1
|
Maksimova V, Panfil AR. Human T-Cell Leukemia Virus Type 1 Envelope Protein: Post-Entry Roles in Viral Pathogenesis. Viruses 2022; 14:v14010138. [PMID: 35062342 PMCID: PMC8778545 DOI: 10.3390/v14010138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 11/16/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that is the causative infectious agent of adult T-cell leukemia/lymphoma (ATL), an aggressive and fatal CD4+ T-cell malignancy, and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a chronic neurological disease. Disease progression in infected individuals is the result of HTLV-1-driven clonal expansion of CD4+ T-cells and is generally associated with the activities of the viral oncoproteins Tax and Hbz. A closely related virus, HTLV-2, exhibits similar genomic features and the capacity to transform T-cells, but is non-pathogenic. In vitro, HTLV-1 primarily immortalizes or transforms CD4+ T-cells, while HTLV-2 displays a transformation tropism for CD8+ T-cells. This distinct tropism is recapitulated in infected people. Through comparative studies, the genetic determinant for this divergent tropism of HTLV-1/2 has been mapped to the viral envelope (Env). In this review, we explore the emerging roles for Env beyond initial viral entry and examine current perspectives on its contributions to HTLV-1-mediated disease development.
Collapse
Affiliation(s)
- Victoria Maksimova
- Biomedical Sciences Graduate Program, Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA;
| | - Amanda R. Panfil
- Center for Retrovirus Research, Comprehensive Cancer Center and Solove Research Institute, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
- Correspondence:
| |
Collapse
|
2
|
Kassay N, Mótyán JA, Matúz K, Golda M, Tőzsér J. Biochemical Characterization, Specificity and Inhibition Studies of HTLV-1, HTLV-2, and HTLV-3 Proteases. Life (Basel) 2021; 11:life11020127. [PMID: 33562087 PMCID: PMC7915765 DOI: 10.3390/life11020127] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 01/03/2023] Open
Abstract
The human T-lymphotropic viruses (HTLVs) are causative agents of severe diseases including adult T-cell leukemia. Similar to human immunodeficiency viruses (HIVs), the viral protease (PR) plays a crucial role in the viral life-cycle via the processing of the viral polyproteins. Thus, it is a potential target of anti-retroviral therapies. In this study, we performed in vitro comparative analysis of human T-cell leukemia virus type 1, 2, and 3 (HTLV-1, -2, and -3) proteases. Amino acid preferences of S4 to S1′ subsites were studied by using a series of synthetic oligopeptide substrates representing the natural and modified cleavage site sequences of the proteases. Biochemical characteristics of the different PRs were also determined, including catalytic efficiencies and dependence of activity on pH, temperature, and ionic strength. We investigated the effects of different HIV-1 PR inhibitors (atazanavir, darunavir, DMP-323, indinavir, ritonavir, and saquinavir) on enzyme activities, and inhibitory potentials of IB-268 and IB-269 inhibitors that were previously designed against HTLV-1 PR. Comparative biochemical analysis of HTLV-1, -2, and -3 PRs may help understand the characteristic similarities and differences between these enzymes in order to estimate the potential of the appearance of drug-resistance against specific HTLV-1 PR inhibitors.
Collapse
Affiliation(s)
- Norbert Kassay
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (N.K.); (K.M.); (M.G.)
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, 4032 Debrecen, Hungary
| | - János András Mótyán
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (N.K.); (K.M.); (M.G.)
- Correspondence: (J.A.M.); (J.T.); Tel.: +36-52-512-900 (J.A.M. & J.T.)
| | - Krisztina Matúz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (N.K.); (K.M.); (M.G.)
| | - Mária Golda
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (N.K.); (K.M.); (M.G.)
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, 4032 Debrecen, Hungary
| | - József Tőzsér
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (N.K.); (K.M.); (M.G.)
- Correspondence: (J.A.M.); (J.T.); Tel.: +36-52-512-900 (J.A.M. & J.T.)
| |
Collapse
|
3
|
Melamed A, Witkover AD, Laydon DJ, Brown R, Ladell K, Miners K, Rowan AG, Gormley N, Price DA, Taylor GP, Murphy EL, Bangham CRM. Clonality of HTLV-2 in natural infection. PLoS Pathog 2014; 10:e1004006. [PMID: 24626195 PMCID: PMC3953477 DOI: 10.1371/journal.ppat.1004006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 02/02/2014] [Indexed: 12/31/2022] Open
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) and type 2 (HTLV-2) both cause lifelong persistent infections, but differ in their clinical outcomes. HTLV-1 infection causes a chronic or acute T-lymphocytic malignancy in up to 5% of infected individuals whereas HTLV-2 has not been unequivocally linked to a T-cell malignancy. Virus-driven clonal proliferation of infected cells both in vitro and in vivo has been demonstrated in HTLV-1 infection. However, T-cell clonality in HTLV-2 infection has not been rigorously characterized. In this study we used a high-throughput approach in conjunction with flow cytometric sorting to identify and quantify HTLV-2-infected T-cell clones in 28 individuals with natural infection. We show that while genome-wide integration site preferences in vivo were similar to those found in HTLV-1 infection, expansion of HTLV-2-infected clones did not demonstrate the same significant association with the genomic environment of the integrated provirus. The proviral load in HTLV-2 is almost confined to CD8+ T-cells and is composed of a small number of often highly expanded clones. The HTLV-2 load correlated significantly with the degree of dispersion of the clone frequency distribution, which was highly stable over ∼8 years. These results suggest that there are significant differences in the selection forces that control the clonal expansion of virus-infected cells in HTLV-1 and HTLV-2 infection. In addition, our data demonstrate that strong virus-driven proliferation per se does not predispose to malignant transformation in oncoretroviral infections. The two human retroviruses HTLV-1 and HTLV-2 are similar in their structure, replication cycle and the manner through which they spread between and within individuals. They differ in their preferred host T-cell type and in their possible clinical outcomes. HTLV-2 has not been linked with a specific disease, whereas HTLV-1 infection can cause leukemia and profound neuropathology. It is well established that HTLV-1-infected cells undergo clonal expansion in infected individuals, but little is known about clonality in HTLV-2 infection. In this work, we demonstrate that the extent of HTLV-2-infected cell expansion significantly exceeds that of HTLV-1-infected cells in healthy carriers, approximating instead to that observed in patients with HTLV-1-associated leukemia. Furthermore, we show that HTLV-2 characteristically resides in a small number of expanded clones that persist over time, and that the degree of oligoclonality significantly correlates with viral burden in HTLV-2-infected individuals. These results highlight the distinction between in vivo clonal proliferation and malignant transformation, and suggest that the infected cell type may be a more important determinant of clinical outcome in retroviral infections.
Collapse
Affiliation(s)
- Anat Melamed
- Section of Immunology, Imperial College London, Wright-Fleming Institute, London, United Kingdom
| | - Aviva D. Witkover
- Section of Immunology, Imperial College London, Wright-Fleming Institute, London, United Kingdom
| | - Daniel J. Laydon
- Section of Immunology, Imperial College London, Wright-Fleming Institute, London, United Kingdom
| | - Rachael Brown
- Section of Immunology, Imperial College London, Wright-Fleming Institute, London, United Kingdom
| | - Kristin Ladell
- Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Kelly Miners
- Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Aileen G. Rowan
- Section of Immunology, Imperial College London, Wright-Fleming Institute, London, United Kingdom
| | | | - David A. Price
- Institute of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Graham P. Taylor
- Section of Infectious Diseases, Imperial College London, Wright-Fleming Institute, London, United Kingdom
| | - Edward L. Murphy
- Departments of Laboratory Medicine and Epidemiology/Biostatistics, University of California San Francisco and Blood Systems Research Institute, San Francisco, California, United States of America
| | - Charles R. M. Bangham
- Section of Immunology, Imperial College London, Wright-Fleming Institute, London, United Kingdom
- * E-mail:
| |
Collapse
|
4
|
Pique C, Jones KS. Pathways of cell-cell transmission of HTLV-1. Front Microbiol 2012; 3:378. [PMID: 23109932 PMCID: PMC3479854 DOI: 10.3389/fmicb.2012.00378] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 10/03/2012] [Indexed: 01/23/2023] Open
Abstract
The deltaretroviruses human T cell lymphotropic virus type 1 (HTLV-1) and human T cell lymphotropic virus type 2 (HTLV-2) have long been believed to differ from retroviruses in other genera by their mode of transmission. While other retroviruses were thought to primarily spread by producing cell-free particles that diffuse through extracellular fluids prior to binding to and infecting target cells, HTLV-1 and HTLV-2 were believed to transmit the virus solely by cell–cell interactions. This difference in transmission was believed to reflect the fact that, relative to other retroviruses, the cell-free virions produced by HTLV-infected cells are very poorly infectious. Since HTLV-1 and HTLV-2 are primarily found in T cells in the peripheral blood, spread of these viruses was believed to occur between infected and uninfected, T cells, although little was known about the cellular and viral proteins involved in this interaction. Recent studies have revealed that the method of transmission of HTLV is not unique: other retroviruses including human immunodeficiency virus (HIV) are also transmitted from cell-to-cell, and this method is dramatically more efficient than cell-free transmission. Moreover, cell–cell transmission of HTLV-1, as well as HIV, can occur following interactions between dendritic cells and T cells, as well as between T cells. Conversely, other studies have shown that cell-free HTLV-1 is not as poorly infectious as previously thought, since it is capable of infecting certain cell types. Here we summarize the recent insights about the mechanisms of cell–cell transmission of HTLV-1 and other retroviruses. We also review in vitro and in vivo studies of infection and discuss how these finding may relate to the spread of HTLV-1 between individuals.
Collapse
Affiliation(s)
- Claudine Pique
- CNRS UMR 8104, INSERM U567, Université Paris-Descartes, Institut Cochin Paris, France
| | | |
Collapse
|
5
|
Distinct transformation tropism exhibited by human T lymphotropic virus type 1 (HTLV-1) and HTLV-2 is the result of postinfection T cell clonal expansion. J Virol 2012; 86:3757-66. [PMID: 22278223 DOI: 10.1128/jvi.06900-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Human T lymphotropic virus type 1 (HTLV-1) and HTLV-2 are related but pathogenically distinct viruses. HTLV-1 mainly causes adult T cell leukemia, while HTLV-2 is not associated with leukemia. In vitro, HTLV-1 and HTLV-2 predominantly transform CD4(+) and CD8(+) T cells, respectively: the genetic determinant maps to the viral envelope. Herein, we investigate whether this transformation tropism occurs during initial infection or subsequently during the cellular transformation process. Since most individuals are chronically infected at the time of detection, we utilized an established rabbit model to longitudinally measure the early HTLV-1 and HTLV-2 infection and replication kinetics in purified CD4(+) and CD8(+) T cells. HTLV-1 and HTLV-2 were detected in both CD4(+) and CD8(+) T cells within 1 week postinoculation. In HTLV-1-infected rabbit CD4(+) T cells, proviral burden and tax/rex mRNA expression peaked early, and expression levels were directly proportional to each other. The late expression of the antisense transcript (Hbz or Aph-2) correlated directly with a late proviral burden peak in HTLV-1- or HTLV-2-infected rabbit CD8(+) T cells, respectively. This study provides the first in vivo evidence that these viruses do not exhibit cellular preference during initial infection. We further evaluated the transformation tropism of HTLV-1 and HTLV-2 over a 9-week period using in vitro cell growth/immortalization assays. At the early weeks, both HTLV-1 and HTLV-2 showed proportionate growth of CD4(+) and CD8(+) T cells. However, beyond week 5, the predominance of one particular T cell type emerged, supporting the conclusion that transformation tropism is a postinfection event due to selective clonal expansion over time.
Collapse
|
6
|
Orlandi C, Forlani G, Tosi G, Accolla RS. Molecular and cellular correlates of the CIITA-mediated inhibition of HTLV-2 Tax-2 transactivator function resulting in loss of viral replication. J Transl Med 2011; 9:106. [PMID: 21736733 PMCID: PMC3141499 DOI: 10.1186/1479-5876-9-106] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 07/07/2011] [Indexed: 11/10/2022] Open
Abstract
Background MHC class II transactivator CIITA inhibits the function of HTLV-2 Tax-2 viral transactivator and, consequently, the replication of the virus in infected cells. Moreover overexpression of the nuclear factor NF-YB, that cooperates with CIITA for the expression of MHC class II genes, results also in inhibition of Tax-2 transactivation. The purpose of this investigation was to assess the cellular and molecular basis of the CIITA-mediated inhibition on Tax-2, and the relative role of NF-YB in this phenomenon. Methods By co-immunoprecipitation of lysates from 293T cells cotransfected with CIITA or fragments of it, and Tax-2 it was assessed whether the two factors interact in vivo. A similar approach was used to assess Tax-2-NF-YB interaction. In parallel, deletion fragments of CIITA were tested for the inhibition of Tax-2-dependent HTLV-2 LTR-luciferase transactivation. Subcellular localization of CIITA and Tax-2 was investigated by immunofluorescence and confocal microscopy. Results CIITA and Tax-2 interact in vivo through at least two independent regions, at the 1-252 N-term and at the 410-1130 C-term, respectively. Interestingly only the 1-252 N-term region mediates Tax-2 functional inhibition. CIITA and Tax-2 are localized both in the cytoplasm and in the nucleus, when separately expressed. Instead, when coexpressed, most of Tax-2 colocalize with CIITA in cytoplasm and around the nuclear membrane. The Tax-2 minor remaining nuclear portion also co-localizes with CIITA. Interestingly, when CIITA nucleus-cytoplasm shuttling is blocked by leptomycin B treatment, most of the Tax-2 molecules are also blocked and co-localize with CIITA in the nucleus, suggesting that CIITA-Tax-2 binding does not preclude Tax-2 entry into the nucleus. Finally, the nuclear factor NF-YB, also strongly binds to Tax-2. Notably, although endogenous NF-YB does not inhibit Tax-2-dependent HTLV-2 LTR transactivation, it still binds to Tax-2, and in presence of CIITA, this binding seems to increase. Conclusions These results strongly suggest that CIITA inhibit Tax-2 by binding the viral transactivator both directly or through a tripartite interaction with NF-YB in. CIITA is therefore a viral restriction factor for HTLV-2 and this open the possibility to control HTLV-2 viral replication and spreading by the controlled induction of CIITA in infected cells
Collapse
Affiliation(s)
- Chiara Orlandi
- Department of Experimental Medicine, University of Insubria, Varese, Italy
| | | | | | | |
Collapse
|
7
|
Human T Lymphotropic Virus Type 1 (HTLV-1): Molecular Biology and Oncogenesis. Viruses 2010; 2:2037-2077. [PMID: 21994719 PMCID: PMC3185741 DOI: 10.3390/v2092037] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 08/25/2010] [Accepted: 09/15/2010] [Indexed: 12/13/2022] Open
Abstract
Human T lymphotropic viruses (HTLVs) are complex deltaretroviruses that do not contain a proto-oncogene in their genome, yet are capable of transforming primary T lymphocytes both in vitro and in vivo. There are four known strains of HTLV including HTLV type 1 (HTLV-1), HTLV-2, HTLV-3 and HTLV-4. HTLV-1 is primarily associated with adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-2 is rarely pathogenic and is sporadically associated with neurological disorders. There have been no diseases associated with HTLV-3 or HTLV-4 to date. Due to the difference in the disease manifestation between HTLV-1 and HTLV-2, a clear understanding of their individual pathobiologies and the role of various viral proteins in transformation should provide insights into better prognosis and prevention strategies. In this review, we aim to summarize the data accumulated so far in the transformation and pathogenesis of HTLV-1, focusing on the viral Tax and HBZ and citing appropriate comparisons to HTLV-2.
Collapse
|
8
|
Oliveira ALA, Hayakawa H, Schor D, Leite ACCB, Espíndola OM, Waters A, Dean J, Doherty DG, Araújo AQC, Hall WW. High frequencies of functionally competent circulating Tax-specific CD8+ T cells in human T lymphotropic virus type 2 infection. THE JOURNAL OF IMMUNOLOGY 2009; 183:2957-65. [PMID: 19657093 DOI: 10.4049/jimmunol.0900508] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human T lymphotropic virus type 2 (HTLV-2) is characterized by a clinically asymptomatic persistent infection in the vast majority of infected individuals. In this study, we have characterized for the first time ex vivo specific CTL responses against the HTLV-2 Tax protein. We could detect CTL responses only against a single HLA-A*0201-restricted Tax2 epitope, comprising residues 11-19 (LLYGYPVYV), among three alleles screened. Virus-specific CTLs could be detected in most evaluated subjects, with frequencies as high as 24% of circulating CD8(+) T cells. The frequency of specific CTLs had a statistically significant positive correlation with proviral load levels. The majority of virus-specific CD8(+) T cells exhibited an effector memory/terminally differentiated phenotype, expressed high levels of cytotoxicity mediators, including perforin and granzyme B, and lysed in vitro target cells pulsed with Tax2((11-19)) synthetic peptide in a dose-dependent manner. Our findings suggest that a strong, effective CTL response may control HTLV-2 viral burden and that this may be a significant factor in maintaining persistent infection and in the prevention of disease in infected individuals.
Collapse
Affiliation(s)
- André L A Oliveira
- Centre for Research in Infectious Diseases, University College Dublin, Dublin, Ireland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Hematologic hints of HTLV-2 in US blood donors. Blood 2008; 112:3919-20. [DOI: 10.1182/blood-2008-09-179085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
10
|
Jones KS, Fugo K, Petrow-Sadowski C, Huang Y, Bertolette DC, Lisinski I, Cushman SW, Jacobson S, Ruscetti FW. Human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 use different receptor complexes to enter T cells. J Virol 2006; 80:8291-302. [PMID: 16912281 PMCID: PMC1563841 DOI: 10.1128/jvi.00389-06] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies using adherent cell lines have shown that glucose transporter-1 (GLUT-1) can function as a receptor for human T-cell leukemia virus type 1 (HTLV). In primary CD4(+) T cells, heparan sulfate proteoglycans (HSPGs) are required for efficient entry of HTLV-1. Here, the roles of HSPGs and GLUT-1 in HTLV-1 and HTLV-2 Env-mediated binding and entry into primary T cells were studied. Examination of the cell surface of activated primary T cells revealed that CD4(+) T cells, the primary target of HTLV-1, expressed significantly higher levels of HSPGs than CD8(+) T cells. Conversely, CD8(+) T cells, the primary target of HTLV-2, expressed GLUT-1 at dramatically higher levels than CD4(+) T cells. Under these conditions, the HTLV-2 surface glycoprotein (SU) binding and viral entry were markedly higher on CD8(+) T cells while HTLV-1 SU binding and viral entry were higher on CD4(+) T cells. Binding studies with HTLV-1/HTLV-2 SU recombinants showed that preferential binding to CD4(+) T cells expressing high levels of HSPGs mapped to the C-terminal portion of SU. Transfection studies revealed that overexpression of GLUT-1 in CD4(+) T cells increased HTLV-2 entry, while expression of HSPGs on CD8(+) T cells increased entry of HTLV-1. These studies demonstrate that HTLV-1 and HTLV-2 differ in their T-cell entry requirements and suggest that the differences in the in vitro cellular tropism for transformation and in vivo pathobiology of these viruses reflect different interactions between their Env proteins and molecules on CD4(+) and CD8(+) T cells involved in entry.
Collapse
Affiliation(s)
- Kathryn S Jones
- Basic Research Program, SAIC-Frederick, Inc., National Cancer Institute-Frederick, Maryland 21702, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Tosi G, Pilotti E, Mortara L, Barbaro ADL, Casoli C, Accolla RS. Inhibition of human T cell leukemia virus type 2 replication by the suppressive action of class II transactivator and nuclear factor Y. Proc Natl Acad Sci U S A 2006; 103:12861-6. [PMID: 16908858 PMCID: PMC1568938 DOI: 10.1073/pnas.0601589103] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2006] [Indexed: 11/18/2022] Open
Abstract
The master regulator of MHC-II gene transcription, class II transactivator (CIITA), acts as a potent inhibitor of human T cell leukemia virus type 2 (HTLV-2) replication by blocking the activity of the viral Tax-2 transactivator. Here, we show that this inhibitory effect takes place at the nuclear level and maps to the N-terminal 1-321 region of CIITA, where we identified a minimal domain, from positions 64-144, that is strictly required to suppress Tax-2 function. Furthermore, we show that Tax-2 specifically cooperates with cAMP response element binding protein-binding protein (CBP) and p300, but not with p300/CBP-associated factor, to enhance transcription from the viral promoter. This finding represents a unique difference with respect to Tax-1, which uses all three coactivators to transactivate the human T cell leukemia virus type 1 LTR. Direct sequestering of CBP or p300 is not the primary mechanism by which CIITA causes suppression of Tax-2. Interestingly, we found that the transcription factor nuclear factor Y, which interacts with CIITA to increase transcription of MHC-II genes, exerts a negative regulatory action on the Tax-2-mediated HTLV-2 LTR transactivation. Thus, CIITA may inhibit Tax-2 function, at least in part, through nuclear factor Y. These findings demonstrate the dual defensive role of CIITA against pathogens: it increases the antigen-presenting function for viral determinants and suppresses HTLV-2 replication in infected cells.
Collapse
Affiliation(s)
- Giovanna Tosi
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| | - Elisabetta Pilotti
- Department of Clinical Medicine, Nephrology, and Health Sciences, University of Parma, 43100 Parma, Italy
| | - Lorenzo Mortara
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| | - Andrea De Lerma Barbaro
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| | - Claudio Casoli
- Department of Clinical Medicine, Nephrology, and Health Sciences, University of Parma, 43100 Parma, Italy
| | - Roberto S. Accolla
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| |
Collapse
|
12
|
Xie L, Green PL. Envelope is a major viral determinant of the distinct in vitro cellular transformation tropism of human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2. J Virol 2006; 79:14536-45. [PMID: 16282453 PMCID: PMC1287554 DOI: 10.1128/jvi.79.23.14536-14545.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 are related deltaretroviruses but are distinct in their disease-inducing capacity. These viruses can infect a variety of cell types, but only T lymphocytes become transformed, which is defined in vitro as showing indefinite interleukin-2-independent growth. Studies have indicated that HTLV-1 has a preferential tropism for CD4+ T cells in vivo and is associated with the development of leukemia and neurological disease. Conversely, the in vivo T-cell tropism of HTLV-2 is less clear, although it appears that CD8+ T cells preferentially harbor the provirus, with only a few cases of disease association. The difference in T-cell transformation tropism has been confirmed in vitro as shown by the preferential transformation of CD4+ T cells by HTLV-1 versus the transformation of CD8+ T cells by HTLV-2. Our previous studies showed that Tax and overlapping Rex do not confer the distinct T-cell transformation tropisms between HTLV-1 and HTLV-2. Therefore, for this study HTLV-1 and HTLV-2 recombinants were generated to assess the contribution of LTR and env sequences in T-cell transformation tropism. Both sets of proviral recombinants expressed p19 Gag following transfection into cells. Furthermore, recombinant viruses were replication competent and had the capacity to transform T lymphocytes. Our data showed that exchange of the env gene resulted in altered T-cell transformation tropism compared to wild-type virus, while exchange of long terminal repeat sequences had no significant effect. HTLV-2/Env1 preferentially transformed CD4+ T cells similarly to wild-type HTLV-1 (wtHTLV-1), whereas HTLV-1/Env2 had a transformation tropism similar to that of wtHTLV-2 (CD8+ T cells). These results indicate that env is a major viral determinant for HTLV T-cell transformation tropism in vitro and provides strong evidence implicating its contribution to the distinct pathogenesis resulting from HTLV-1 versus HTLV-2 infections.
Collapse
Affiliation(s)
- Li Xie
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | | |
Collapse
|
13
|
Dezzutti CS, Patel PP, Owen SM, Switzer WM, Meshulam J, Lal RB. Sensitivity and specificity of a DNA polymerase chain reaction nonisotopic-based detection method for the confirmation of infection with human T-lymphotropic virus types I and II. ACTA ACUST UNITED AC 2005; 6:103-10. [PMID: 15566896 DOI: 10.1016/0928-0197(96)00232-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/1995] [Accepted: 04/23/1996] [Indexed: 11/15/2022]
Abstract
BACKGROUND A convenient, standard format for the detection of polymerase chain reaction (PCR) amplicons would increase the use of PCR for the confirmation of infection with human T-lymphotropic virus types I and II (HTLV-I and HTLV-II). OBJECTIVES To determine the sensitivity and specificity of an enzyme oligonucleotide assay (EOA) for the confirmation of infection with HTLV-I or HTLV-II. STUDY DESIGN The sensitivity of the EOA was determined by examining 88 specimens representing diverse geographic-associated genotypes and clinical manifestations. The specificity was determined by testing 40 HTLV-seroindeterminate (PCR-negative) specimens. RESULTS Of the 52 HTLV-I-positive specimens tested, 46 (88%) were confirmed positive for HTLV-I by the EOA; these included 25 of 30 (83%) specimens from asymptomatic carriers, 14 of 15 (93%) specimens from patients with HTLV-I-associated myelopathy, and all 7 specimens from patients with adult T-cell leukemia. Similarly, 33 of 36 (92%) HTLV-II-positive specimens were confirmed positive for HTLV-II. None of the specimens were wrongly classified. All specimens tested with distinct geographic-associated genotypes for HTLV-I and -II were detected by EOA. Analysis of seroindeterminate specimens, all of which were previously shown to be negative by nested PCR, showed that none of 40 were detected by either the HTLV-I or HTLV-II EOA. CONCLUSIONS The overall sensitivity of the EOA detection for confirmation of HTLV-I and HTLV-II was 79 of 88 (90%) and the overall specificity was 100%. These findings demonstrate that the EOA provides a simple, standardized assay system for reliable confirmation and typing of HTLV infection.
Collapse
Affiliation(s)
- C S Dezzutti
- Retrovirus Diseases Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Mail Stop G19, 1600 Clifton Road, Atlanta, GA 30333, USA
| | | | | | | | | | | |
Collapse
|
14
|
Younis I, Green PL. The human T-cell leukemia virus Rex protein. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2005; 10:431-45. [PMID: 15574380 PMCID: PMC2659543 DOI: 10.2741/1539] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A critical step in the life cycle of complex retroviruses, including HTLV-1 and HTLV-2 is the ability of these viruses to adopt a mechanism by which the genome-length unspliced mRNA as well as the partially spliced mRNAs are exported from the nucleus instead of being subjected to splicing or degradation. In HTLV, this is accomplished through the expression of the viral Rex, which recognizes a specific response element on the incompletely spliced mRNAs, stabilizes them, inhibits their splicing, and utilizes the CRM1-dependent cellular pathway for transporting them from the nucleus to the cytoplasm. Rex itself is regulated by phosphorylation, which implies that proper activation of the protein in response to certain cellular cues is an important tool for the virus to ensure that specific viral gene expression is allowed only when the host cell can provide the best conditions for virion production. Having such a critical role in HTLV life cycle, Rex is indispensable for efficient viral replication, infection and spread. Indeed, Rex is considered to regulate the switch between the latent and productive phases of the HTLV life cycle. Without a functional Rex, the virus would still produce regulatory and some accessory gene products; however, structural and enzymatic post-transcriptional gene expression would be severely repressed, essentially leading to non-productive viral replication. More detailed understanding of the exact molecular mechanism of action of Rex will thus allow for better design of therapeutic drugs against Rex function and ultimately HTLV replication. Herein we summarize the progress made towards understanding Rex function and its role in the HTLV life cycle.
Collapse
Affiliation(s)
- Ihab Younis
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210
- Molecular, Cellular and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH 43210
| | - Patrick L. Green
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, OH 43210
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210
- Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210
- Molecular, Cellular and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH 43210
| |
Collapse
|
15
|
Murphy EL, Wang B, Sacher RA, Fridey J, Smith JW, Nass CC, Newman B, Ownby HE, Garratty G, Hutching ST, Schreiber GB. Respiratory and urinary tract infections, arthritis, and asthma associated with HTLV-I and HTLV-II infection. Emerg Infect Dis 2004; 10:109-16. [PMID: 15078605 PMCID: PMC3322766 DOI: 10.3201/eid1001.020714] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Human T-lymphotropic virus types I and II (HTLV-I and -II) cause myelopathy; HTLV-I, but not HTLV-II, causes adult T-cell leukemia. Whether HTLV-II is associated with other diseases is unknown. Using survival analysis, we studied medical history data from a prospective cohort of HTLV-I– and HTLV-II–infected and –uninfected blood donors, all HIV seronegative. A total of 152 HTLV-I, 387 HTLV-II, and 799 uninfected donors were enrolled and followed for a median of 4.4, 4.3, and 4.4 years, respectively. HTLV-II participants had significantly increased incidences of acute bronchitis (incidence ratio [IR] = 1.68), bladder or kidney infection (IR = 1.55), arthritis (IR = 2.66), and asthma (IR = 3.28), and a borderline increase in pneumonia (IR = 1.82, 95% confidence interval [CI] 0.98 to 3.38). HTLV-I participants had significantly increased incidences of bladder or kidney infection (IR = 1.82), and arthritis (IR = 2.84). We conclude that HTLV-II infection may inhibit immunologic responses to respiratory infections and that both HTLV-I and -II may induce inflammatory or autoimmune reactions.
Collapse
Affiliation(s)
- Edward L Murphy
- Laboratory Medicine and Epidemiology/Biostatistics, University of California San Francisco, California 94118, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Casoli C, De Lerma Barbaro A, Pilotti E, Bertazzoni U, Tosi G, Accolla RS. The MHC class II transcriptional activator (CIITA) inhibits HTLV-2 viral replication by blocking the function of the viral transactivator Tax-2. Blood 2003; 103:995-1001. [PMID: 14525769 DOI: 10.1182/blood-2003-07-2503] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human T-cell leukemia virus type 2 (HTLV-2), an oncogenic retrovirus closely related to HTLV-1, produces a lifelong infection whose possible association to certain human diseases is still debated. Although some viral products can influence the expression and action of cellular genes, very little is known about the molecular mechanisms involved. Here we show that the AIR-1-encoded human major histocompatibility complex (MHC) class II transactivator (CIITA) strongly inhibits viral replication, but not virus entry, in human B- and T-cell susceptible targets. This effect results from CIITA inhibiting the Tax-mediated transactivation of the HTLV-2 long-term repeat. Further molecular analysis shows that the N-terminal region of CIITA encompassing the first 321 amino acids is responsible for the inhibitory effect on viral replication. This region is crucial for the transactivation of human MHC class II genes and includes the activation domain as well as domains interacting with coactivators that also are used by the viral transactivator Tax to modulate cellular functions. These results represent the first evidence that a cellular transcriptional activator, controlling the coordinate expression of the entire family of MHC class II antigen-presenting molecules, inhibits HTLV-2 viral replication by a distinct mechanism. In this new role CIITA may represent a new tool for therapeutic strategies aimed at counteracting HTLV-2 replication and spreading.
Collapse
Affiliation(s)
- Claudio Casoli
- Department of Clinical Medicine, Nephrology, and Health Sciences, School of Medicine, University of Parma; Via Gramsci 14, 43100 Parma, Italy.
| | | | | | | | | | | |
Collapse
|
17
|
Ye J, Xie L, Green PL. Tax and overlapping rex sequences do not confer the distinct transformation tropisms of human T-cell leukemia virus types 1 and 2. J Virol 2003; 77:7728-35. [PMID: 12829812 PMCID: PMC161933 DOI: 10.1128/jvi.77.14.7728-7735.2003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2003] [Accepted: 04/15/2003] [Indexed: 11/20/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 are distinct oncogenic retroviruses that infect several cell types but display their biological and pathogenic activity only in T cells. Previous studies have indicated that in vivo HTLV-1 has a preferential tropism for CD4+ T cells, whereas HTLV-2 in vivo tropism is less clear but appears to favor CD8+ T cells. Both CD4+ and CD8+ T cells are susceptible to HTLV-1 and HTLV-2 infection in vitro, and HTLV-1 has a preferential immortalization and transformation tropism of CD4+ T cells, whereas HTLV-2 immortalizes and transforms primarily CD8+ T cells. The molecular mechanism that determines this tropism of HTLV-1 and HTLV-2 has not been determined. HTLV-1 and HTLV-2 carry the tax and rex transregulatory genes in separate but partially overlapping reading frames. Since Tax has been shown to be critical for cellular transformation in vitro and interacts with numerous cellular processes, we hypothesized that the viral determinant of transformation tropism is encoded by tax. Using molecular clones of HTLV-1 (Ach) and HTLV-2 (pH6neo), we constructed recombinants in which tax and overlapping rex genes of the two viruses were exchanged. p19 Gag expression from proviral clones transfected into 293T cells indicated that both recombinants contained functional Tax and Rex but with significantly altered activity compared to the wild-type clones. Stable transfectants expressing recombinant viruses were established, irradiated, and cocultured with peripheral blood mononuclear cells. Both recombinants were competent to transform T lymphocytes with an efficiency similar to that of the parental viruses. Flow cytometry analysis indicated that HTLV-1 and HTLV-1/TR2 had a preferential tropism for CD4+ T cells and that HTLV-2 and HTLV-2/TR1 had a preferential tropism for CD8(+) T cells. Our results indicate that tax/rex in different genetic backgrounds display altered functional activity but ultimately do not contribute to the different in vitro transformation tropisms. This first study with recombinants between HTLV-1 and HTLV-2 is the initial step in elucidating the different pathobiologies of HTLV-1 and HTLV-2.
Collapse
Affiliation(s)
- Jianxin Ye
- Department of Veterinary Bioscience, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
| | | | | |
Collapse
|
18
|
Ariga H, Lee TH, Laycock ME, Mohr BA, Kalish LA, Yomtovian R, Gernsheimer T, Busch MP. Residual WBC subsets in filtered prestorage RBCs. Transfusion 2003; 43:98-106. [PMID: 12519437 DOI: 10.1046/j.1537-2995.2003.00270.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND New-generation RBC filters reduce WBC concentrations by 4 to 5 logs and may prevent or decrease transfusion complications such as HLA alloimmunization, nonhemolytic febrile reaction, and transfusion-transmitted infections. The residual level of WBC subsets may influence efficacy of WBC reduction for preventing various complications. This study analyzed subsets of residual WBCs in WBC-reduced RBC components prepared for a large, multicenter prospective study. STUDY DESIGN AND METHODS The Viral Activation Transfusion Study (VATS) assessed the impact of WBC reduction in HIV-1-infected patients undergoing RBC transfusion. WBC-reduced RBC from 11 clinical sites with variable filtration practices were sorted into "low,""middle," and "high" groups based on residual WBC concentration. Subsets were isolated from units by immunocapture (anti-CD4-, anti-CD8-, anti-CD15-, and anti-CD19-coated magnetic beads) and quantified by PCR amplification. RESULTS After validation studies confirming test methodology, 105 VATS WBC-reduced RBC samples were analyzed. Concentrations of subsets in low and middle residual WBC groups were very low in contrast to relatively high concentrations in the high group. Although highly significant differences were identified between the middle and high groups for total WBCs and all subsets, no single subset predominated. CONCLUSION These results suggest that overall efficacy of WBC filtration correlates with removal of WBC subsets.
Collapse
Affiliation(s)
- Hiromichi Ariga
- Department of Medicine, Neonatal Intensive Care Unit, Fukushima Medical University, Japan
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Bovolenta C, Pilotti E, Mauri M, Panzeri B, Sassi M, Dall'Aglio P, Bertazzoni U, Poli G, Casoli C. Retroviral interference on STAT activation in individuals coinfected with human T cell leukemia virus type 2 and HIV-1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:4443-9. [PMID: 12370379 DOI: 10.4049/jimmunol.169.8.4443] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human T cell leukemia virus (HTLV) type-2 is a human retrovirus whose infection has not been tightly linked to human diseases. However, the fairly high prevalence of this infection among HIV-1-positive individuals indicates the importance of better understanding the potential interference of HTLV-2 infection on HIV-1 infection and AIDS. We previously demonstrated that one signature of PBMC freshly derived from HIV-1-infected individuals is the constitutive activation of a C-terminal truncated STAT5 (STAT5Delta). Therefore, we analyzed the potential activation of STATs in HTLV-2 monoinfected and HTLV-2/HIV-1 dually infected individuals. We observed that PBMC of HTLV-2-infected individuals do not show STAT activation unless they are cultivated ex vivo, in the absence of any mitogenic stimuli, for at least 8 h. The emergence of STAT activation, namely of STAT1, in culture was mostly related to the secretion of IFN-gamma. Of note, this phenomenon is not only a characteristic feature of HTLV-2-infected individuals but also occurred with PBMC of HIV-1(+) individuals. Surprisingly, HTLV-2/HIV-1 coinfection resulted in low/absent STAT activation in vivo that paralleled a diminished secretion of IFN-gamma after ex vivo cultivation. Our findings indicate that both HTLV-2 and HIV-1 infection prime T lymphocytes for STAT1 activation, but they also highlight an interference exerted by HTLV-2 on HIV-1-induced STAT1 activation. Although the nature of such a phenomenon is unclear at the present, these findings support the hypothesis that HTLV-2 may interfere with HIV-1 infection at multiple levels.
Collapse
Affiliation(s)
- Chiara Bovolenta
- Department of Immunology and Infectious Disease, San Raffaele Scientific Institute, via Olgettina 58, 20132 Milan, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Bovolenta C, Pilotti E, Mauri M, Turci M, Ciancianaini P, Fisicaro P, Bertazzoni U, Poli G, Casoli C. Human T-cell leukemia virus type 2 induces survival and proliferation of CD34(+) TF-1 cells through activation of STAT1 and STAT5 by secretion of interferon-gamma and granulocyte macrophage-colony-stimulating factor. Blood 2002; 99:224-31. [PMID: 11756175 DOI: 10.1182/blood.v99.1.224] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human T-cell leukemia-lymphoma virus (HTLV) type-2 can induce the survival and proliferation of CD34(+) TF-1 cells deprived of interleukin (IL)-3. This effect did not require productive infection and occurred when HTLV-2 was produced from T cells (CMo), but not from B cells (BMo), unless the latter virus was complexed with anti-HLA-DR monoclonal antibodies (mAbs). Cellular and molecular mechanisms triggered by HTLV-2 interaction with TF-1 cells were here investigated. Activation of signal transducer and activator of transcription (STAT) 5 protein occurred in TF-1 cells incubated either with IL-3 or with HTLV-2/CMo; in addition the virus, but not IL-3, activated STAT1. The effect of HTLV-2 required several hours, suggesting dependence on the induction of cellular factors. By screening a panel of secreted factors, granulocyte macrophage-colony-stimulating factor (GM-CSF), interferon (IFN)-gamma, and stem cell factor (SCF) were found induced by HTLV-2 in TF-1 cells. Of note is the fact that these molecules induce a variety of biologic effects through the activation of STAT proteins, including STAT1 and STAT5. Neutralization experiments indicated that GM-CSF and IFN-gamma, but not SCF, were responsible for HTLV-2-induced STAT activation, whereas anti-GM-CSF antibodies greatly inhibited TF-1 cell proliferation. Finally, incubation of BMo virus with anti-HLA-DR mAb rescued TF-1 cell survival in the absence of IL-3. Thus, HTLV-2 interaction with CD34(+) precursor cells may lead to the expression of cytokines that, by inducing autocrine activation of STATs, may influence the host's regenerative capacity and immune response to HTLV-2 and to other infectious agents.
Collapse
Affiliation(s)
- Chiara Bovolenta
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, Milan, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Poiesz BJ, Papsidero LD, Ehrlich G, Sherman M, Dube S, Poiesz M, Dillon K, Ruscetti FW, Slamon D, Fang C, Williams A, Duggan D, Glaser J, Gottlieb A, Goldberg J, Ratner L, Phillips P, Han T, Friedman-Kien A, Siegal F, Rai K, Sawitsky A, Sheremata LW, Dosik H, Cunningham C, Montagna R. Prevalence of HTLV-I-associated T-cell lymphoma. Am J Hematol 2001; 66:32-8. [PMID: 11426489 DOI: 10.1002/1096-8652(200101)66:1<32::aid-ajh1004>3.0.co;2-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In order to assess the prevalence rate of HTLV-1-associated T-cell lymphomas and human retrovirus infection in general, approximately 21,000 individuals representing various patient populations, retroviral risk groups, and blood donors were examined for HTLV-I, HTLV-II, HIV-1, or HIV-2 infection using serologic and PCR assays. The prevalence rates among volunteer blood donors were 0.02% and 0% for HTLV and HIV, respectively. Significantly increased HTLV prevalence rates were observed among paid blood donors, African American health care clinic patients, Amerindians, recipients of HTLV-positive cellular blood products, intravenous drug users, sexual contacts and family members of HTLV-positive people, and patients with primary thrombocytosis and other-than-low-grade non-Hodgkin's lymphoma (NHL). Among some of these groups there were significant differences in the prevalence of HTLV-I versus HTLV-II. The eight HTLV-positive NHL patients all had mature, high-grade, CD4+ T-cell lymphomas with clonally integrated HTLV-I, for a prevalence of 4% among other-than-low-grade NHL patients. Seven of the eight died from their disease within 2 years despite treatment. Interestingly, two groups at risk for HTLV infection, namely needle stick victims and recipients of HTLV-infected and/or pooled plasma products, showed no evidence for infection. Significantly increased HIV-1 prevalence was observed among paid blood donors, African Americans, homosexuals, female prostitutes, hemophiliacs, and other-than-low-grade NHL patients. Only one patient was infected with HIV-2. Of the nine HIV-positive, other-than-low-grade NHL patients, seven HIV-1 positives had B-cell lymphomas, one HIV-1 positive had an HTLV-I-positive CD4+ T-cell lymphoma, and one infected with HIV-2 had a CD4+ T-cell lymphoma that was HTLV negative. The data indicate that HTLV-I lymphoma, while uncommon, is not necessarily rare among other-than-low-grade NHL cases in the United States and, given its poor prognosis, should probably be studied separately in clinical trials.
Collapse
Affiliation(s)
- B J Poiesz
- Department of Medicine, State University of New York Health Science Center, Syracuse, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Twizere JC, Kerkhofs P, Burny A, Portetelle D, Kettmann R, Willems L. Discordance between bovine leukemia virus tax immortalization in vitro and oncogenicity in vivo. J Virol 2000; 74:9895-902. [PMID: 11024116 PMCID: PMC102026 DOI: 10.1128/jvi.74.21.9895-9902.2000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Bovine leukemia virus (BLV) Tax protein, a transcriptional activator of viral expression, is essential for viral replication in vivo. Tax is believed to be involved in leukemogenesis because of its second function, immortalization of primary cells in vitro. These activities of Tax can be dissociated on the basis of point mutations within specific regions of the protein. For example, mutation of the phosphorylation sites at serines 106 and 293 abrogates immortalization potential in vitro but maintains transcriptional activity. This type of mutant is thus particularly useful for unraveling the role of Tax immortalization activity during leukemogenesis independently of viral replication. In this report, we describe the biological properties of BLV recombinant proviruses mutated in the Tax phosphorylation sites (BLVTax106+293). Titration of the proviral loads by semiquantitative PCR revealed that the BLV mutants propagated at wild-type levels in vivo. Furthermore, two animals (sheep 480 and 296) infected with BLVTax106+293 developed leukemia or lymphosarcoma after 16 and 36 months, respectively. These periods of time are within the normal range of latencies preceding the onset of pathogenesis induced by wild-type viruses. The phenotype of the mutant-infected cells was characteristic of a B lymphocyte (immunoglobulin M positive) expressing CD11b and CD5 (except at the final stage for the latter marker), a pattern that is typical of wild-type virus-infected target cells. Interestingly, the transformed B lymphocytes from sheep 480 also coexpressed the CD8 marker, a phenotype rarely observed in tumor biopsies from chronic lymphocytic leukemia patients. Finally, direct sequencing of the tax gene demonstrated that the leukemic cells did not harbor revertant proviruses. We conclude that viruses expressing a Tax mutant unable to transform primary cells in culture are still pathogenic in the sheep animal model. Our data thus provide a clear example of the discordant conclusions that can be drawn from in vitro immortalization assays and in vivo experiments. These observations could be of interest for other systems, such as the related human T-cell leukemia virus type 1, which currently lack animal models allowing the study of the leukemogenic process.
Collapse
Affiliation(s)
- J C Twizere
- Department of Applied Biochemistry and Biology, Faculty of Agronomy, Gembloux, Belgium
| | | | | | | | | | | |
Collapse
|
23
|
Wang TG, Ye J, Lairmore MD, Green PL. In vitro cellular tropism of human T cell leukemia virus type 2. AIDS Res Hum Retroviruses 2000; 16:1661-8. [PMID: 11080807 DOI: 10.1089/08892220050193119] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human T cell leukemia virus type 1 (HTLV-1) and 2 (HTLV-2) are distinct oncogenic retroviruses that infect several cell types, but display their biologic/pathogenic activity only in T lymphocytes. HTLV-1 is associated with adult T cell leukemia, a malignancy of mature CD4(+) T cells, and a chronic neurological disorder termed HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-2 is less pathogenic and has been associated with a few cases of a variant of hairy cell leukemia and neurological disease. Previous studies have indicated that in vivo HTLV-1 has a preferential tropism for CD4(+) T cells, whereas HTLV-2 in vivo tropism is less clear, but appears to favor CD8(+) T cells. The molecular mechanism that determines the cellular tropism of HTLV-1 and HTLV-2 has not been precisely determined. However, one study by our group has provided evidence that HTLV-1-enhanced viral transcription in CD4(+) T cells may be responsible for its tropism. In an effort to understand HTLV-2 tropism we tested the ability of HTLV-2 to infect, replicate in, and transform purified CD4(+) or CD8(+) T cells in cell culture. After cocultures of purified primary human CD4(+) and CD8(+) T cells with an HTLV-2-producer cell line we measured viral transcription by reverse transcription PCR analysis, virus production by p19(gag) ELISA, proviral integration by DNA slot-blot analysis, surface phenotype by FACS analysis, and cellular transformation. We also measured HTLV-2 long terminal repeat-directed transcription in the presence and absence of Tax in purified CD4(+) and CD8(+) T cells, using transient transfection assays. Our data indicate that CD4(+) and CD8(+) T cells are equally susceptible to HTLV-2 infection. We observed no significant difference in viral transcription based on mRNA and virus production in CD4(+) and CD8(+) T cell cocultures. Although LTR transcription was enhanced 12- to 16-fold in the presence of Tax, there was no significant difference in CD4(+) or CD8(+) T cells. Interestingly, we show that HTLV-2 preferentially transforms CD8(+) T cells in culture. Together, our data indicate that, unlike HTLV-1, HTLV-2 cell tropism is not due to inhibition of viral infection and inefficient gene expression in CD4(+) versus CD8(+) T cells, and likely involves unique interactions with viral and CD8(+) T cell-specific proteins.
Collapse
Affiliation(s)
- T G Wang
- Center for Retrovirus Research and Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210, USA
| | | | | | | |
Collapse
|
24
|
Poiesz B, Dube D, Dube S, Love J, Papsidero L, Uner A, Hutchinson R. HTLV-II-associated cutaneous T-cell lymphoma in a patient with HIV-1 infection. N Engl J Med 2000; 342:930-6. [PMID: 10738051 DOI: 10.1056/nejm200003303421304] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- B Poiesz
- Department of Medicine, State University of New York Upstate Medical University, Syracuse 13210, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Zehender G, Meroni L, Varchetta S, De Maddalena C, Cavalli B, Gianotto M, Bosisio AB, Colasante C, Rizzardini G, Moroni M, Galli M. Human T-lymphotropic virus type 2 (HTLV-2) provirus in circulating cells of the monocyte/macrophage lineage in patients dually infected with human immunodeficiency virus type 1 and HTLV-2 and having predominantly sensory polyneuropathy. J Virol 1998; 72:7664-8. [PMID: 9696872 PMCID: PMC110036 DOI: 10.1128/jvi.72.9.7664-7668.1998] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/1998] [Accepted: 05/22/1998] [Indexed: 11/20/2022] Open
Abstract
We investigated the presence of human T-lymphotropic virus type 2 (HTLV-2) DNA in the peripheral blood mononuclear cell subsets obtained from 18 patients coinfected with human immunodeficiency virus type 1 and HTLV-2, 6 of whom also had predominantly sensory polyneuropathy (PSP). HTLV-2 DNA and RNA were found in CD8- and CD19-positive cells, and, for patients with PSP, in CD14-positive cells as well. Furthermore, the patients with PSP had higher proviral loads than those without PSP.
Collapse
Affiliation(s)
- G Zehender
- Istituto di Malattie Infettive e Tropicali, Università degli Studi di Milano," Milan, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Love JL, Marchioli CC, Dube S, Bryz-Gornia V, Loughran TP, Glaser JB, Esteban E, Feldman L, Ferrer JF, Poiesz BJ. Expansion of clonotypic T-cell populations in the peripheral blood of asymptomatic Gran Chaco Amerindians infected with HTLV-IIB. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1998; 18:178-85. [PMID: 9637583 DOI: 10.1097/00042560-199806010-00010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Peripheral blood mononuclear cells from asymptomatic HTLV-II-infected and uninfected Gran Chaco Amerindians were analyzed using polymerase chain reaction (PCR) for expansions of T-cell receptor (TCR) V-beta gene clonotypes. Analyses were performed using primer pairs designed to identify expanded T-cell familial clonotypes based on their unique TCR beta gene rearrangements. Of the 30 HTLV-IIB-positive samples tested, five showed evidence of V-beta clonotypic T-cell expansion. Of the five expansions, two were monoclonotypic and the remaining three were oligoclonotypic. In comparison, 30 HTLV-II-negative Amerindians showed no evidence of clonotypic T-cell expansion. Amplified DNA from one of the monoclonotypic samples was subsequently cloned and sequenced and was found to have uniform variable/ diversity/joining sequences confirming its unique monoclonal T-cell expansion. This method of detecting clonal TCR beta gene rearrangements has the advantage over traditional Southern blot techniques of being more sensitive and specific even with suboptimal specimens. The prognostic significance of clonotypic T-cell expansion in a group such as the HTLV-II-infected Gran Chaco Amerindians remains to be determined.
Collapse
Affiliation(s)
- J L Love
- Department of Medicine, State University of New York Health Science Center at Syracuse, 13210, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Human T-Cell Leukemia Virus Type II Directly Acts on CD34+ Hematopoietic Precursors by Increasing Their Survival Potential. Envelope-Associated HLA Class II Molecules Reverse This Effect. Blood 1998. [DOI: 10.1182/blood.v91.7.2296] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe role of human T-cell leukemia virus type II (HTLV-II) in human lymphoproliferative and hematopoietic abnormalities in which the retrovirus can be isolated is still elusive. Here we show that the C344 T-cell–derived lymphotropic HTLV-II type IIa Mo strain acts directly on CD34+ hematopoietic precursors by rescuing them from apoptosis induced by interleukin-3 (IL-3) deprivation. This effect is viral strain-specific, as it is not observed with the B-lymphotropic HTLV-II type IIb Gu strain, it does not require infection of the hematopoietic precursors, and, interestingly, it is strongly dependent on the infected cellular host from which the virus was derived. Indeed, growth adaptation of the Mo strain to the permissive B-cell line, BJAB, renders the virus no longer capable of mediating the antiapoptotic effect. However, pretreatment of the BJAB-adapted Mo strain with antibodies specific for HLA class II, but not class I, histocompatibility antigens restores the antiapoptotic potential of the virus. These results constitute the first evidence that HTLV-II retrovirus can directly influence the homeostasis of human progenitors, without infecting them, and that this crucial activity is strongly inhibited by the presence of host-derived envelope-associated HLA class II antigens.
Collapse
|
28
|
Ding YS, Owen SM, Lal RB, Ikeda RA. Efficient expression and rapid purification of human T-cell leukemia virus type 1 protease. J Virol 1998; 72:3383-6. [PMID: 9525666 PMCID: PMC109825 DOI: 10.1128/jvi.72.4.3383-3386.1998] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is an oncovirus that is clinically associated with adult T-cell leukemia. We report here the construction of a pET19-based expression clone containing HTLV-1 protease fused to a decahistidine-containing leader peptide. The recombinant protein is efficiently expressed in Escherichia coli, and the fusion protein can be easily purified by affinity chromatography. Active mature protease in yields in excess of 3 mg/liter of culture can then be obtained by a novel two-step refolding and autoprocessing procedure. The purified enzyme exhibited Km and Kcat, values of 0.3 mM and 0.143 sec(-1) at pH 5.3 and was inhibited by pepstatin A.
Collapse
Affiliation(s)
- Y S Ding
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332-0400, USA
| | | | | | | |
Collapse
|
29
|
Human T-Cell Leukemia Virus Type II Directly Acts on CD34+ Hematopoietic Precursors by Increasing Their Survival Potential. Envelope-Associated HLA Class II Molecules Reverse This Effect. Blood 1998. [DOI: 10.1182/blood.v91.7.2296.2296_2296_2304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of human T-cell leukemia virus type II (HTLV-II) in human lymphoproliferative and hematopoietic abnormalities in which the retrovirus can be isolated is still elusive. Here we show that the C344 T-cell–derived lymphotropic HTLV-II type IIa Mo strain acts directly on CD34+ hematopoietic precursors by rescuing them from apoptosis induced by interleukin-3 (IL-3) deprivation. This effect is viral strain-specific, as it is not observed with the B-lymphotropic HTLV-II type IIb Gu strain, it does not require infection of the hematopoietic precursors, and, interestingly, it is strongly dependent on the infected cellular host from which the virus was derived. Indeed, growth adaptation of the Mo strain to the permissive B-cell line, BJAB, renders the virus no longer capable of mediating the antiapoptotic effect. However, pretreatment of the BJAB-adapted Mo strain with antibodies specific for HLA class II, but not class I, histocompatibility antigens restores the antiapoptotic potential of the virus. These results constitute the first evidence that HTLV-II retrovirus can directly influence the homeostasis of human progenitors, without infecting them, and that this crucial activity is strongly inhibited by the presence of host-derived envelope-associated HLA class II antigens.
Collapse
|
30
|
Ross TM, Pettiford SM, Green PL. The tax gene of human T-cell leukemia virus type 2 is essential for transformation of human T lymphocytes. J Virol 1996; 70:5194-202. [PMID: 8764028 PMCID: PMC190475 DOI: 10.1128/jvi.70.8.5194-5202.1996] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The mechanism of human T-cell leukemia virus (HTLV)-mediated transformation and induction of malignancy is unknown; however, several studies have implicated the viral gene product, Tax. Conclusive evidence for the role of Tax in the HTLV malignant process has been impeded by the inability to mutate tax in the context of an infectious virus and dissociate viral replication from cellular transformation. To circumvent this problem we constructed a mutant of HTLV type 2 (HTLV-2) that replicates by a Tax-independent mechanism. For these studies, the Tax response element in the viral long terminal repeat was replaced with the cytomegalovirus immediate-early promoter enhancer (C-enh). Transcription of the chimeric HTLV-2 (HTLVC-enh) was efficiently directed by this heterologous promoter. Also, the chimeric virus transformed primary human T lymphocytes with an efficiency similar to that of wild-type HTLV-2. A tax-knockout virus, termed HTLVC-enhDeltaTax, was constructed to directly assess the importance of Tax in cellular transformation. Transfection and infection studies indicated that HTLVC-enhDeltaTax was replication competent; however, HTLVC-enhDeltaTax failed to transform primary human T lymphocytes. We conclude that Tax is essential for HTLV-mediated transformation of human T lymphocytes. Furthermore, this chimeric HTLV, that replicates in the absence of Tax, should facilitate studies to determine the precise mechanism of T-lymphocyte transformation by HTLV.
Collapse
Affiliation(s)
- T M Ross
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2363, USA
| | | | | |
Collapse
|
31
|
Feuer G, Fraser JK, Zack JA, Lee F, Feuer R, Chen IS. Human T-cell leukemia virus infection of human hematopoietic progenitor cells: maintenance of virus infection during differentiation in vitro and in vivo. J Virol 1996; 70:4038-44. [PMID: 8648741 PMCID: PMC190282 DOI: 10.1128/jvi.70.6.4038-4044.1996] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Human T-cell leukemia virus type I (HTLV-1) is the etiologic agent of adult T-cell leukemia and lymphoma and HTLV-1-associated myelopathy-tropical spastic paraparesis. We examined whether HTLV could productively infect human hematopoietic progenitor cells. CD34+ cells were enriched from human fetal liver cells and cocultivated with cell lines transformed with HTLV-1 and -2. HTLV-1 infection was established in between 10 and >95% of the enriched CD34+ cell population, as demonstrated by quantitative PCR analysis. HTLV-1 p19 Gag expression was also detected in infected hematopoietic progenitor cells. HTLV-1-infected hematopoietic progenitor cells were cultured in semisolid medium permissive for the development of erythbroid (BFU-E), myeloid (CFU-GM), and primitive progenitor (CFU-GEMM, HPP-CFC, or CFU-A) colonies. HTLV-1 sequences were detected in colonies of all hematopoietic lineages; furthermore, the ratio of HTLV genomes to the number of human cells in each infected colony was 1:1, consistent with each colony arising from a single infected hematopoietic progenitor cell. Severe combined immunodeficient mice engrafted with human fetal thymus and liver tissues (SCID-hu) develop a conjoint organ which supports human thymocyte differentiation and maturation. Inoculation of SCID-hu mice with HTLV-1-infected T cells or enriched populations of CD34+ cells established viral infection of thymocytes 4 to 6 weeks postreconstitution. Thymocytes from two mice with the greatest HTLV-1 proviral burdens showed increased expression of the CD25 marker and the interleukin 2 receptor alpha chain and perturbation of CD4+ and CD8+ thymocyte subset distribution profiles. Hematopoietic progenitor cells and thymuses may be targets for HTLV infection in humans, and these events may play a role in the pathogenesis associated with infection.
Collapse
Affiliation(s)
- G Feuer
- Department of Medicine, University of California at Los Angeles School of Medicine, 90095-1678, USA
| | | | | | | | | | | |
Collapse
|
32
|
Hall WW, Ishak R, Zhu SW, Novoa P, Eiraku N, Takahashi H, Ferreira MDC, Azevedo V, Ishak MO, Ferreira ODC, Monken C, Kurata T. Human T lymphotropic virus type II (HTLV-II): epidemiology, molecular properties, and clinical features of infection. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1996; 13 Suppl 1:S204-14. [PMID: 8797725 DOI: 10.1097/00042560-199600001-00031] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Human T lymphotropic virus, type II (HTLV-II), infection has been shown to be endemic in a number of American Indian populations, and high rates of infection have also been documented in intravenous drug abusers in urban areas throughout the world. Although the role of HTLV-II in human disease has yet to be clearly defined, there is accumulating evidence that like HTLV-I, infection may also be associated with rare lymphoproliferative and neurological disorders. In this article we review and summarize the epidemiology, molecular properties and clinical features of HTLV-II infection.
Collapse
Affiliation(s)
- W W Hall
- Laboratory of Medical Virology, Rockefeller University, New York, New York, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|