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Rocha-Junior MC, Rodrigues ES, Slavov SN, Assone T, Pedreschi M, de La Roque DGL, Sousa M, Olavarria V, Galvão-Castro B, da Fonseca BAL, Penalva de Oliveira AC, Smid J, Takayanagui OM, Casseb J, Covas DT, Kashima S. Rapid and Sensitive Qualitative Duoplex Real-Time PCR Method for Discriminatory and Confirmatory Diagnosis of HTLV-1 and HTLV-2 Infections: Brazilian Multicentric Study. Front Med (Lausanne) 2022; 9:881630. [PMID: 35755037 PMCID: PMC9218175 DOI: 10.3389/fmed.2022.881630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/09/2022] [Indexed: 11/13/2022] Open
Abstract
Human T cell lymphotropic virus (HTLV) is the caustive agent of two main conditions i. e., the HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and the adult T-cell leukemia/lymphoma (ATLL). HTLV diagnosis is based on serological and molecular approaches; however, an accurate and validated method is still needed. The objective of this study was to establish a rapid and sensitive molecular test to confirm and discriminate HTLV 1/2 types. The test validation was performed as a multicentric study involving HTLV confirmation centers throughout Brazil. Proviral DNA was extracted from whole blood and the amplification was performed using in-house designed primer and probe sets targeting the pol genomic region. An internal control to validate the extraction and amplification was also included. The limit of detection (LoD) of the assay was four copies/reaction for HTLV-1 and 10.9 copies/reaction for HTLV-2. The diagnostic sensitivity of the platform was 94.6% for HTLV-1, 78.6% for HTLV-2, and the specificity was 100% for both viruses. Cross-reactions of the test with human viruses including HAV, HBV, HCV, HIV-1/2, and parvovirus B19 were not observed. During the multicentric validation, the test was used to screen a total of 692 blood samples obtained from previously confirmed HTLV-positive individuals. From these, 91.1% tested positive being concordant with the previously obtained results. In conclusion, our duoplex-RT-PCR-HTLV1 /2 presented adequate efficiency for HTLV-1/2 differentiation showing high sensitivity and specificity. Therefore, it can be a suitable tool for confirmation of suspected and inconclusive HTLV cases, prenatal and pre-transplant diagnosis, in Brazil and in other countries HTLV-endemic countries.
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Affiliation(s)
- Mauricio Cristiano Rocha-Junior
- Regional Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.,Graduate Program in Biosciences and Biotechnology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Evandra Strazza Rodrigues
- Regional Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.,Center for Cell-Based Therapy CTC, Regional Blood Center of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Svetoslav Nanev Slavov
- Regional Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.,Center for Cell-Based Therapy CTC, Regional Blood Center of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Tatiane Assone
- Laboratory of Medical Investigation LIM 56, Division of Dermatology, Medical School, University of São Paulo, São Paulo, Brazil
| | - Maíra Pedreschi
- Laboratory of Medical Investigation LIM 56, Division of Dermatology, Medical School, University of São Paulo, São Paulo, Brazil
| | - Debora Glenda Lima de La Roque
- Regional Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.,Tropical Medicine Center, Federal University of Para, Belém, Brazil
| | - Maisa Sousa
- Tropical Medicine Center, Federal University of Para, Belém, Brazil
| | - Viviana Olavarria
- Centro de HTLV, Escola Bahiana de Medicina e Saúde Pública, Salvador, Brazil
| | | | | | | | - Jerusa Smid
- Laboratory of Medical Investigation LIM 56, Division of Dermatology, Medical School, University of São Paulo, São Paulo, Brazil
| | | | - Jorge Casseb
- Laboratory of Medical Investigation LIM 56, Division of Dermatology, Medical School, University of São Paulo, São Paulo, Brazil
| | - Dimas Tadeu Covas
- Regional Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.,Center for Cell-Based Therapy CTC, Regional Blood Center of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.,Department of Neurology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Simone Kashima
- Regional Blood Center of Ribeirão Preto, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.,Graduate Program in Biosciences and Biotechnology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.,Center for Cell-Based Therapy CTC, Regional Blood Center of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
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Castro GM, Balangero MC, Maturano E, Mangeaud A, Gallego SV. Development and validation of a real-time PCR assay for a novel HTLV-1 tax sequence detection and proviral load quantitation. J Virol Methods 2013; 189:383-7. [PMID: 23499262 DOI: 10.1016/j.jviromet.2013.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/18/2013] [Accepted: 02/21/2013] [Indexed: 12/14/2022]
Abstract
A quantitative real-time PCR (qPCR) assay using SYBR Green dye was established in order to detect and quantify the proviral DNA of HTLV-1 in peripheral blood mononuclear cells (PBMCs). Primers were designed, and the assay was standardized to amplify a novel, conserved HTLV-1 tax region. Proviral load was normalized to the amount of cellular DNA by quantitation of the human albumin gene. Firstly, the qPCR was assessed determining the specificity, sensitivity, dynamic range and intra- and inter-assay reproducibility of the technique. The limit of detection as determined by PROBIT analysis using dilutions of the standard was 2.97 copies. The assay had an excellent dynamic range from 10⁵ to 10¹ copies per reaction and good intra- and inter-assay reproducibility, CVs less than 2%. Secondly, the performance of the qPCR was tested on 40 HTLV-1 seropositive individuals. Proviral load for HTLV-1 carriers ranged from 2.2×10² to more than 8.3×10⁴ copies/10⁶ PBMCs. The high sensitivity and wide dynamic range allowed the determination of a broad range of HTLV-1 proviral loads in infected individuals. This assay is a valuable alternative diagnostic tool when current available serological assays are insufficient. In addition, it will facilitate the study of the relationship between proviral load and pathogenesis.
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Affiliation(s)
- Gonzalo M Castro
- Laboratorio de Virus Linfotrópicos Humanos-Retrovirus HIV-HTLV, Instituto de Virología, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Enfermera Gordillo s/n, Ciudad Universitaria, CP: X5000HUA Córdoba, Argentina.
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Norris PJ, Hirschkorn DF, DeVita DA, Lee TH, Murphy EL. Human T cell leukemia virus type 1 infection drives spontaneous proliferation of natural killer cells. Virulence 2011; 1:19-28. [PMID: 20640055 DOI: 10.4161/viru.1.1.9868] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Most human T cell leukemia virus type 1 (HTLV-1) infected subjects remain asymptomatic throughout their lives, with a few individuals developing HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) or adult T cell leukemia. Lymphocytes from about half of HTLV-1 infected subjects spontaneously proliferate in vitro, and how this phenomenon relates to symptomatic disease outcome and viral burden is poorly understood. Spontaneous proliferation was measured in lymphocyte subsets, and these findings were correlated with HTLV-1 proviral load and Tax expression in PBMCs. We found that in addition to previously described vigorous CD8+ T cell spontaneous proliferation, natural killer (NK) cells spontaneously proliferated to a similar high level, resulting in expansion of CD56-expressing NK cells. Spontaneous NK cell proliferation positively correlated with HTLV-1 proviral load but not with Tax expression or the presence of HAM/TSP. The strongest correlate with clinical outcome in this cohort was the ability of cells to express Tax, while HTLV-1 proviral load was more closely related to spontaneous NK cell proliferation. These results demonstrate that spontaneous proliferation, Tax expression, and proviral load are inter-related but not equivalent, and that spontaneous lymphocyte proliferation is not restricted to T cells, the targets of HTLV-1 infection.
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Affiliation(s)
- Philip J Norris
- Blood Systems Research Institute, and Department of Laboratory Medicine, University of California, San Francisco, CA, USA.
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Integrase inhibitors effective against human T-cell leukemia virus type 1. Antimicrob Agents Chemother 2011; 55:2011-7. [PMID: 21343468 DOI: 10.1128/aac.01413-10] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Drugs targeting the viral enzyme integrase have been in use for several years as part of the treatment regimen for patients with human immunodeficiency virus type 1 (HIV-1), and similar classes of compounds have been shown to inhibit human T-cell leukemia virus type 1 (HTLV-1) integration in vitro. The current study shows that the clinically approved HIV-1 integrase inhibitor, raltegravir, as well as the more recent diketo acid derivative, MK-2048, are active inhibitors of HTLV-1 infection in vitro. These agents were effective in inhibiting cell-free and cell-to-cell transmission of HTLV-1 in lymphoid and nonlymphoid cells. The drugs also inhibited HTLV-1 immortalization of human peripheral blood mononuclear cells. A novel adaptation of the Alu assay for viral integration was used to show that the drugs inhibit viral integration without affecting reverse transcription. These data support the administration of raltegravir and other integrase inhibitors as treatments for patients with HTLV-1-associated diseases.
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Shao H, Yuan CM, Xi L, Raffeld M, Morris JC, Janik JE, Stetler-Stevenson M. Minimal residual disease detection by flow cytometry in adult T-cell leukemia/lymphoma. Am J Clin Pathol 2010; 133:592-601. [PMID: 20231613 DOI: 10.1309/ajcps1k0ohljywwv] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Little information exists regarding the detection of minimal residual disease (MRD) in adult T-cell leukemia/lymphoma (ATLL). We evaluated 75 peripheral blood samples from 17 ATLL cases using flow cytometry (FC); 50 of the samples were concurrently evaluated by polymerase chain reaction (PCR) for clonal T-cell receptor gamma chain (TRG) gene rearrangement and the presence of human T-cell lymphotropic virus-1 proviral sequences. Residual ATLL cells were identified using a multiparametric approach to identify aberrant T-cell immunophenotypes. Malignant T cells were CD4+, CD3 dim+, CD26-, CD25 bright, CD7+, and CD27+, with occasional dim expression of CD2 or CD5. FC exhibited a high sensitivity, detecting as few as 0.29% ATLL cells/WBC (4.9 cells/microL) in the peripheral blood. PCR for TRG gene rearrangement was slightly more sensitive, and FC and PCR complemented each other in detecting MRD. In 2 patients, there was complete remission; 4 patients had disease refractory to therapy, and 3 died; 11 others had persistent disease with variable numbers of ATLL cells in the peripheral blood. Higher levels of ATLL cells appeared to correlate with disease severity. FC detection of aberrant T cells permits sensitive and quantitative monitoring of MRD in ATLL.
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Gudo ES, Abreu CM, Mussá T, Augusto ADR, Otsuki K, Chambo E, Amade N, Tanuri A, Ferreira OC, Jani IV. Serologic and molecular typing of human T-lymphotropic virus among blood donors in Maputo City, Mozambique. Transfusion 2009; 49:1146-50. [PMID: 19222818 DOI: 10.1111/j.1537-2995.2009.02100.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Screening for human T-lymphotropic virus-1/2 (HTLV-1/2) infection is not performed in blood banks in Mozambique. The aim was to determine the prevalence of HTLV-1/2 among blood donors of the Maputo Central Hospital Blood Bank and measure the coinfection rate of HTLV-1/2 with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and syphilis. STUDY DESIGN AND METHODS A total of 2019 consecutive blood donors were screened for HTLV-1/2 antibodies, HIV-1/2 antibodies, hepatitis B surface antigen (HBsAg), and rapid plasma reagin (RPR) for syphilis. Specimens reactive on a first HTLV-1/2 enzyme immunoassay (EIA) were retested using a second EIA. Specimens that were dually reactive on both EIAs were further tested using Western blot (WB) and real-time polymerase chain reaction (PCR). RESULTS All 18 dually reactive specimens (0.89%; 95% confidence interval, 0.48%-1.30%) were positive for the presence of HTLV-1 by WB and real-time PCR. HTLV-2 was not detected. The prevalences of anti-HIV, HBsAg, and reactivity in the RPR test were 5.72, 6.01, and 0.98 percent, respectively. There was no significant association between HTLV-1 infection and demographic variables (age and sex) or serologic markers (HIV, HBsAg, and RPR). For the 17 HTLV-1-positive donors for whom serologic data for HIV, HBsAg, and syphilis RPR were available, 2 showed coinfection with HIV and 1 with HBV. CONCLUSION Compared to other infectious agents, HTLV-1 is present at relatively low levels among blood donors in Mozambique. Cost and logistics will present as major challenges for introducing HTLV-1/2 screening in blood banks. In blood banks in Southern Africa where EIA testing is possible, a sequential algorithm of two EIAs may be a cost-efficient option for HTLV-1/2 screening.
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Affiliation(s)
- Eduardo Samo Gudo
- Departamento de Imunologia, Instituto Nacional de Saúde, Maputo, Mozambique
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Burmeister T, Schwartz S, Hummel M, Hoelzer D, Thiel E. No genetic evidence for involvement of Deltaretroviruses in adult patients with precursor and mature T-cell neoplasms. Retrovirology 2007; 4:11. [PMID: 17284327 PMCID: PMC1802090 DOI: 10.1186/1742-4690-4-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Accepted: 02/07/2007] [Indexed: 12/03/2022] Open
Abstract
Background The Deltaretrovirus genus comprises viruses that infect humans (HTLV), various simian species (STLV) and cattle (BLV). HTLV-I is the main causative agent in adult T-cell leukemia in endemic areas and some of the simian T-cell lymphotropic viruses have been implicated in the induction of malignant lymphomas in their hosts. BLV causes enzootic bovine leukosis in infected cattle or sheep. During the past few years several new Deltaretrovirus isolates have been described in various primate species. Two new HTLV-like viruses in humans have recently been identified and provisionally termed HTLV-III and HTLV-IV. In order to identify a broad spectrum of Deltaretroviruses by a single PCR approach we have established a novel consensus PCR based on nucleotide sequence data obtained from 42 complete virus isolates (HTLV-I/-II, STLV-I/-II/-III, BLV). The primer sequences were based on highly interspecies-conserved virus genome regions. We used this PCR to detect Deltaretroviruses in samples from adult patients with a variety of rare T-cell neoplasms in Germany. Results The sensitivity of the consensus PCR was at least between 10-2 and 10-3 with 100% specificity as demonstrated by serial dilutions of cell lines infected with either HTLV-I, HTLV-II or BLV. Fifty acute T-cell lymphoblastic leukemia (T-ALL) samples and 33 samples from patients with various rare mature T-cell neoplasms (T-PLL, Sézary syndrome and other T-NHL) were subsequently investigated. There were no cases with HTLV-I, HTLV-II or any other Deltaretroviruses. Conclusion The results rule out a significant involvement of HTLV-I or HTLV-II in these disease entities and show that other related Deltaretroviruses are not likely to be involved. The newly established Deltaretrovirus PCR may be a useful tool for identifying new Deltaretroviruses.
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Affiliation(s)
- Thomas Burmeister
- Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Medizinische Klinik III, Hindenburgdamm 30, 12200 Berlin, Germany
| | - Stefan Schwartz
- Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Medizinische Klinik III, Hindenburgdamm 30, 12200 Berlin, Germany
| | - Michael Hummel
- Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Institut für Pathologie, Hindenburgdamm 30, 12200 Berlin, Germany
| | - Dieter Hoelzer
- Johann Wolfgang Goethe-Universität, Medizinische Klinik III, Theodor Stern-Kai 7, 60590 Frankfurt/Main, Germany
| | - Eckhard Thiel
- Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Medizinische Klinik III, Hindenburgdamm 30, 12200 Berlin, Germany
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Adaui V, Verdonck K, Best I, González E, Tipismana M, Arévalo J, Vanham G, Campos M, Zimic M, Gotuzzo E. SYBR Green-based quantitation of human T-lymphotropic virus type 1 proviral load in Peruvian patients with neurological disease and asymptomatic carriers: influence of clinical status, sex, and familial relatedness. J Neurovirol 2007; 12:456-65. [PMID: 17162661 DOI: 10.1080/13550280601039634] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
To evaluate the human T-lymphotropic virus type 1 (HTLV-1) proviral DNA load in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-1 carriers, a SYBR Green-based real-time quantitative polymerase chain reaction (qPCR) assay was developed. HTLV-1 proviral DNA in peripheral blood mononuclear cells (PBMCs) was quantified using primers targeting the pX region and the HTLV-1 copy number normalized to the amount of ERV-3 (Endogenous Retrovirus 3) cellular DNA. Thirty-three asymptomatic HTLV-1 carriers (ACs) and 39 patients with HAM/TSP were enrolled. Some participants were relatives of HAM/TSP cases (16 ACs and 7 patients with HAM/TSP). On multiple linear regression analysis, the authors found a significant association between clinical status and HTLV-1 proviral load (P < .01), but only among women. ACs showed a median proviral load of 561 copies per 104 PBMCs (interquartile range: 251-1623). In HAM/TSP patients, the median proviral load was 1783 (1385-2914). ACs related to HAM/TSP patients presented a relatively high proviral load (median 1152); however, the association between relatedness to a HAM/TSP patient and proviral load was not significant (P = .1). In HAM/TSP patients, no association was found between proviral load and disease duration, progression or severity. The fact that the effect of HAM/TSP upon the HTLV-1 proviral load differed between sexes and the finding of a high proviral load among asymptomatic relatives of HAM/TSP patients suggest that not yet identified genetic or environmental factors influence the pathogenesis of HTLV-1 infection.
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Affiliation(s)
- Vanessa Adaui
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
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Nair AM, Michael B, Datta A, Fernandez S, Lairmore MD. Calcium-dependent enhancement of transcription of p300 by human T-lymphotropic type 1 p12I. Virology 2006; 353:247-57. [PMID: 16843515 PMCID: PMC3044894 DOI: 10.1016/j.virol.2006.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 02/10/2006] [Accepted: 06/06/2006] [Indexed: 10/24/2022]
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) p12I localizes to the endoplasmic reticulum and Golgi causing sustained release of calcium, T cell activation, and enhanced expression of several calcium-regulated genes. In recent microarray studies, p300 mRNA was increased in T cells expressing p12I. The co-activator p300 is a key regulator of cellular and viral transcription; however, factors that influence its transcriptional regulation are less well studied. We hypothesized that the transcription of p300 is calcium dependent and that sustained low magnitude increases in intracellular calcium may enhance the transcription of p300. Herein, we report enhanced expression of p300 in T cells by p12I in a calcium-dependent, but calcineurin-independent manner. Sustained low magnitude calcium release induced by ionomycin in T cells was sufficient to increased mRNA and protein levels of p300 resulting in enhanced transcription from a p300-dependent promoter. Promoter analysis of the p300 gene was used to predict calcium-responsive transcription factor binding sites. Using mutant forms of p12I, we demonstrate that ER localization of the viral protein is required to increase p300. In addition, p12I reversed the repression of HTLV-1 LTR-driven transcription by HTLV-1 p30II, a p300-binding protein. HTLV-1 p12I-mediated enhancement of p300 expression represents a novel mechanism of regulation of cellular gene expression by viral proteins. By targeting a ubiquitous second messenger such as calcium, HTLV-1 p12I may regulate the expression of the cellular transcriptional co-activator p300 to modulate viral gene expression and promote lymphocyte survival.
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Affiliation(s)
- Amrithraj M. Nair
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Bindhu Michael
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Antara Datta
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Soledad Fernandez
- The Center for Statistics, College of Mathematical and Physical Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Michael D. Lairmore
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Graduate Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University, Columbus, OH 43210, USA
- Comprehensive Cancer Center, The Arthur G. James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Corresponding author. Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA. Fax: +1 614 292 6473, (M.D. Lairmore)
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Vitone F, Gibellini D, Schiavone P, D'Antuono A, Gianni L, Bon I, Re MC. Human T-lymphotropic virus type 1 (HTLV-1) prevalence and quantitative detection of DNA proviral load in individuals with indeterminate/positive serological results. BMC Infect Dis 2006; 6:41. [PMID: 16512894 PMCID: PMC1450284 DOI: 10.1186/1471-2334-6-41] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Accepted: 03/02/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HTLV-1 infection is currently restricted to endemic areas. To define the prevalence of HTLV-1 infection in patients living in Italy, we first carried out a retrospective serological analysis in a group of people originating from African countries referred to our hospital from January 2003 to February 2005. We subsequently applied a real time PCR on peripheral blood mononuclear cells from subjects with positive or indeterminate serological results. METHODS All the sera were first analysed by serological methods (ELISA and/or Western Blotting) and then the peripheral blood mononuclear cells from subjects with positive or inconclusive serological results were analyzed for the presence of proviral DNA by a sensitive SYBR Green real time PCR. In addition, twenty HTLV-I ELISA negative samples were assayed by real time PCR approach as negative controls. RESULTS Serological results disclosed serum reactivity by ELISA (absorbance values equal or greater than the cut-off value) in 9 out of 3408 individuals attending the Sexually Transmitted Diseases Clinic and/or Oncology Department, and 2 out 534 blood donors enrolled as a control population. Irrespective of positive or inconclusive serological results, all these subjects were analyzed for the presence of proviral DNA in peripheral blood mononuclear cells by SYBR real time PCR. A clear-cut positive result for the presence of HTLV-1 DNA was obtained in two subjects from endemic areas. CONCLUSION SYBR real time PCR cut short inconclusive serological results. This rapid and inexpensive assay showed an excellent linear dynamic range, specificity and reproducibility readily revealing and quantifying the presence of virus in PBMCs. Our results highlight the need to monitor the presence of HTLV-1 in countries which have seen a large influx of immigrants in recent years. Epidemiological surveillance and correct diagnosis are recommended to verify the prevalence and incidence of a new undesirable phenomenon.
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Affiliation(s)
- Francesca Vitone
- Section of Microbiology, Department of Clinical and Experimental Medicine, University of Bologna, 40138 Bologna, Italy
| | - Davide Gibellini
- Section of Microbiology, Department of Clinical and Experimental Medicine, University of Bologna, 40138 Bologna, Italy
| | - Pasqua Schiavone
- Section of Microbiology, Department of Clinical and Experimental Medicine, University of Bologna, 40138 Bologna, Italy
| | - Antonietta D'Antuono
- Dermatology, Department of Clinical and Experimental Medicine, University of Bologna, 40138 Bologna, Italy
| | - Lorenzo Gianni
- Oncology Division, Ospedale Infermi, 47900 Rimini, Italy
| | - Isabella Bon
- Section of Microbiology, Department of Clinical and Experimental Medicine, University of Bologna, 40138 Bologna, Italy
| | - Maria Carla Re
- Section of Microbiology, Department of Clinical and Experimental Medicine, University of Bologna, 40138 Bologna, Italy
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Nair A, Michael B, Hiraragi H, Fernandez S, Feuer G, Boris-Lawrie K, Lairmore M. Human T lymphotropic virus type 1 accessory protein p12I modulates calcium-mediated cellular gene expression and enhances p300 expression in T lymphocytes. AIDS Res Hum Retroviruses 2005; 21:273-84. [PMID: 15943569 PMCID: PMC2668121 DOI: 10.1089/aid.2005.21.273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia/lymphoma (ATLL), an aggressive CD4+ T lymphocyte malignancy. Activation of T lymphocytes is required for effective retroviral integration into the host cell genome and subsequent viral replication, but the molecular mechanisms involved in HTLV-1-mediated T cell activation remain unclear. HTLV-1 encodes various accessory proteins such as p12I, which has been demonstrated to be critical for HTLV-1 infectivity in vivo in rabbits and in vitro in quiescent primary human T lymphocytes. This hydrophobic protein localizes in the endoplasmic reticulum, increases intracellular calcium, and activates nuclear factor of activated T cell-mediated transcription. To further elucidate the role of p12I in regulation of cellular gene expression, we performed gene array analysis on stable p12I-expressing Jurkat T cells, using Affymetrix U133A arrays. Our data indicate that p12I altered the expression of genes associated with a network of interrelated pathways including T cell signaling, cell proliferation, and apoptosis. Expression of several calcium-regulated genes was found to be altered by p12I, consistent with known properties of the viral protein. Gene array findings were confirmed by semiquantitative RT-PCR in Jurkat T cells and primary CD4+ T lymphocytes. Furthermore, dose-dependent expression of p12I in Jurkat T cells resulted in significant increases in p300 and p300-dependent transcription. This is the first report of a viral protein influencing the transcription of p300, a rate-limiting coadapter critical in HTLV-1-mediated T cell activation. Collectively, our data strongly indicate that HTLV-1 p12I modulates cellular gene expression patterns to hasten the activation of T lymphocytes and thereby promote efficient viral infection.
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Affiliation(s)
- Amrithraj Nair
- Center for Retrovirus Research and Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210, USA
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Lee TH, Chafets DM, Busch MP, Murphy EL. Quantitation of HTLV-I and II proviral load using real-time quantitative PCR with SYBR Green chemistry. J Clin Virol 2005; 31:275-82. [PMID: 15494269 DOI: 10.1016/j.jcv.2004.05.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/27/2004] [Accepted: 05/28/2004] [Indexed: 10/26/2022]
Abstract
BACKGROUND Human T-lymphotropic virus type I (HTLV-I) is linked etiologically with adult T cell leukemia/lymphoma and HTLV-I-associated myelopathy/tropical spastic paraparsis (HAM/TSP). Human T-lymphotropic virus type II (HTLV-II) is associated with HAM/TSP and, in HIV coinfected patients only, rare cases of cutaneous T cell lymphoma. Proviral load may be important in the pathogenesis of HTLV-associated disease. MATERIALS AND METHODS A real time quantitative PCR assay using SYBR Green intercalation was established. Primers targeting the tax region were standardized against MT2 and MOT cell line DNA for HTLV-I and HTLV-II, respectively. HTLV-I/II copy number was normalized to the amount of cellular DNA by quantitation of the HLA-DQ alpha gene. We measured proviral load in peripheral blood mononuclear cells (PBMCs) in a large cohort of 120 HTLV-I and 335 HTLV-II seropositive former blood donors. We also assessed the intra- and inter-assay reproducibility of the assay. RESULTS Proviral load for HTLV-I infected patients ranged from 3.1 x 10(0) to 1.8 x 10(5)copies/10(6) PBMCs with a mean of 1.6 x 10(4) and a median of 3.0 x 10(3). HTLV-I was undetectable in 7 of 120 cases (5.8%). Proviral load for HTLV-II infected patients ranged from 1.1 x 10(0) to 1.0 x 10(6)copies/10(6) PBMCs with a mean of 2.8 x 10(4) and a median of 5.0 x 10(2). HTLV-II was undetectable in 31 out of 335 cases (9.3%). CONCLUSION The assay has excellent dynamic range from 10(6) to 10(0)copies/reaction, good intra- and inter-assay reproducibility, and a lower limit of detection of a single copy per reaction. The sensitivity and high dynamic range allow determination of a broad range of HTLV-I/II proviral load in clinical subjects. This assay will facilitate the study of the relationship between proviral load and pathogenesis.
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Affiliation(s)
- Tzong-Hae Lee
- Blood Systems Research Institute, San Francisco, CA 94118, USA
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13
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Anderson MD, Ye J, Xie L, Green PL. Transformation studies with a human T-cell leukemia virus type 1 molecular clone. J Virol Methods 2004; 116:195-202. [PMID: 14738988 DOI: 10.1016/j.jviromet.2003.11.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In in vitro studies human T-cell leukemia virus type 1 (HTLV-1) may be produced by stable or transient transfection of target cells with an infectious molecular clone. Studies using primary human T cells, the natural targets of HTLV-1 infection, are hampered by difficulty in achieving significant infection with cell-free virus and a poor efficiency of transfection of primary cells. A method is described for the generation of stable cell lines expressing HTLV-1 from an infectious proviral clone. The stably transfected cells can be irradiated and cocultured with human peripheral blood mononuclear cells (PBMC) resulting in infected primary cells. These cells become immortalized, IL-2 dependent lines, which contain integrated copies of provirus and express a full spectrum of viral proteins. Analysis of cellular markers indicates that immortalized cell lines consist of CD3+/CD4+ T cells, matching the most common adult T-cell leukemia (ATL) cell phenotype. The method described has great utility in the study of the replication and transformation capacity of HTLV and HTLV mutant viruses in their natural targets, primary human T lymphocytes.
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Affiliation(s)
- Matthew D Anderson
- Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA
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14
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Silverman LR, Phipps AJ, Montgomery A, Ratner L, Lairmore MD. Human T-cell lymphotropic virus type 1 open reading frame II-encoded p30II is required for in vivo replication: evidence of in vivo reversion. J Virol 2004; 78:3837-45. [PMID: 15047799 PMCID: PMC374265 DOI: 10.1128/jvi.78.8.3837-3845.2004] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma and exhibits high genetic stability in vivo. HTLV-1 contains four open reading frames (ORFs) in its pX region. ORF II encodes two proteins, p30(II) and p13(II), both of which are incompletely characterized. p30(II) localizes to the nucleus or nucleolus and has distant homology to the transcription factors Oct-1, Pit-1, and POU-M1. In vitro studies have demonstrated that at low concentrations, p30(II) differentially regulates cellular and viral promoters through an interaction with CREB binding protein/p300. To determine the in vivo significance of p30(II), we inoculated rabbits with cell lines expressing either a wild-type clone of HTLV-1 (ACH.1) or a clone containing a mutation in ORF II, which eliminated wild-type p30(II) expression (ACH.30.1). ACH.1-inoculated rabbits maintained higher HTLV-1-specific antibody titers than ACH.30.1-inoculated rabbits, and all ACH.1-inoculated rabbits were seropositive for HTLV-1, whereas only two of six ACH.30.1-inoculated rabbits were seropositive. Provirus could be consistently PCR amplified from peripheral blood mononuclear cell (PBMC) DNA in all ACH.1-inoculated rabbits but in only three of six ACH.30.1-inoculated rabbits. Quantitative competitive PCR indicated higher PBMC proviral loads in ACH.1-inoculated rabbits. Interestingly, sequencing of ORF II from PBMC of provirus-positive ACH.30.1-inoculated rabbits revealed a reversion to wild-type sequence with evidence of early coexistence of mutant and wild-type sequence. Our data provide evidence that HTLV-1 must maintain its key accessory genes to survive in vivo and that in vivo pressures select for maintenance of wild-type ORF II gene products during the early course of infection.
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Affiliation(s)
- Lee R Silverman
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA
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15
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Gabet AS, Gessain A, Wattel E. High simian T-cell leukemia virus type 1 proviral loads combined with genetic stability as a result of cell-associated provirus replication in naturally infected, asymptomatic monkeys. Int J Cancer 2003; 107:74-83. [PMID: 12925959 DOI: 10.1002/ijc.11329] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Simian T-cell leukemia virus type 1 (STLV-1) is a primate T cell leukemia virus of the group of oncogenic delta retroviruses. Sharing a high level of genetic homology with human T cell leukemia virus type 1 (HTLV-1), it is etiologically linked to the development of simian T cell malignancies that closely resemble HTLV-1 associated leukemias and lymphomas and might thus constitute an interesting model of study. The precise nature of STLV-1 replication in vivo remains unknown. The STLV-1 circulating proviral load of 14 naturally infected Celebes macaques (Macaca tonkeana) was measured by real-time quantitative PCR. The mean proportion of infected peripheral mononuclear cells was 7.9%, ranging from <0.4% to 38.9%. Values and distributions were closely reminiscent of those observed in symptomatic and asymptomatic HTLV-1 infected humans. Sequencing more than 32 kb of LTRs deriving from 2 animals with high proviral load showed an extremely low STLV-1 genetic variability (0.113%). This paradoxical combination of elevated proviral load and remarkable genetic stability was finally explained by the demonstration of a cell-associated dissemination of the virus in vivo. Inverse PCR (IPCR) amplification of STLV-1 integration sites evidenced clones of infected cells in all infected animals. The pattern of STLV-1 replication in these asymptomatic monkeys was indistinguishable from that of HTLV-1 in asymptomatic carriers or in patients with inflammatory diseases. We conclude that, as HTLV-1, STLV-1 mainly replicates by the clonal expansion of infected cells; accordingly, STLV-1 natural monkey infection constitutes an appropriate and promising model for the study of HTLV-1 associated leukemogenesis in vivo.
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16
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Mortreux F, Gabet AS, Wattel E. Molecular and cellular aspects of HTLV-1 associated leukemogenesis in vivo. Leukemia 2003; 17:26-38. [PMID: 12529656 DOI: 10.1038/sj.leu.2402777] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2002] [Accepted: 07/31/2002] [Indexed: 11/09/2022]
Abstract
Most cancers and leukemias are preceded by a prolonged period of clinical latency during which cellular, chromosomal and molecular aberrations help move normal cell towards the malignant phenotype. The problem is that premalignant cells are usually indistinguishable from their normal counterparts, thereby ruling out the possibility to investigate the events that govern early leukemogenesis in vivo. Adult T cell leukemia/lymphoma (ATLL) is a T cell malignancy that occurs after a 40-60-year period of clinical latency in about 3-5% of HTLV-1-infected individuals. ATLL cells are monoclonally expanded and harbor an integrated provirus. A persistent oligo/polyclonal expansion of HTLV-1-bearing cells has been shown to precede ATLL, supporting the fact that in ATLL tumor cells arise from a clonally expanding non-malignant cell. It is possible to isolate infected, ie preleukemic, cells during the premalignant asymptomatic phase of the infection, thus providing an exceptional system to study the mechanisms underlying human cancers. Here we review some of the consequences of HTLV-1 on its host cell in vivo, at different stages of infection.
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Affiliation(s)
- F Mortreux
- Unité d'Oncogenèse Virale, UMR5537 CNRS-Université Claude Bernard, Centre Léon Bérard, Lyon, France
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17
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Albrecht B, Lairmore MD. Critical role of human T-lymphotropic virus type 1 accessory proteins in viral replication and pathogenesis. Microbiol Mol Biol Rev 2002; 66:396-406, table of contents. [PMID: 12208996 PMCID: PMC120794 DOI: 10.1128/mmbr.66.3.396-406.2002] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) infection is associated with a diverse range of lymphoproliferative and neurodegenerative diseases, yet pathogenic mechanisms induced by the virus remain obscure. This complex retrovirus contains typical structural and enzymatic genes but also unique regulatory and accessory genes in four open reading frames (ORFs) of the pX region of the viral genome (pX ORFs I to IV). The regulatory proteins encoded by pX ORFs III and IV, Tax and Rex, respectively, have been extensively characterized. In contrast the contribution of the four accessory proteins p12(I), p27(I), p13(II), and p30(II), encoded by pX ORFs I and II, to viral replication and pathogenesis remained unclear. Proviral clones that are mutated in either pX ORF I or II, while fully competent in cell culture, are severely limited in their replicative capacity in a rabbit model. Emerging evidence indicates that the HTLV-1 accessory proteins are critical for establishment of viral infectivity, enhance T-lymphocyte activation, and potentially alter gene transcription and mitochondrial function. HTLV-1 pX ORF I expression is critical to the viral infectivity in resting primary lymphocytes, suggesting a role for p12(I) in lymphocyte activation. The endoplasmic reticulum and cis-Golgi localizing p12(I), encoded from pX ORF I, activates NFAT, a key T-cell transcription factor, through calcium-mediated signaling pathways and may lower the threshold of lymphocyte activation via the JAK/STAT pathway. In contrast p30(II) localizes to the nucleus and represses viral promoter activity, but may regulate cellular gene expression through p300/CBP or related coactivators of transcription. p13(II) targets mitochondrial proteins, where it alters the organelle morphology and may influence energy metabolism. Collectively, studies of the molecular functions of the HTLV-1 accessory proteins provide insight into strategies used by retroviruses that are associated with lymphoproliferative diseases.
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Affiliation(s)
- Björn Albrecht
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA
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18
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Dehée A, Césaire R, Désiré N, Lézin A, Bourdonné O, Béra O, Plumelle Y, Smadja D, Nicolas JC. Quantitation of HTLV-I proviral load by a TaqMan real-time PCR assay. J Virol Methods 2002; 102:37-51. [PMID: 11879691 DOI: 10.1016/s0166-0934(01)00445-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A quantitative real-time PCR assay was developed to measure the proviral load of human T-lymphotropic virus type I (HTLV-I) in peripheral blood mononuclear cells (PBMCs). The HTLV-I copy number was referred to the actual amount of cellular DNA by means of the quantitation of the albumin gene. Ten copies of HTLV-I DNA could be detected with 100% sensitivity, and the assay had a wide range of at least 5 log(10). Intra- and inter-assay reproducibility was evaluated using independent extractions of PBMCs from an HTLV-I-infected patient (coefficients of variation, 24 and 7% respectively). The performance of this TaqMan PCR assay, coupled with its high throughput, thus allows reliable routine follow-up of HTLV-I proviral load in infected patients. Preliminary results using clinical samples indicate a higher proviral load in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis than in asymptomatic carriers, and also suggest the usefulness of this quantitative measurement to assess the etiological link between HTLV-I and adult T-cell leukaemia/lymphoma-like syndromes.
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Affiliation(s)
- Axelle Dehée
- Laboratoire de Microbiologie, Hôpital Rothschild, Paris, France
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19
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Grant C, Barmak K, Alefantis T, Yao J, Jacobson S, Wigdahl B. Human T cell leukemia virus type I and neurologic disease: events in bone marrow, peripheral blood, and central nervous system during normal immune surveillance and neuroinflammation. J Cell Physiol 2002; 190:133-59. [PMID: 11807819 DOI: 10.1002/jcp.10053] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Human T cell lymphotropic/leukemia virus type I (HTLV-I) has been identified as the causative agent of both adult T cell leukemia (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the exact sequence of events that occur during the early stages of infection are not known in detail, the initial route of infection may predetermine, along with host, environmental, and viral factors, the subset of target cells and/or the primary immune response encountered by HTLV-I, and whether an HTLV-I-infected individual will remain asymptomatic, develop ATL, or progress to the neuroinflammatory disease, HAM/TSP. Although a large number of studies have indicated that CD4(+) T cells represent an important target for HTLV-I infection in the peripheral blood (PB), additional evidence has accumulated over the past several years demonstrating that HTLV-I can infect several additional cellular compartments in vivo, including CD8(+) T lymphocytes, PB monocytes, dendritic cells, B lymphocytes, and resident central nervous system (CNS) astrocytes. More importantly, extensive latent viral infection of the bone marrow, including cells likely to be hematopoietic progenitor cells, has been observed in individuals with HAM/TSP as well as some asymptomatic carriers, but to a much lesser extent in individuals with ATL. Furthermore, HTLV-I(+) CD34(+) hematopoietic progenitor cells can maintain the intact proviral genome and initiate viral gene expression during the differentiation process. Introduction of HTLV-I-infected bone marrow progenitor cells into the PB, followed by genomic activation and low level viral gene expression may lead to an increase in proviral DNA load in the PB, resulting in a progressive state of immune dysregulation including the generation of a detrimental cytotoxic Tax-specific CD8(+) T cell population, anti-HTLV-I antibodies, and neurotoxic cytokines involved in disruption of myelin-producing cells and neuronal degradation characteristic of HAM/TSP.
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Affiliation(s)
- Christian Grant
- Laboratory for Molecular Retrovirology and Viral Neuropathogenesis, Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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20
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Yamano Y, Nagai M, Brennan M, Mora CA, Soldan SS, Tomaru U, Takenouchi N, Izumo S, Osame M, Jacobson S. Correlation of human T-cell lymphotropic virus type 1 (HTLV-1) mRNA with proviral DNA load, virus-specific CD8(+) T cells, and disease severity in HTLV-1-associated myelopathy (HAM/TSP). Blood 2002; 99:88-94. [PMID: 11756157 DOI: 10.1182/blood.v99.1.88] [Citation(s) in RCA: 199] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
To investigate the role of viral expression in individuals infected with human T-cell lymphotropic virus type 1 (HTLV-1), a real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) of HTLV-1 tax messenger RNA (mRNA) using ABI Prism 7700 Sequence Detection System was developed. Using this system, the HTLV-1 tax mRNA load was compared with HTLV-1 proviral DNA load, HTLV-1 Tax protein expression, HTLV-1 Tax-specific CD8(+) T-cell frequency, and disease severity of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). This approach was a sensitive and specific technique for the precise quantification of HTLV-1 tax mRNA. The total amount of HTLV-1 tax mRNA and mRNA expression level in HTLV-1-infected cells (mRNA/DNA ratio) were higher in HAM/TSP patients than in asymptomatic HTLV-1 carriers. The HTLV-1 tax mRNA load correlated with the HTLV-1 proviral DNA load ex vivo, the Tax protein expression in vitro, and the Tax-specific CD8(+) T-cell frequency ex vivo. The HTLV-1 tax mRNA load also correlated with disease severity in HAM/TSP patients. These data suggest that increased HTLV-1 expression plays an important role in the pathogenesis of HAM/TSP, and the HTLV-1 tax mRNA level could be a useful predictor of disease progression in patients with HAM/TSP.
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Affiliation(s)
- Yoshihisa Yamano
- Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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21
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D'Agostino DM, Zotti L, Ferro T, Cavallori I, Silic-Benussi M, Chieco-Bianchi L, Ciminale V. Expression and functional properties of proteins encoded in the x-II ORF of HTLV-I. Virus Res 2001; 78:35-43. [PMID: 11520578 DOI: 10.1016/s0168-1702(01)00282-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the aim of identifying viral proteins that contribute to the distinctive properties of HTLV-I biology and pathogenicity, several laboratories have investigated the coding potential of the X region of the genome, which includes five partially overlapping open reading frames (ORFs). We and others have shown that, in addition to the essential regulatory proteins Rex and Tax, a number of accessory proteins encoded in the X region can be produced by alternative splicing and multicistronic translation. One X region ORF, termed X-II, produces two protein isoforms named Tof/p30II and p13II, which are expressed from a doubly- and singly-spliced mRNA, respectively. Initial functional analyses demonstrated that Tof/p30II is a nucleolar/nuclear protein that possesses a region capable of binding to RNA, and p13II is a mitochondrial protein that alters the morphology and function of this organelle. Together with data from other laboratories demonstrating the production of antibodies and CTL against x-II ORF products in HTLV-I infected subjects and the requirement of this ORF for efficient viral replication in vivo, these findings suggest that further characterization of Tof/p30II and p13II will yield insight into remaining undefined aspects of HTLV-I pathogenicity and replication.
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Affiliation(s)
- D M D'Agostino
- Department of Oncology and Surgical Sciences, University of Padva, Via Gattamelata 64, 35128, Padua, Italy
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22
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Richard V, Lairmore MD, Green PL, Feuer G, Erbe RS, Albrecht B, D'Souza C, Keller ET, Dai J, Rosol TJ. Humoral hypercalcemia of malignancy: severe combined immunodeficient/beige mouse model of adult T-cell lymphoma independent of human T-cell lymphotropic virus type-1 tax expression. THE AMERICAN JOURNAL OF PATHOLOGY 2001; 158:2219-28. [PMID: 11395400 PMCID: PMC1891995 DOI: 10.1016/s0002-9440(10)64694-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The majority of patients with adult T-cell leukemia/lymphoma (ATL) resulting from human T-cell lymphotropic virus type-1 (HTLV-1) infection develop humoral hypercalcemia of malignancy (HHM). We used an animal model using severe combined immunodeficient (SCID)/beige mice to study the pathogenesis of HHM. SCID/beige mice were inoculated intraperitoneally with a human ATL line (RV-ATL) and were euthanized 20 to 32 days after inoculation. SCID/beige mice with engrafted RV-ATL cells developed lymphoma in the mesentery, liver, thymus, lungs, and spleen. The lymphomas stained positively for human CD45RO surface receptor and normal mouse lymphocytes stained negatively confirming the human origin of the tumors. The ATL cells were immunohistochemically positive for parathyroid hormone-related protein (PTHrP). In addition, PTHrP mRNA was highly expressed in lymphomas when compared to MT-2 cells (HTLV-1-positive cell line). Mice with lymphoma developed severe hypercalcemia. Plasma PTHrP concentrations were markedly increased in mice with hypercalcemia, and correlated with the increase in plasma calcium concentrations. Bone densitometry and histomorphometry in lymphoma-bearing mice revealed significant bone loss because of a marked increase in osteoclastic bone resorption. RV-ATL cells contained 1.5 HTLV-1 proviral copies of the tax gene as determined by quantitative real-time polymerase chain reaction (PCR). However, tax expression was not detected by Western blot or reverse transcriptase (RT)-PCR in RV-ATL cells, which suggests that factors other than Tax are modulators of PTHrP gene expression. The SCID/beige mouse model mimics HHM as it occurs in ATL patients, and will be useful to investigate the regulation of PTHrP expression by ATL cells in vivo.
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MESH Headings
- Animals
- Bone Density
- Calcium/blood
- Cell Division
- Disease Models, Animal
- Gene Products, tax/biosynthesis
- Gene Products, tax/genetics
- Human T-lymphotropic virus 1/genetics
- Humans
- Hypercalcemia/etiology
- Hypercalcemia/genetics
- Hypercalcemia/metabolism
- Immunophenotyping
- Leukemia-Lymphoma, Adult T-Cell/complications
- Leukemia-Lymphoma, Adult T-Cell/pathology
- Leukemia-Lymphoma, Adult T-Cell/virology
- Mice
- Mice, SCID
- Neoplasm Proteins/blood
- Neoplasm Transplantation
- Parathyroid Hormone-Related Protein
- Protein Biosynthesis
- Proteins/genetics
- Proviruses/genetics
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Transplantation, Heterologous
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Affiliation(s)
- V Richard
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43212, USA
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23
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Mortreux F, Kazanji M, Gabet AS, de Thoisy B, Wattel E. Two-step nature of human T-cell leukemia virus type 1 replication in experimentally infected squirrel monkeys (Saimiri sciureus). J Virol 2001; 75:1083-9. [PMID: 11134325 PMCID: PMC114008 DOI: 10.1128/jvi.75.2.1083-1089.2001] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2000] [Accepted: 10/25/2000] [Indexed: 11/20/2022] Open
Abstract
After experimental infection of squirrel monkeys (Saimiri sciureus) with human T-cell leukemia virus type 1 (HTLV-1)-infected cells, the virus is transcribed only transiently in circulating blood, spleen, and lymph nodes. Stable disappearance of viral expression occurs at 2 to 3 weeks after inoculation. This coincides with the development of the anti-HTLV-1 immune response and persistent detection of the provirus in peripheral blood mononuclear cells (PBMCs). In this study, the HTLV-1 replication pattern was analyzed over time in PBMCs and various organs from two HTLV-1-infected squirrel monkeys. Real-time quantitative PCR confirmed that PBMCs and lymphoid organs constitute the major reservoirs for HTLV-1. The PCR amplification of HTLV-1 flanking sequences from PBMCs evidenced a pattern of clonal expansion of infected cells identical to that observed in humans. Dissemination of the virus in body compartments appeared to result from cellular transport of the integrated provirus. The circulating proviral burden increased as a function of time in one animal studied over a period of 4 years. The high proviral loads observed in the last samples resulted from the accumulation of infected cells via the extensive proliferation of a restricted number of persistent clones on a background of polyclonally expanded HTLV-1-positive cells. Therefore, HTLV-1 primary infection in squirrel monkeys is a two-step process involving a transient phase of reverse transcription followed by persistent multiplication of infected cells. This suggests that the choice of the target for blocking HTLV-1 replication might depend on the stage of infection.
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Affiliation(s)
- F Mortreux
- Unité 524 INSERM, Institut de Recherche sur le Cancer de Lille, Lille, France
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24
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Albrecht B, Collins ND, Burniston MT, Nisbet JW, Ratner L, Green PL, Lairmore MD. Human T-lymphotropic virus type 1 open reading frame I p12(I) is required for efficient viral infectivity in primary lymphocytes. J Virol 2000; 74:9828-35. [PMID: 11024109 PMCID: PMC102019 DOI: 10.1128/jvi.74.21.9828-9835.2000] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) is a complex retrovirus encoding regulatory and accessory genes in four open reading frames (ORF I to IV) of the pX region. Emerging evidence indicates an important role for the pX ORF I-encoded accessory protein p12(I) in viral replication, but its contribution to viral pathogenesis remains to be defined. p12(I) is a conserved, membrane-associated protein containing four SH3-binding motifs (PXXP). Its interaction with the interleukin-2 (IL-2) receptor beta- and gamma-chains implies an involvement of p12(I) in intracellular signaling pathways. In addition, we have demonstrated that expression of pX ORF I p12(I) is essential for persistent infection in rabbits. In contrast, standard in vitro systems have thus far failed to demonstrate a contribution of p12(I) to viral infectivity and ultimately cellular transformation. In this study we developed multiple in vitro coculture assays to evaluate the role of p12(I) in viral infectivity in quiescent peripheral blood mononuclear cells to more accurately reflect the virus-cell interactions as they occur in vivo. Using these assays, we demonstrate a dramatic reduction in viral infectivity in quiescent T lymphocytes for a p12 mutant viral clone (ACH.p12) in comparison to the wild-type clone ACH. Moreover, addition of IL-2 and phytohemagglutinin during the infection completely rescued the ability of ACH.p12 to infect primary lymphocytes. When newly infected primary lymphocytes are used to passage virus, ACH.p12 also exhibited a reduced ability to productively infect activated lymphocytes. Our data are the first to demonstrate a functional role for pX ORF I in the infection of primary lymphocytes and suggest a role for p12(I) in activation of host cells during early stages of infection.
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Affiliation(s)
- B Albrecht
- Center for Retrovirus Research and Department of Veterinary Biosciences, Immunology and Medical Genetics, The Ohio State University, Columbus, Ohio 43210, USA
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25
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D'Agostino DM, Zotti L, Ferro T, Franchini G, Chieco-Bianchi L, Ciminale V. The p13II protein of HTLV type 1: comparison with mitochondrial proteins coded by other human viruses. AIDS Res Hum Retroviruses 2000; 16:1765-70. [PMID: 11080824 DOI: 10.1089/08892220050193281] [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: 12/18/2022] Open
Abstract
In addition to the essential regulatory proteins Rex and Tax, the HTLV-1 genome encodes several accessory proteins of yet undefined function. One of these "orphan" proteins, named p13(II), was recently shown to be selectively targeted to mitochondria and to induce specific changes in mitochondrial morphology suggestive of altered inner membrane permeability and swelling. This represented the first report of a retroviral gene product targeted to mitochondria, and suggested that p13(II)-induced alterations in the function of this organelle may play a role in HTLV-1 replication and/or pathogenesis. The more recent findings that both Vpr and Tat of HIV-1 are targeted to mitochondria reinforces the proposed relevance of mitochondrial metabolism to the life cycle of retroviruses. Thus, p13(II), Vpr, and Tat can be added to the growing list of mitochondrial proteins produced by clinically important human viruses, including Epstein-Barr virus, human cytomegalovirus, and hepatitis B virus. Mitochondria are known to play a critical role by providing an amplification loop required for the execution of signaling pathways leading to programmed cell death. The functional consequences of the interactions between viral proteins and mitochondria described so far have been attributed to either the positive or negative control of apoptotic responses mediated by this organelle. Further analysis of the effects of p13(II) on mitochondrial function is likely to add to our understanding of the mechanisms underlying the development of HTLV-1-associated diseases.
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Affiliation(s)
- D M D'Agostino
- Department of Oncology and Surgical Sciences, University of Padova, I-35128 Padua, Italy
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Bartoe JT, Albrecht B, Collins ND, Robek MD, Ratner L, Green PL, Lairmore MD. Functional role of pX open reading frame II of human T-lymphotropic virus type 1 in maintenance of viral loads in vivo. J Virol 2000; 74:1094-100. [PMID: 10627519 PMCID: PMC111443 DOI: 10.1128/jvi.74.3.1094-1100.2000] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma and is associated with a variety of immune-mediated disorders. The role of four open reading frames (ORFs), located between env and the 3' long terminal repeat of HTLV-1, in mediating disease is not entirely clear. By differential splicing, ORF II encodes two proteins, p13(II) and p30(II), both of which have not been functionally defined. p13(II) localizes to mitochondria and may alter the configuration of the tubular network of this cellular organelle. p30(II) localizes to the nucleolus and shares homology with the transcription factors Oct-1 and -2, Pit-1, and POU-M1. Both p13(II) and p30(II) are dispensable for infection and immortalization of primary human and rabbit lymphocytes in vitro. To test the role of ORF II gene products in vivo, we inoculated rabbits with lethally irradiated cell lines expressing the wild-type molecular clone of HTLV-1 (ACH.1) or a clone containing selected mutations in ORF II (ACH.30/13.1). ACH.1-inoculated animals maintained higher HTLV-1-specific antibody titers than animals inoculated with ACH.30/13.1. Viral p19 antigen was transiently detected in ex vivo cultures of peripheral blood mononuclear cells (PBMC) from only two ACH.30/13.1-inoculated rabbits, while PBMC cultures from all ACH.1-inoculated rabbits routinely produced p19 antigen. In only three of six animals exposed to the ACH. p30(II)/p13(II) clone could provirus be consistently PCR amplified from extracted PBMC DNA and quantitative competitive PCR showed the proviral loads in PBMC from ACH.p30(II)/p13(II)-infected rabbits to be dramatically lower than the proviral loads in rabbits exposed to ACH. Our data indicate selected mutations in pX ORF II diminish the ability of HTLV-1 to maintain high viral loads in vivo and suggest an important function for p13(II) and p30(II) in viral pathogenesis.
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Affiliation(s)
- J T Bartoe
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210-1093, USA
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