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Chinna P, Bratl K, Lambarey H, Blumenthal MJ, Schäfer G. The Impact of Co-Infections for Human Gammaherpesvirus Infection and Associated Pathologies. Int J Mol Sci 2023; 24:13066. [PMID: 37685871 PMCID: PMC10487760 DOI: 10.3390/ijms241713066] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
The two oncogenic human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause significant disease burden, particularly in immunosuppressed individuals. Both viruses display latent and lytic phases of their life cycle with different outcomes for their associated pathologies. The high prevalence of infectious diseases in Sub-Saharan Africa (SSA), particularly HIV/AIDS, tuberculosis, malaria, and more recently, COVID-19, as well as their associated inflammatory responses, could potentially impact either virus' infectious course. However, acute or lytically active EBV and/or KSHV infections often present with symptoms mimicking these predominant diseases leading to misdiagnosis or underdiagnosis of oncogenic herpesvirus-associated pathologies. EBV and/or KSHV infections are generally acquired early in life and remain latent until lytic reactivation is triggered by various stimuli. This review summarizes known associations between infectious agents prevalent in SSA and underlying EBV and/or KSHV infection. While presenting an overview of both viruses' biphasic life cycles, this review aims to highlight the importance of co-infections in the correct identification of risk factors for and diagnoses of EBV- and/or KSHV-associated pathologies, particularly in SSA, where both oncogenic herpesviruses as well as other infectious agents are highly pervasive and can lead to substantial morbidity and mortality.
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Affiliation(s)
- Prishanta Chinna
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town 7925, South Africa; (P.C.); (K.B.); (H.L.); (M.J.B.)
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Katrin Bratl
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town 7925, South Africa; (P.C.); (K.B.); (H.L.); (M.J.B.)
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Humaira Lambarey
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town 7925, South Africa; (P.C.); (K.B.); (H.L.); (M.J.B.)
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Melissa J. Blumenthal
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town 7925, South Africa; (P.C.); (K.B.); (H.L.); (M.J.B.)
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Georgia Schäfer
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town 7925, South Africa; (P.C.); (K.B.); (H.L.); (M.J.B.)
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
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Kaposi Sarcoma, a Trifecta of Pathogenic Mechanisms. Diagnostics (Basel) 2022; 12:diagnostics12051242. [PMID: 35626397 PMCID: PMC9140574 DOI: 10.3390/diagnostics12051242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/29/2022] [Accepted: 05/13/2022] [Indexed: 01/10/2023] Open
Abstract
Kaposi’s sarcoma is a rare disease with four known variants: classic, epidemic, endemic and iatrogenic (transplant-related), all caused by an oncogenic virus named Human Herpes Virus 8. The viral infection in itself, along with the oncogenic properties of HHV8 and with immune system dysfunction, forms the grounds on which Kaposi’s Sarcoma may develop. Infection with HHV8 occurs through saliva via close contacts, blood, blood products, solid organ donation and, rarely, vertical transmission. Chronic inflammation and oncogenesis are promoted by a mix of viral genes that directly promote cell survival and transformation or interfere with the regular cell cycle and cell signaling (of particular note: LANA-1, v-IL6, vBCL-2, vIAP, vIRF3, vGPCR, gB, K1, K8.1, K15). The most common development sites for Kaposi’s sarcoma are the skin, mucocutaneous zones, lymph nodes and visceral organs, but it can also rarely appear in the musculoskeletal system, urinary system, endocrine organs, heart or eye. Histopathologically, spindle cell proliferation with slit-like vascular spaces, plasma cell and lymphocyte infiltrate are characteristic. The clinical presentation is heterogenic depending on the variant; some patients have indolent disease and others have aggressive disease. The treatment options include highly active antiretroviral therapy, surgery, radiation therapy, chemotherapy, and immunotherapy. A literature search was carried out using the MEDLINE/PubMed, SCOPUS and Google Scholar databases with a combination of keywords with the aim to provide critical, concise, and comprehensive insights into advances in the pathogenic mechanism of Kaposi’s sarcoma.
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Herrera-Ortíz A, Meng W, Gao SJ. Nitric oxide is induced and required for efficient Kaposi's sarcoma-associated herpesvirus lytic replication. J Med Virol 2021; 93:6323-6332. [PMID: 34297418 DOI: 10.1002/jmv.27228] [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] [Received: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/08/2022]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus associated with several human malignancies. KSHV lytic replication promotes the spread of infection and progression of KSHV-associated malignancies; however, the mechanism regulating KSHV lytic replication remains unclear. In this study, we investigated the role of nitric oxide (NO) in KSHV lytic replication. In the TREx BCBL1-RTA KSHV lytic replication cell system, induction of KSHV lytic replication increased intracellular and extracellular NO. Chemical inhibition of NO production resulted in a lower level of KSHV lytic replication as shown by a reduced level of infectious virions, and decreased levels of viral lytic transcripts and proteins. In a second KSHV lytic replication system of iSLK-RGB-BAC16 cells, we confirmed that KSHV lytic replication increased NO production. Chemical inhibition of NO production resulted in reduced numbers of cells expressing enhanced green fluorescent protein and blue fluorescent protein, two reporters that closely track the expression of KSHV early and late genes, respectively. Consistent with these results, inhibition of NO production resulted in reduced levels of infectious virions, and viral lytic transcripts and proteins. Importantly, exogenous addition of a NO donor was sufficient to enhance the full KSHV lytic replication program. These results demonstrate that NO is required for efficient KSHV lytic replication, and NO plays a crucial role in the KSHV life cycle and KSHV-induced malignancies.
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Affiliation(s)
- Antonia Herrera-Ortíz
- Department of Immunology and Molecular Microbiology, University of Southern California Keck School of Medicine, University of Southern California, Los Angeles, California, USA.,Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Wen Meng
- Department of Microbiology and Molecular Genetics, Cancer Virology Program, UPMC Hillman Caner Center, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shou-Jiang Gao
- Department of Immunology and Molecular Microbiology, University of Southern California Keck School of Medicine, University of Southern California, Los Angeles, California, USA.,Department of Microbiology and Molecular Genetics, Cancer Virology Program, UPMC Hillman Caner Center, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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4
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Samarina N, Ssebyatika G, Tikla T, Waldmann JY, Abere B, Nanna V, Marasco M, Carlomagno T, Krey T, Schulz TF. Recruitment of phospholipase Cγ1 to the non-structural membrane protein pK15 of Kaposi Sarcoma-associated herpesvirus promotes its Src-dependent phosphorylation. PLoS Pathog 2021; 17:e1009635. [PMID: 34143834 PMCID: PMC8244865 DOI: 10.1371/journal.ppat.1009635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 06/30/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022] Open
Abstract
Kaposi Sarcoma-associated herpesvirus (KSHV) causes three human malignancies, Kaposi Sarcoma (KS), Primary Effusion Lymphoma (PEL) and the plasma cell variant of multicentric Castleman’s Disease (MCD), as well as an inflammatory cytokine syndrome (KICS). Its non-structural membrane protein, pK15, is among a limited set of viral proteins expressed in KSHV-infected KS tumor cells. Following its phosphorylation by Src family tyrosine kinases, pK15 recruits phospholipase C gamma 1 (PLCγ1) to activate downstream signaling cascades such as the MEK/ERK, NFkB and PI3K pathway, and thereby contributes to the increased proliferation and migration as well as the spindle cell morphology of KSHV-infected endothelial cells. Here, we show that a phosphorylated Y481EEVL motif in pK15 preferentially binds into the PLCγ1 C-terminal SH2 domain (cSH2), which is involved in conformational changes occurring during the activation of PLCγ1 by receptor tyrosine kinases. We determined the crystal structure of a pK15 12mer peptide containing the phosphorylated pK15 Y481EEVL motif in complex with a shortened PLCγ1 tandem SH2 (tSH2) domain. This structure demonstrates that the pK15 peptide binds to the PLCγ1 cSH2 domain in a position that is normally occupied by the linker region connecting the PLCγ1 cSH2 and SH3 domains. We also show that longer pK15 peptides containing the phosphorylated pK15 Y481EEVL motif can increase the Src-mediated phosphorylation of the PLCγ1 tSH2 region in vitro. This pK15-induced increase in Src-mediated phosphorylation of PLCγ1 can be inhibited with the small pK15-derived peptide which occupies the PLCγ1 cSH2 domain. Our findings thus suggest that pK15 may act as a scaffold protein to promote PLCγ1 activation in a manner similar to the cellular scaffold protein SLP-76, which has been shown to promote PLCγ1 activation in the context of T-cell receptor signaling. Reminiscent of its positional homologue in Epstein-Barr Virus, LMP2A, pK15 may therefore mimic aspects of antigen-receptor signaling. Our findings also suggest that it may be possible to inhibit the recruitment and activation of PLCγ1 pharmacologically. Kaposi’s Sarcoma-Associated Herpesvirus (KSHV) causes three human malignancies (Kaposi Sarcoma, Primary Effusion Lymphoma, Multicentric Castleman’s Disease) and an inflammatory condition, KICS. One of its non-structural membrane proteins, pK15, is expressed in tumor cells and has previously been shown to contribute to its ability to reactivate from latency and to its pathogenetic properties in endothelial cells by recruiting the cellular signaling enzyme phospholipase Cγ1 (PLCγ1). Here we investigate the interaction of pK15 with PLCγ1, report the structure of a PLCγ1 domain in complex with a pK15 peptide and show that pK15 primes PLCγ1 for phosphorylation by the cellular kinase Src. We also show that the pK15-dependent activation of PLCγ1 can be inhibited with a small peptide. Our findings therefore identify the pK15-PLCγ1 interaction as a putative druggable target and provide the basis for the development of small molecule inhibitors that could perhaps serve to inhibit KSHV replication and pathogenesis.
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Affiliation(s)
- Naira Samarina
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | | | - Tanvi Tikla
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | - Ja-Yun Waldmann
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | - Bizunesh Abere
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
| | - Vittoria Nanna
- Institute of Organic Chemistry, Leibniz University Hannover, Hannover, Germany
| | | | - Teresa Carlomagno
- Institute of Organic Chemistry, Leibniz University Hannover, Hannover, Germany
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, Hannover, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover Braunschweig Site, Hannover, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, Hannover, Germany
- * E-mail:
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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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Eliassen E, Lum E, Pritchett J, Ongradi J, Krueger G, Crawford JR, Phan TL, Ablashi D, Hudnall SD. Human Herpesvirus 6 and Malignancy: A Review. Front Oncol 2018; 8:512. [PMID: 30542640 PMCID: PMC6277865 DOI: 10.3389/fonc.2018.00512] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/19/2018] [Indexed: 12/21/2022] Open
Abstract
In order to determine the role of human herpesvirus 6 (HHV-6) in human disease, several confounding factors, including methods of detection, types of controls, and the ubiquitous nature of the virus, must be considered. This is particularly problematic in the case of cancer, in which rates of detection vary greatly among studies. To determine what part, if any, HHV-6 plays in oncogenesis, a review of the literature was performed. There is evidence that HHV-6 is present in certain types of cancer; however, detection of the virus within tumor cells is insufficient for assigning a direct role of HHV-6 in tumorigenesis. Findings supportive of a causal role for a virus in cancer include presence of the virus in a large proportion of cases, presence of the virus in most tumor cells, and virus-induced in-vitro cell transformation. HHV-6, if not directly oncogenic, may act as a contributory factor that indirectly enhances tumor cell growth, in some cases by cooperation with other viruses. Another possibility is that HHV-6 may merely be an opportunistic virus that thrives in the immunodeficient tumor microenvironment. Although many studies have been carried out, it is still premature to definitively implicate HHV-6 in several human cancers. In some instances, evidence suggests that HHV-6 may cooperate with other viruses, including EBV, HPV, and HHV-8, in the development of cancer, and HHV-6 may have a role in such conditions as nodular sclerosis Hodgkin lymphoma, gastrointestinal cancer, glial tumors, and oral cancers. However, further studies will be required to determine the exact contributions of HHV-6 to tumorigenesis.
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Affiliation(s)
- Eva Eliassen
- HHV-6 Foundation, Santa Barbara, CA, United States
| | - Emily Lum
- HHV-6 Foundation, Santa Barbara, CA, United States
| | - Joshua Pritchett
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, United States
| | - Joseph Ongradi
- Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary
| | - Gerhard Krueger
- Department of Pathology and Laboratory Medicine, University of Texas- Houston Medical School, Houston, TX, United States
| | - John R Crawford
- Department of Neurosciences and Pediatrics, University of California San Diego and Rady Children's Hospital, San Diego, CA, United States
| | - Tuan L Phan
- HHV-6 Foundation, Santa Barbara, CA, United States.,Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
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Yan Q, Zhao R, Shen C, Wang F, Li W, Gao SJ, Lu C. Upregulation of MicroRNA 711 Mediates HIV-1 Vpr Promotion of Kaposi's Sarcoma-Associated Herpesvirus Latency and Induction of Pro-proliferation and Pro-survival Cytokines by Targeting the Notch/NF-κB-Signaling Axis. J Virol 2018; 92:JVI.00580-18. [PMID: 29976660 PMCID: PMC6146700 DOI: 10.1128/jvi.00580-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/21/2018] [Indexed: 02/05/2023] Open
Abstract
Coinfection with HIV-1 and Kaposi's sarcoma-associated herpesvirus (KSHV) often leads to AIDS-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). The interaction between HIV and KSHV plays a pivotal role in the progression of these malignancies. We have previously demonstrated that, by upregulating miR-942-5p, HIV-1 viral protein R (Vpr) inhibits KSHV lytic replication by targeting IκBα to activate the NF-κB signaling (Q. Yan, C. Shen, J. Qin, W. Li, M. Hu, H. Lu, D. Qin, J. Zhu, S. J. Gao, C. Lu, J Virol 90:8739-8753, 2016). Here, we show that Vpr inactivates Notch signaling, resulting in inhibition of KSHV lytic replication and induction of pro-proliferative and -survival cytokines, including interleukin-2 (IL-2), TIMP-1, IGF-1, and NT-4. Mechanistically, Vpr upregulates miR-711, which directly targets the Notch1 3' untranslated region. Suppression of miR-711 relieved Notch1 and reduced Vpr inhibition of KSHV lytic replication and Vpr induction of pro-proliferation and -survival cytokines, while overexpression of miR-711 exhibited the opposite effect. Finally, overexpression of Notch1 reduced Vpr induction of NF-κB activity by promoting IκBα promoter activity. Our novel findings reveal that by upregulating miR-711 to target Notch1, Vpr silences Notch signaling to activate the NF-κB pathway by reducing IκBα expression, leading to inhibition of KSHV lytic replication and induction of pro-proliferation and -survival cytokines. Therefore, the miR-711/Notch/NF-κB axis is important in the pathogenesis of AIDS-related malignancies and could be an attractive therapeutic target.IMPORTANCE HIV-1 infection significantly increases the risk of KS and PEL in KSHV-infected individuals. Our previous study has shown that HIV-1 Vpr regulates the KSHV life cycle by targeting IκBα to activate NF-κB signaling through upregulating cellular miR-942-5p. In this study, we have further found that Vpr inactivates Notch signaling to promote KSHV latency and production of pro-proliferation and -survival cytokines. Another Vpr-upregulated cellular microRNA, miR-711, participates in this process by directly targeting Notch1. As a result, Notch1 upregulation of the IκBα promoter activity is attenuated, resulting in reduced levels of IκBα transcript and protein. Overall, these results illustrate an alternative mechanism of HIV-1 Vpr regulation of KSHV latency and aberrant cytokines through the miR-711/Notch/NF-κB axis. Our novel findings further demonstrate the role of an HIV-1-secreted regulatory protein in the KSHV life cycle and KSHV-related malignancies.
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Affiliation(s)
- Qin Yan
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People's Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Runran Zhao
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Chenyou Shen
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Fei Wang
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Wan Li
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Shou-Jiang Gao
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
- Laboratory of Human Virology and Oncology, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
- UPMC Hillman Cancer Center, Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Chun Lu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People's Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology, Nanjing Medical University, Nanjing, People's Republic of China
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8
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Eliassen E, Krueger G, Luppi M, Ablashi D. Lymphoproliferative Syndromes Associated with Human Herpesvirus-6A and Human Herpesvirus-6B. Mediterr J Hematol Infect Dis 2018; 10:e2018035. [PMID: 29755712 PMCID: PMC5937953 DOI: 10.4084/mjhid.2018.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/28/2022] Open
Abstract
Human herpesvirus 6A and 6B (HHV-6A and HHV-6B) have been noted since their discovery for their T-lymphotropism. Although it has proven difficult to determine the extent to which HHV-6A and HHV-6B are involved in the pathogenesis of many diseases, evidence suggests that primary infection and reactivation of both viruses may induce or contribute to the progression of several lymphoproliferative disorders, ranging from benign to malignant and including infectious mononucleosis-like illness, drug induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS), and nodular sclerosis Hodgkin's lymphoma. Herein, we discuss the conditions associated with the lymphoproliferative capacity of HHV-6, as well as the potential mechanisms behind them. Continued exploration on this topic may add to our understanding of the interactions between HHV-6 and the immune system and may open the doors to more accurate diagnosis and treatment of certain lymphoproliferative disorders.
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Affiliation(s)
- Eva Eliassen
- HHV-6 Foundation, Santa Barbara, California, USA
| | - Gerhard Krueger
- Department of Pathology and Laboratory Medicine, University of Texas, Houston, Texas, USA
| | - Mario Luppi
- Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy
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9
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Abere B, Mamo TM, Hartmann S, Samarina N, Hage E, Rückert J, Hotop SK, Büsche G, Schulz TF. The Kaposi's sarcoma-associated herpesvirus (KSHV) non-structural membrane protein K15 is required for viral lytic replication and may represent a therapeutic target. PLoS Pathog 2017; 13:e1006639. [PMID: 28938025 PMCID: PMC5627962 DOI: 10.1371/journal.ppat.1006639] [Citation(s) in RCA: 19] [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: 05/16/2017] [Revised: 10/04/2017] [Accepted: 09/09/2017] [Indexed: 12/18/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is the infectious cause of the highly vascularized tumor Kaposi’s sarcoma (KS), which is characterized by proliferating spindle cells of endothelial origin, extensive neo-angiogenesis and inflammatory infiltrates. The KSHV K15 protein contributes to the angiogenic and invasive properties of KSHV-infected endothelial cells. Here, we asked whether K15 could also play a role in KSHV lytic replication. Deletion of the K15 gene from the viral genome or its depletion by siRNA lead to reduced virus reactivation, as evidenced by the decreased expression levels of KSHV lytic proteins RTA, K-bZIP, ORF 45 and K8.1 as well as reduced release of infectious virus. Similar results were found for a K1 deletion virus. Deleting either K15 or K1 from the viral genome also compromised the ability of KSHV to activate PLCγ1, Erk1/2 and Akt1. In infected primary lymphatic endothelial (LEC-rKSHV) cells, which have previously been shown to spontaneously display a viral lytic transcription pattern, transfection of siRNA against K15, but not K1, abolished viral lytic replication as well as KSHV-induced spindle cell formation. Using a newly generated monoclonal antibody to K15, we found an abundant K15 protein expression in KS tumor biopsies obtained from HIV positive patients, emphasizing the physiological relevance of our findings. Finally, we used a dominant negative inhibitor of the K15-PLCγ1 interaction to establish proof of principle that pharmacological intervention with K15-dependent pathways may represent a novel approach to block KSHV reactivation and thereby its pathogenesis. Both the latent and lytic replication phases of the KSHV life cycle are thought to contribute to its persistence and pathogenesis. The non-structural signaling membrane protein K15 is involved in the angiogenic and invasive properties of KSHV-infected endothelial cells. Here we show that the K15 protein is required for virus replication, early viral gene expression and virus production through its activation of the cellular signaling pathways PLCγ1 and Erk 1/2. K15 is abundantly expressed in KSHV-infected lymphatic endothelial cells (LECs) and contributes to KSHV-induced endothelial spindle cell formation. The abundant K15 protein expression observed in LECs is also observed in KS tumors. We also show that it may be possible to target K15 in order to intervene therapeutically with KSHV lytic replication and pathogenesis.
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Affiliation(s)
- Bizunesh Abere
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Tamrat M. Mamo
- Institute of Molecular Biology, Hannover Medical School, Hannover, Germany
| | - Silke Hartmann
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Naira Samarina
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Elias Hage
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Jessica Rückert
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Sven-Kevin Hotop
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
- Department of Chemical Biology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Guntram Büsche
- Institute of Pathology, Hannover Medical School, Hannover, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
- * E-mail:
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10
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Fine-Tuning of the Kaposi's Sarcoma-Associated Herpesvirus Life Cycle in Neighboring Cells through the RTA-JAG1-Notch Pathway. PLoS Pathog 2016; 12:e1005900. [PMID: 27760204 PMCID: PMC5070770 DOI: 10.1371/journal.ppat.1005900] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/27/2016] [Indexed: 12/16/2022] Open
Abstract
Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) is an oncogenic pathogen that displays latent and lytic life cycles. In KS lesions, infiltrated immune cells, secreted viral and/or cellular cytokines, and hypoxia orchestrate a chronic pro-lytic microenvironment that can promote KSHV reactivation. However, only a small subset of viruses spontaneously undergoes lytic replication in this pro-lytic microenvironment while the majority remains in latency. Here, we show that the expression of the Notch ligand JAG1 is induced by KSHV-encoded replication and transcription activator (RTA) during reactivation. JAG1 up-regulation activates Notch signaling in neighboring cells and prevents viral lytic replication. The suppression of JAG1 and Notch1 with inhibitors or small interfering RNA promotes lytic replication in the presence of RTA induction or under conditions of hypoxia. The underlying mechanism involves the Notch downstream effector hairy and enhancer of split 1 (Hes1), which directly binds lytic gene promoters and attenuates viral lytic gene expression. RTA interacts with lymphoid enhancer-binding factor 1 (LEF1), disrupts LEF1/Groucho/TLE suppressive complexes and releases LEF1 to activate JAG1 expression. Taken together, our results suggest that cells with viral lytic replication can inhibit KSHV reactivation in neighboring cells through an RTA-JAG1-Notch pathway. These data provide insight into the mechanism by which the virus maintains the balance between lytic and latent infection in the pro-lytic tumor microenvironment. KSHV infected cells display significant heterogeneity in viral lytic replication within the universal pro-lytic inflammatory milieu, suggesting that the balance between latency and reactivation is carefully regulated. This fine-tuned regulatory mechanism is essential for KSHV to persist in the host and drive cells to malignancy. In the present study, we show that KSHV can usurp the Notch signaling pathway to inhibit the viral lytic life cycle in neighboring cells. Notch signaling in surrounding cells can be activated through an RTA-JAG1-Notch pathway initiated by cells in which KSHV is reactivated. Activated Notch inhibits KSHV reactivation through its downstream effector Hes1. These findings suggest that the ability of Notch to determine the fate of adjacent cells is hijacked by KSHV to maintain its life cycle, providing a mechanistic explanation for the phenomenon by which only a small fraction of viruses enters lytic replication in the common pro-lytic microenvironment.
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11
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HIV-1 Vpr Inhibits Kaposi's Sarcoma-Associated Herpesvirus Lytic Replication by Inducing MicroRNA miR-942-5p and Activating NF-κB Signaling. J Virol 2016; 90:8739-53. [PMID: 27440900 DOI: 10.1128/jvi.00797-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/15/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) infection is required for the development of several AIDS-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). The high incidence of AIDS-KS has been ascribed to the interaction of KSHV and HIV-1. We have previously shown that HIV-1-secreted proteins Tat and Nef regulate the KSHV life cycle and synergize with KSHV oncogenes to promote angiogenesis and tumorigenesis. Here, we examined the regulation of KSHV latency by HIV-1 viral protein R (Vpr). We found that soluble Vpr inhibits the expression of KSHV lytic transcripts and proteins, as well as viral particle production by activating NF-κB signaling following internalization into PEL cells. By analyzing the expression profiles of microRNAs combined with target search by bioinformatics and luciferase reporter analyses, we identified a Vpr-upregulated cellular microRNA (miRNA), miR-942-5p, that directly targeted IκBα. Suppression of miR-942-5p relieved the expression of IκBα and reduced Vpr inhibition of KSHV lytic replication, while overexpression of miR-942-5p enhanced Vpr inhibition of KSHV lytic replication. Our findings collectively illustrate that, by activating NF-κB signaling through upregulating a cellular miRNA to target IκBα, internalized HIV-1 Vpr inhibits KSHV lytic replication. These results have demonstrated an essential role of Vpr in the life cycle of KSHV. IMPORTANCE Coinfection by HIV-1 promotes the aggressive growth of Kaposi's sarcoma-associated herpesvirus (KSHV)-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). In this study, we have shown that soluble HIV-1 Vpr inhibits KSHV lytic replication by activating NF-κB signaling following internalization into PEL cells. Mechanistic studies revealed that a cellular microRNA upregulated by Vpr, miR-942-5p, directly targeted IκBα. Suppression of miR-942-5p relieved IκBα expression and reduced Vpr inhibition of KSHV replication, while overexpression of miR-942-5p enhanced Vpr inhibition of KSHV replication. These results indicate that by activating NF-κB signaling through upregulating a cellular miRNA to target IκBα, internalized Vpr inhibits KSHV lytic replication. This work illustrates a molecular mechanism by which HIV-1-secreted regulatory protein Vpr regulates KSHV latency and the pathogenesis of AIDS-related malignancies.
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12
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Strahan R, Uppal T, Verma SC. Next-Generation Sequencing in the Understanding of Kaposi's Sarcoma-Associated Herpesvirus (KSHV) Biology. Viruses 2016; 8:92. [PMID: 27043613 PMCID: PMC4848587 DOI: 10.3390/v8040092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/21/2016] [Accepted: 03/23/2016] [Indexed: 12/16/2022] Open
Abstract
Non-Sanger-based novel nucleic acid sequencing techniques, referred to as Next-Generation Sequencing (NGS), provide a rapid, reliable, high-throughput, and massively parallel sequencing methodology that has improved our understanding of human cancers and cancer-related viruses. NGS has become a quintessential research tool for more effective characterization of complex viral and host genomes through its ever-expanding repertoire, which consists of whole-genome sequencing, whole-transcriptome sequencing, and whole-epigenome sequencing. These new NGS platforms provide a comprehensive and systematic genome-wide analysis of genomic sequences and a full transcriptional profile at a single nucleotide resolution. When combined, these techniques help unlock the function of novel genes and the related pathways that contribute to the overall viral pathogenesis. Ongoing research in the field of virology endeavors to identify the role of various underlying mechanisms that control the regulation of the herpesvirus biphasic lifecycle in order to discover potential therapeutic targets and treatment strategies. In this review, we have complied the most recent findings about the application of NGS in Kaposi’s sarcoma-associated herpesvirus (KSHV) biology, including identification of novel genomic features and whole-genome KSHV diversities, global gene regulatory network profiling for intricate transcriptome analyses, and surveying of epigenetic marks (DNA methylation, modified histones, and chromatin remodelers) during de novo, latent, and productive KSHV infections.
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Affiliation(s)
- Roxanne Strahan
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, 1664 N, Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Timsy Uppal
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, 1664 N, Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Subhash C Verma
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, 1664 N, Virginia Street, MS 320, Reno, NV 89557, USA.
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13
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Thakker S, Verma SC. Co-infections and Pathogenesis of KSHV-Associated Malignancies. Front Microbiol 2016; 7:151. [PMID: 26913028 PMCID: PMC4753363 DOI: 10.3389/fmicb.2016.00151] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/27/2016] [Indexed: 12/25/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV), also known as human herpes virus 8 (HHV-8) is one of the several carcinogenic viruses that infect humans. KSHV infection has been implicated in the development of Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman’s Disease. While KSHV infection is necessary for the development of KSHV associated malignancies, it is not sufficient to induce tumorigenesis. Evidently, other co-factors are essential for the progression of KSHV induced malignancies. One of the most important co-factors, necessary for the progression of KSHV induced tumors, is immune suppression that frequently arises during co-infection with HIV and also by other immune suppressants. In this mini-review, we discuss the roles of co-infection with HIV and other pathogens on KSHV infection and pathogenesis.
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14
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Agut H, Bonnafous P, Gautheret-Dejean A. Laboratory and clinical aspects of human herpesvirus 6 infections. Clin Microbiol Rev 2015; 28:313-35. [PMID: 25762531 PMCID: PMC4402955 DOI: 10.1128/cmr.00122-14] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) is a widespread betaherpesvirus which is genetically related to human cytomegalovirus (HCMV) and now encompasses two different species: HHV-6A and HHV-6B. HHV-6 exhibits a wide cell tropism in vivo and, like other herpesviruses, induces a lifelong latent infection in humans. As a noticeable difference with respect to other human herpesviruses, genomic HHV-6 DNA is covalently integrated into the subtelomeric region of cell chromosomes (ciHHV-6) in about 1% of the general population. Although it is infrequent, this may be a confounding factor for the diagnosis of active viral infection. The diagnosis of HHV-6 infection is performed by both serologic and direct methods. The most prominent technique is the quantification of viral DNA in blood, other body fluids, and organs by means of real-time PCR. Many active HHV-6 infections, corresponding to primary infections, reactivations, or exogenous reinfections, are asymptomatic. However, the virus may be the cause of serious diseases, particularly in immunocompromised individuals. As emblematic examples of HHV-6 pathogenicity, exanthema subitum, a benign disease of infancy, is associated with primary infection, whereas further virus reactivations can induce severe encephalitis cases, particularly in hematopoietic stem cell transplant recipients. Generally speaking, the formal demonstration of the causative role of HHV-6 in many acute and chronic human diseases is difficult due to the ubiquitous nature of the virus, chronicity of infection, existence of two distinct species, and limitations of current investigational tools. The antiviral compounds ganciclovir, foscarnet, and cidofovir are effective against active HHV-6 infections, but the indications for treatment, as well as the conditions of drug administration, are not formally approved to date. There are still numerous pending questions about HHV-6 which should stimulate future research works on the pathophysiology, diagnosis, and therapy of this remarkable human virus.
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Affiliation(s)
- Henri Agut
- Sorbonne Universités, UPMC, CIMI-Paris UMRS CR7, PVI Team, Paris, France INSERM, CIMI-Paris U1135, PVI Team, Paris, France AP-HP, Hôpitaux Universitaires Pitié Salpêtrière-Charles Foix, Service de Virologie, Paris, France
| | - Pascale Bonnafous
- Sorbonne Universités, UPMC, CIMI-Paris UMRS CR7, PVI Team, Paris, France INSERM, CIMI-Paris U1135, PVI Team, Paris, France
| | - Agnès Gautheret-Dejean
- Sorbonne Universités, UPMC, CIMI-Paris UMRS CR7, PVI Team, Paris, France INSERM, CIMI-Paris U1135, PVI Team, Paris, France AP-HP, Hôpitaux Universitaires Pitié Salpêtrière-Charles Foix, Service de Virologie, Paris, France Université René Descartes, Faculté de Pharmacie, Laboratoire de Microbiologie UPRES EA 4065, Paris, France
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15
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Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) primarily persists as a latent episome in infected cells. During latent infection, only a limited number of viral genes are expressed that help to maintain the viral episome and prevent lytic reactivation. The latent KSHV genome persists as a highly ordered chromatin structure with bivalent chromatin marks at the promoter-regulatory region of the major immediate-early gene promoter. Various stimuli can induce chromatin modifications to an active euchromatic epigenetic mark, leading to the expression of genes required for the transition from the latent to the lytic phase of KSHV life cycle. Enhanced replication and transcription activator (RTA) gene expression triggers a cascade of events, resulting in the modulation of various cellular pathways to support viral DNA synthesis. RTA also binds to the origin of lytic DNA replication to recruit viral, as well as cellular, proteins for the initiation of the lytic DNA replication of KSHV. In this review we will discuss some of the pivotal genetic and epigenetic factors that control KSHV reactivation from the transcriptionally restricted latent program.
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16
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Prusty BK, Siegl C, Gulve N, Mori Y, Rudel T. GP96 interacts with HHV-6 during viral entry and directs it for cellular degradation. PLoS One 2014; 9:e113962. [PMID: 25470779 PMCID: PMC4254946 DOI: 10.1371/journal.pone.0113962] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 11/03/2014] [Indexed: 11/27/2022] Open
Abstract
CD46 and CD134 mediate attachment of Human Herpesvirus 6A (HHV-6A) and HHV-6B to host cell, respectively. But many cell types interfere with viral infection through rapid degradation of viral DNA. Hence, not all cells expressing these receptors are permissive to HHV-6 DNA replication and production of infective virions suggesting the involvement of additional factors that influence HHV-6 propagation. Here, we used a proteomics approach to identify other host cell proteins necessary for HHV-6 binding and entry. We found host cell chaperone protein GP96 to interact with HHV-6A and HHV-6B and to interfere with virus propagation within the host cell. In human peripheral blood mononuclear cells (PBMCs), GP96 is transported to the cell surface upon infection with HHV-6 and interacts with HHV-6A and -6B through its C-terminal end. Suppression of GP96 expression decreased initial viral binding but increased viral DNA replication. Transient expression of human GP96 allowed HHV-6 entry into CHO-K1 cells even in the absence of CD46. Thus, our results suggest an important role for GP96 during HHV-6 infection, which possibly supports the cellular degradation of the virus.
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MESH Headings
- Animals
- CHO Cells
- Cell Line, Tumor
- Cells, Cultured
- Cricetinae
- Cricetulus
- DNA, Viral/metabolism
- HeLa Cells
- Herpesvirus 6, Human/genetics
- Herpesvirus 6, Human/metabolism
- Herpesvirus 6, Human/physiology
- Host-Pathogen Interactions
- Humans
- Immunoblotting
- Leukocytes, Mononuclear/metabolism
- Leukocytes, Mononuclear/virology
- Membrane Cofactor Protein/metabolism
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Microscopy, Confocal
- Models, Biological
- Protein Binding
- Proteolysis
- RNA Interference
- Viral Proteins/metabolism
- Virus Internalization
- Virus Replication
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Affiliation(s)
- Bhupesh K. Prusty
- Biocenter, Chair of Microbiology, University of Würzburg, 97074 Würzburg, Germany
- * E-mail: (TR); (BKP)
| | - Christine Siegl
- Biocenter, Chair of Microbiology, University of Würzburg, 97074 Würzburg, Germany
| | - Nitish Gulve
- Biocenter, Chair of Microbiology, University of Würzburg, 97074 Würzburg, Germany
| | - Yasuko Mori
- Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Thomas Rudel
- Biocenter, Chair of Microbiology, University of Würzburg, 97074 Würzburg, Germany
- * E-mail: (TR); (BKP)
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17
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Chang PJ, Hung CH, Wang SS, Tsai PH, Shih YJ, Chen LY, Huang HY, Wei LH, Yen JB, Lin CL, Chen LW. Identification and characterization of two novel spliced genes located in the orf47-orf46-orf45 gene locus of Kaposi's sarcoma-associated herpesvirus. J Virol 2014; 88:10092-109. [PMID: 24965448 PMCID: PMC4136336 DOI: 10.1128/jvi.01445-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 06/16/2014] [Indexed: 12/29/2022] Open
Abstract
UNLABELLED The orf47-orf46-orf45 gene cluster of Kaposi's sarcoma-associated herpesvirus (KSHV) is known to serially encode glycoprotein L (gL), uracil DNA glycosylase, and a viral tegument protein. Here, we identify two novel mRNA variants, orf47/45-A and orf47/45-B, alternatively spliced from a tricistronic orf47-orf46-orf45 mRNA that is expressed in the orf47-orf46-orf45 gene locus during the early stages of viral reactivation. The spliced gene products, ORF47/45-A and ORF47/45-B, consist of only a partial region of gL (ORF47), a unique 7-amino-acid motif, and the complete tegument protein ORF45. Like the ORF45 protein, ORF47/45-A and ORF47/45-B expressed in cells sufficiently activate the phosphorylation of p90 ribosomal S6 kinase (RSK) and extracellular signal-regulated protein kinase (ERK). However, unlike ORF45, both ORF47/45-A and ORF47/45-B contain a signal peptide sequence and are localized at the endoplasmic reticulum (ER). Additionally, we found that ORF47/45-A and ORF47/45-B have an extra function that mediates the upregulation of GRP78, a master regulator of ER homeostasis. The important event regarding GRP78 upregulation can be observed in all tested KSHV-positive cell lines after viral reactivation, and knockdown of GRP78 in cells significantly impairs viral lytic cycle progression, especially at late lytic stages. Compared with some other viral glycoproteins synthesized through the ER, our results strongly implicate that the ORF47/45 proteins may serve as key effectors for controlling GRP78 expression and ER homeostasis in cells. Taken together, our findings provide evidence showing the reciprocal association between the modulation of ER homeostasis and the progression of the KSHV lytic cycle. IMPORTANCE Emerging evidence has shown that several viruses appear to use different strategies to control ER homeostasis for supporting their productive infections. The two parts of this study identify two aspects of the association between the regulation of ER homeostasis and the progression of the KSHV lytic cycle. The first part characterizes the function of two early lytic cycle proteins, ORF47/45-A and ORF47/45-B, on the activation of a major ER chaperone protein, GRP78. In addition to the ability to promote GRP78 upregulation, the ORF47/45 proteins also activate the phosphorylation of RSK and ERK. The second part reveals that upregulation of GRP78 is essential for the progression of the KSHV lytic cycle, especially at late stages. We therefore propose that activation of GRP78 expression by viral proteins at the early lytic stage may aid with the protection of host cells from severe ER stress and may directly involve the assembly or release of virions.
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MESH Headings
- DNA, Recombinant
- DNA, Viral/chemistry
- DNA, Viral/genetics
- Endoplasmic Reticulum Chaperone BiP
- Gene Expression Regulation, Viral
- Genes, Viral
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/physiology
- Humans
- Immediate-Early Proteins/genetics
- Molecular Sequence Data
- Multigene Family
- RNA, Messenger/genetics
- RNA, Viral/genetics
- Sequence Analysis, DNA
- Virus Replication
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Affiliation(s)
- Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan Department of Medical Research, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Chien-Hui Hung
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Shie-Shan Wang
- Department of Pediatric Surgery, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Ping-Hsin Tsai
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Ying-Ju Shih
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Li-Yu Chen
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Hsiao-Yun Huang
- Department of Pediatric Surgery, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Ling-Huei Wei
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Ju-Bei Yen
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan Department of Pediatrics, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Chun-Liang Lin
- Department of Nephrology, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Lee-Wen Chen
- Department of Respiratory Care, Chang-Gung University of Science and Technology, Chiayi, Taiwan
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18
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Cox JE, Sullivan CS. Balance and Stealth: The Role of Noncoding RNAs in the Regulation of Virus Gene Expression. Annu Rev Virol 2014; 1:89-109. [PMID: 26958716 DOI: 10.1146/annurev-virology-031413-085439] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the past two decades, our knowledge of gene regulation has been greatly expanded by the discovery of microRNAs (miRNAs). miRNAs are small (19-24 nt) noncoding RNAs (ncRNAs) found in metazoans, plants, and some viruses. They have been shown to regulate many cellular processes, including differentiation, maintenance of homeostasis, apoptosis, and the immune response. At present, there are over 300 known viral miRNAs encoded by diverse virus families. One well-characterized function of some viral miRNAs is the regulation of viral transcripts. Host miRNAs can also regulate viral gene expression. We propose that viruses take advantage of both host and viral ncRNA regulation to balance replication and infectious state (for example, latent versus lytic infection). As miRNA regulation can be reversed upon certain cellular stresses, we hypothesize that ncRNAs can serve viruses as barometers for cellular stress.
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Affiliation(s)
- Jennifer E Cox
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712;
| | - Christopher S Sullivan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712;
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19
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Activation of Kaposi's sarcoma-associated herpesvirus (KSHV) by inhibitors of class III histone deacetylases: identification of sirtuin 1 as a regulator of the KSHV life cycle. J Virol 2014; 88:6355-67. [PMID: 24672028 DOI: 10.1128/jvi.00219-14] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) establishes persistent latent infection in immunocompetent hosts. Disruption of KSHV latency results in viral lytic replication, which promotes the development of KSHV-related malignancies in immunocompromised individuals. While inhibitors of classes I and II histone deacetylases (HDACs) potently reactivate KSHV from latency, the role of class III HDAC sirtuins (SIRTs) in KSHV latency remains unclear. Here, we examined the effects of inhibitors of SIRTs, nicotinamide (NAM) and sirtinol, on KSHV reactivation from latency. Treatment of latently KSHV-infected cells with NAM or sirtinol induced transcripts and proteins of the master lytic transactivator RTA (ORF50), early lytic genes ORF57 and ORF59, and late lytic gene ORF65 and increased the production of infectious virions. NAM increased the acetylation of histones H3 and H4 as well as the level of the active histone H3 trimethyl Lys4 (H3K4me3) mark but decreased the level of the repressive histone H3 trimethyl Lys27 (H3K27me3) mark in the RTA promoter. Consistent with these results, we detected SIRT1 binding to the RTA promoter. Importantly, knockdown of SIRT1 was sufficient to increase the expression of KSHV lytic genes. Accordingly, the level of the H3K4me3 mark in the RTA promoter was increased following SIRT1 knockdown, while that of the H3K27me3 mark was decreased. Furthermore, SIRT1 interacted with RTA and inhibited RTA transactivation of its own promoter and that of its downstream target, the viral interleukin-6 gene. These results indicate that SIRT1 regulates KSHV latency by inhibiting different stages of viral lytic replication and link the cellular metabolic state with the KSHV life cycle. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) is the causal agent of several malignancies, including Kaposi's sarcoma, commonly found in immunocompromised patients. While latent infection is required for the development of KSHV-induced malignancies, viral lytic replication also promotes disease progression. However, the mechanism controlling KSHV latent versus lytic replication remains unclear. In this study, we found that class III histone deacetylases (HDACs), also known as SIRTs, whose activities are linked to the cellular metabolic state, mediate KSHV replication. Inhibitors of SIRTs can reactivate KSHV from latency. SIRTs mediate KSHV latency by epigenetically silencing a key KSHV lytic replication activator, RTA. We found that one of the SIRTs, SIRT1, binds to the RTA promoter to mediate KSHV latency. Knockdown of SIRT1 is sufficient to induce epigenetic remodeling and KSHV lytic replication. SIRT1 also interacts with RTA and inhibits RTA's transactivation function, preventing the expression of its downstream genes. Our results indicate that SIRTs regulate KSHV latency by inhibiting different stages of viral lytic replication and link the cellular metabolic state with the KSHV life cycle.
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20
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Toth Z, Brulois K, Jung JU. The chromatin landscape of Kaposi's sarcoma-associated herpesvirus. Viruses 2013; 5:1346-73. [PMID: 23698402 PMCID: PMC3712311 DOI: 10.3390/v5051346] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 12/15/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus is an oncogenic γ-herpesvirus that causes latent infection in humans. In cells, the viral genome adopts a highly organized chromatin structure, which is controlled by a wide variety of cellular and viral chromatin regulatory factors. In the past few years, interrogation of the chromatinized KSHV genome by whole genome-analyzing tools revealed that the complex chromatin landscape spanning the viral genome in infected cells has important regulatory roles during the viral life cycle. This review summarizes the most recent findings regarding the role of histone modifications, histone modifying enzymes, DNA methylation, microRNAs, non-coding RNAs and the nuclear organization of the KSHV epigenome in the regulation of latent and lytic viral gene expression programs as well as their connection to KSHV-associated pathogenesis.
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Affiliation(s)
- Zsolt Toth
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Harlyne J. Norris Cancer Research Tower, 1450 Biggy Street, Los Angeles, CA 90033, USA.
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21
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Chang PJ, Wang SS, Chen LY, Hung CH, Huang HY, Shih YJ, Yen JB, Liou JY, Chen LW. ORF50-dependent and ORF50-independent activation of the ORF45 gene of Kaposi's sarcoma-associated herpesvirus. Virology 2013; 442:38-50. [PMID: 23601787 DOI: 10.1016/j.virol.2013.03.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/13/2013] [Accepted: 03/25/2013] [Indexed: 01/13/2023]
Abstract
The ORF45 gene of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a multifunctional tegument protein. Here, we characterize the transcriptional control of the ORF45 gene and show that its promoter can be activated by ORF50 protein, a latent-lytic switch transactivator. The ORF45 promoter can also be induced by sodium butyrate (SB), a histone deacetylase inhibitor, in the absence of ORF50 protein. Although SB induces the ORF45 gene independently of ORF50, its full activation may require the presence of ORF50. Deletion and point mutation analyses revealed that two RBP-Jκ-binding sites in the ORF45 promoter confer the ORF50 responsiveness, whereas NF-Y and Sp1-binding sites mediate the response to SB. Direct binding of NF-Y, Sp1, or RBP-Jκ protein to the ORF45 promoter is required for the promoter activation induced by SB or by ORF50. In conclusion, our study demonstrates both ORF50-dependent and ORF50-independent transcriptional mechanisms operated on the activation of the ORF45 gene.
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Affiliation(s)
- Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
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Yan Q, Li W, Tang Q, Yao S, Lv Z, Feng N, Ma X, Bai Z, Zeng Y, Qin D, Lu C. Cellular microRNAs 498 and 320d regulate herpes simplex virus 1 induction of Kaposi's sarcoma-associated herpesvirus lytic replication by targeting RTA. PLoS One 2013; 8:e55832. [PMID: 23418466 PMCID: PMC3572171 DOI: 10.1371/journal.pone.0055832] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/02/2013] [Indexed: 12/31/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for KS development without other cofactors. We have previously reported that herpes simplex virus (HSV)-1 was an important cofactor that reactivated KSHV from latency by inducing the expression of KSHV replication and transcription activator (RTA), the lytic switch protein. Here, we further investigated the possible cellular microRNAs (miRNAs) involved in regulation of RTA during HSV-1-induced KSHV replication. The differential profiles of miRNAs expression between Mock- and HSV-1-infected body cavity-based lymphoma (BCBL-1) cells were identified by miRNA microarray analysis. Bioinformatics and luciferase reporter analyses showed that two of the HSV-1-downregulated cellular miRNAs, miR-498 and miR-320d, directly targeted the 3′ untranslated region (UTR) of KSHV RTA. As a result, overexpression of these two miRNAs significantly inhibited HSV-1-induced KSHV replication, whereas repression of these miRNAs with specific suppressors enhanced HSV-1-mediated KSHV replication. In addition, miR-498 or miR-320d alone, without HSV-1 infection, regulated KSHV replication in BCBL-1 cells. Finally, bioinformatics Gene Ontology (GO) analysis indicated that targets of HSV-1-regulated miRNAs were enriched for proteins, whose roles were involved in protein binding, enzyme activity, biological regulation, and several potential signaling pathways including transforming growth factor (TGF)-β were likely to participate in HSV-1-induced KSHV replication. Collectively, these novel findings demonstrated that host-encoded miR-498 and miR-320d regulated HSV-1 induction of KSHV lytic replication by targeting RTA, which provided further insights into the molecular mechanisms controlling KSHV lytic replication.
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Affiliation(s)
- Qin Yan
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People’s Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People’s Republic of China
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
| | - Wan Li
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
| | - Qiao Tang
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
- Department of Clinical Laboratory, The Affiliated Nanjing First Hospital of Nanjing Medical University, Nanjing, People’s Republic of China
| | - Shuihong Yao
- Department of Medicine, Quzhou College, Quzhou, People's Republic of China
| | - Zhigang Lv
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
- Department of Clinical Laboratory, Jiangsu Province Official Hospital, Nanjing, People’s Republic of China
| | - Ninghan Feng
- Department of Urology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, People’s Republic of China
| | - Xinting Ma
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
| | - Zhiqiang Bai
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
| | - Yi Zeng
- Department of Microbiology and Immunology, Youjiang Medical College for Nationalities, Bose, People’s Republic of China
| | - Di Qin
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People’s Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People’s Republic of China
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
- * E-mail: (CL); (DQ)
| | - Chun Lu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People’s Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People’s Republic of China
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People’s Republic of China
- * E-mail: (CL); (DQ)
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Tamburro KM, Yang D, Poisson J, Fedoriw Y, Roy D, Lucas A, Sin SH, Malouf N, Moylan V, Damania B, Moll S, van der Horst C, Dittmer DP. Vironome of Kaposi sarcoma associated herpesvirus-inflammatory cytokine syndrome in an AIDS patient reveals co-infection of human herpesvirus 8 and human herpesvirus 6A. Virology 2012; 433:220-5. [PMID: 22925337 DOI: 10.1016/j.virol.2012.08.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 07/06/2012] [Accepted: 08/01/2012] [Indexed: 10/28/2022]
Abstract
KSHV inflammatory cytokine syndrome (KICS) is a newly described condition characterized by systemic illness as a result of systemic, lytic KSHV infection. We used Illumina sequencing to establish the DNA vironome of blood from such a patient. It identified concurrent high-level viremia of human herpesvirus (HHV) 8 and 6a. The HHV8 plasma viral load was 5,300,000 copies/ml, which is the highest reported to date; this despite less than five skin lesions and no HHV8 associated lymphoma. This is the first report of systemic HHV6a/KSHV co-infection in a patient. It is the first whole genome KSHV sequence to be determined directly from patient plasma rather than cultured or biopsied tumor material. This case supports KICS as a new clinical entity associated with KSHV.
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Affiliation(s)
- Kristen M Tamburro
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7290, USA.
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24
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Tang Q, Qin D, Lv Z, Zhu X, Ma X, Yan Q, Zeng Y, Guo Y, Feng N, Lu C. Herpes simplex virus type 2 triggers reactivation of Kaposi's sarcoma-associated herpesvirus from latency and collaborates with HIV-1 Tat. PLoS One 2012; 7:e31652. [PMID: 22347501 PMCID: PMC3276581 DOI: 10.1371/journal.pone.0031652] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 01/16/2012] [Indexed: 01/23/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for Kaposi's sarcoma (KS) development without other cofactors. Previously, we identified that both human immunodeficiency type 1 (HIV-1) Tat and herpes simplex virus 1 (HSV-1) were important cofactors reactivating KSHV from latency. Here, we further investigated the potential of herpes simplex virus 2 (HSV-2) to influence KSHV replication and examined the role of Tat in this procedure. We demonstrated that HSV-2 was a potentially important factor in the pathogenesis of KS, as determined by production of lytic phase mRNA transcripts, viral proteins and infectious viral particles in BCBL-1 cells. These results were further confirmed by an RNA interference experiment using small interfering RNA targeting KSHV Rta and a luciferase reporter assay testing Rta promoter-driven luciferase activity. Mechanistic studies showed that HSV-2 infection activated nuclear factor-kappa B (NF-κB) signaling pathway. Inhibition of NF-κB pathway enhanced HSV-2-mediated KSHV activation, whereas activation of NF-κB pathway suppressed KSHV replication in HSV-2-infected BCBL-1 cells. Additionally, ectopic expression of Tat enhanced HSV-2-induced KSHV replication. These novel findings suggest a role of HSV-2 in the pathogenesis of KS and provide the first laboratory evidence that Tat may participate HSV-2-mediated KSHV activation, implying the complicated pathogenesis of acquired immunodeficiency syndrome (AIDS)-related KS (AIDS-KS) patients.
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Affiliation(s)
- Qiao Tang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People's Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Clinical Laboratory, the Affiliated Nanjing First Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Di Qin
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Zhigang Lv
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Clinical Laboratory, Jiangsu Province Official Hospital, Nanjing, People's Republic of China
| | - Xiaolei Zhu
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Xinting Ma
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Qin Yan
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Yi Zeng
- Department of Microbiology and Immunology, Youjiang Medical College for Nationalities, Bose, People's Republic of China
| | - Yuanyuan Guo
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Ninghan Feng
- Department of Urology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Chun Lu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, People's Republic of China
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, People's Republic of China
- * E-mail:
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25
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Longitudinal analysis of human herpesvirus-8 DNA and antibodies in an Italian allogeneic stem cell transplant recipient. J Clin Virol 2011; 52:247-50. [DOI: 10.1016/j.jcv.2011.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 07/05/2011] [Accepted: 07/05/2011] [Indexed: 01/16/2023]
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26
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Qin D, Feng N, Fan W, Ma X, Yan Q, Lv Z, Zeng Y, Zhu J, Lu C. Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's sarcoma-associated herpesvirus by herpes simplex virus type 1. BMC Microbiol 2011; 11:240. [PMID: 22032493 PMCID: PMC3215226 DOI: 10.1186/1471-2180-11-240] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/27/2011] [Indexed: 12/14/2022] Open
Abstract
Background Kaposi's sarcoma-associated herpesvirus (KSHV) is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1) was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. Results By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3) or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB, also called AKT) pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN) and glycogen synthase kinase-3β (GSK-3β). PTEN/PI3K/AKT/GSK-3β pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK) mitogen-activated protein kinase (MAPK) pathway also partially contributed to HSV-1-induced KSHV replication. Conclusions HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.
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Affiliation(s)
- Di Qin
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, PR China
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27
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Zhu X, Zhou F, Qin D, Zeng Y, Lv Z, Yao S, Lu C. Human immunodeficiency virus type 1 induces lytic cycle replication of Kaposi's-sarcoma-associated herpesvirus: role of Ras/c-Raf/MEK1/2, PI3K/AKT, and NF-κB signaling pathways. J Mol Biol 2011; 410:1035-51. [PMID: 21763505 DOI: 10.1016/j.jmb.2011.03.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 03/20/2011] [Accepted: 03/24/2011] [Indexed: 01/13/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection significantly increases the risk and development of Kaposi's sarcoma (KS) in individuals infected with KS-associated herpesvirus (KSHV). Previously, we reported that HIV-1 Tat protein induced KSHV replication by modulating the Janus kinase/signal transducers and activators of transcription signaling pathway. Here, we further investigated the possible signaling pathways involved in HIV-1-induced reactivation of KSHV. We showed that HIV-1 infection of primary effusion lymphoma cell lines triggered the reactivation of KSHV, as demonstrated by the expression of KSHV replication and transcription activator, the early viral lytic protein vIL-6 and ORF59 and the production of progeny virions. By utilizing microarray gene expression analyses, transfecting a series of dominant negative mutants, and adding pharmacologic inhibitors, we identified a group of diverse cellular signaling proteins and found that HIV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase/AKT (also called protein kinase B, PKB) pathway and inactivated phosphatase and tensin homolog deleted on chromosome ten and glycogen synthase kinase-3β, which partially modulated HIV-1-induced KSHV reactivation. Furthermore, activation of Ras/c-Raf/MAPK/ERK kinase1/2 pathway contributed to HIV-1-induced KSHV replication. Finally, we discovered that HIV-1 infection activated nuclear factor κB signaling, which exhibits an inhibitory effect on KSHV reactivation in BCBL-1 cells. Collectively, our data demonstrated that HIV-1 infection stimulated these cell signaling pathways that, in turn, contributed to KSHV reactivation, which may be of therapeutic value in acquired immunodeficiency syndrome-related KS patients.
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Affiliation(s)
- Xiaolei Zhu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, People's Republic of China
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28
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Reactive oxygen species hydrogen peroxide mediates Kaposi's sarcoma-associated herpesvirus reactivation from latency. PLoS Pathog 2011; 7:e1002054. [PMID: 21625536 PMCID: PMC3098240 DOI: 10.1371/journal.ppat.1002054] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 03/16/2011] [Indexed: 01/17/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) establishes a latent
infection in the host following an acute infection. Reactivation from latency
contributes to the development of KSHV-induced malignancies, which include
Kaposi's sarcoma (KS), the most common cancer in untreated AIDS patients,
primary effusion lymphoma and multicentric Castleman's disease. However,
the physiological cues that trigger KSHV reactivation remain unclear. Here, we
show that the reactive oxygen species (ROS) hydrogen peroxide
(H2O2) induces KSHV reactivation from latency through
both autocrine and paracrine signaling. Furthermore, KSHV spontaneous lytic
replication, and KSHV reactivation from latency induced by oxidative stress,
hypoxia, and proinflammatory and proangiogenic cytokines are mediated by
H2O2. Mechanistically, H2O2
induction of KSHV reactivation depends on the activation of mitogen-activated
protein kinase ERK1/2, JNK, and p38 pathways. Significantly,
H2O2 scavengers N-acetyl-L-cysteine (NAC), catalase
and glutathione inhibit KSHV lytic replication in culture. In a mouse model of
KSHV-induced lymphoma, NAC effectively inhibits KSHV lytic replication and
significantly prolongs the lifespan of the mice. These results directly relate
KSHV reactivation to oxidative stress and inflammation, which are physiological
hallmarks of KS patients. The discovery of this novel mechanism of KSHV
reactivation indicates that antioxidants and anti-inflammation drugs could be
promising preventive and therapeutic agents for effectively targeting KSHV
replication and KSHV-related malignancies. Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of all
clinical forms of Kaposi's sarcoma (KS) and several other malignancies. The
life cycle of KSHV consists of latent and lytic phases. While establishment of
viral latency is essential for KSHV to evade host immune surveillances, viral
lytic replication promotes KSHV-induced malignancies. In this study, we show
that the reactive oxygen species (ROS) hydrogen peroxide
(H2O2) induces KSHV reactivation from latency.
Furthermore, induction of KSHV reactivation by oxidative stress, hypoxia, and
proinflammatory and proangiogenic cytokines, which are physiological hallmarks
in all clinical forms of KS patients, is mediated by H2O2.
Significantly, antioxidants inhibit H2O2-induced KSHV
lytic replication in culture and in a mouse model of KSHV-induced lymphoma.
These results show that ROS is likely an important physiological cue that
triggers KSHV replication. The discovery of this novel mechanism of KSHV
reactivation indicates that antioxidants and anti-inflammation drugs might be
promising preventive and therapeutic agents for effectively targeting KSHV
replication and KSHV-related malignancies.
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29
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Traylen CM, Patel HR, Fondaw W, Mahatme S, Williams JF, Walker LR, Dyson OF, Arce S, Akula SM. Virus reactivation: a panoramic view in human infections. Future Virol 2011; 6:451-463. [PMID: 21799704 DOI: 10.2217/fvl.11.21] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Viruses are obligate intracellular parasites, relying to a major extent on the host cell for replication. An active replication of the viral genome results in a lytic infection characterized by the release of new progeny virus particles, often upon the lysis of the host cell. Another mode of virus infection is the latent phase, where the virus is 'quiescent' (a state in which the virus is not replicating). A combination of these stages, where virus replication involves stages of both silent and productive infection without rapidly killing or even producing excessive damage to the host cells, falls under the umbrella of a persistent infection. Reactivation is the process by which a latent virus switches to a lytic phase of replication. Reactivation may be provoked by a combination of external and/or internal cellular stimuli. Understanding this mechanism is essential in developing future therapeutic agents against viral infection and subsequent disease. This article examines the published literature and current knowledge regarding the viral and cellular proteins that may play a role in viral reactivation. The focus of the article is on those viruses known to cause latent infections, which include herpes simplex virus, varicella zoster virus, Epstein-Barr virus, human cytomegalovirus, human herpesvirus 6, human herpesvirus 7, Kaposi's sarcoma-associated herpesvirus, JC virus, BK virus, parvovirus and adenovirus.
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Affiliation(s)
- Christopher M Traylen
- Department of Microbiology & Immunology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
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Ruocco V, Ruocco E, Schwartz RA, Janniger CK. Kaposi sarcoma and quinine: a potentially overlooked triggering factor in millions of Africans. J Am Acad Dermatol 2011; 64:434-6. [PMID: 21238829 DOI: 10.1016/j.jaad.2009.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 11/11/2009] [Accepted: 12/02/2009] [Indexed: 11/15/2022]
Abstract
Kaposi sarcoma (KS)-associated herpesvirus, also known as human herpesvirus 8, is necessary but not sufficient for the development of KS. Lytic reactivation of human herpesvirus 8 may be important in KS pathogenesis. KS and its causative agent, KS-associated herpesvirus, have distinctive largely unexplained geographic distributions. We note the recent "oncoweed" hypothesis of biologic plants in the environment accounting for this reactivation. We believe that quinine and its derivatives might better explain the epidemiology of KS than oncoweeds. Indeed, we propose an "oncodrug" hypothesis, specifically with regard to quinine and its derivatives, a linkage first advanced by one of us (V. R.) and associates in 1984.
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Affiliation(s)
- Vincenzo Ruocco
- Dermatology, Seconda Università degli Studi di Napoli, Naples, Italy
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31
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Liang D, Gao Y, Lin X, He Z, Zhao Q, Deng Q, Lan K. A human herpesvirus miRNA attenuates interferon signaling and contributes to maintenance of viral latency by targeting IKKε. Cell Res 2011; 21:793-806. [PMID: 21221132 DOI: 10.1038/cr.2011.5] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Type I interferon (IFN) signaling is the principal response mediating antiviral innate immunity. IFN transcription is dependent upon the activation of transcription factors IRF3/IRF7 and NF-κB. Many viral proteins have been shown as being capable of interfering with IFN signaling to facilitate evasion from the host innate immune response. Here, we report that a viral miRNA, miR-K12-11, encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) is critical for the modulation of IFN signaling and acts through targeting I-kappa-B kinase epsilon (IKKɛ). Ectopic expression of miR-K12-11 resulted in decreased IKKɛ expression, while inhibition of miR-K12-11 was found to restore IKKɛ expression in KSHV-infected cells. Importantly, expression of miR-K12-11 attenuated IFN signaling by decreasing IKKɛ-mediated IRF3/IRF7 phosphorylation and by inhibiting the activation of IKKɛ-dependent IFN stimulating genes (ISGs), allowing miR-K12-11 suppression of antiviral immunity. Our data suggest that IKKɛ targeting by miR-K12-11 is an important strategy utilized by KSHV to modulate IFN signaling during the KSHV lifecycle, especially in latency. We also demonstrated that IKKɛ was able to enhance KSHV reactivation synergistically with the treatment of 12-O-tetradecanoylphorbol 13-acetate. Moreover, inhibition of miR-K12-11 enhanced KSHV reactivation induced by vesicular stomatitis virus infection. Taken together, our findings also suggest that miR-K12-11 can contribute to maintenance of KSHV latency by targeting IKKɛ.
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Affiliation(s)
- Deguang Liang
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 225 South Chongqing Road, Shanghai 200025, China
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Abstract
The life cycle of Kaposi's sarcoma-associated herpesvirus (KSHV) consists of latent and lytic replication phases. During latent infection, only a limited number of KSHV genes are expressed. However, this phase of replication is essential for persistent infection, evasion of host immune response, and induction of KSHV-related malignancies. KSHV reactivation from latency produces a wide range of viral products and infectious virions. The resulting de novo infection and viral lytic products modulate diverse cellular pathways and stromal microenvironment, which promote the development of Kaposi's sarcoma (KS). The mechanisms controlling KSHV latency and reactivation are complex, involving both viral and host factors, and are modulated by diverse environmental factors. Here, we review the cellular and molecular basis of KSHV latency and reactivation with a focus on the most recent advancements in the field.
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Human immunodeficiency virus type 1 Tat accelerates Kaposi sarcoma-associated herpesvirus Kaposin A-mediated tumorigenesis of transformed fibroblasts in vitro as well as in nude and immunocompetent mice. Neoplasia 2010; 11:1272-84. [PMID: 20019835 DOI: 10.1593/neo.09494] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 05/18/2009] [Accepted: 05/26/2009] [Indexed: 12/30/2022] Open
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV) is necessary but not sufficient to cause Kaposi sarcoma (KS). Coinfection with human immunodeficiency virus type 1 (HIV-1), in the absence of antiretroviral suppressive therapy, drastically increases the risk of KS. Previously, we identified that HIV-1 transactivative transcription protein (Tat) was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the potential of Tat to influence tumorigenesis induced by KSHV Kaposin A, a product of KSHV that was encoded by the open reading frame K12 (a KSHV-transforming gene). By using colony formation in soft agar, (3)H-TdR incorporation, cell cycle, and microarray gene expression analyses, we demonstrated that Tat enhanced proliferation as well as mitogen-activated protein kinase, signal transducer and activator of transcription 3, and phosphatidylinositol 3-kinase/protein kinase B signaling induced by Kaposin A in NIH3T3 cells. Animal experiments further demonstrated that Tat accelerated tumorigenesis by Kaposin A in athymic nu/nu mice. Cells obtained from primary tumors of nude mice succeeded inducing tumors in immunocompetent mice. These data suggest that Tat can accelerate tumorigenesis induced by Kaposin A. Our data present the first line of evidence that Tat may participate in KS pathogenesis by collaborating with Kaposin A in acquired immunodeficiency syndrome (AIDS)-related KS (AIDS-KS) patients. Our data also suggest that the model for Kaposin and Tat-mediated oncogenesis will contribute to our understanding of the pathogenesis of AIDS-KS at the molecular level and may even be important in exploring a novel therapeutic method for AIDS-KS.
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Epithelial raft cultures for investigations of virus growth, pathogenesis and efficacy of antiviral agents. Antiviral Res 2009; 85:431-49. [PMID: 19883696 DOI: 10.1016/j.antiviral.2009.10.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 10/20/2009] [Accepted: 10/22/2009] [Indexed: 12/12/2022]
Abstract
The organotypic epithelial raft cultures, originally developed to study keratinocytes differentiation, represent a novel approach to the study of viruses able to infect epithelial cells. Organotypic epithelial raft cultures accurately reproduce the process of epithelial differentiation in vitro and can be prepared from normal keratinocytes, explanted epithelial tissue, or established cell lines. This culture system permits cells to proliferate and fully differentiate at the air-liquid interface on a dermal-equivalent support. Normal primary human keratinocytes (PHKs) stratify and fully differentiate in a manner similar to the normal squamous epithelial tissues, while transformed cell lines exhibit dysplastic morphologies similar to the (pre)neoplastic lesions seen in vivo. This three-dimensional (3D) culture system provides an essential tool for investigations of virus growth, virus-host cell interactions, for the genetic analysis of viral proteins and regulatory sequences, and for the evaluation of antiviral agents. The 3D epithelial cultures have proven a breakthrough in the research on papillomaviruses, since their life cycle is strictly linked to the differentiation of the host epithelium. In the last years, several reports have shown the usefulness of the 3D epithelial cultures for the study of other viruses that target at least during a part of their life cycles epithelial cells. The 3D epithelial cultures allow the analysis of virus-host cell interactions in stratified epithelia that more closely resemble the in vivo situation. In this review we describe the advances on research on 3D epithelial cultures for the study of virus growth and pathogenesis of different families of viruses, including papilloma-, herpes-, pox-, adeno-, and parvoviruses.
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Cheng B, Martínez FP, Katano H, Tang Q. Evidence of inability of human cytomegalovirus to reactivate Kaposi's sarcoma-associated herpesvirus from latency in body cavity-based lymphocytes. J Clin Virol 2009; 46:244-8. [PMID: 19726225 DOI: 10.1016/j.jcv.2009.07.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 07/05/2009] [Accepted: 07/14/2009] [Indexed: 11/17/2022]
Abstract
BACKGROUND Kaposi's sarcoma-associated herpesvirus (KSHV; also known as human herpesvirus 8 (HHV-8)) has been determined to be the most frequent cause of malignancies in AIDS patients. It is associated primarily with Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL), as well as with multicentric Castleman's disease (MCD).(2) The switch from the latent to the lytic stage is important in the maintenance of malignancy and viral infection. So far, the mechanism of its reactivation has not been fully understood. OBJECTIVES Human cytomegalovirus (HCMV) and KSHV might infect the same cells, and it was found by other groups that several viruses could reactivate KSHV from latency. We investigate whether HCMV infection could reactivate KSHV from latency in body cavity-based lymphocyte (BCBL-1) cells. STUDY DESIGN AND RESULTS Laboratory strains of HCMV cannot infect B cells. In this article, we demonstrate that the UL131-repaired HCMV (vDW215-BADrUL131) derived from AD169 strain is able to infect B lymphocytes. We directly infected KSHV latent cells including BCBL-1 with vDW215-BADrUL131 to evaluate the ability of HCMV to reactivate KSHV. Inconsistent with previous reports in human fibroblast cells, our results provide direct evidence that HCMV is unable to reactivate KSHV from latency-to-lytic infection in BCBL-1 cell lines. As a control, herpes simplex virus type 1 (HSV-1) was shown to be able to reactivate KSHV. CONCLUSIONS Our observations, different from others, suggest that reactivation mechanisms for KSHV might vary in different cells.
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Affiliation(s)
- Bo Cheng
- Department of Dermatology, Fujian Medical University, Fujian, PR China
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The human cytomegalovirus UL112-113 locus can activate the full Kaposi's sarcoma-associated herpesvirus lytic replication cycle. J Virol 2009; 83:4695-9. [PMID: 19211735 DOI: 10.1128/jvi.02241-08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection of a cell containing latent Kaposi's sarcoma-associated herpesvirus (KSHV) results in the activation of KSHV lytic replication and the production of infectious virus. In this study, we examined the HCMV genes identified as having a role in the activation of HCMV early genes for their ability to activate KSHV lytic replication. It was found that the UL112-113 locus was able to activate the complete KSHV lytic cycle, while the UL122-123 locus, encoding the IE1 and IE2 proteins, known to be strong transactivators, did not.
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Nindl I, Rösl F. Molecular concepts of virus infections causing skin cancer in organ transplant recipients. Am J Transplant 2008; 8:2199-204. [PMID: 18785959 DOI: 10.1111/j.1600-6143.2008.02392.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Globally approximately 15% of all malignant tumors are caused by viruses and even a higher percentage is observed in organ transplant recipients (OTR). Here, nonmelanoma skin cancer (NMSC) is the most frequent malignancy, which correlates with cutaneous human papilloma virus (HPV) infection. In the present review, we reflect on some recent general concepts how tumor viruses can either act as direct or indirect carcinogens in the multistep process of carcinogenesis. Immunosuppressive drugs in OTR, which reduce the risk of organ rejection, could be critical in increasing the activation of persisting viral infections, thereby enhancing the probability to develop skin tumors. We discuss virus-induced transformation with special emphasis on the function of HPV as an indirect and HHV-8 as direct carcinogen in the development of NMSC and Kaposi sarcoma (KS), respectively. Moreover, we describe a rodent model system useful to examine future strategies in preventing skin tumor formation in immunosuppressed OTR.
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Affiliation(s)
- I Nindl
- DKFZ-Charité Cooperation, Viral Skin Carcinogenesis, German Cancer Research Center, Heidelberg, Germany.
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Schwartz RA, Micali G, Nasca MR, Scuderi L. Kaposi sarcoma: a continuing conundrum. J Am Acad Dermatol 2008; 59:179-206; quiz 207-8. [PMID: 18638627 DOI: 10.1016/j.jaad.2008.05.001] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 04/20/2008] [Accepted: 05/05/2008] [Indexed: 12/11/2022]
Abstract
UNLABELLED Kaposi sarcoma (KS) remains a challenge. Its classic or Mediterranean form tends to be benign. In transplant recipients it may be less so. As part of the AIDS pandemic, of which it was an original defining component, it may be life-threatening. It is due to human herpesvirus-8, which is necessary but not sufficient to produce the disease. KS has a low prevalence in the general population of the United States and United Kingdom, with an intermediate rate in Italy and Greece, and a high one in parts of Africa. In Italy, hot spots include its southern regions, the Po River Valley, and Sardinia, possibly related to a high density of blood-sucking insects. An important challenge is to treat KS patients without immunocompromising them. The potential of effective anti-herpes virus therapy and the use of sirolimus in transplantation recipients have added new opportunities for KS prevention. LEARNING OBJECTIVES At the conclusion of this learning activity, participants should be able to provide the most recent information about Kaposi sarcoma in the context in which it occurs. Its classic or Mediterranean form, its pattern in transplant recipients and others iatrogenically immunosuppressed, and its occurrence as a potentially life-threatening part of the AIDS pandemic will be stressed. Its etiology and transmission will be discussed in detail to facilitate understanding of Kaposi sarcoma and of human herpesvirus-8 infection in the general population of the United States and United Kingdom, in Italy and Greece, and in certain parts of Africa. Its therapy, including the concept of doing it without immunocompromising the patient, will be stressed. New opportunities for Kaposi sarcoma prevention will also be discussed.
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Affiliation(s)
- Robert A Schwartz
- Department of Dermatology, New Jersey Medical School, Newark, New Jersey 07103-2714, USA.
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Qin D, Zeng Y, Qian C, Huang Z, Lv Z, Cheng L, Yao S, Tang Q, Chen X, Lu C. Induction of lytic cycle replication of Kaposi's sarcoma-associated herpesvirus by herpes simplex virus type 1: involvement of IL-10 and IL-4. Cell Microbiol 2007; 10:713-28. [PMID: 18042256 DOI: 10.1111/j.1462-5822.2007.01079.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Previously, we identified that both human herpesvirus 6 and human immunodeficiency virus type 1 Tat were important cofactors that activated lytic cycle replication of Kaposi's sarcoma-associated herpesvirus (KSHV). Here, we further investigated the potential of herpes simplex virus type 1 (HSV-1) to influence KSHV replication. We demonstrated that HSV-1 was a potentially important factor in the pathogenesis of Kaposi's sarcoma, as determined by production of lytic phase mRNA transcripts, viral proteins and infectious viral particles in BCBL-1 cells. These results were further confirmed by an RNA interference experiment using small interfering RNA targeting KSHV ORF50 and a luciferase reporter assay testing ORF50 promoter-driven luciferase activity. Finally, we discovered that production of human interleukin-10 (IL-10) and IL-4 partially contributed to HSV-1-induced KSHV replication. Our data present the first direct evidence that HSV-1 can activate KSHV lytic replication and suggest a role of HSV-1 in KSHV pathogenesis.
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Affiliation(s)
- Di Qin
- Laboratory of Reproductive Medicine, Key Laboratory of Pathogen Biology of Jiangsu Province, and Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, China
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40
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Zeng Y, Zhang X, Huang Z, Cheng L, Yao S, Qin D, Chen X, Tang Q, Lv Z, Zhang L, Lu C. Intracellular Tat of human immunodeficiency virus type 1 activates lytic cycle replication of Kaposi's sarcoma-associated herpesvirus: role of JAK/STAT signaling. J Virol 2006; 81:2401-17. [PMID: 17151125 PMCID: PMC1865948 DOI: 10.1128/jvi.02024-06] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection significantly increases the risk of Kaposi's sarcoma (KS) occurrence in individuals infected with Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV infection appears to be necessary but not sufficient for KS development without other cofactors. However, factors that facilitate KSHV to cause KS have not been well defined. Previously, we determined that human herpesvirus 6 was one of the cofactors that activated lytic cycle replication of KSHV. Here, we demonstrate that the Tat protein of HIV-1 is a potentially important factor in the pathogenesis of KS, as determined by production of lytic phase mRNA transcripts and viral proteins in BCBL-1 cells. Mechanistic studies showed ectopic expression of Tat induced the production of human interleukin-6 (huIL-6) and its receptor (huIL-6Ra) and activated STAT3 signaling. Neutralization of huIL-6 or huIL-6R or inhibition of STAT3 signaling enhanced the replication. In addition, IL-4/STAT6 signaling also partially contributed to Tat-induced KSHV replication. These findings suggest that Tat may participate in KS pathogenesis by inducing KSHV replication and increasing KSHV viral load. These data also suggest that JAK/STAT signaling may be of therapeutic value in AIDS-related KS patients.
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MESH Headings
- Animals
- Base Sequence
- Callithrix
- Cell Line
- DNA Primers/genetics
- Gene Expression
- Gene Products, tat/genetics
- Gene Products, tat/physiology
- Genes, tat
- HIV Infections/complications
- HIV Infections/virology
- HIV-1/genetics
- HIV-1/physiology
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/pathogenicity
- Herpesvirus 8, Human/physiology
- Humans
- Interleukin-4/genetics
- Interleukin-6/genetics
- Janus Kinases/metabolism
- Mice
- NIH 3T3 Cells
- Receptors, Interleukin-6/genetics
- STAT Transcription Factors/metabolism
- STAT6 Transcription Factor/genetics
- Sarcoma, Kaposi/etiology
- Sarcoma, Kaposi/genetics
- Sarcoma, Kaposi/virology
- Signal Transduction
- Virus Replication/genetics
- Virus Replication/physiology
- tat Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Yi Zeng
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, People's Republic of China
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