitro and in vivo models can regulate the different branches of UPR and the various stages of macro autophagy. As is true with other viral infections, the relationship is complicated because the same virus (or the viral protein) exerts different effects on UPR and Autophagy. The nature of this response is determined by the cell types, or in some cases, the presence of diverse extracellular stimuli. The vice versa is equally valid, i.e., UPR and autophagy exhibit both anti-tumor and pro-tumor properties based on the cell type and other factors like concentrations of different metabolites. Thus, we have tried to coherently summarize the existing knowledge, the crux of which can hopefully be harnessed to design vaccines and therapies targeted at viral carcinogenesis.
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Affiliation(s)
- Shovan Dutta
- Center for Immunotherapy & Precision Immuno-Oncology (CITI), Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Anirban Ganguly
- Department of Biochemistry, All India Institute of Medical Sciences, Deoghar, Jharkhand, India
| | - Sounak Ghosh Roy
- Henry M Jackson for the Advancement of Military Medicine, Naval Medical Research Command, Silver Spring, MD, United States.
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Moy MA, Collins-McMillen D, Crawford L, Parkins C, Zeltzer S, Caviness K, Zaidi SSA, Caposio P, Goodrum F. Stabilization of the human cytomegalovirus UL136p33 reactivation determinant overcomes the requirement for UL135 for replication in hematopoietic cells. J Virol 2023; 97:e0014823. [PMID: 37565749 PMCID: PMC10506481 DOI: 10.1128/jvi.00148-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 06/20/2023] [Indexed: 08/12/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a beta herpesvirus that persists indefinitely in the human host through a latent infection. The polycistronic UL133-UL138 gene locus of HCMV encodes genes regulating latency and reactivation. While UL138 is pro-latency, restricting virus replication in CD34+ hematopoietic progenitor cells (HPCs), UL135 overcomes this restriction and is required for reactivation. By contrast, UL136 is expressed with later kinetics and encodes multiple proteins with differential roles in latency and reactivation. Like UL135, the largest UL136 isoform, UL136p33, is required for reactivation from latency in HPCs; viruses failing to express either protein are unresponsive to reactivation stimuli. Furthermore, UL136p33 is unstable, and its instability is important for the establishment of latency, and sufficient accumulation of UL136p33 is a checkpoint for reactivation. We hypothesized that stabilizing UL136p33 might overcome the requirement of UL135 for replication. We generated recombinant viruses lacking UL135 that expressed a stabilized variant of UL136p33. Stabilizing UL136p33 did not impact the replication of the UL135 mutant virus in fibroblasts. However, in the context of infection in HPCs, stabilization of UL136p33 strikingly compensated for the loss of UL135, resulting in increased replication in CD34+ HPCs and in humanized NOD-scid IL2Rγcnull (huNSG) mice. This finding suggests that while UL135 is essential for replication in HPCs, it functions largely at steps preceding the accumulation of UL136p33, and that stabilized expression of UL136p33 largely overcomes the requirement for UL135. Taken together, our genetic evidence indicates an epistatic relationship between UL136p33 and UL135, whereby UL135 may initiate events early in reactivation that drive the accumulation of UL136p33 to a threshold required for productive reactivation. IMPORTANCE Human cytomegalovirus (HCMV) is one of nine human herpesviruses and a significant human pathogen. While HCMV establishes a lifelong latent infection that is typically asymptomatic in healthy individuals, its reactivation from latency can have devastating consequences in the immunocompromised. Defining viral genes important in the establishment of or reactivation from latency is important to defining the molecular basis of latent and replicative states and in controlling infection and CMV disease. Here we define a genetic relationship between two viral genes in controlling virus reactivation from latency using primary human hematopoietic progenitor cells and humanized mouse models.
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Affiliation(s)
- Melissa A. Moy
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, Arizona, USA
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Donna Collins-McMillen
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Lindsey Crawford
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Christopher Parkins
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Sebastian Zeltzer
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Katie Caviness
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
- Graduate Interdisciplinary Program in Genetics, University of Arizona, Tucson, Arizona, USA
| | | | - Patrizia Caposio
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Felicia Goodrum
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, Arizona, USA
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
- Graduate Interdisciplinary Program in Genetics, University of Arizona, Tucson, Arizona, USA
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Moy MA, Collins-McMillen D, Crawford L, Parkins C, Zeltzer S, Caviness K, Caposio P, Goodrum F. UL135 and UL136 Epistasis Controls Reactivation of Human Cytomegalovirus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.24.525282. [PMID: 36747736 PMCID: PMC9900790 DOI: 10.1101/2023.01.24.525282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Human cytomegalovirus (HCMV) is beta herpesvirus that persists indefinitely in the human host through a protracted, latent infection. The polycistronic UL133-UL138 gene locus of HCMV encodes genes regulating latency and reactivation. While UL138 is pro-latency, restricting virus replication in CD34+ hematopoietic progenitor cells (HPCs), UL135 overcomes this restriction for reactivation. By contrast, UL136 is expressed with later kinetics and encodes multiple protein isoforms with differential roles in latency and reactivation. Like UL135, the largest UL136 isoform, UL136p33, is required for reactivation from latency in hematopoietic cells. Furthermore, UL136p33 is unstable, and its instability is important for the establishment of latency and sufficient accumulation of UL136p33 is a checkpoint for reactivation. We hypothesized that stabilizing UL136p33 might overcome the requirement of UL135 for reactivation. To test this, we generated recombinant viruses lacking UL135 that expressed a stabilized variant of UL136p33. Stabilizing UL136p33 did not impact replication of the UL135-mutant virus in fibroblasts. However, in the context of infection in hematopoietic cells, stabilization of UL136p33 strikingly compensated for the loss of UL135, resulting in increased replication in CD34+ HPCs and in humanized NOD- scid IL2Rγ c null (NSG) mice. This finding suggests that while UL135 is essential for reactivation, it functions at steps preceding the accumulation of UL136p33 and that stabilized expression of UL136p33 largely overcomes the requirement for UL135 in reactivation. Taken together, our genetic evidence indicates an epistatic relationship between UL136p33 and UL135 whereby UL135 may initiate events early in reactivation that will result in the accumulation of UL136p33 to a threshold required for productive reactivation. SIGNIFICANCE Human cytomegalovirus (HCMV) is one of nine human herpesviruses and a significant human pathogen. While HCMV establishes a life-long latent infection that is typically asymptomatic in healthy individuals, its reactivation from latency can have devastating consequences in the immune compromised. Defining virus-host and virus-virus interactions important for HCMV latency, reactivation and replication is critical to defining the molecular basis of latent and replicative states and in controlling infection and CMV disease. Here we define a genetic relationship between two viral genes in controlling virus reactivation from latency using primary human hematopoietic progenitor cell and humanized mouse models.
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Majerciak V, Alvarado-Hernandez B, Lobanov A, Cam M, Zheng ZM. Genome-wide regulation of KSHV RNA splicing by viral RNA-binding protein ORF57. PLoS Pathog 2022; 18:e1010311. [PMID: 35834586 PMCID: PMC9321434 DOI: 10.1371/journal.ppat.1010311] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 07/26/2022] [Accepted: 06/14/2022] [Indexed: 02/06/2023] Open
Abstract
RNA splicing plays an essential role in the expression of eukaryotic genes. We previously showed that KSHV ORF57 is a viral splicing factor promoting viral lytic gene expression. In this report, we compared the splicing profile of viral RNAs in BCBL-1 cells carrying a wild-type (WT) versus the cells containing an ORF57 knock-out (57KO) KSHV genome during viral lytic infection. Our analyses of viral RNA splice junctions from RNA-seq identified 269 RNA splicing events in the WT and 255 in the 57KO genome, including the splicing events spanning large parts of the viral genome and the production of vIRF4 circRNAs. No circRNA was detectable from the PAN region. We found that the 57KO alters the RNA splicing efficiency of targeted viral RNAs. Two most susceptible RNAs to ORF57 splicing regulation are the K15 RNA with eight exons and seven introns and the bicistronic RNA encoding both viral thymidylate synthase (ORF70) and membrane-associated E3-ubiquitin ligase (K3). ORF57 inhibits splicing of both K15 introns 1 and 2. ORF70/K3 RNA bears two introns, of which the first intron is within the ORF70 coding region as an alternative intron and the second intron in the intergenic region between the ORF70 and K3 as a constitutive intron. In the WT cells expressing ORF57, most ORF70/K3 transcripts retain the first intron to maintain an intact ORF70 coding region. In contrast, in the 57KO cells, the first intron is substantially spliced out. Using a minigene comprising of ORF70/K3 locus, we further confirmed ORF57 regulation of ORF70/K3 RNA splicing, independently of other viral factors. By monitoring protein expression, we showed that ORF57-mediated retention of the first intron leads to the expression of full-length ORF70 protein. The absence of ORF57 promotes the first intron splicing and expression of K3 protein. Altogether, we conclude that ORF57 regulates alternative splicing of ORF70/K3 bicistronic RNA to control K3-mediated immune evasion and ORF70 participation of viral DNA replication in viral lytic infection.
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Affiliation(s)
- Vladimir Majerciak
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research (CCR), National Cancer Institute, NIH, Frederick, Maryland, Unites States of America
- * E-mail: (VM); (Z-MZ)
| | - Beatriz Alvarado-Hernandez
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research (CCR), National Cancer Institute, NIH, Frederick, Maryland, Unites States of America
| | - Alexei Lobanov
- CCR Collaborative Bioinformatics Resource, National Cancer Institute, NIH, Bethesda, Maryland, Unites States of America
| | - Maggie Cam
- CCR Collaborative Bioinformatics Resource, National Cancer Institute, NIH, Bethesda, Maryland, Unites States of America
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research (CCR), National Cancer Institute, NIH, Frederick, Maryland, Unites States of America
- * E-mail: (VM); (Z-MZ)
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Hale AE, Moorman NJ. The Ends Dictate the Means: Promoter Switching in Herpesvirus Gene Expression. Annu Rev Virol 2021; 8:201-218. [PMID: 34129370 DOI: 10.1146/annurev-virology-091919-072841] [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: 11/09/2022]
Abstract
Herpesvirus gene expression is dynamic and complex, with distinct complements of viral genes expressed at specific times in different infection contexts. These complex patterns of viral gene expression arise in part from the integration of multiple cellular and viral signals that affect the transcription of viral genes. The use of alternative promoters provides an increased level of control, allowing different promoters to direct the transcription of the same gene in response to distinct temporal and contextual cues. While once considered rare, herpesvirus alternative promoter usage was recently found to be far more pervasive and impactful than previously thought. Here we review several examples of promoter switching in herpesviruses and discuss the functional consequences on the transcriptional and post-transcriptional regulation of viral gene expression.
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Affiliation(s)
- Andrew E Hale
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA;
| | - Nathaniel J Moorman
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA;
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Abstract
Gammaherpesviruses, such as Epstein-Barr virus (EBV), Kaposi's sarcoma associated virus (KSHV), and murine γ-herpesvirus 68 (MHV68), establish latent infection in B cells, macrophages, and non-lymphoid cells, and can induce both lymphoid and non-lymphoid cancers. Research on these viruses has relied heavily on immortalized B cell and endothelial cell lines. Therefore, we know very little about the cell type specific regulation of virus infection. We have previously shown that treatment of MHV68-infected macrophages with the cytokine interleukin-4 (IL-4) or challenge of MHV68-infected mice with an IL-4-inducing parasite leads to virus reactivation. However, we do not know if all latent reservoirs of the virus, including B cells, reactivate the virus in response to IL-4. Here we used an in vivo approach to address the question of whether all latently infected cell types reactivate MHV68 in response to a particular stimulus. We found that IL-4 receptor expression on macrophages was required for IL-4 to induce virus reactivation, but that it was dispensable on B cells. We further demonstrated that the transcription factor, STAT6, which is downstream of the IL-4 receptor and binds virus gene 50 N4/N5 promoter in macrophages, did not bind to the virus gene 50 N4/N5 promoter in B cells. These data suggest that stimuli that promote herpesvirus reactivation may only affect latent virus in particular cell types, but not in others.Importance Herpesviruses establish life-long quiescent infections in specific cells in the body, and only reactivate to produce infectious virus when precise signals induce them to do so. The signals that induce herpesvirus reactivation are often studied only in one particular cell type infected with the virus. However, herpesviruses establish latency in multiple cell types in their hosts. Using murine gammaherpesvirus-68 (MHV68) and conditional knockout mice, we examined the cell type specificity of a particular reactivation signal, interleukin-4 (IL-4). We found that IL-4 only induced herpesvirus reactivation from macrophages, but not from B cells. This work indicates that regulation of virus latency and reactivation is cell type specific. This has important implications for therapies aimed at either promoting or inhibiting reactivation for the control or elimination of chronic viral infections.
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Suares A, Medina MV, Coso O. Autophagy in Viral Development and Progression of Cancer. Front Oncol 2021; 11:603224. [PMID: 33763351 PMCID: PMC7982729 DOI: 10.3389/fonc.2021.603224] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 01/12/2021] [Indexed: 12/12/2022] Open
Abstract
Autophagy is a complex degradative process by which eukaryotic cells capture cytoplasmic components for subsequent degradation through lysosomal hydrolases. Although this catabolic process can be triggered by a great variety of stimuli, action in cells varies according to cellular context. Autophagy has been previously linked to disease development modulation, including cancer. Autophagy helps suppress cancer cell advancement in tumor transformation early stages, while promoting proliferation and metastasis in advanced settings. Oncoviruses are a particular type of virus that directly contribute to cell transformation and tumor development. Extensive molecular studies have revealed complex ways in which autophagy can suppress or improve oncovirus fitness while still regulating viral replication and determining host cell fate. This review includes recent advances in autophagic cellular function and emphasizes its antagonistic role in cancer cells.
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Affiliation(s)
- Alejandra Suares
- Departamento de Fisiología y Biología Molecular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Victoria Medina
- Departamento de Fisiología y Biología Molecular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Omar Coso
- Departamento de Fisiología y Biología Molecular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
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Suares A, Medina MV, Coso O. Autophagy in Viral Development and Progression of Cancer. Front Oncol 2021. [DOI: 10.3389/fonc.2021.603224
expr 816899697 + 824303767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Autophagy is a complex degradative process by which eukaryotic cells capture cytoplasmic components for subsequent degradation through lysosomal hydrolases. Although this catabolic process can be triggered by a great variety of stimuli, action in cells varies according to cellular context. Autophagy has been previously linked to disease development modulation, including cancer. Autophagy helps suppress cancer cell advancement in tumor transformation early stages, while promoting proliferation and metastasis in advanced settings. Oncoviruses are a particular type of virus that directly contribute to cell transformation and tumor development. Extensive molecular studies have revealed complex ways in which autophagy can suppress or improve oncovirus fitness while still regulating viral replication and determining host cell fate. This review includes recent advances in autophagic cellular function and emphasizes its antagonistic role in cancer cells.
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Ouwendijk WJD, Depledge DP, Rajbhandari L, Lenac Rovis T, Jonjic S, Breuer J, Venkatesan A, Verjans GMGM, Sadaoka T. Varicella-zoster virus VLT-ORF63 fusion transcript induces broad viral gene expression during reactivation from neuronal latency. Nat Commun 2020; 11:6324. [PMID: 33303747 PMCID: PMC7730162 DOI: 10.1038/s41467-020-20031-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
Varicella-zoster virus (VZV) establishes lifelong neuronal latency in most humans world-wide, reactivating in one-third to cause herpes zoster and occasionally chronic pain. How VZV establishes, maintains and reactivates from latency is largely unknown. VZV transcription during latency is restricted to the latency-associated transcript (VLT) and RNA 63 (encoding ORF63) in naturally VZV-infected human trigeminal ganglia (TG). While significantly more abundant, VLT levels positively correlated with RNA 63 suggesting co-regulated transcription during latency. Here, we identify VLT-ORF63 fusion transcripts and confirm VLT-ORF63, but not RNA 63, expression in human TG neurons. During in vitro latency, VLT is transcribed, whereas VLT-ORF63 expression is induced by reactivation stimuli. One isoform of VLT-ORF63, encoding a fusion protein combining VLT and ORF63 proteins, induces broad viral gene transcription. Collectively, our findings show that VZV expresses a unique set of VLT-ORF63 transcripts, potentially involved in the transition from latency to lytic VZV infection.
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Affiliation(s)
- Werner J D Ouwendijk
- Department of Viroscience, Erasmus Medical Centre, 3015 CN, Rotterdam, The Netherlands
| | - Daniel P Depledge
- Department of Medicine, New York University School of Medicine, New York, NY, 10016, USA
| | - Labchan Rajbhandari
- Division of Neuroimmunology and Neuroinfectious Diseases, Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 6-113, Baltimore, MD, 21287, USA
| | - Tihana Lenac Rovis
- Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, 51000, Croatia
| | - Stipan Jonjic
- Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, 51000, Croatia
| | - Judith Breuer
- Division of Infection and Immunity, University College London, London, WC1E 6BT, UK
| | - Arun Venkatesan
- Division of Neuroimmunology and Neuroinfectious Diseases, Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Meyer 6-113, Baltimore, MD, 21287, USA
| | - Georges M G M Verjans
- Department of Viroscience, Erasmus Medical Centre, 3015 CN, Rotterdam, The Netherlands
| | - Tomohiko Sadaoka
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
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Collins-McMillen D, Kamil J, Moorman N, Goodrum F. Control of Immediate Early Gene Expression for Human Cytomegalovirus Reactivation. Front Cell Infect Microbiol 2020; 10:476. [PMID: 33072616 PMCID: PMC7533536 DOI: 10.3389/fcimb.2020.00476] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 08/03/2020] [Indexed: 12/16/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a beta herpesvirus that persists for life in the majority of the world's population. The persistence of HCMV in the human population is due to the exquisite ability of herpesviruses to establish a latent infection that evades elimination by the host immune response. How the virus moves into and out of the latent state has been an intense area of research focus and debate. The prevailing paradigm is that the major immediate early promoter (MIEP), which drives robust expression of the major immediate early (MIE) transactivators, is epigenetically silenced during the establishment of latency, and must be reactivated for the virus to exit latency and re-enter productive replication. While it is clear that the MIEP is silenced by the association of repressive chromatin remodeling factors and histone marks, the mechanisms by which HCMV de-represses MIE gene expression for reactivation are less well understood. We have identified alternative promoter elements within the MIE locus that drive a second or delayed phase of MIE gene expression during productive infection. In the context of reactivation in THP-1 macrophages and primary CD34+ human progenitor cells, MIE transcripts are predominantly derived from initiation at these alternative promoters. Here we review the mechanisms by which alternative viral promoters might tailor the control of viral gene expression and the corresponding pattern of infection to specific cell types. Alternative promoter control of the HCMV MIE locus increases versatility in the system and allows the virus to tightly repress viral gene expression for latency but retain the ability to sense and respond to cell type-specific host cues for reactivation of replication.
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Affiliation(s)
- Donna Collins-McMillen
- Department of Immunobiology and BIO5 Institute, University of Arizona, Tucson, AZ, United States
| | - Jeremy Kamil
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center - Shreveport, Shreveport, LA, United States
| | - Nathaniel Moorman
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Felicia Goodrum
- Department of Immunobiology and BIO5 Institute, University of Arizona, Tucson, AZ, United States
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Elbasani E, Falasco F, Gramolelli S, Nurminen V, Günther T, Weltner J, Balboa D, Grundhoff A, Otonkoski T, Ojala PM. Kaposi's Sarcoma-Associated Herpesvirus Reactivation by Targeting of a dCas9-Based Transcription Activator to the ORF50 Promoter. Viruses 2020; 12:v12090952. [PMID: 32867368 PMCID: PMC7552072 DOI: 10.3390/v12090952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/15/2020] [Accepted: 08/24/2020] [Indexed: 12/16/2022] Open
Abstract
CRISPR activation (CRISPRa) has revealed great potential as a tool to modulate the expression of targeted cellular genes. Here, we successfully applied the CRISPRa system to trigger the Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation in latently infected cells by selectively activating ORF50 gene directly from the virus genome. We found that a nuclease-deficient Cas9 (dCas9) fused to a destabilization domain (DD) and 12 copies of the VP16 activation domain (VP192) triggered a more efficient KSHV lytic cycle and virus production when guided to two different sites on the ORF50 promoter, instead of only a single site. To our surprise, the virus reactivation induced by binding of the stable DD-dCas9-VP192 on the ORF50 promoter was even more efficient than reactivation induced by ectopic expression of ORF50. This suggests that recruitment of additional transcriptional activators to the ORF50 promoter, in addition to ORF50 itself, are needed for the efficient virus production. Further, we show that CRISPRa can be applied to selectively express the early lytic gene, ORF57, without disturbing the viral latency. Therefore, CRISPRa-based systems can be utilized to facilitate virus-host interaction studies by controlling the expression of not only cellular but also of specific KSHV genes.
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Affiliation(s)
- Endrit Elbasani
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (F.F.); (S.G.); (V.N.)
- Correspondence: (E.E.); (P.M.O.)
| | - Francesca Falasco
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (F.F.); (S.G.); (V.N.)
| | - Silvia Gramolelli
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (F.F.); (S.G.); (V.N.)
| | - Veijo Nurminen
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (F.F.); (S.G.); (V.N.)
| | - Thomas Günther
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany; (T.G.); (A.G.)
| | - Jere Weltner
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (J.W.); (D.B.); (T.O.)
| | - Diego Balboa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (J.W.); (D.B.); (T.O.)
| | - Adam Grundhoff
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany; (T.G.); (A.G.)
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (J.W.); (D.B.); (T.O.)
| | - Päivi M. Ojala
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland; (F.F.); (S.G.); (V.N.)
- Department of Infectious Diseases, Imperial College London, London W2 1NY, UK
- Correspondence: (E.E.); (P.M.O.)
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Collins-McMillen D, Rak M, Buehler JC, Igarashi-Hayes S, Kamil JP, Moorman NJ, Goodrum F. Alternative promoters drive human cytomegalovirus reactivation from latency. Proc Natl Acad Sci U S A 2019; 116:17492-17497. [PMID: 31409717 PMCID: PMC6717278 DOI: 10.1073/pnas.1900783116] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Reactivation from latency requires reinitiation of viral gene expression and culminates in the production of infectious progeny. The major immediate early promoter (MIEP) of human cytomegalovirus (HCMV) drives the expression of crucial lytic cycle transactivators but is silenced during latency in hematopoietic progenitor cells (HPCs). Because the MIEP has poor activity in HPCs, it is unclear how viral transactivators are expressed during reactivation. It has been presumed that viral gene expression is reinitiated via de-repression of the MIEP. We demonstrate that immediate early transcripts arising from reactivation originate predominantly from alternative promoters within the canonical major immediate early locus. Disruption of these intronic promoters results in striking defects in re-expression of viral genes and viral genome replication in the THP-1 latency model. Furthermore, we show that these promoters are necessary for efficient reactivation in primary CD34+ HPCs. Our findings shift the paradigm for HCMV reactivation by demonstrating that promoter switching governs reactivation from viral latency in a context-specific manner.
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Affiliation(s)
| | - Mike Rak
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721
| | | | | | - Jeremy P Kamil
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, Shreveport, LA 71103
| | - Nathaniel J Moorman
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Felicia Goodrum
- BIO5 Institute, University of Arizona, Tucson, AZ 85721;
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721
- Department of Immunobiology, University of Arizona, Tucson, AZ 85721
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13
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He M, Cheng F, da Silva SR, Tan B, Sorel O, Gruffaz M, Li T, Gao SJ. Molecular Biology of KSHV in Relation to HIV/AIDS-Associated Oncogenesis. Cancer Treat Res 2019; 177:23-62. [PMID: 30523620 DOI: 10.1007/978-3-030-03502-0_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Discovered in 1994, Kaposi's sarcoma-associated herpesvirus (KSHV) has been associated with four human malignancies including Kaposi's sarcoma, primary effusion lymphoma, a subset of multicentric Castleman's disease, and KSHV inflammatory cytokine syndrome. These malignancies mostly occur in immunocompromised patients including patients with acquired immunodeficiency syndrome and often cause significant mortality because of the lack of effective therapies. Significant progresses have been made to understand the molecular basis of KSHV infection and KSHV-induced oncogenesis in the last two decades. This chapter provides an update on the recent advancements focusing on the molecular events of KSHV primary infection, the mechanisms regulating KSHV life cycle, innate and adaptive immunity, mechanism of KSHV-induced tumorigenesis and inflammation, and metabolic reprogramming in KSHV infection and KSHV-transformed cells.
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Affiliation(s)
- Meilan He
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Fan Cheng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Suzane Ramos da Silva
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Brandon Tan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Océane Sorel
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Marion Gruffaz
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Tingting Li
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Shou-Jiang Gao
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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14
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Chandrasekharan JA, Sharma-Walia N. Arachidonic Acid Derived Lipid Mediators Influence Kaposi's Sarcoma-Associated Herpesvirus Infection and Pathogenesis. Front Microbiol 2019; 10:358. [PMID: 30915039 PMCID: PMC6422901 DOI: 10.3389/fmicb.2019.00358] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/11/2019] [Indexed: 12/30/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) infection, particularly latent infection is often associated with inflammation. The arachidonic acid pathway, the home of several inflammation and resolution associated lipid mediators, is widely altered upon viral infections. Several in vitro studies show that these lipid mediators help in the progression of viral pathogenesis. This review summarizes the findings related to human herpesvirus KSHV infection and arachidonic acid pathway metabolites. KSHV infection has been shown to promote inflammation by upregulating cyclooxygenase-2 (COX-2), 5 lipoxygenase (5LO), and their respective metabolites prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) to promote latency and an inflammatory microenvironment. Interestingly, the anti-inflammatory lipid mediator lipoxin is downregulated during KSHV infection to facilitate infected cell survival. These studies aid in understanding the role of arachidonic acid pathway metabolites in the progression of viral infection, the host inflammatory response, and pathogenesis. With limited therapeutic options to treat KSHV infection, use of inhibitors to these inflammatory metabolites and their synthetic pathways or supplementing anti-inflammatory lipid mediators could be an effective alternative therapeutic.
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Affiliation(s)
- Jayashree A Chandrasekharan
- Department of Microbiology and Immunology, H.M. Bligh Cancer Research Laboratories, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
| | - Neelam Sharma-Walia
- Department of Microbiology and Immunology, H.M. Bligh Cancer Research Laboratories, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
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15
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Mui UN, Haley CT, Tyring SK. Viral Oncology: Molecular Biology and Pathogenesis. J Clin Med 2017; 6:E111. [PMID: 29186062 PMCID: PMC5742800 DOI: 10.3390/jcm6120111] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/17/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
Oncoviruses are implicated in approximately 12% of all human cancers. A large number of the world's population harbors at least one of these oncoviruses, but only a small proportion of these individuals go on to develop cancer. The interplay between host and viral factors is a complex process that works together to create a microenvironment conducive to oncogenesis. In this review, the molecular biology and oncogenic pathways of established human oncoviruses will be discussed. Currently, there are seven recognized human oncoviruses, which include Epstein-Barr Virus (EBV), Human Papillomavirus (HPV), Hepatitis B and C viruses (HBV and HCV), Human T-cell lymphotropic virus-1 (HTLV-1), Human Herpesvirus-8 (HHV-8), and Merkel Cell Polyomavirus (MCPyV). Available and emerging therapies for these oncoviruses will be mentioned.
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Affiliation(s)
- Uyen Ngoc Mui
- Center for Clinical Studies, Houston, TX 77004, USA.
| | | | - Stephen K Tyring
- Center for Clinical Studies, Houston, TX 77004, USA.
- Department of Dermatology, University of Texas Health Science Center at Houston, Houston, TX 77004, USA.
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16
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Quantitative Analysis of the KSHV Transcriptome Following Primary Infection of Blood and Lymphatic Endothelial Cells. Pathogens 2017; 6:pathogens6010011. [PMID: 28335496 PMCID: PMC5371899 DOI: 10.3390/pathogens6010011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/07/2017] [Accepted: 03/15/2017] [Indexed: 12/14/2022] Open
Abstract
The transcriptome of the Kaposi’s sarcoma-associated herpesvirus (KSHV/HHV8) after primary latent infection of human blood (BEC), lymphatic (LEC) and immortalized (TIME) endothelial cells was analyzed using RNAseq, and compared to long-term latency in BCBL-1 lymphoma cells. Naturally expressed transcripts were obtained without artificial induction, and a comprehensive annotation of the KSHV genome was determined. A set of unique coding sequence (UCDS) features and a process to resolve overlapping transcripts were developed to accurately quantitate transcript levels from specific promoters. Similar patterns of KSHV expression were detected in BCBL-1 cells undergoing long-term latent infections and in primary latent infections of both BEC and LEC cultures. High expression levels of poly-adenylated nuclear (PAN) RNA and spliced and unspliced transcripts encoding the K12 Kaposin B/C complex and associated microRNA region were detected, with an elevated expression of a large set of lytic genes in all latently infected cultures. Quantitation of non-overlapping regions of transcripts across the complete KSHV genome enabled for the first time accurate evaluation of the KSHV transcriptome associated with viral latency in different cell types. Hierarchical clustering applied to a gene correlation matrix identified modules of co-regulated genes with similar correlation profiles, which corresponded with biological and functional similarities of the encoded gene products. Gene modules were differentially upregulated during latency in specific cell types indicating a role for cellular factors associated with differentiated and/or proliferative states of the host cell to influence viral gene expression.
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