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Retrovirology Aug 2019Human T cell leukemia virus type 1 (HTLV-1) was the first discovered human retrovirus and the etiologic agent of adult T-cell leukemia and HTLV-1-associated... (Comparative Study)
Comparative Study Review
Human T cell leukemia virus type 1 (HTLV-1) was the first discovered human retrovirus and the etiologic agent of adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. Shortly after the discovery of HTLV-1, human T-cell leukemia virus type 2 (HTLV-2) was isolated from a patient with hairy cell leukemia. Despite possession of similar structural features to HTLV-1, HTLV-2 has not been definitively associated with lymphoproliferative disease. Since their discovery, studies have been performed with the goal of highlighting the differences between HTLV-1 and HTLV-2. A better understanding of these differences will shed light on the specific pathogenic mechanisms of HTLV-1 and lead to novel therapeutic targets. This review will compare and contrast the two oldest human retroviruses with regards to epidemiology, genomic structure, gene products, and pathobiology.
Topics: HTLV-I Infections; HTLV-II Infections; Human T-lymphotropic virus 1; Human T-lymphotropic virus 2; Humans; Leukemia-Lymphoma, Adult T-Cell; Leukocytes, Mononuclear; Paraparesis, Tropical Spastic
PubMed: 31391116
DOI: 10.1186/s12977-019-0483-0 -
Practical Neurology Feb 2022A 53-year-old woman developed subacute onset of upper limb weakness, sensory loss and cerebellar dysfunction. She was known to have human T-lymphotropic virus type 1... (Review)
Review
A 53-year-old woman developed subacute onset of upper limb weakness, sensory loss and cerebellar dysfunction. She was known to have human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy. MR scan of the brain showed extensive T2 hyperintensity within the deep and subcortical white matter, with punctate contrast enhancement. Cerebrospinal fluid (CSF) was lymphocytic with very high levels of HTLV-1 provirus in both CSF and peripheral blood lymphocytes. We diagnosed HTLV-1 encephalomyelitis and started high-dose methylprednisolone followed by a slow corticosteroid taper. She recovered well and regained functional independence in the upper limbs. Neurological manifestations of HTLV-1 infection extend beyond classical 'tropical spastic paraparesis' and are under-recognised. We review the literature on HTLV-1 encephalitis and discuss its diagnosis and management.
Topics: Brain; Encephalitis; Female; Human T-lymphotropic virus 1; Humans; Middle Aged; Paraparesis, Tropical Spastic; White Matter
PubMed: 34462338
DOI: 10.1136/practneurol-2021-003053 -
Frontiers in Immunology 2022HTLV-1 is a global infection with 5-20 million infected individuals. Although only a minority of infected individuals develop myelopathy, lymphoproliferative malignancy,... (Review)
Review
HTLV-1 is a global infection with 5-20 million infected individuals. Although only a minority of infected individuals develop myelopathy, lymphoproliferative malignancy, or inflammatory disorders, infection is associated with immunosuppression and shorter survival. Transmission of HTLV-1 is through contaminated blood or needles, mother-to-child exposure through breast-feeding, and sexual intercourse. HTLV-1 is a delta retrovirus that expresses immunogenic Gag, Envelope, TAX, and Hbz proteins. Neutralizing antibodies have been identified directed against the surface envelope protein, and cytotoxic T-cell epitopes within TAX have been characterized. Thus far, there have been few investigations of vaccines directed against each of these proteins, with limited responses, thus far. However, with new technologies developed in the last few years, a renewed investigation is warranted in search for a safe and effective HTLV-1 vaccine.
Topics: Antibodies, Neutralizing; Epitopes, T-Lymphocyte; Female; HTLV-I Infections; Human T-lymphotropic virus 1; Humans; Infectious Disease Transmission, Vertical; Vaccines
PubMed: 36159878
DOI: 10.3389/fimmu.2022.953650 -
Viruses Apr 2022HTLV-1 uveitis (HU) is the third clinical entity to be designated as an HTLV-1-associated disease. Although HU is considered to be the second-most frequent... (Review)
Review
HTLV-1 uveitis (HU) is the third clinical entity to be designated as an HTLV-1-associated disease. Although HU is considered to be the second-most frequent HTLV-1-associated disease in Japan, information on HU is limited compared to that on adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy (HAM). Recent studies have addressed several long-standing uncertainties about HU. HTLV-1-related diseases are known to be caused mainly through vertical transmission (mother-to-child transmission), but emerging HTLV-1 infection by horizontal transmission (such as sexual transmission) has become a major problem in metropolitan areas, such as Tokyo, Japan. Investigation in Tokyo showed that horizontal transmission of HTLV-1 was responsible for HU with severe and persistent ocular inflammation. The development of ATL and HAM is known to be related to a high provirus load and hence involves a long latency period. On the other hand, factors contributing to the development of HU are poorly understood. Recent investigations revealed that severe HU occurs against a background of Graves' disease despite a low provirus load and short latency period. This review highlights the recent knowledge on HU and provides an update on the topic of HU in consideration of a recent nationwide survey.
Topics: Adult; Female; HTLV-I Infections; Human T-lymphotropic virus 1; Humans; Infectious Disease Transmission, Vertical; Paraparesis, Tropical Spastic; Proviruses; Uveitis
PubMed: 35458524
DOI: 10.3390/v14040794 -
Bioscience Reports Mar 2022Human T-cell leukemia virus type 1 (HTLV-1) is the only identified oncogenic human retrovirus. HTLV-1 infects approximately 5-10 million people worldwide and is the... (Review)
Review
Human T-cell leukemia virus type 1 (HTLV-1) is the only identified oncogenic human retrovirus. HTLV-1 infects approximately 5-10 million people worldwide and is the infectious cause of adult T-cell leukemia/lymphoma (ATL) and several chronic inflammatory diseases, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), dermatitis, and uveitis. Unlike other oncogenic retroviruses, HTLV-1 does not capture a cellular proto-oncogene or induce proviral insertional mutagenesis. HTLV-1 is a trans-activating retrovirus and encodes accessory proteins that induce cellular transformation over an extended period of time, upwards of several years to decades. Inarguably the most important viral accessory protein involved in transformation is Tax. Tax is a multifunctional protein that regulates several different pathways and cellular processes. This single viral protein is able to modulate viral gene expression, activate NF-κB signaling pathways, deregulate the cell cycle, disrupt apoptosis, and induce genomic instability. The summation of these processes results in cellular transformation and virus-mediated oncogenesis. Interestingly, HTLV-1 also encodes a protein called Hbz from the antisense strand of the proviral genome that counters many Tax functions in the infected cell, such as Tax-mediated viral transcription and NF-κB activation. However, Hbz also promotes cellular proliferation, inhibits apoptosis, and disrupts genomic integrity. In addition to viral proteins, there are other cellular factors such as MEF-2, superoxide-generating NAPDH oxidase 5-α (Nox5α), and PDLIM2 which have been shown to be critical for HTLV-1-mediated T-cell transformation. This review will highlight the important viral and cellular factors involved in HTLV-1 transformation and the available in vitro and in vivo tools used to study this complex process.
Topics: Adult; Basic-Leucine Zipper Transcription Factors; Human T-lymphotropic virus 1; Humans; LIM Domain Proteins; Microfilament Proteins; NF-kappa B; Paraparesis, Tropical Spastic; Retroviridae Proteins; Viral Proteins
PubMed: 35169839
DOI: 10.1042/BSR20211921 -
Viruses Jul 2020Basic leucine zipper (bZIP) transcription factors (TFs) govern diverse cellular processes and cell fate decisions. The hallmark of the leucine zipper domain is the... (Review)
Review
Basic leucine zipper (bZIP) transcription factors (TFs) govern diverse cellular processes and cell fate decisions. The hallmark of the leucine zipper domain is the heptad repeat, with leucine residues at every seventh position in the domain. These leucine residues enable homo- and heterodimerization between ZIP domain α-helices, generating coiled-coil structures that stabilize interactions between adjacent DNA-binding domains and target DNA substrates. Several cancer-causing viruses encode viral bZIP TFs, including human T-cell leukemia virus (HTLV), hepatitis C virus (HCV) and the herpesviruses Marek's disease virus (MDV), Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV). Here, we provide a comprehensive review of these viral bZIP TFs and their impact on viral replication, host cell responses and cell fate.
Topics: Animals; Basic-Leucine Zipper Transcription Factors; Deltaretrovirus; Herpesvirus 4, Human; Herpesvirus 8, Human; Humans; Mardivirus; Oncogenic Viruses; Phylogeny; Tumor Virus Infections; Unfolded Protein Response
PubMed: 32674309
DOI: 10.3390/v12070757 -
Microbial Pathogenesis Aug 2022Human T lymphotropic virus (HTLV-I) is a retrovirus that has been recognized as a causative agent of two crucidal diseases, HTLV-I-Associated Myelopathy/Tropical Spastic... (Review)
Review
Human T lymphotropic virus (HTLV-I) is a retrovirus that has been recognized as a causative agent of two crucidal diseases, HTLV-I-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) and Adult T cell Leukemia-Lymphoma (ATLL). The virus not only induces those diseases in a small proportion of HTLV-I carriers (3-5%) but also it is associated with other diseases such as HTLV-I-Associated Arthropathy (HAAP), Cutaneous T Cell Lymphoma (CTCL), Graves' disease, uveitis, polymyositis, chronic respiratory diseases, lymphadenitis and dermatitis. Furthermore, HTLV related and accelerated disorders were more investigated, and the factors that might implicate in the development or progression of diseases have been discussed. We founded 13 categories of non-associated disease in studies such as Reproductive Disorders, Coronary Artery Disease (CAD), non -ATLL lymphoma, Co-infection, non-HAM/TSP neurological associated disease, non ATLL cutaneous associated disease, Autoimmune-Inflammatory related disease, Kidney disease, Liver disease, Respiratory disease, TB disease and Thyroid disease. With regard to the reviewed studies suggested HTLV-I disorders can divide into three manifests; related, accelerated and associated disease. However, interaction between HTLV-I infection and host immune response was complicated and vague. Some infectious patients indicated the involvement of inflammatory response of immune system, but in other individuals function of anti-inflammatory elements was observed. For a better understanding of this classification, more systematic studies should be designed and need to provide a global network to control and prevent HTLV affiliated diseases.
Topics: Adult; Autoimmune Diseases; Deltaretrovirus Infections; Human T-lymphotropic virus 1; Humans; Leukemia-Lymphoma, Adult T-Cell; Paraparesis, Tropical Spastic; Skin
PubMed: 35688412
DOI: 10.1016/j.micpath.2022.105622 -
Current Topics in Medicinal Chemistry 2017Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus which is endemic to certain regions of the world and infects around 10-20 million people. HTLV-1 is the... (Review)
Review
Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus which is endemic to certain regions of the world and infects around 10-20 million people. HTLV-1 is the etiologic agent of Adult T cell leukemia/lymphoma and HTLV-1 associated neurological disorders including mainly HTLV-1 associated myelopathy/Tropical spastic paraparesis. The involvement of the central nervous diseases occurs among: HTLV-1 infected patients from endemic areas, HIV positive individuals and drug users. The ability of HTLV-1 to cause associated neuropathies starts with the virus crossing the blood brain barrier (BBB), then entering and infecting the cells of the central nervous system. As a consequence, to the viral attack, HTLV-1 infected lymphocytes produce pro-inflammatory cytokines like tumor necrosis factor alpha, Interleukin 1 beta and interleukin 6 which further disrupts the BBB. Different serological tests have been used in the diagnosis of HTLV-1. These include: ELISA, Western Blotting (WB), Immunofluorescence, Particle Agglutination and Polymerase Chain Reaction which is used as a confirmatory test. Danazol, pentoxifylline, azathioprine and vitamin C have been used in the treatment of the HTLV-1 associated neurological disorders. Other antiviral drugs (lamivudine, zidovudine), monoclonal antibodies (Daclizumab) and therapeutic agents (valporic acid, interferons) have also been evaluated. No known drug, so far, has been shown to be efficacious. The aim of this review is to present the complexities of HTLV-1 associated neurological disorders and their current ongoing treatment. In addition to discussing future possible therapeutic strategies, by targeting HTVL-1 viral components and gene/s products, for the treatment of those neurological conditions.
Topics: Antiviral Agents; Central Nervous System; Human T-lymphotropic virus 1; Humans; Nervous System Diseases
PubMed: 28017149
DOI: 10.2174/1568026616666161222141318 -
Viruses Apr 2023During the early 1980s, the first 3 human retroviruses were identified: human T-lymphotropic virus 1 and 2 (HTLV-1 and HTLV-2) and human immunodeficiency virus (HIV)...
During the early 1980s, the first 3 human retroviruses were identified: human T-lymphotropic virus 1 and 2 (HTLV-1 and HTLV-2) and human immunodeficiency virus (HIV) [...].
Topics: Humans; Human T-lymphotropic virus 1; HTLV-I Infections; Coinfection; HIV Infections; Human T-lymphotropic virus 2
PubMed: 37112943
DOI: 10.3390/v15040963 -
Biomolecules Oct 2023Human T-cell leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL). HTLV-1 carriers have a lifelong asymptomatic balance between infected cells and... (Review)
Review
Human T-cell leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL). HTLV-1 carriers have a lifelong asymptomatic balance between infected cells and host antiviral immunity; however, 5-10% of carriers lose this balance and develop ATL. Coinfection with promotes ATL development, suggesting that the immunological status of infected individuals is a determinant of HTLV-1 pathogenicity. As CD4+ T cells play a central role in host immunity, the deregulation of their function and differentiation via HTLV-1 promotes the immune evasion of infected T cells. During ATL development, the accumulation of genetic and epigenetic alterations in key host immunity-related genes further disturbs the immunological balance. Various approaches are available for treating these abnormalities; however, hematopoietic stem cell transplantation is currently the only treatment with the potential to cure ATL. The patient's immune state may contribute to the treatment outcome. Additionally, the activity of the anti-CC chemokine receptor 4 antibody, mogamulizumab, depends on immune function, including antibody-dependent cytotoxicity. In this comprehensive review, we summarize the immunopathogenesis of HTLV-1 infection in ATL and discuss the clinical findings that should be considered when developing treatment strategies for ATL.
Topics: Adult; Humans; Human T-lymphotropic virus 1; Leukemia-Lymphoma, Adult T-Cell; CD4-Positive T-Lymphocytes; Lymphoma
PubMed: 37892225
DOI: 10.3390/biom13101543