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Tran F, Scharmacher A, Baran N, Mishra N, Wozny M, Chavez SP, Bhardwaj A, Hinz S, Juzenas S, Bernardes JP, Sievers LK, Lessing M, Aden K, Lassen A, Bergfeld A, Weber HJ, Neas L, Vetrano S, Schreiber S, Rosenstiel P. Dynamic changes in extracellular vesicle-associated miRNAs elicited by ultrasound in inflammatory bowel disease patients. Sci Rep 2024; 14:10925. [PMID: 38740826 DOI: 10.1038/s41598-024-61532-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024] Open
Abstract
Blood-based biomarkers that reliably indicate disease activity in the intestinal tract are an important unmet need in the management of patients with IBD. Extracellular vesicles (EVs) are cell-derived membranous microparticles, which reflect the cellular and functional state of their site of site of origin. As ultrasound waves may lead to molecular shifts of EV contents, we hypothesized that application of ultrasound waves on inflamed intestinal tissue in IBD may amplify the inflammation-specific molecular shifts in EVs like altered EV-miRNA expression, which in turn can be detected in the peripheral blood. 26 patients with IBD were included in the prospective clinical study. Serum samples were collected before and 30 min after diagnostic transabdominal ultrasound. Differential miRNA expression was analyzed by sequencing. Candidate inducible EV-miRNAs were functionally assessed in vitro by transfection of miRNA mimics and qPCR of predicted target genes. Serum EV-miRNA concentration at baseline correlated with disease severity, as determined by clinical activity scores and sonographic findings. Three miRNAs (miR-942-5p, mir-5588, mir-3195) were significantly induced by sonography. Among the significantly regulated EV-miRNAs, miR-942-5p was strongly induced in higher grade intestinal inflammation and correlated with clinical activity in Crohn's disease. Prediction of target regulation and transfection of miRNA mimics inferred a role of this EV-miRNA in regulating barrier function in inflammation. Induction of mir-5588 and mir-3195 did not correlate with inflammation grade. This proof-of-concept trial highlights the principle of induced molecular shifts in EVs from inflamed tissue through transabdominal ultrasound. These inducible EVs and their molecular cargo like miRNA could become novel biomarkers for intestinal inflammation in IBD.
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Affiliation(s)
- Florian Tran
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany.
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany.
| | - Alena Scharmacher
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
| | - Nathan Baran
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
| | - Neha Mishra
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
| | - Marek Wozny
- Department of Biomedical Sciences, Humanitas University, 20072, Pieve Emanuele, Italy
| | - Samuel Pineda Chavez
- Department of Biomedical Sciences, Humanitas University, 20072, Pieve Emanuele, Italy
| | - Archana Bhardwaj
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
| | - Sophia Hinz
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Simonas Juzenas
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
- Institute of Biotechnology, Life Science Centre, Vilnius University, Vilnius, Lithuania
| | - Joana P Bernardes
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
| | - Laura Katharina Sievers
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Matthias Lessing
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Konrad Aden
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Arne Lassen
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Arne Bergfeld
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Hauke Jann Weber
- Department of Gastroenterology, Asklepios Westklinikum, 22559, Hamburg, Germany
- Institute of Infection Medicine, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, 24105, Kiel, Germany
| | - Lennart Neas
- Department of Internal Medicine III, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Stefania Vetrano
- Department of Biomedical Sciences, Humanitas University, 20072, Pieve Emanuele, Italy
- IBD Unit, Department of Gastroenterology, IRCCS Humanitas Research Hospital, 20089, Rozzano, Italy
| | - Stefan Schreiber
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, 24105, Kiel, Germany
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Christian Albrecht University Kiel, Campus Kiel, Rosalind-Franklin-Strasse 12, 24105, Kiel, Germany
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2
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HIV-1 and HTLV-1 Transmission Modes: Mechanisms and Importance for Virus Spread. Viruses 2022; 14:v14010152. [PMID: 35062355 PMCID: PMC8779814 DOI: 10.3390/v14010152] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 12/13/2022] Open
Abstract
So far, only two retroviruses, human immunodeficiency virus (HIV) (type 1 and 2) and human T-cell lymphotropic virus type 1 (HTLV-1), have been recognized as pathogenic for humans. Both viruses mainly infect CD4+ T lymphocytes. HIV replication induces the apoptosis of CD4 lymphocytes, leading to the development of acquired immunodeficiency syndrome (AIDS). After a long clinical latency period, HTLV-1 can transform lymphocytes, with subsequent uncontrolled proliferation and the manifestation of a disease called adult T-cell leukemia (ATLL). Certain infected patients develop neurological autoimmune disorder called HTLV-1-associated myelopathy, also known as tropical spastic paraparesis (HAM/TSP). Both viruses are transmitted between individuals via blood transfusion, tissue/organ transplantation, breastfeeding, and sexual intercourse. Within the host, these viruses can spread utilizing either cell-free or cell-to-cell modes of transmission. In this review, we discuss the mechanisms and importance of each mode of transmission for the biology of HIV-1 and HTLV-1.
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Aghajanian S, Teymoori-Rad M, Molaverdi G, Mozhgani SH. Immunopathogenesis and Cellular Interactions in Human T-Cell Leukemia Virus Type 1 Associated Myelopathy/Tropical Spastic Paraparesis. Front Microbiol 2020; 11:614940. [PMID: 33414779 PMCID: PMC7783048 DOI: 10.3389/fmicb.2020.614940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/17/2020] [Indexed: 01/15/2023] Open
Abstract
HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a neuropathological disorder in 1–3% of individuals infected with Human T-lymphotropic virus 1 (HTLV-1). This condition is characterized by progressive spastic lower limb weakness and paralysis, lower back pain, bladder incontinence, and mild sensory disturbances resembling spinal forms of multiple sclerosis. This disease also causes chronic disability and is therefore associated with high health burden in areas where HTLV-1 infection is endemic. Despite various efforts in understanding the virus and discovery of novel diagnostic markers, and cellular and viral interactions, HAM/TSP management is still unsatisfactory and mainly focused on symptomatic alleviation, and it hasn’t been explained why only a minority of the virus carriers develop HAM/TSP. This comprehensive review focuses on host and viral factors in association with immunopathology of the disease in hope of providing new insights for drug therapies or other forms of intervention.
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Affiliation(s)
- Sepehr Aghajanian
- Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran
| | - Majid Teymoori-Rad
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Ghazale Molaverdi
- Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran
| | - Sayed-Hamidreza Mozhgani
- Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.,Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
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Otaguiri KK, Dos Santos DF, Slavov SN, Depieri LV, Palma PVB, Meirelles FV, Covas DT, da Silveira JC, Kashima S. TAX-mRNA-Carrying Exosomes from Human T Cell Lymphotropic Virus Type 1-Infected Cells Can Induce Interferon-Gamma Production In Vitro. AIDS Res Hum Retroviruses 2018; 34:1075-1082. [PMID: 30229663 DOI: 10.1089/aid.2018.0115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human T cell lymphotropic virus type 1 (HTLV-1) is the etiological agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T cell leukemia/lymphoma. The development of HAM/TSP, a chronic neuroinflammatory disease, is correlated to complex interaction between the host immune response and the infecting virus. Tax expression plays an important role in HAM/TSP pathogenesis by activating various cellular genes, including the cytokines interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Exosomes have emerged as an important factor of cell-to-cell communication contributing to diverse cellular processes, including immune modulation. Considering the potential role of exosomes in modulating the immune response and inflammation, the main objective of this study was to examine if HTLV-1-infected cells produce exosomes carrying viral proteins or inflammatory molecules, which can participate in the chronic inflammation that is observed in patients with HAM/TSP. Exosomes were isolated from HTLV-1-infected cell line, evaluated for the tax mRNA presence, and tested for the ability to activate peripheral mononuclear cells (PBMC) in inducing an inflammatory immune response. We observed that the proinflammatory cytokines, IFN-γ and TNF-α, were upregulated in T cells after treatment of the PBMC with Tax-carrying exosomes compared to the negative control. Interleukin-4, Granzyme B, and Perforin did not show alterations. Taken together, these results suggest that exosomes carrying tax-mRNA isolated from HTLV-1-infected cells might induce the production of proinflammatory cytokines and activate T helper (Th)1, and not Th2-immune response. If this finding is further confirmed, this study may have impact on investigations on the pathogenesis of HAM-TSP and the inflammatory response involved in this disease.
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Affiliation(s)
- Katia Kaori Otaguiri
- Department of Clinical, Toxicological and Bromatological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- Faculty of Medicine of Ribeirão Preto, Regional Blood Center of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Daiane Fernanda Dos Santos
- Department of Clinical, Toxicological and Bromatological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- Faculty of Medicine of Ribeirão Preto, Regional Blood Center of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Svetoslav Nanev Slavov
- Faculty of Medicine of Ribeirão Preto, Regional Blood Center of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lívia Vieira Depieri
- Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Patricia Vianna Bonini Palma
- Faculty of Medicine of Ribeirão Preto, Regional Blood Center of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Flávio Vieira Meirelles
- Department of Veterinary Medicine, Faculty of Animal Sciences and Food Engineering, University of São Paulo, Pirassununga, Brazil
| | - Dimas Tadeu Covas
- Faculty of Medicine of Ribeirão Preto, Regional Blood Center of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- Department of Veterinary Medicine, Faculty of Animal Sciences and Food Engineering, University of São Paulo, Pirassununga, Brazil
| | - Juliano Coelho da Silveira
- Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Simone Kashima
- Department of Clinical, Toxicological and Bromatological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- Faculty of Medicine of Ribeirão Preto, Regional Blood Center of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
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5
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Anderson M, Kashanchi F, Jacobson S. Role of Exosomes in Human Retroviral Mediated Disorders. J Neuroimmune Pharmacol 2018; 13:279-291. [PMID: 29656370 DOI: 10.1007/s11481-018-9784-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/15/2018] [Indexed: 02/07/2023]
Abstract
Retroviruses comprise an ancient and varied group of viruses with the unique ability to integrate DNA from an RNA transcript into the genome, a subset of which are able to integrate in humans. The timing of these integrations during human history has dictated whether these viruses have remained exogenous and given rise to various human diseases or have become inseparable from the host genome (endogenous retroviruses). Given the ability of retroviruses to integrate into the host and subsequently co-opt host cellular process for viral propagation, retroviruses have been shown to be closely associated with several cellular processes including exosome formation. Exosomes are 30-150 nm unilamellar extracellular vesicles that originate from intraluminal vesicles (ILVs) that form in the endosomal compartment. Exosomes have been shown to be important in intercellular communication and immune cell function. Almost every cell type studied has been shown to produce these types of vesicles, with the cell type dictating the contents, which include proteins, mRNA, and miRNAs. Importantly, recent evidence has shown that infection by viruses, including retroviruses, alter the contents and subsequent function of produced exosomes. In this review, we will discuss the important retroviruses associated with human health and disease. Furthermore, we will delve into the impact of exosome formation and manipulation by integrated retroviruses on human health, survival, and human retroviral disease pathogenesis.
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Affiliation(s)
- Monique Anderson
- National Institute of Neurological Disorders and Stroke, Neuroimmunology Branch, Viral Immunology Section, National Institutes of Health, Bethesda, MD, 20892, USA. .,Department of Pathology, Molecular and Cellular Basis of Disease Graduate Program, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA.
| | - Fatah Kashanchi
- National Center for Biodefense and Infectious Disease, Laboratory of Molecular Virology, George Mason University, Manassas, VA, 20110, USA
| | - Steven Jacobson
- National Institute of Neurological Disorders and Stroke, Neuroimmunology Branch, Viral Immunology Section, National Institutes of Health, Bethesda, MD, 20892, USA
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Sawada L, Nagano Y, Hasegawa A, Kanai H, Nogami K, Ito S, Sato T, Yamano Y, Tanaka Y, Masuda T, Kannagi M. IL-10-mediated signals act as a switch for lymphoproliferation in Human T-cell leukemia virus type-1 infection by activating the STAT3 and IRF4 pathways. PLoS Pathog 2017; 13:e1006597. [PMID: 28910419 PMCID: PMC5614654 DOI: 10.1371/journal.ppat.1006597] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/26/2017] [Accepted: 08/22/2017] [Indexed: 11/20/2022] Open
Abstract
Human T-cell leukemia virus type-1 (HTLV-1) causes two distinct diseases, adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Since there are no disease-specific differences among HTLV-1 strains, the etiological mechanisms separating these respective lymphoproliferative and inflammatory diseases are not well understood. In this study, by using IL-2-dependent HTLV-1-infected T-cell lines (ILTs) established from patients with ATL and HAM/TSP, we demonstrate that the anti-inflammatory cytokine IL-10 and its downstream signals potentially act as a switch for proliferation in HTLV-1-infected cells. Among six ILTs used, ILTs derived from all three ATL patients grew much faster than those from three HAM/TSP patients. Although most of the ILTs tested produced IFN-γ and IL-6, the production of IL-10 was preferentially observed in the rapid-growing ILTs. Interestingly, treatment with exogenous IL-10 markedly enhanced proliferation of the slow-growing HAM/TSP-derived ILTs. The IL-10-mediated proliferation of these ILTs was associated with phosphorylation of STAT3 and induction of survivin and IRF4, all of which are characteristics of ATL cells. Knockdown of STAT3 reduced expression of IL-10, implying a positive-feedback regulation between STAT3 and IL-10. STAT3 knockdown also reduced survivin and IRF4 in the IL-10- producing or IL-10- treated ILTs. IRF4 knockdown further suppressed survivin expression and the cell growth in these ILTs. These findings indicate that the IL-10-mediated signals promote cell proliferation in HTLV-1-infected cells through the STAT3 and IRF4 pathways. Our results imply that, although HTLV-1 infection alone may not be sufficient for cell proliferation, IL-10 and its signaling pathways within the infected cell itself and/or its surrounding microenvironment may play a critical role in pushing HTLV-1-infected cells towards proliferation at the early stages of HTLV-1 leukemogenesis. This study provides useful information for understanding of disease mechanisms and disease-prophylactic strategies in HTLV-1 infection.
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Affiliation(s)
- Leila Sawada
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
| | - Yoshiko Nagano
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
| | - Atsuhiko Hasegawa
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
| | - Hikari Kanai
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
| | - Kai Nogami
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
| | - Sayaka Ito
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
- Department of Medical Technology, School of Health Sciences, Tokyo University of Technology, Ota-ku, Tokyo, Japan
| | - Tomoo Sato
- Department of Rare Disease Research, Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Yoshihisa Yamano
- Department of Rare Disease Research, Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Yuetsu Tanaka
- Department of Immunology, Graduate school of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa, Japan
| | - Takao Masuda
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
| | - Mari Kannagi
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Bunkyo-ku, Tokyo, Japan
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7
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Abstract
Viruses have evolved many mechanisms by which to evade and subvert the immune system to ensure survival and persistence. However, for each method undertaken by the immune system for pathogen removal, there is a counteracting mechanism utilized by pathogens. The new and emerging role of microvesicles in immune intercellular communication and function is no different. Viruses across many different families have evolved to insert viral components in exosomes, a subtype of microvesicle, with many varying downstream effects. When assessed cumulatively, viral antigens in exosomes increase persistence through cloaking viral genomes, decoying the immune system, and even by increasing viral infection in uninfected cells. Exosomes therefore represent a source of viral antigen that can be used as a biomarker for disease and targeted for therapy in the control and eradication of these disorders. With the rise in the persistence of new and reemerging viruses like Ebola and Zika, exploring the role of exosomes become more important than ever.
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Affiliation(s)
- Monique R Anderson
- National Institutes of Health, National Institute of Neurological Disorders and Stroke, Neuroimmunology Branch, Viral Immunology Section, Bethesda, MD, 20892, USA.
- Department of Pathology Molecular and Cellular Basis of Disease Graduate Program, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA.
| | - Fatah Kashanchi
- George Mason University, National Center for Biodefense and Infectious Disease, Laboratory of Molecular Virology, Manassas, VA, 20110, USA
| | - Steven Jacobson
- National Institutes of Health, National Institute of Neurological Disorders and Stroke, Neuroimmunology Branch, Viral Immunology Section, Bethesda, MD, 20892, USA
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Wang C, Long W, Peng C, Hu L, Zhang Q, Wu A, Zhang X, Duan X, Wong CCL, Tanaka Y, Xia Z. HTLV-1 Tax Functions as a Ubiquitin E3 Ligase for Direct IKK Activation via Synthesis of Mixed-Linkage Polyubiquitin Chains. PLoS Pathog 2016; 12:e1005584. [PMID: 27082114 PMCID: PMC4833305 DOI: 10.1371/journal.ppat.1005584] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/29/2016] [Indexed: 11/29/2022] Open
Abstract
The HTLV-1 oncoprotein Tax plays a key role in CD4+ T cell transformation by promoting cell proliferation and survival, mainly through permanent activation of the NK-κB pathway and induction of many NF-κB target genes. Elucidating the underlying molecular mechanism is therefore critical in understanding HTLV-1-mediated transformation. Current studies have suggested multiple but controversial mechanisms regarding Tax-induced IKK activation mainly due to blending of primary Tax-induced IKK activation events and secondary IKK activation events induced by cytokines secreted by the primary Tax-induced IKK-NF-κB activation events. We reconstituted Tax-stimulated IKK activation in a cell-free system to dissect the essential cellular components for primary IKK activation by Tax and studied the underlying biochemical mechanism. We found that Tax is a putative E3 ubiquitin ligase, which, together with UbcH2, UhcH5c, or UbcH7, catalyzes the assembly of free mixed-linkage polyubiquitin chains. These free mixed-linkage polyubiquitin chains are then responsible for direct IKK activation by binding to the NEMO subunit of IKK. Our studies revealed the biochemical function of Tax in the process of IKK activation, which utilizes the minimal cellular ubiquitination components for NF-κB activation. Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM), a distinct neurological disorder with inflammatory symptoms and incomplete paralysis of the limbs, and adult T-cell leukemia/lymphoma (ATL), a highly aggressive malignant proliferation of CD4+ T lymphocytes. Both TSP/HAM and ATL are mainly driven by the activation of IκB kinase (IKK)-NF-κB stimulated by HTLV-1 oncoprotein Tax. The molecular mechanism by which Tax activates IKK remains unclear. Here, we found that Tax is an E3 ubiquitin ligase, which, together with its cognate ubiquitin-conjugating enzymes (E2s) UbcH2, UhcH5c, or UbcH7, catalyzes the assembly of unanchored free mixed-linkage polyubiquitin chains. The polyubiquitin chains can activate IKK complex directly by binding to the NEMO subunit. Our studies uncovered the essential cellular factors hijacked by HTLV-1 for infection and pathogenesis, as well as the biochemical function and the underlying mechanism of Tax in the process of IKK activation. Our work might shed light on potential development of therapeutics for TSP/HAM and ATL.
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Affiliation(s)
- Chong Wang
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wenying Long
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chao Peng
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, China
| | - Lin Hu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qiong Zhang
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ailing Wu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoqing Zhang
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaotao Duan
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Catherine C. L. Wong
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai, China
| | - Yuetsu Tanaka
- Department of Immunology, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa, Japan
| | - Zongping Xia
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
- * E-mail:
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9
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Medina F, Quintremil S, Alberti C, Godoy F, Pando ME, Bustamante A, Barriga A, Cartier L, Puente J, Tanaka Y, Valenzuela MA, Ramírez E. Tax secretion from peripheral blood mononuclear cells and Tax detection in plasma of patients with human T-lymphotropic virus-type 1-associated myelopathy/tropical spastic paraparesis and asymptomatic carriers. J Med Virol 2015; 88:521-31. [PMID: 26241614 DOI: 10.1002/jmv.24342] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2015] [Indexed: 11/09/2022]
Abstract
Human T-lymphotropic virus-type 1 (HTLV-1) is the etiologic agent of the neurologic disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Tax viral protein plays a critical role in viral pathogenesis. Previous studies suggested that extracellular Tax might involve cytokine-like extracellular effects. We evaluated Tax secretion in 18 h-ex vivo peripheral blood mononuclear cells (PBMCs) cultures from 15 HAM/TSP patients and 15 asymptomatic carriers. Futhermore, Tax plasma level was evaluated from other 12 HAM/TSP patients and 10 asymptomatic carriers. Proviral load and mRNA encoding Tax were quantified by PCR and real-time RT-PCR, respectively. Intracellular Tax in CD4(+)CD25(+) cells occurred in 100% and 86.7% of HAM/TSP patients and asymptomatic carriers, respectively. Percentage of CD4(+)CD25(+) Tax+, proviral load and mRNA encoding Tax were significantly higher in HAM/TSP patients. Western blot analyses showed higher secretion levels of ubiquitinated Tax in HAM/TSP patients than in asymptomatic carriers. In HTLV-1-infected subjects, Western blot of plasma Tax showed higher levels in HAM/TSP patients than in asymptomatic carriers, whereas no Tax was found in non-infected subjects. Immunoprecipitated plasma Tax resolved on SDS-PAGE gave two major bands of 57 and 48 kDa allowing identification of Tax and Ubiquitin peptides by mass spectrometry. Relative percentage of either CD4(+)CD25(+) Tax+ cells, or Tax protein released from PBMCs, or plasma Tax, correlates neither with tax mRNA nor with proviral load. This fact could be explained by a complex regulation of Tax expression. Tax secreted from PBMCs or present in plasma could potentially become a biomarker to distinguish between HAM/TSP patients and asymptomatic carriers.
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Affiliation(s)
- Fernando Medina
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Sebastián Quintremil
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Carolina Alberti
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Fabián Godoy
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - María E Pando
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Andrés Bustamante
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Andrés Barriga
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Luis Cartier
- Faculty of Medicine, Department of Neurological Sciences, University of Chile, Santiago, Chile
| | - Javier Puente
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Yuetsu Tanaka
- Department of Immunology, Graduate School and Faculty of Medicine, University of the Ryukyus, Ryukyus, Japan
| | - María A Valenzuela
- Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, University of Chile, Santiago, Chile
| | - Eugenio Ramírez
- Faculty of Medicine, Program of Virology, ICBM, University of Chile, Santiago, Chile.,Department of Virology, Public Health Institute of Chile, Santiago, Chile
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10
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Gudo ES, Silva-Barbosa SD, Linhares-Lacerda L, Ribeiro-Alves M, Real SC, Bou-Habib DC, Savino W. HAM/TSP-derived HTLV-1-infected T cell lines promote morphological and functional changes in human astrocytes cell lines: possible role in the enhanced T cells recruitment into Central Nervous System. Virol J 2015; 12:165. [PMID: 26458945 PMCID: PMC4603815 DOI: 10.1186/s12985-015-0398-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/01/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mechanisms through which HTLV-1 leads to and maintains damage in the central nervous system of patients undergoing HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) are still poorly understood. In recent years, increasing evidence indicates that, not only lymphocytes but also glial cells, in particular astrocytes, play a role in the pathophysiology of HAM/TSP. In this study we used a model of co-culture between human HTLV-1-infected (CIB and C91PL) and non-infected (CEM) T lymphocyte cell lines and astrocyte (U251 and U87) cell lines to mimic the in vivo T cell-astrocyte interactions. RESULTS We first observed that CIB and C91PL adhere strongly to cultured astrocytes cell lines, and that co-cultures of HTLV-1 infected and astrocyte cell lines cells resulted in rapid syncytium formation, accompanied by severe morphological alterations and increased apoptotic cell death of astrocyte cells. Additionally, cultures of astrocyte cell lines in presence of supernatants harvested from HTLV-1-infected T cell cultures resulted in significant increase in the mRNA of CCL2, CXCL1, CXCL2, CXCL3, CXCL10, IL-13, IL-8, NFKB1, TLR4, TNF, MMP8 and VCAM1, as compared with the values obtained when we applied supernatants of non-infected T- cell lines. Lastly, soluble factors secreted by cultured astrocytic cell lines primed through 1-h interaction with infected T cell lines, further enhanced migratory responses, as compared to the effect seen when supernatants from astrocytic cell lines were primed with non-infected T cell lines. CONCLUSION Collectively, our results show that HTLV-1 infected T lymphocyte cell lines interact strongly with astrocyte cell lines, leading to astrocyte damage and increased secretion of attracting cytokines, which in turn may participate in the further attraction of HTLV-1-infected T cells into central nervous system (CNS), thus amplifying and prolonging the immune damage of CNS.
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Affiliation(s)
- Eduardo Samo Gudo
- National Institute of Health, Ministry of Health, Av. Eduardo Mondlane, 1008, Maputo, Mozambique. .,Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
| | | | - Leandra Linhares-Lacerda
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
| | - Marcelo Ribeiro-Alves
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
| | - Suzana Corte Real
- Laboratory of Structural Biology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
| | - Dumith Chequer Bou-Habib
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
| | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
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11
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Francisco NM, Hsu NJ, Keeton R, Randall P, Sebesho B, Allie N, Govender D, Quesniaux V, Ryffel B, Kellaway L, Jacobs M. TNF-dependent regulation and activation of innate immune cells are essential for host protection against cerebral tuberculosis. J Neuroinflammation 2015; 12:125. [PMID: 26112704 PMCID: PMC4488051 DOI: 10.1186/s12974-015-0345-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/16/2015] [Indexed: 11/10/2022] Open
Abstract
Background Tuberculosis (TB) affects one third of the global population, and TB of the central nervous system (CNS-TB) is the most severe form of tuberculosis which often associates with high mortality. The pro-inflammatory cytokine tumour necrosis factor (TNF) plays a critical role in the initial and long-term host immune protection against Mycobacterium tuberculosis (M. tuberculosis) which involves the activation of innate immune cells and structure maintenance of granulomas. However, the contribution of TNF, in particular neuron-derived TNF, in the control of cerebral M. tuberculosis infection and its protective immune responses in the CNS were not clear. Methods We generated neuron-specific TNF-deficient (NsTNF−/−) mice and compared outcomes of disease against TNFf/f control and global TNF−/− mice. Mycobacterial burden in brains, lungs and spleens were compared, and cerebral pathology and cellular contributions analysed by microscopy and flow cytometry after M. tuberculosis infection. Activation of innate immune cells was measured by flow cytometry and cell function assessed by cytokine and chemokine quantification using enzyme-linked immunosorbent assay (ELISA). Results Intracerebral M. tuberculosis infection of TNF−/− mice rendered animals highly susceptible, accompanied by uncontrolled bacilli replication and eventual mortality. In contrast, NsTNF−/− mice were resistant to infection and presented with a phenotype similar to that in TNFf/f control mice. Impaired immunity in TNF−/− mice was associated with altered cytokine and chemokine synthesis in the brain and characterised by a reduced number of activated innate immune cells. Brain pathology reflected enhanced inflammation dominated by neutrophil influx. Conclusion Our data show that neuron-derived TNF has a limited role in immune responses, but overall TNF production is necessary for protective immunity against CNS-TB.
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Affiliation(s)
- Ngiambudulu M Francisco
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Nai-Jen Hsu
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Roanne Keeton
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Philippa Randall
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Boipelo Sebesho
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Nasiema Allie
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa. .,Division for Postgraduate Studies, University of the Western Cape, Bellville, South Africa.
| | - Dhirendra Govender
- Division of Anatomical Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. .,National Health Laboratory Service, Johannesburg, South Africa.
| | - Valerie Quesniaux
- Experimental and Molecular Immunology and Neurogenetics, University of Orleans, Orleans, France. .,CNRS UMR7355, Orleans, France.
| | - Bernhard Ryffel
- Experimental and Molecular Immunology and Neurogenetics, University of Orleans, Orleans, France. .,CNRS UMR7355, Orleans, France.
| | - Lauriston Kellaway
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
| | - Muazzam Jacobs
- Division of Immunology, Department of Clinical Laboratory Science, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925, South Africa. .,National Health Laboratory Service, Johannesburg, South Africa.
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12
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Jaworski E, Narayanan A, Van Duyne R, Shabbeer-Meyering S, Iordanskiy S, Saifuddin M, Das R, Afonso PV, Sampey GC, Chung M, Popratiloff A, Shrestha B, Sehgal M, Jain P, Vertes A, Mahieux R, Kashanchi F. Human T-lymphotropic virus type 1-infected cells secrete exosomes that contain Tax protein. J Biol Chem 2014; 289:22284-305. [PMID: 24939845 DOI: 10.1074/jbc.m114.549659] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. The HTLV-1 transactivator protein Tax controls many critical cellular pathways, including host cell DNA damage response mechanisms, cell cycle progression, and apoptosis. Extracellular vesicles called exosomes play critical roles during pathogenic viral infections as delivery vehicles for host and viral components, including proteins, mRNA, and microRNA. We hypothesized that exosomes derived from HTLV-1-infected cells contain unique host and viral proteins that may contribute to HTLV-1-induced pathogenesis. We found exosomes derived from infected cells to contain Tax protein and proinflammatory mediators as well as viral mRNA transcripts, including Tax, HBZ, and Env. Furthermore, we observed that exosomes released from HTLV-1-infected Tax-expressing cells contributed to enhanced survival of exosome-recipient cells when treated with Fas antibody. This survival was cFLIP-dependent, with Tax showing induction of NF-κB in exosome-recipient cells. Finally, IL-2-dependent CTLL-2 cells that received Tax-containing exosomes were protected from apoptosis through activation of AKT. Similar experiments with primary cultures showed protection and survival of peripheral blood mononuclear cells even in the absence of phytohemagglutinin/IL-2. Surviving cells contained more phosphorylated Rb, consistent with the role of Tax in regulation of the cell cycle. Collectively, these results suggest that exosomes may play an important role in extracellular delivery of functional HTLV-1 proteins and mRNA to recipient cells.
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Affiliation(s)
- Elizabeth Jaworski
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Aarthi Narayanan
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Rachel Van Duyne
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110, the Department of Microbiology, Immunology, and Tropical Medicine and
| | - Shabana Shabbeer-Meyering
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Sergey Iordanskiy
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110, the Department of Microbiology, Immunology, and Tropical Medicine and
| | - Mohammed Saifuddin
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Ravi Das
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Philippe V Afonso
- the Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département de Virologie, Institut Pasteur, F-75015 Paris, France, CNRS, UMR3569, F-75015 Paris, France, and
| | - Gavin C Sampey
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Myung Chung
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Anastas Popratiloff
- the Department of Chemistry, George Washington University, Washington, D. C. 20037
| | - Bindesh Shrestha
- Center for Microscopy and Image Analysis, George Washington University Medical Center, Washington, D. C. 20037
| | - Mohit Sehgal
- the Department of Microbiology and Immunology, Drexel Institute for Biotechnology and Virology Research, Drexel University College of Medicine, Doylestown, Pennsylvania 18902
| | - Pooja Jain
- the Department of Microbiology and Immunology, Drexel Institute for Biotechnology and Virology Research, Drexel University College of Medicine, Doylestown, Pennsylvania 18902
| | - Akos Vertes
- Center for Microscopy and Image Analysis, George Washington University Medical Center, Washington, D. C. 20037
| | - Renaud Mahieux
- the Equipe Oncogenèse Rétrovirale, Equipe labelisée "Ligue Nationale Contre le Cancer," International Center for Research in Infectiology, INSERM U1111-CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon 1, Lyon 69364 Cedex 07, France
| | - Fatah Kashanchi
- From the School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110,
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13
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Read SA, Douglas MW. Virus induced inflammation and cancer development. Cancer Lett 2013; 345:174-81. [PMID: 23941825 DOI: 10.1016/j.canlet.2013.07.030] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/19/2013] [Accepted: 07/28/2013] [Indexed: 12/12/2022]
Abstract
Chronic inflammation as a result of viral infection significantly increases the likelihood of cancer development. A handful of diverse viruses have confirmed roles in cancer development and progression, but the list of suspected oncogenic viruses is continually growing. Viruses induce cancer directly and indirectly, by activating inflammatory signalling pathways and cytokines, stimulating growth of infected cells and inhibiting apoptosis. Although oncogenic viruses induce inflammation by various mechanisms, it is generally mediated by the MAPK, NFκB and STAT3 signalling pathways. This review will explore the unique mechanisms by which different oncogenic viruses induce inflammation to promote cancer initiation and progression.
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Affiliation(s)
- Scott A Read
- Storr Liver Unit, Westmead Millennium Institute, University of Sydney at Westmead Hospital, Sydney, Australia
| | - Mark W Douglas
- Storr Liver Unit, Westmead Millennium Institute, University of Sydney at Westmead Hospital, Sydney, Australia; Centre for Infectious Diseases and Microbiology, Marie Bashir Institute for Infectious Diseases and Biosecurity University of Sydney at Westmead Hospital, Sydney, Australia.
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14
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Currer R, Van Duyne R, Jaworski E, Guendel I, Sampey G, Das R, Narayanan A, Kashanchi F. HTLV tax: a fascinating multifunctional co-regulator of viral and cellular pathways. Front Microbiol 2012; 3:406. [PMID: 23226145 PMCID: PMC3510432 DOI: 10.3389/fmicb.2012.00406] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 11/12/2012] [Indexed: 12/18/2022] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) has been identified as the causative agent of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The virus infects between 15 and 20 million people worldwide of which approximately 2-5% develop ATL. The past 35 years of research have yielded significant insight into the pathogenesis of HTLV-1, including the molecular characterization of Tax, the viral transactivator, and oncoprotein. In spite of these efforts, the mechanisms of oncogenesis of this pleiotropic protein remain to be fully elucidated. In this review, we illustrate the multiple oncogenic roles of Tax by summarizing a recent body of literature that refines our understanding of cellular transformation. A focused range of topics are discussed in this review including Tax-mediated regulation of the viral promoter and other cellular pathways, particularly the connection of the NF-κB pathway to both post-translational modifications (PTMs) of Tax and subcellular localization. Specifically, recent research on polyubiquitination of Tax as it relates to the activation of the IkappaB kinase (IKK) complex is highlighted. Regulation of the cell cycle and DNA damage responses due to Tax are also discussed, including Tax interaction with minichromosome maintenance proteins and the role of Tax in chromatin remodeling. The recent identification of HTLV-3 has amplified the importance of the characterization of emerging viral pathogens. The challenge of the molecular determination of pathogenicity and malignant disease of this virus lies in the comparison of the viral transactivators of HTLV-1, -2, and -3 in terms of transformation and immortalization. Consequently, differences between the three proteins are currently being studied to determine what factors are required for the differences in tumorogenesis.
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Affiliation(s)
- Robert Currer
- National Center for Biodefense and Infectious Diseases, George Mason University Manassas, VA, USA
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15
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Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma (ATL), whereas the highly related HTLV-2 is not associated with ATL or other cancers. In addition to ATL leukemogenesis, studies of the HTLV viruses also provide an exceptional model for understanding basic pathogenic mechanisms of virus-host interactions and human oncogenesis. Accumulating evidence suggests that the viral regulatory protein Tax and host inflammatory transcription factor NF-κB are largely responsible for the different pathogenic potentials of HTLV-1 and HTLV-2. Here, we discuss the molecular mechanisms of HTLV-1 oncogenic pathogenesis with a focus on the interplay between the Tax oncoprotein and NF-κB pro-oncogenic signaling. We also outline some of the most intriguing and outstanding questions in the fields of HTLV and NF-κB. Answers to those questions will greatly advance our understanding of ATL leukemogenesis and other NF-κB-associated tumorigenesis and will help us design personalized cancer therapies.
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16
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Maldonado H, Ramírez E, Utreras E, Pando ME, Kettlun AM, Chiong M, Kulkarni AB, Collados L, Puente J, Cartier L, Valenzuela MA. Inhibition of cyclin-dependent kinase 5 but not of glycogen synthase kinase 3-β prevents neurite retraction and tau hyperphosphorylation caused by secretable products of human T-cell leukemia virus type I-infected lymphocytes. J Neurosci Res 2011; 89:1489-98. [PMID: 21671254 PMCID: PMC3381896 DOI: 10.1002/jnr.22678] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 03/30/2011] [Accepted: 03/31/2011] [Indexed: 12/16/2022]
Abstract
Human T-cell leukemia virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurodegenerative disease characterized by selective loss of axons and myelin in the corticospinal tracts. This central axonopathy may originate from the impairment of anterograde axoplasmic transport. Previous work showed tau hyperphosphorylation at T(181) in cerebrospinal fluid of HAM/TSP patients. Similar hyperphosphorylation occurs in SH-SY5Y cells incubated with supernatant from MT-2 cells (HTLV-I-infected lymphocytes secreting viral proteins, including Tax) that produce neurite shortening. Tau phosphorylation at T(181) is attributable to glycogen synthase kinase 3-β (GSK3-β) and cyclin-dependent kinase 5 (CDK5) activation. Here we investigate whether neurite retraction in the SH-SY5Y model associates with concurrent changes in other tau hyperphosphorylable residues. Threonine 181 turned out to be the only tau hyperphosphorylated residue. We also evaluate the role of GSK3-β and CDK5 in this process by using specific kinase inhibitors (LiCl, TDZD-8, and roscovitine). Changes in both GSK3-β active and inactive forms were followed by measuring the regulatory phosphorylable sites (S(9) and Y(216) , inactivating and activating phosphorylation, respectively) together with changes in β-catenin protein levels. Our results showed that LiCl and TDZD-8 were unable to prevent MT-2 supernatant-mediated neurite retraction and also that neither Y(216) nor S(9) phosphorylations were changed in GSK3-β. Thus, GSK3-β seems not to play a role in T(181) hyperphosphorylation. On the other hand, the CDK5 involvement in tau phosphorylation was confirmed by both the increase in its enzymatic activity and the absence of MT-2 neurite retraction in the presence of roscovitine or CDK5 siRNA transfection.
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Affiliation(s)
- Horacio Maldonado
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Eugenio Ramírez
- Programa de Virología, Departamento de Virología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Elias Utreras
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, NIDCR, NIH, Bethesda, Maryland
| | - María E. Pando
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Ana M. Kettlun
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Mario Chiong
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Ashok B. Kulkarni
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, NIDCR, NIH, Bethesda, Maryland
| | - Lucía Collados
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Javier Puente
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Luis Cartier
- Departamento de Ciencias Neurológicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - María A. Valenzuela
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
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17
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Shibata Y, Tanaka Y, Gohda J, Inoue JI. Activation of the IκB kinase complex by HTLV-1 Tax requires cytosolic factors involved in Tax-induced polyubiquitination. J Biochem 2011; 150:679-86. [PMID: 21862596 DOI: 10.1093/jb/mvr106] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Activation of NF-κB by human T cell leukaemia virus type 1 Tax is thought to be crucial in T-cell transformation and the onset of adult T cell leukaemia. Tax activates NF-κB through activation of the IκB kinase (IKK) complex, similar to cytokine-induced NF-κB activation, which involves active signalling complex formation using polyubiquitin chains as a platform. Although polyubiquitination of Tax was reported to be required for IKK activation, most studies have been performed using intact cells, in which secondary NF-κB activation can be induced by various cytokines that are secreted due to Tax-mediated primary NF-κB activation. Therefore, a cell-free assay system, in which IKK can be activated by adding highly purified recombinant Tax to cytosolic extract, was used to analyse Tax-induced IKK activation. In contrast to the cytosolic extract, the purified IKK complex was not activated by Tax, whereas, it was efficiently activated by MEKK1, that does not require polyubiquitination to activate IKK. Moreover, Tax-induced IKK activation was blocked when the cytosolic extract was mixed with either lysine-free, methylated or K63R ubiquitin. These results obtained through our cell-free assay suggest that K63-linked polyubiquitination is critical, but linear polyubiquitination is dispensable or insufficient for Tax-induced IKK activation.
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Affiliation(s)
- Yuri Shibata
- Department of Cancer Biology, Division of Cellular and Molecular Biology, Institute of Medical Science, University of Tokyo, Shirokane-dai, Minato-ku, Tokyo 108-8639, Japan
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18
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Lepoutre V, Jain P, Quann K, Wigdahl B, Khan ZK. Role of resident CNS cell populations in HTLV-1-associated neuroinflammatory disease. Front Biosci (Landmark Ed) 2009; 14:1152-68. [PMID: 19273122 DOI: 10.2741/3300] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Human T cell leukemia virus type 1 (HTLV-1), the first human retrovirus discovered, is the etiologic agent for a number of disorders; the two most common pathologies include adult T cell leukemia (ATL) and a progressive demyelinating neuroinflammatory disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The neurologic dysfunction associated with HAM/TSP is a result of viral intrusion into the central nervous system (CNS) and the generation of a hyperstimulated host response within the peripheral and central nervous system that includes expanded populations of CD4+ and CD8+ T cells and proinflammatory cytokines/chemokines in the cerebrospinal fluid (CSF). This robust, yet detrimental immune response likely contributes to the death of myelin producing oligodendrocytes and degeneration of neuronal axons. The mechanisms of neurological degeneration in HAM/TSP have yet to be fully delineated in vivo and may involve the immunogenic properties of the HTLV-1 transactivator protein Tax. This comprehensive review characterizes the available knowledge to date concerning the effects of HTLV-1 on CNS resident cell populations with emphasis on both viral and host factors contributing to the genesis of HAM/TSP.
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Affiliation(s)
- Veronique Lepoutre
- Department of Microbiology and Immunology, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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19
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Jain P, Mostoller K, Flaig KE, Ahuja J, Lepoutre V, Alefantis T, Khan ZK, Wigdahl B. Identification of Human T Cell Leukemia Virus Type 1 Tax Amino Acid Signals and Cellular Factors Involved in Secretion of the Viral Oncoprotein. J Biol Chem 2007; 282:34581-93. [PMID: 17897946 DOI: 10.1074/jbc.m707317200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of a number of pathologic abnormalities, including adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The viral oncoprotein Tax has been implicated in the pathogenesis of these diseases. Recently, cell-free Tax was detected in the cerebrospinal fluid of HAM/TSP patients, implying that extracellular Tax may be relevant to neurologic disease. Additionally, the presence of a nuclear export signal within Tax and its active secretion has been demonstrated in vitro. However, the mechanism of Tax secretion remains to be established. Studies reported herein elucidate the process of Tax secretion and identify domains of Tax critical to its subcellular localization and secretion. Tax was shown to interact with a number of cellular secretory pathway proteins in both the model cell line BHK (baby hamster kidney)-21 and an HTLV-1-infected T cell line, C8166, physiologically relevant to HTLV-1-induced disease. Silencing of selected components of the secretory pathway affected Tax secretion, further confirming regulated secretion of Tax. Additionally, mutations in two putative secretory signals within Tax DHE and YTNI resulted in aberrant subcellular localization of Tax and significantly altered protein secretion. Together, these studies demonstrate that Tax secretion is a regulated event facilitated by its interactions with proteins of the cellular secretory pathway and the presence of secretory signals within the carboxyl-terminal domain of the protein.
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MESH Headings
- Animals
- Cricetinae
- Gene Products, tax/cerebrospinal fluid
- Gene Products, tax/genetics
- Gene Products, tax/metabolism
- Gene Silencing
- Human T-lymphotropic virus 1/genetics
- Human T-lymphotropic virus 1/metabolism
- Human T-lymphotropic virus 1/pathogenicity
- Humans
- Jurkat Cells
- Leukemia-Lymphoma, Adult T-Cell/cerebrospinal fluid
- Leukemia-Lymphoma, Adult T-Cell/genetics
- Leukemia-Lymphoma, Adult T-Cell/virology
- Nuclear Export Signals/physiology
- Paraparesis, Tropical Spastic/cerebrospinal fluid
- Paraparesis, Tropical Spastic/genetics
- Paraparesis, Tropical Spastic/virology
- Protein Structure, Tertiary/physiology
- Protein Transport/physiology
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Affiliation(s)
- Pooja Jain
- Department of Microbiology and Immunology, Center for Molecular Virology and Neuroimmunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
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20
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Zhang J, Yamada O, Kawagishi K, Yoshida H, Araki H, Yamaoka S, Hattori T, Shimotohno K. Up-regulation of hepatitis C virus replication by human T cell leukemia virus type I-encoded Tax protein. Virology 2007; 369:198-205. [PMID: 17765943 DOI: 10.1016/j.virol.2007.07.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 07/18/2007] [Accepted: 07/31/2007] [Indexed: 11/28/2022]
Abstract
Co-infection of hepatitis C virus (HCV) with other blood-borne pathogens such as human T cell leukemia virus (HTLV) is common in highly endemic areas. Clinical evidence showing a correlation between HTLV-I co-infection and rapid progression of HCV-associated liver disease promoted us to investigate the effect of HTLV-I-encoded Tax protein on HCV replication. Reporter assay showed that HCV replicon-encoded luciferase expression was significantly augmented by co-transfection of the Tax-expressing plasmid. Further, HCV RNA replication in replicon cells was increased either by co-culture with cells stably expressing Tax protein (Huhtax) or by culture in the presence of Huhtax-conditioned medium, indicating that Tax could also modulate HCV replication of adjacent cells in a paracrine manner. Additionally, HCV replication in Huhtax exhibited a reduced responsiveness to interferon-alpha-induced antiviral activity. This study demonstrates the facilitation of HCV replication by Tax protein, which may partially account for severer clinical consequences of HCV-related disease in HCV/HTLV co-infected individuals.
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Affiliation(s)
- Jing Zhang
- Research and Development Center, FUSO Pharmaceutical Industries, LTD., 2-3-30 Morinomiya, Joto-ku, Osaka 536-8523, Japan.
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21
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Pandya D, Rahman S, Wigdahl B, Khan ZK, Jain P. New insights into the pathogenesis, diagnosis and treatment of human T-cell leukemia virus type 1-induced disease. Future Virol 2007. [DOI: 10.2217/17460794.2.5.481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It has been over 25 years since the discovery of human T-cell leukemia virus type 1 (HTLV-1); however, the exact sequence of events that occur during primary infection, clinical latency or the development of disease remains unresolved. The advances in molecular virology and neuroimmunology have contributed significantly to our understanding of HTLV-1 pathogenesis, but also uncovered the complexity of the virus–host interaction both in the peripheral blood and the CNS. Here, we overview the general pathologic features of HTLV-1, molecular mechanisms of oncogenic transformation and characteristics of the host immune response during the associated neuroinflammatory process. We also discuss both current and new approaches in the diagnosis and therapy of HTLV-1 associated diseases – adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. Finally, potentially important emerging areas of research that may have an impact on our understanding of the pathogenic mechanism have been briefly introduced.
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Affiliation(s)
- Devanshi Pandya
- Drexel University College of Medicine, Department of Microbiology & Immunology, and, Center for Cancer Biology, Institute for Molecular Medicine & Infectious Disease, Philadelphia, PA 19102, USA
| | - Saifur Rahman
- Drexel University College of Medicine, Department of Microbiology & Immunology, and, Center for Cancer Biology, Institute for Molecular Medicine & Infectious Disease, Philadelphia, PA 19102, USA
| | - Brian Wigdahl
- Drexel University College of Medicine, Department of Microbiology & Immunology, and, Center for Cancer Biology, Institute for Molecular Medicine & Infectious Disease, Philadelphia, PA 19102, USA
| | - Zafar K Khan
- Drexel University College of Medicine, Department of Microbiology & Immunology, and, Center for Cancer Biology, Institute for Molecular Medicine & Infectious Disease, Philadelphia, PA 19102, USA
| | - Pooja Jain
- Drexel University College of Medicine, Department of Microbiology & Immunology, Institute for Molecular Medicine & Infectious Disease, New College Building, Room 18311, 245 North 15th Street, Philadelphia, PA 19102, USA
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22
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Jain P, Ahuja J, Khan ZK, Shimizu S, Meucci O, Jennings SR, Wigdahl B. Modulation of dendritic cell maturation and function by the Tax protein of human T cell leukemia virus type 1. J Leukoc Biol 2007; 82:44-56. [PMID: 17442856 PMCID: PMC2712352 DOI: 10.1189/jlb.1006641] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Human T cell leukemia virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is characterized by the generation of an intense CTL cell response directed against the viral transactivator protein Tax. In addition, patients diagnosed with HAM/TSP exhibit rapid activation and maturation of dendritic cells (DC), likely contributing to the robust, Tax-specific CTL response. In this study, extracellular Tax has been shown to induce maturation and functional alterations in human monocyte-derived DC, critical observations being confirmed in freshly isolated myeloid DC. Tax was shown to promote the production of proinflammatory cytokines and chemokines involved in the DC activation process in a dose- and time-dependent manner. Furthermore, Tax induced the expression of DC activation (CD40, CD80, and CD86) and maturation (CD83) markers and enhanced the T cell proliferation capability of DC. Heat inactivation of Tax resulted in abrogation of these effects, indicating a requirement for the native structure of Tax, which was found to bind efficiently to the DC membrane and was internalized within a few hours, suggesting that extracellular Tax may possess an intracellular mechanism of action subsequent to entry. Finally, inhibitors of cellular signaling pathways, NF-kappaB, protein kinase, tyrosine kinase, and phospholipase C, were shown to inhibit Tax-mediated DC activation. This is the first study reporting the immunomodulatory effects of extracellular Tax in the DC compartment. These results suggest that DC, once exposed to Tax by uptake from the extracellular environment, can undergo activation, providing constant antigen presentation and costimulation to T cells, leading to the intense T cell proliferation and inflammatory responses underlying HAM/TSP.
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Affiliation(s)
- Pooja Jain
- Department of Microbiology and Immunology Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Jaya Ahuja
- Department of Microbiology and Immunology Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Zafar K. Khan
- Department of Microbiology and Immunology Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Saori Shimizu
- Department of Pharmacology and Physiology, Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Stephen R. Jennings
- Department of Microbiology and Immunology Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology Institute for Molecular Medicine and Infectious Disease and Centers for Molecular Virology and Neuroimmunology and Cancer Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
- Correspondence: Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA. E-mail:
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23
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Alefantis T, Flaig KE, Wigdahl B, Jain P. Interaction of HTLV-1 Tax protein with calreticulin: implications for Tax nuclear export and secretion. Biomed Pharmacother 2007; 61:194-200. [PMID: 17395420 PMCID: PMC2043122 DOI: 10.1016/j.biopha.2007.02.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 02/06/2007] [Indexed: 11/23/2022] Open
Abstract
Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 transcriptional transactivator protein Tax plays an integral role in virus replication and disease progression. Traditionally, Tax is described as a nuclear protein where it performs its primary role as a transcriptional transactivator. However, recent studies have clearly shown that Tax can also be localized to the cytoplasm where it has been shown to interact with a number of host transcription factors most notably NF-kappaB, constitutive expression of which is directly related to the T cell transforming properties of Tax in ATL patients. The presence of a functional nuclear export signal (NES) within Tax and the secretion of full-length Tax have also been demonstrated previously. Additionally, release of Tax from HTLV-1-infected cells and the presence of cell-free Tax was demonstrated in the CSF of HAM/TSP patients suggesting that the progression to HAM/TSP might be mediated by the ability of Tax to function as an extracellular cytokine. Therefore, in both ATL and HAM/TSP Tax nuclear export and nucleocytoplasmic shuttling may play a critical role, the mechanism of which remains unknown. In this study, we have demonstrated that the calcium binding protein calreticulin interacts with Tax by co-immunoprecipitation. This interaction was found to localize to a region at or near the nuclear membrane. In addition, differential expression of calreticulin was demonstrated in various cell types that correlated with their ability to retain cytoplasmic Tax, particularly in astrocytes. Finally, a comparison of a number of HTLV-1-infected T cell lines to non-infected T cells revealed higher expression of calreticulin in infected cells implicating a direct role for this protein in HTLV-1 infection.
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Affiliation(s)
| | - Katherine E. Flaig
- Department of Microbiology and Immunology, and Center for Molecular Virology and Neuroimmunology, Center for Cancer Biology, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, 19102, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, and Center for Molecular Virology and Neuroimmunology, Center for Cancer Biology, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, 19102, USA
| | - Pooja Jain
- Department of Microbiology and Immunology, and Center for Molecular Virology and Neuroimmunology, Center for Cancer Biology, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, 19102, USA
- *Corresponding Author, Mailing address: Department of Microbiology and Immunology, Institute for Molecular Medicine and Infectious Disease, New College Building, Room #18311, Drexel University College of Medicine, 245 North 15 Street, Philadelphia, PA 19102, USA, Telephone Number: (215) 762-8586, Fax Number: (215) 762-1955, E-mail Address: ,
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24
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Ahuja J, Lepoutre V, Wigdahl B, Khan ZK, Jain P. Induction of pro-inflammatory cytokines by human T-cell leukemia virus type-1 Tax protein as determined by multiplexed cytokine protein array analyses of human dendritic cells. Biomed Pharmacother 2007; 61:201-8. [PMID: 17391906 PMCID: PMC2043123 DOI: 10.1016/j.biopha.2007.02.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 02/06/2007] [Indexed: 11/28/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is characterized by a hyperstimulated immune response, including elevated levels of inflammatory cytokines/chemokines and oligoclonal expansion of virus-specific CD8(+) T cells in the cerebrospinal fluid. Studies have shown that the HTLV-1 transactivator protein Tax is available for immune recognition by antigen presenting cells (APCs), such as dendritic cells (DCs). DCs are relevant to the pathogenesis of HAM/TSP because the presentation of Tax peptides by activated DCs to naïve CD8(+) T cells may play an important role in the induction of the Tax-specific immune response that is observed in HAM/TSP. In this study, a human cytokine protein array was used to study the secretion of cytokines by monocyte-derived DCs (MDDCs) exposed to Tax. Of the 16 cytokines analyzed, 6 cytokines were secreted in significantly high amounts (> or =2-fold), including Th1 cytokines (IFN-gamma, IL-12, and TNF-alpha) and C-C chemokines (Eotaxin, MCP-1, and MCP-3). Selected cytokines were further examined at two concentrations of Tax and at two time periods. Furthermore, a transient exposure to Tax did not result in any cytokine production when examined at three different time points after exposure, indicating that a prolonged presence of Tax is required for its activity. Finally, inhibition of the NF-kappaB signaling pathway by specific inhibitors, abrogated Tax-mediated cytokine secretion. Collectively, these findings suggest a role for Tax-induced cytokine secretion from MDDCs, which may be critical for the cellular activation and tissue damage that has been observed in HAM/TSP.
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Affiliation(s)
| | | | | | | | - Pooja Jain
- *Corresponding author, Mailing address: Department of Microbiology and Immunology, Room #18311, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 North 15 Street, Philadelphia, PA 19102, USA, Telephone Number: (215) 762-8586, Fax Number: (215) 762-1955, E-mail Address: ,
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25
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Lafon M, Megret F, Lafage M, Prehaud C. The innate immune facet of brain: human neurons express TLR-3 and sense viral dsRNA. J Mol Neurosci 2007; 29:185-94. [PMID: 17085778 DOI: 10.1385/jmn:29:3:185] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 11/30/1999] [Accepted: 10/03/2005] [Indexed: 12/25/2022]
Abstract
Inflammation is an important factor in the pathogenesis of neurodegenerative diseases, such as Alzheimer's disease or multiple sclerosis, and during microbial infections of the nervous system. Glial cells were thought to be the main contributor for cytokine and chemokine production and Toll-like receptor (TLR) expression in the brain. Here, we report that human neurons express TLR-3, a major receptor in virus-mediated innate immune response. We established that these cells can mount a strong inflammatory response characterized by the expression of inflammatory cytokines (TNF-alpha, IL-6), chemokines (CCL-5 and CXCL-10), and antiviral molecules (2'5'OAS and IFN-beta) after treatment with dsRNA - a by-product of viral infection and ligand of TLR-3. This work firmly establishes that human neurons, in absence of glia, have the intrinsic machinery to trigger robust inflammatory, chemoattractive, and antiviral responses.
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Affiliation(s)
- Monique Lafon
- Unité de Neuroimmunologie Virale, Department of Neuroscience, Institut Pasteur, 75724 Paris, France.
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26
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Moriuchi M, Moriuchi H. Induction of lactoferrin gene expression in myeloid or mammary gland cells by human T-cell leukemia virus type 1 (HTLV-1) tax: implications for milk-borne transmission of HTLV-1. J Virol 2006; 80:7118-26. [PMID: 16809317 PMCID: PMC1489047 DOI: 10.1128/jvi.00409-06] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1), the causative agent of adult T-cell leukemia, is transmitted vertically via breastfeeding. We have previously demonstrated that lactoferrin, a major milk protein, enhances HTLV-1 replication, at least in part by upregulating the HTLV-1 long terminal repeat promoter. We now report that HTLV-1 infection can induce lactoferrin gene expression. Coculture with HTLV-1-infected MT-2 cells increased the levels of lactoferrin mRNA in myeloid-differentiated HL-60 cells, as well as MCF-7 cells, models of two probable sources (neutrophils and mammary epithelium) of lactoferrin in breast milk. MT-2 cell coculture could be replaced with cell-free culture supernatants of MT-2 cells to exert the same effect. Furthermore, extracellularly administered Tax protein also induced lactoferrin gene expression at physiologically relevant concentrations. In transient-expression assays, Tax transactivated the lactoferrin gene promoter in HL-60 or MCF-7 cells. Experiments with Tax mutants, as well as site-directed mutants of the lactoferrin promoter reporters, indicated that the NF-kappaB transactivation pathway is critical for Tax induction of the lactoferrin gene promoter activity in myeloid-differentiated HL-60 cells, but not in MCF-7 cells. These results suggest that HTLV-1 infection may be able to induce expression of lactoferrin in a paracrine manner in the lactic compartment. Our findings, in conjunction with our previous study, implicate that mutual interaction between HTLV-1 and lactoferrin would benefit milk-borne transmission of this virus.
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Affiliation(s)
- Masako Moriuchi
- Deparment of Molecular Microbiology and Immunology, Division of Medical Virology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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27
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Ahuja J, Kampani K, Datta S, Wigdahl B, Flaig KE, Jain P. Use of human antigen presenting cell gene array profiling to examine the effect of human T-cell leukemia virus type 1 Tax on primary human dendritic cells. J Neurovirol 2006; 12:47-59. [PMID: 16595374 DOI: 10.1080/13550280600614981] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is etiologically linked to adult T-cell leukemia and a progressive demyelinating disorder termed HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). One of the most striking features of the immune response in HAM/TSP centers on the expansion of HTLV-1-specific CD8(+) cytotoxic T lymphocyte (CTL) compartment in the peripheral blood and cerebrospinal fluid. More than 90% of the HTLV-1-specific CTLs are directed against the viral Tax (11-19) peptide implying that Tax is available for immune recognition by antigen presenting cells, such as dendritic cells (DCs). DCs obtained from HAM/TSP patients have been shown to be infected with HTLV-1 and exhibit rapid maturation. Therefore, we hypothesized that presentation of Tax peptides by activated DCs to naIve CD8(+) T cells may play an important role in the induction of a Tax-specific CTL response and neurologic dysfunction. In this study, a pathway-specific antigen presenting cell gene array was used to study transcriptional changes induced by exposure of monocyte-derived DCs to extracellular HTLV-1 Tax protein. Approximately 100 genes were differentially expressed including genes encoding toll-like receptors, cell surface receptors, proteins involved in antigen uptake and presentation and adhesion molecules. The differential regulation of chemokines and cytokines characteristic of functional DC activation was also observed by the gene array analyses. Furthermore, the expression pattern of signal transduction genes was also significantly altered. These results have suggested that Tax-mediated DC gene regulation might play a critical role in cellular activation and the mechanisms resulting in HTLV-1-induced disease.
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Affiliation(s)
- Jaya Ahuja
- Department of Microbiology and Immunology, Institute for Molecular Medicine and Infectious Disease, Center for Molecular Virology and Neuroimmunology, Center for Cancer Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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28
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Ozden S, Mouly V, Prevost MC, Gessain A, Butler-Browne G, Ceccaldi PE. Muscle wasting induced by HTLV-1 tax-1 protein: an in vitro and in vivo study. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 167:1609-19. [PMID: 16314474 PMCID: PMC1613204 DOI: 10.1016/s0002-9440(10)61245-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Besides tropical spastic paraparesis/human T-cell leukemia virus type-1 (HTLV-1)-associated myelopathy, the human retrovirus HTLV-1 causes inflammatory disorders such as myositis. Although the pathogenesis of HTLV-1-associated myositis is primarily unknown, a direct effect of cytokines or viral proteins in myocytotoxicity is suspected. We have developed an in vitro cell culture model to study the interactions between primary human muscle cells and HTLV-1 chronically infected cells. When HTLV-1-infected cell lines were added to differentiated muscle cultures, cytopathic changes such as fiber shrinking were observed as early as 1 day after contact. This was accompanied by alterations in desmin and vimentin organization, occurring in the absence of muscle cell infection but with Tax-1 present in myotubes. Cytopathic changes were also observed when infected culture supernatants were added to the muscle cells. Fiber atrophy and cytoskeletal disorganization were confirmed in muscle biopsies from two HTLV-1-infected patients with myositis. Transduction of cultured muscle cells with a lentiviral vector containing the HTLV-1 Tax gene reproduced such effects in vitro. The present data indicate that the myocytotoxicity that is observed in HTLV-1-associated myopathies can be due to a direct effect of the Tax-1 protein expressed in infected inflammatory cells, in the absence of muscle cell infection.
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Affiliation(s)
- Simona Ozden
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département Ecosystèmes et Epidémiologie des Maladies Infectieuses, Institut Pasteur, Paris, France
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29
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Virus infection switches TLR-3-positive human neurons to become strong producers of beta interferon. J Virol 2005. [PMID: 16188991 DOI: 10.1128/jiv.79.20.12893-12904.2005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To study the capacity of human neurons to mount innate immunity responses to viral infections, we infected cells of a human postmitotic neuron-derivative cell line, NT2-N, with rabies virus (RABV) and herpes simplex type 1 (HSV-1). Changes in neuronal gene expression were analyzed by use of Affymetrix microarrays. Applying a twofold cutoff, RABV increased the transcription of 228 genes, and HSV-1 increased the transcription of 263 genes. The most striking difference between the two infections concerns genes involved in immunity. These genes represent 24% of the RABV-upregulated genes and only 4.9% of the HSV-1-upregulated genes. Following RABV infection, the most upregulated genes belong to the immunity cluster and included almost exclusively genes for beta interferon (IFN-beta) primary and secondary responses as well as genes for chemokines (CCL-5, CXCL-10) and inflammatory cytokines (interleukin 6 [IL-6], tumor necrosis factor alpha, interleukin 1 alpha). In contrast, HSV-1 infection did not increase IFN-beta gene transcripts and triggered the production of only IL-6 and interferon regulatory factor 1 mRNAs. The microarray results were confirmed by real-time PCR, immunocytochemistry, and enzyme-linked immunosorbent assay. Human neurons were found to express Toll-like receptor 3. They produced IFN-beta after treatment with poly(I:C) but not with lipopolysaccharide. Thus, human neurons can mount an innate immunity response to double-stranded RNA. These observations firmly establish that human neurons, in absence of glia, have the intrinsic machinery to sense virus infection.
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30
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Alefantis T, Jain P, Ahuja J, Mostoller K, Wigdahl B. HTLV-1 Tax nucleocytoplasmic shuttling, interaction with the secretory pathway, extracellular signaling, and implications for neurologic disease. J Biomed Sci 2005; 12:961-74. [PMID: 16228291 DOI: 10.1007/s11373-005-9026-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Accepted: 08/23/2005] [Indexed: 10/25/2022] Open
Abstract
The human T cell leukemia virus type 1 (HTLV-1) oncoprotein Tax interacts with numerous cellular pathways promoting both the survival and pathogenesis of the virus in the human population. Tax has been studied extensively with respect to its role in transcriptional transactivation and its involvement in the up-regulation of a number of cellular genes during the process of oncogenic transformation. These processes are dependent on Tax localization to the nucleus where it interacts with a number of cellular transcription factors during its course of nuclear action. However, there is mounting evidence suggesting that Tax may shuttle between the nucleus and cytoplasm, localize to several cytoplasmic organelles with subsequent secretion from both Tax-transfected cells as well as HTLV-1-infected cells. In addition, the presence of cell-free Tax in cerebral spinal fluid (CSF) was recently demonstrated to occur during all stages of HAM/TSP. This has brought about an increased interest in the cytoplasmic localization of Tax and the implications this localization may have with respect to the progression of HTLV-1-associated disease processes. This review addresses the functional implications relevant to the localization and accumulation of Tax in the cytoplasm including the Tax amino acid signals and cellular protein interactions that may regulate this process. Specifically, we have discussed three important processes associated with the cytoplasmic localization of Tax. First, the process of Tax shuttling between the nucleus and cytoplasm will be described and how this process may be involved in regulating different transcriptional activation pathways. Second, cytoplasmic localization of Tax will be discussed with relevance to Tax secretion and the interaction of Tax with proteins in the cellular secretory pathway. Finally, the secretion of Tax and the effects of extracellular Tax on HTLV-1 pathogenesis will be addressed.
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31
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Préhaud C, Mégret F, Lafage M, Lafon M. Virus infection switches TLR-3-positive human neurons to become strong producers of beta interferon. J Virol 2005; 79:12893-904. [PMID: 16188991 PMCID: PMC1235836 DOI: 10.1128/jvi.79.20.12893-12904.2005] [Citation(s) in RCA: 266] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 07/18/2005] [Indexed: 12/25/2022] Open
Abstract
To study the capacity of human neurons to mount innate immunity responses to viral infections, we infected cells of a human postmitotic neuron-derivative cell line, NT2-N, with rabies virus (RABV) and herpes simplex type 1 (HSV-1). Changes in neuronal gene expression were analyzed by use of Affymetrix microarrays. Applying a twofold cutoff, RABV increased the transcription of 228 genes, and HSV-1 increased the transcription of 263 genes. The most striking difference between the two infections concerns genes involved in immunity. These genes represent 24% of the RABV-upregulated genes and only 4.9% of the HSV-1-upregulated genes. Following RABV infection, the most upregulated genes belong to the immunity cluster and included almost exclusively genes for beta interferon (IFN-beta) primary and secondary responses as well as genes for chemokines (CCL-5, CXCL-10) and inflammatory cytokines (interleukin 6 [IL-6], tumor necrosis factor alpha, interleukin 1 alpha). In contrast, HSV-1 infection did not increase IFN-beta gene transcripts and triggered the production of only IL-6 and interferon regulatory factor 1 mRNAs. The microarray results were confirmed by real-time PCR, immunocytochemistry, and enzyme-linked immunosorbent assay. Human neurons were found to express Toll-like receptor 3. They produced IFN-beta after treatment with poly(I:C) but not with lipopolysaccharide. Thus, human neurons can mount an innate immunity response to double-stranded RNA. These observations firmly establish that human neurons, in absence of glia, have the intrinsic machinery to sense virus infection.
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32
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Rostasy K, Monti L, Lipton SA, Hedreen JC, Gonzalez RG, Navia BA. HIV leucoencephalopathy and TNFalpha expression in neurones. J Neurol Neurosurg Psychiatry 2005; 76:960-4. [PMID: 15965202 PMCID: PMC1739718 DOI: 10.1136/jnnp.2004.036889] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Human immunodeficiency virus (HIV) leucoencephalopathy (HIVL) is an uncommon and rapidly progressive form of AIDS dementia complex (ADC) that has remained poorly understood. Tumour necrosis factor alpha (TNFalpha), which has been implicated in the pathogenesis of ADC, is predominantly localised in macrophages in the HIV infected brain, although in vitro studies indicate that neurones can express this cytokine. OBJECTIVE To examine the clinical/neuroradiological features of HIVL and the expression of TNFalpha in HIVL. METHODS Six patients who presented with rapidly progressive dementia within four to 12 weeks of the primary manifestation of their HIV infection were evaluated. Clinical history, treatment regimens, and imaging studies were reviewed, and brain samples from three of the patients were studied by means of immunohistochemistry. RESULTS Imaging studies showed diffuse bilateral deep white matter changes in all six patients. Clinical and imaging abnormalities improved in five of the six patients within weeks after initiation of antiretroviral treatment. Brain biopsies of two showed pronounced microglia/macrophage activation, but only scant viral protein (gp41) expression. Staining for TNFalpha was found in microglia/macrophages, and surprisingly, in neurones also. Postmortem analysis of a third patient also showed TNFalpha expression in neurones of the frontal cortex and basal ganglia. CONCLUSION This study provides the first demonstration of staining for TNFalpha in the neurones of the HIV infected brain, and suggests that the process underlying this rapidly progressive form of ADC may reflect indirect mechanisms mediated by host factors, particularly TNFalpha.
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Affiliation(s)
- K Rostasy
- Paediatric Neurology, University of Göttingen, Germany
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Alefantis T, Mostoller K, Jain P, Harhaj E, Grant C, Wigdahl B. Secretion of the Human T Cell Leukemia Virus Type I Transactivator Protein Tax. J Biol Chem 2005; 280:17353-62. [PMID: 15659397 DOI: 10.1074/jbc.m409851200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human T cell leukemia virus type I (HTLV-I) is the etiologic agent of adult T cell leukemia and HTLV-I-associated myelopathy/tropical spastic paraparesis. The HTLV-I protein Tax is well known as a transcriptional transactivator and inducer of cellular transformation. However, it is also known that extracellular Tax induces the production and release of cytokines, such as tumor necrosis factor-alpha and interleukin-6, which have adverse effects on cells of the central nervous system. The cellular process by which Tax exits the cell into the extracellular environment is currently unknown. In most cell types, Tax has been shown to localize primarily to the nucleus. However, Tax has also been found to accumulate in the cytoplasm. The results contained herein begin to characterize the process of Tax secretion from the cell. Specifically, cytoplasmic Tax was demonstrated to localize to organelles associated with the cellular secretory process including the endoplasmic reticulum and Golgi complex. Additionally, it was demonstrated that full-length Tax was secreted from both baby hamster kidney cells and a human kidney tumor cell line, suggesting that Tax enters the secretory pathway in a leaderless manner. Tax secretion was partially inhibited by brefeldin A, suggesting that Tax migrated from the endoplasmic reticulum to the Golgi complex. In addition, combined treatment of Tax-transfected BHK-21 cells with phorbol myristate acetate and ionomycin resulted in a small increase in the amount of Tax secreted, suggesting that a fraction of cytoplasmic Tax was present in the regulated secretory pathway. These studies begin to provide a link between Tax localization to the cytoplasm, the detection of Tax in the extracellular environment, its possible role as an extracellular effector molecule, and a potential role in neurodegenerative disease associated with HTLV-I infection.
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Affiliation(s)
- Timothy Alefantis
- Department of Microbiology and Immunology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033, USA
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Kehn K, Deng L, de la Fuente C, Strouss K, Wu K, Maddukuri A, Baylor S, Rufner R, Pumfery A, Bottazzi ME, Kashanchi F. The role of cyclin D2 and p21/waf1 in human T-cell leukemia virus type 1 infected cells. Retrovirology 2004; 1:6. [PMID: 15169570 PMCID: PMC420262 DOI: 10.1186/1742-4690-1-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Accepted: 04/13/2004] [Indexed: 11/23/2022] Open
Abstract
Background The human T-cell leukemia virus type 1 (HTLV-1) Tax protein indirectly influences transcriptional activation, signal transduction, cell cycle control, and apoptosis. The function of Tax primarily relies on protein-protein interactions. We have previously shown that Tax upregulates the cell cycle checkpoint proteins p21/waf1 and cyclin D2. Here we describe the consequences of upregulating these G1/S checkpoint regulators in HTLV-1 infected cells. Results To further decipher any physical and functional interactions between cyclin D2 and p21/waf1, we used a series of biochemical assays from HTLV-1 infected and uninfected cells. Immunoprecipitations from HTLV-1 infected cells showed p21/waf1 in a stable complex with cyclin D2/cdk4. This complex is active as it phosphorylates the Rb protein in kinase assays. Confocal fluorescent microscopy indicated that p21/waf1 and cyclin D2 colocalize in HTLV-1 infected, but not in uninfected cells. Furthermore, in vitro kinase assays using purified proteins demonstrated that the addition of p21/waf1 to cyclin D2/cdk4 increased the kinase activity of cdk4. Conclusion These data suggest that the p21/cyclin D2/cdk4 complex is not an inhibitory complex and that p21/waf1 could potentially function as an assembly factor for the cyclin D2/cdk4 complex in HTLV-1 infected cells. A by-product of this assembly with cyclin D2/cdk4 is the sequestration of p21/waf1 away from the cyclin E/cdk2 complex, allowing this active cyclin-cdk complex to phosphorylate Rb pocket proteins efficiently and push cells through the G1/S checkpoint. These two distinct functional and physical activities of p21/waf1 suggest that RNA tumor viruses manipulate the G1/S checkpoint by deregulating cyclin and cdk complexes.
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Affiliation(s)
- Kylene Kehn
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Longwen Deng
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Cynthia de la Fuente
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Katharine Strouss
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Kaili Wu
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Anil Maddukuri
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Shanese Baylor
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Robyn Rufner
- Center for Microscopy and Image Analysis, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Anne Pumfery
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Maria Elena Bottazzi
- Department of Microbiology and Tropical Medicine, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Fatah Kashanchi
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
- The Institute for Genomics Research, Rockville, MD 20850, USA
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Tripp A, Liu Y, Sieburg M, Montalbano J, Wrzesinski S, Feuer G. Human T-cell leukemia virus type 1 tax oncoprotein suppression of multilineage hematopoiesis of CD34+ cells in vitro. J Virol 2003; 77:12152-64. [PMID: 14581552 PMCID: PMC254283 DOI: 10.1128/jvi.77.22.12152-12164.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2003] [Accepted: 08/13/2003] [Indexed: 11/20/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 are highly related viruses that differ in disease manifestation. HTLV-1 is the etiologic agent of adult T-cell leukemia and lymphoma, an aggressive clonal malignancy of human CD4-bearing T lymphocytes. Infection with HTLV-2 has not been conclusively linked to lymphoproliferative disorders. We previously showed that human hematopoietic progenitor (CD34(+)) cells can be infected by HTLV-1 and that proviral sequences were maintained after differentiation of infected CD34(+) cells in vitro and in vivo. To investigate the role of the Tax oncoprotein of HTLV on hematopoiesis, bicistronic lentiviral vectors were constructed encoding the HTLV-1 or HTLV-2 tax genes (Tax1 and Tax2, respectively) and the green fluorescent protein marker gene. Human hematopoietic progenitor (CD34(+)) cells were infected with lentivirus vectors, and transduced cells were cultured in a semisolid medium permissive for the development of erythroid, myeloid, and primitive progenitor colonies. Tax1-transduced CD34(+) cells displayed a two- to fivefold reduction in the total number of hematopoietic clonogenic colonies that arose in vitro, in contrast to Tax2-transduced cells, which showed no perturbation of hematopoiesis. The ratio of colony types that developed from Tax1-transduced CD34(+) cells remained unaffected, suggesting that Tax1 inhibited the maturation of relatively early, uncommitted hematopoietic stem cells. Since previous reports have linked Tax1 expression with initiation of apoptosis, lentiviral vector-mediated transduction of Tax1 or Tax2 was investigated in CEM and Jurkat T-cell lines. Ectopic expression of either Tax1 or Tax2 failed to induce apoptosis in T-cell lines. These data demonstrate that Tax1 expression perturbs development and maturation of pluripotent hematopoietic progenitor cells, an activity that is not displayed by Tax2, and that the suppression of hematopoiesis is not attributable to induction of apoptosis. Since hematopoietic progenitor cells may serve as a latently infected reservoir for HTLV infection in vivo, the different abilities of HTLV-1 and -2 Tax to suppress hematopoiesis may play a role in the respective clinical outcomes after infection with HTLV-1 or -2.
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Affiliation(s)
- Adam Tripp
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, New York 13210, USA
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Tzagarakis-Foster C, Geleziunas R, Lomri A, An J, Leitman DC. Estradiol represses human T-cell leukemia virus type 1 Tax activation of tumor necrosis factor-alpha gene transcription. J Biol Chem 2002; 277:44772-7. [PMID: 12237295 DOI: 10.1074/jbc.m205355200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Adult T-cell leukemia is caused by human T-cell leukemia virus type I (HTLV-I). The HTLV-I Tax protein is essential for clinical manifestations because it activates viral and cellular gene transcription. Tax enhances production of tumor necrosis factor-alpha (TNF-alpha), which may lead to bone and joint destruction. Because estrogens might prevent osteoporosis by repressing TNF-alpha gene transcription, we investigated whether estrogens inhibit the transcriptional effects of Tax on the TNF-alpha promoter. Tax activated the -1044, -163, and -125 TNF-alpha promoters by 9-25-fold but not the -82 promoter, demonstrating that Tax activation requires the -125 to -82 region, known as the TNF response element (TNF-RE). Three copies of the TNF-RE upstream of the minimal thymidine kinase promoter conferred a similar magnitude of activation by Tax. We demonstrated that c-Jun, NFkappaB, p50, and p65 interact with and activate the TNF-RE by using mutational analysis of the TNF-RE, Tax mutants that selectively activate NFkappaB or the cAMP-response element binding protein/activating transcription factor pathway, and gel shift assays with nuclear extracts. Estradiol markedly repressed Tax-activated transcription of the TNF-alpha gene with estrogen receptor (ER) alpha or beta. Nuclear extracts from U2OS cells stably transfected with ER(alpha) demonstrated that ERs interact with the TNF-RE. Our studies provide evidence that ERs repress Tax-activated TNF-alpha transcription by interacting with a c-Jun and NFkappaB platform on the TNF-RE. Estrogens may ameliorate bone and inflammatory joint diseases in patients infected with HTLV-I by repressing transcription of the TNF-alpha gene.
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Affiliation(s)
- Christina Tzagarakis-Foster
- Department of Obstetrics, Gynecology and Reproductive Sciences, Center for Reproductive Sciences, University of California, San Francisco 94143-0556, USA
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Chlichlia K, Los M, Schulze-Osthoff K, Gazzolo L, Schirrmacher V, Khazaie K. Redox events in HTLV-1 Tax-induced apoptotic T-cell death. Antioxid Redox Signal 2002; 4:471-7. [PMID: 12215214 DOI: 10.1089/15230860260196263] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A number of studies implicate reactive oxygen intermediates in the induction of DNA damage and apoptosis. Recent studies suggest that the human T-cell leukemia virus type 1 (HTLV-1) Tax protein induces oxidative stress and apoptotic T-cell death. Activation of the T-cell receptor/CD3 pathway enhances the Tax-mediated oxidative and apoptotic effects. Tax-mediated apoptosis and oxidative stress as well as activation of nuclear factor-kappaB can be potently suppressed by antioxidants. This review focuses on Tax-dependent changes in the intracellular redox status and their role in Tax-mediated DNA damage and apoptosis. The relevance of these observations to HTLV-1 virus-mediated T-cell transformation and leukemogenesis are discussed.
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Affiliation(s)
- Katerina Chlichlia
- Division of Cellular Immunology (G0100), Tumor Immunology Program, German Cancer Research Center, Im Neuenheimer Feld 280, D69120 Heidelberg, Germany.
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Azimi N, Nagai M, Jacobson S, Waldmann TA. IL-15 plays a major role in the persistence of Tax-specific CD8 cells in HAM/TSP patients. Proc Natl Acad Sci U S A 2001; 98:14559-64. [PMID: 11717409 PMCID: PMC64721 DOI: 10.1073/pnas.251540598] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2001] [Indexed: 11/18/2022] Open
Abstract
IL-15 is a critical cytokine for the maintenance of memory-phenotype CD8 cells in mice. Here, we investigated the role of IL-15 in the neurological disease termed human T cell lymphotropic virus I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The high number of viral-specific CD8 cells in these patients is associated with inflammatory responses in the central nervous system. Because IL-15 is overexpressed in these patients, we asked whether IL-15 contributes to the persistence of human T cell lymphotropic virus I viral-specific CD8 cells. Using ex vivo cultures of HAM/TSP peripheral blood mononuclear cells, we demonstrated that in the majority of patients examined here blocking IL-15 action resulted in a decrease in the number of viral-specific CD8 cells. This decrease was caused by both inhibition of proliferation and induction of apoptosis in these cells. The data indicate that IL-15 plays a major role in the maintenance of viral-specific CD8 cells in HAM/TSP.
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MESH Headings
- Antibodies, Blocking/pharmacology
- Antigens, Viral
- Apoptosis
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/pathology
- Cell Division
- Cytotoxicity, Immunologic
- Gene Products, tax/immunology
- Humans
- In Vitro Techniques
- Interleukin-15/antagonists & inhibitors
- Interleukin-15/physiology
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/pathology
- Paraparesis, Tropical Spastic/immunology
- Paraparesis, Tropical Spastic/pathology
- Protein Subunits
- Receptors, Interleukin-15
- Receptors, Interleukin-2/chemistry
- Receptors, Interleukin-2/metabolism
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Affiliation(s)
- N Azimi
- Metabolism Branch, Center for Cancer Research, National Cancer Institute, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1374, USA.
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Torgeman A, Ben-Aroya Z, Grunspan A, Zelin E, Butovsky E, Hallak M, Löchelt M, Flügel RM, Livneh E, Wolfson M, Kedar I, Aboud M. Activation of HTLV-I long terminal repeat by stress-inducing agents and protection of HTLV-I-infected T-cells from apoptosis by the viral tax protein. Exp Cell Res 2001; 271:169-79. [PMID: 11697893 DOI: 10.1006/excr.2001.5363] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
HTLV-I is etiologically implicated with tropical spastic paraparesis/HTLV-I associated myelopathy, adult T-cell leukemia and certain other diseases. However, after infection the virus enters into a dormant state, whereas the characteristics of the HTLV-I related diseases indicate that their genesis requires activation of the dormant virus by a Tax-independent mechanism. In the present study we demonstrate that a variety of stress-inducing agents (TPA, cisplatin, etoposide, taxol, and 3-methylcholanthrene) are capable of Tax-independent activation of HTLV-I LTR and that this activation is detected mainly in cells that are undergoing through the apoptotic process. Furthermore, it is demonstrated that both apoptosis induction and HTLV-I LTR activation are inhibited by Bcl-2 and by PKC, indicating that these two processes are mechanistically cross-linked. In addition, using an HTLV-I producing human T-cell line which permanently express the negatively transdominant tax mutant, Delta58tax, under the Tet-Off control system, we prove that the virally encoded Tax protein protects the host cells from apoptosis. Together, these data suggest that activation of the dormant virus in the carriers' infected T-cells by certain stress-inducing conditions and protecting these cells from the consequent apoptotic death by the viral Tax protein emerging after this activation, might be the basis for switching the virus from latency to a pathogenic phase.
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Affiliation(s)
- A Torgeman
- Department of Microbiology and Immunology, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
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Paludan SR, Mogensen SC. Virus-cell interactions regulating induction of tumor necrosis factor alpha production in macrophages infected with herpes simplex virus. J Virol 2001; 75:10170-8. [PMID: 11581385 PMCID: PMC114591 DOI: 10.1128/jvi.75.21.10170-10178.2001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Macrophages respond to virus infections by rapidly secreting proinflammatory cytokines, which play an important role in the first line of defense. Tumor necrosis factor alpha (TNF-alpha) is one of the major macrophage-produced cytokines. In this study we have investigated the virus-cell interactions responsible for induction of TNF-alpha expression in herpes simplex virus (HSV)-infected macrophages. Both HSV type 1 (HSV-1) and HSV-2 induced TNF-alpha expression in macrophages activated with gamma interferon (IFN-gamma). This induction was to some extent sensitive to UV treatment of the virus. Virus particles unable to enter the cells displayed reduced capacity to stimulate TNF-alpha expression but retained a significant portion which was abolished by HSV-specific antibodies. Recombinant HSV-1 glycoprotein D was able to trigger TNF-alpha secretion in concert with IFN-gamma. Sugar moieties of HSV glycoproteins have been reported to be involved in induction of IFN-alpha but did not contribute to TNF-alpha expression in macrophages. Moreover, the entry-dependent portion of the TNF-alpha induction was investigated with HSV-1 mutants and found to be independent of the tegument proteins VP16 and UL13 and partly dependent on nuclear translocation of the viral DNA. Finally, we found that macrophages expressing an inactive mutant of the double-stranded RNA (dsRNA)-activated protein kinase (PKR) produced less TNF-alpha in response to infectious HSV infection than the empty-vector control cell line but displayed the same responsiveness to UV-inactivated virus. These results indicate that HSV induces TNF-alpha expression in macrophages through mechanisms involving (i) viral glycoproteins, (ii) early postentry events occurring prior to nuclear translocation of viral DNA, and (iii) viral dsRNA-PKR.
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Affiliation(s)
- S R Paludan
- Department of Medical Microbiology and Immunology, University of Aarhus, Aarhus, Denmark.
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Sanders VJ, Wiley CA, Hamilton RL. The mechanisms of neuronal damage in retroviral infections of the nervous system. Curr Top Microbiol Immunol 2001; 253:179-201. [PMID: 11417135 DOI: 10.1007/978-3-662-10356-2_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- V J Sanders
- Department of Neuroscience, University of California, San Diego, La Jolla, CA 92302, USA
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Abstract
Virus infections induce a proinflammatory response including expression of cytokines and chemokines. The subsequent leukocyte recruitment and antiviral effector functions contribute to the first line of defense against viruses. The molecular virus-cell interactions initiating these events have been studied intensively, and it appears that viral surface glycoproteins, double-stranded RNA, and intracellular viral proteins all have the capacity to activate signal transduction pathways leading to the expression of cytokines and chemokines. The signaling pathways activated by viral infections include the major proinflammatory pathways, with the transcription factor NF-kappaB having received special attention. These transcription factors in turn promote the expression of specific inducible host proteins and participate in the expression of some viral genes. Here we review the current knowledge of virus-induced signal transduction by seven human pathogenic viruses and the most widely used experimental models for viral infections. The molecular mechanisms of virus-induced expression of cytokines and chemokines is also analyzed.
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Affiliation(s)
- T H Mogensen
- Department of Medical Microbiology and Immunology, University of Aarhus, DK-8000 Aarhus C, Denmark
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Szymocha R, Akaoka H, Dutuit M, Malcus C, Didier-Bazes M, Belin MF, Giraudon P. Human T-cell lymphotropic virus type 1-infected T lymphocytes impair catabolism and uptake of glutamate by astrocytes via Tax-1 and tumor necrosis factor alpha. J Virol 2000; 74:6433-41. [PMID: 10864655 PMCID: PMC112151 DOI: 10.1128/jvi.74.14.6433-6441.2000] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/1999] [Accepted: 04/26/2000] [Indexed: 12/18/2022] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of a chronic progressive myelopathy called tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). In this disease, lesions of the central nervous system (CNS) are associated with perivascular infiltration by lymphocytes. We and others have hypothesized that these T lymphocytes infiltrating the CNS may play a prominent role in TSP/HAM. Here, we show that transient contact of human or rat astrocytes with T lymphocytes chronically infected by HTLV-1 impairs some of the major functions of brain astrocytes. Uptake of extracellular glutamate by astrocytes was significantly decreased after transient contact with infected T cells, while the expression of the glial transporters GLAST and GLT-1 was decreased. In two-compartment cultures avoiding direct cell-to-cell contact, similar results were obtained, suggesting possible involvement of soluble factors, such as cytokines and the viral protein Tax-1. Recombinant Tax-1 and tumor necrosis factor alpha (TNF-alpha) decreased glutamate uptake by astrocytes. Tax-1 probably acts by inducing TNF-alpha, as the effect of Tax-1 was abolished by anti-TNF-alpha antibody. The expression of glutamate-catabolizing enzymes in astrocytes was increased for glutamine synthetase and decreased for glutamate dehydrogenase, the magnitudes of these effects being correlated with the level of Tax-1 transcripts. In conclusion, Tax-1 and cytokines produced by HTLV-1-infected T cells impair the ability of astrocytes to manage the steady-state level of glutamate, which in turn may affect neuronal and oligodendrocytic functions and survival.
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Affiliation(s)
- R Szymocha
- Experimental Neurobiology and Physiopathology Unit, INSERM U433, Lyon, France
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Sun SC, Ballard DW. Persistent activation of NF-kappaB by the tax transforming protein of HTLV-1: hijacking cellular IkappaB kinases. Oncogene 1999; 18:6948-58. [PMID: 10602469 DOI: 10.1038/sj.onc.1203220] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Biochemical coupling of transcription factor NF-kappaB to antigen and co-stimulatory receptors is required for the temporal control of T-cell proliferation. In contrast to its transitory activation during normal growth-signal transduction, NF-kappaB is constitutively deployed in T-cells transformed by the type 1 human T-cell leukemia virus (HTLV-1). This viral/host interaction is mediated by the HTLV-1-encoded Tax protein, which has potent oncogenic properties. As reviewed here, Tax activates NF-kappaB primarily via a pathway leading to the chronic phosphorylation and degradation of IkappaBalpha, a cytoplasmic inhibitor of NF-kappaB. To access this pathway, Tax associates stably with a cytokine-inducible IkappaB kinase (IKK), which contains both catalytic (IKKalpha and IKKbeta) and noncatalytic (IKKgamma) subunits. Unlike their transiently induced counterparts in cytokine-treated cells, Tax-associated forms of IKKalpha and IKKbeta are persistently activated in HTLV-1-infected T cells. Acquisition of the deregulated IKK phenotype is contingent on the presence of IKKgamma, which functions as a molecular adaptor in the assembly of pathologic Tax/IkappaB kinase complexes. These findings highlight a key mechanistic role for IKK in the Tax/NF-kappaB signaling axis and define new intracellular targets for the therapeutic control of HTLV-1-associated disease.
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Affiliation(s)
- S C Sun
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, Pennsylvania, PA 17033, USA
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45
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Cowan EP, Nemo GJ, Williams AE, Alexander RK, Vallejo A, Hewlett IK, Lal RB, Dezzutti CS, Gallahan D, George K, Pancake BA, Zucker-Franklin D, McCurdy PR, Tabor E. Absence of human T-lymphotropic virus type I tax sequences in a population of normal blood donors in the Baltimore, MD/Washington, DC, area: results from a multicenter study. Transfusion 1999; 39:904-9. [PMID: 10504129 DOI: 10.1046/j.1537-2995.1999.39080904.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND It was reported recently that sequences corresponding to the human T-lymphotropic virus type I (HTLV-I) tax gene were detected in peripheral blood mononuclear cells from 8 to 11 percent of healthy blood donors without detectable antibodies to HTLV-I. A multicenter blind study was conducted to determine if these results could be independently confirmed. STUDY DESIGN AND METHODS Specimens were collected from 100 anti-HTLV-I-negative healthy blood donors and from 11 anti-HTLV-I- or anti-HTLV-II-positive individuals. All samples were coded and distributed to each of four independent testing laboratories for polymerase chain reaction analysis to detect sequences of the HTLV-I or HTLV-II tax gene, using detailed procedures specified by the laboratory reporting the original observation. Each laboratory also tested a dilution panel of a plasmid containing HTLV-I tax to determine the analytical sensitivity of the procedure. RESULTS The analytical sensitivity of the screening methods permitted detection of as few as 1 to 10 copies of the tax gene. However, HTLV-I tax sequences could not be detected in any of the anti-HTLV-I-negative blood donors at more than one test site. CONCLUSION HTLV-I tax sequences appear not to be present in this population of 100 blood donors negative for anti-HTLV-I.
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Affiliation(s)
- E P Cowan
- Transfusion Medicine Scientific Research Group, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA.
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Sakai K, Kitagawa Y, Hirose G. Binding of neuronal ELAV-like proteins to the uridine-rich sequence in the 3'-untranslated region of tumor necrosis factor-alpha messenger RNA. FEBS Lett 1999; 446:157-62. [PMID: 10100634 DOI: 10.1016/s0014-5793(99)00206-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that is involved in the pathogenesis of several human CNS disorders. The AU-rich element (ARE) in the 3'-untranslated region (UTR) of TNF-alpha mRNA is implicated in post-transcriptional control of TNF-alpha. In this study, we showed that a human neuronal ELAV-like protein binds to the ARE in the 3'-UTR of TNF-alpha mRNA. The protein binds to the uridine stretch in AUUUA pentanucleotides inside the ARE in the 3'-UTR of TNF-alpha mRNA. The TNF-alpha mRNA-binding region in the protein appears to be identical to the c-myc and IL-3 mRNA-binding regions. Moreover, this study showed that in vitro treatment of neuroblastoma cells with interleukin-4 (IL-4), which inhibits TNF-alpha production, reduced the expression of the neuronal ELAV-like proteins. These results suggest that the expression of neuronal ELAV-like proteins may be closely associated with the expression of TNF-alpha in neuronal cells.
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Affiliation(s)
- K Sakai
- Department of Neurology, Kanazawa Medical University, Ishikawa, Japan.
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47
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Kitzmueller E, Labudova O, Rink H, Cairns N, Lubec G. Altered gene expression in fetal Down syndrome brain as revealed by the gene hunting technique of subtractive hybridization. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1999; 57:99-124. [PMID: 10666671 DOI: 10.1007/978-3-7091-6380-1_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Information on gene expression in brain of patients with Down Syndrome (DS, trisomy 21) is limited and molecular biological research is focussing on mapping and sequencing chromosome 21. The information on gene expression in DS available follows the current concept of a gene dosage effect due to a third copy of chromosome 21 claiming overexpression of genes encoded on this chromosome. Based upon the availability of fetal brain and recent technology of gene hunting, we decided to use subtractive hybridization to evaluate differences in gene expression between DS and control brains. Subtractive hybridization was applied on two fetal brains with DS and two age and sex matched controls, 23rd week of gestation, and mRNA steady state levels were evaluated generating a subtractive library. Subtracted sequences were identified by gene bank and assigned by alignments to individual genes. We found a series of up- and downregulated sequences consisting of chromosomal transcripts, enzymes of intermediary metabolism, hormones, transporters/channels and transcription factors (TFs). We show that trisomy 21 or aneuploidy leads to the deterioration of gene expression and the derangement of transcripts describes the impairment of transport, carriers, channels, signaling, known metabolic and hormone imbalances. The dys-coordinated expression of transcription factors including homeobox genes, POU-domain TFs, helix-loop-helix-motifs, LIM domain containing TFs, leucine zippers, forkhead genes, maybe of pathophysiological significance for abnormal brain development and wiring found in patients with DS. This is the first description of the concomitant expression of a large series of sequences indicating disruption of the concerted action of genes in this disorder.
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Affiliation(s)
- E Kitzmueller
- Department of Pediatrics, University of Vienna, Austria
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Sipe KJ, Dantzer R, Kelley KW, Weyhenmeyer JA. Expression of the 75 kDA TNF receptor and its role in contact-mediated neuronal cell death. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 62:111-21. [PMID: 9813268 DOI: 10.1016/s0169-328x(98)00221-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We previously demonstrated TNF toxicity, at high TNF doses or in the presence of actinomycin D, in the N1E-115 neuronal cell line (N1Es), which expresses only the 55 kDa TNF receptor (TNFR). To determine whether presence of the 75 kDa TNFR increases N1E sensitivity to TNF toxicity, cells were transfected with a 75 kDa TNFR expression construct. However, 75 kDa TNFR protein expression was undetectable in stably transfected N1Es. Further investigation revealed endogenous membrane-associated TNF in this neuronal line. Co-transfection with beta-galactosidase and the 75 kDa TNFR or empty vector (pcDNA3) indicated cell loss in the 75 kDa TNFR-transfected population relative to vector-transfected populations, while inhibition of membrane-associated TNF with a neutralizing antibody led to increased 75 kDa TNFR expression in transiently transfected N1Es. We conclude that neutralization of membrane-associated TNF inhibits its interaction with the introduced 75 kDa TNFR, increasing neuronal survival and promoting 75 kDa TNFR expression. Induced 75 kDa TNFR expression in the presence of membrane-associated TNF and the 55 kDa TNFR results in lymphocyte cell death [J.K. Lazdins, M. Grell, M.R. Walker, K. Woods-Cook, P. Scheurich, K. Pfizenmaier, Membrane tumor necrosis factor (TNF) induced cooperative signaling of the TNFR60 and TNFR80 favors induction of cell death rather than virus production in HIV-infected T cells, J. Exp. Med. 185 (1997) 81-90]. This report demonstrates that membrane-associated TNF and the 75 kDa TNFR similarly contribute to neuronal cell death.
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Affiliation(s)
- K J Sipe
- Department of Anatomy and Neurobiology, University of Kentucky, MN-224 Chandler Medical Center, 800 Rose St., Lexington, KY 40536-0298, USA.
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Aono H, Fujisawa K, Hasunuma T, Marriott SJ, Nishioka K. Extracellular human T cell leukemia virus type I tax protein stimulates the proliferation of human synovial cells. ARTHRITIS AND RHEUMATISM 1998; 41:1995-2003. [PMID: 9811055 DOI: 10.1002/1529-0131(199811)41:11<1995::aid-art15>3.0.co;2-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The present study was designed to investigate whether the proliferation of normal synovial cells from patients with meniscus injury is stimulated by human T cell leukemia virus type I (HTLV-I) Tax protein. METHODS The effect of Tax protein on the proliferation of synovial cells was evaluated using a 3H-thymidine incorporation assay. Production of cytokines was determined by enzyme-linked immunosorbent assay. Nuclear factor kappaB (NF-kappaB) DNA binding activity and the transcription of several NF-kappaB-mediated genes was detected by electrophoretic mobility shift assay and reverse transcriptase-polymerase chain reaction. RESULTS The proliferation of synovial cells, as well as their expression of tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor, and interleukin-6, was significantly enhanced by extracellular Tax at concentrations of 2.5 pM to 25 nM. In contrast, extracellular bacterial extract did not change the cytokine expression or the proliferation of these cells. Proliferation of synovial cells induced by Tax protein may be due to activated expression of several cytokines and protooncogenes that contain NF-kappaB regulatory sequences. CONCLUSION Our results suggest that extracellular Tax can regulate the expression of endogenous cellular genes in synovial cells and may contribute to the NF-kappaB-mediated synovial hyperplasia.
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Affiliation(s)
- H Aono
- St. Marianna University School of Medicine, Kawasaki, Japan
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Chen X, Zachar V, Chang C, Ebbesen P, Liu X. Differential expression of Nur77 family members in human T-lymphotropic virus type 1-infected cells: transactivation of the TR3/nur77 gene by Tax protein. J Virol 1998; 72:6902-6. [PMID: 9658143 PMCID: PMC109903 DOI: 10.1128/jvi.72.8.6902-6906.1998] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/1998] [Accepted: 05/12/1998] [Indexed: 02/08/2023] Open
Abstract
We analyzed the differential expression and regulation of three members of the Nur77 transcription factor family by the human T-lymphotropic virus type 1 (HTLV-1) Tax protein. We have demonstrated that in both HTLV-1-infected cells and Tax-expressing JPX-9 cells, TR3/nur77 is highly expressed, whereas neither NOR-1 nor NOT expression is detectable. Transient transfection analysis further confirmed the Tax transactivation of the TR3/nur77 promoter but not the NOR-1 promoter in different cell types. Furthermore, expression of a luciferase reporter gene driven by the NGFI-B (rat homolog of TR3/Nur77) response element (NBRE) provided evidence that Tax-mediated transactivation resulted in the induction of a functional protein. Cotransfection assays with the TR3/nur77 promoter sequence or the NBRE binding motif together with a series of Tax mutants have shown that Tax-induced TR3/nur77 expression is mediated by CREB/ATF-related transcription factors.
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MESH Headings
- Activating Transcription Factor 1
- Cell Line, Transformed
- DNA-Binding Proteins/genetics
- Gene Expression Regulation
- Gene Products, tax/genetics
- Gene Products, tax/metabolism
- Human T-lymphotropic virus 1/metabolism
- Human T-lymphotropic virus 1/physiology
- Humans
- Jurkat Cells
- NF-kappa B/genetics
- NF-kappa B/metabolism
- Nerve Tissue Proteins/genetics
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Nuclear Receptor Subfamily 4, Group A, Member 2
- Promoter Regions, Genetic
- Receptors, Cytoplasmic and Nuclear
- Receptors, Steroid
- Receptors, Thyroid Hormone
- Regulatory Sequences, Nucleic Acid
- T-Lymphocytes/metabolism
- T-Lymphocytes/virology
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation
- Tumor Cells, Cultured
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Affiliation(s)
- X Chen
- Department of Virus and Cancer, Danish Cancer Society, DK-8000 Aarhus C, Denmark
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