HTLV-1-associated Myelopathy/tropical Spastic Paraparesis Research Articles

The Expression of Tax and HBZ Genes in Serum-Derived Extracellular Vesicles From HTLV-1 Carriers Correlates to Proviral Load and Inflammatory Markers.

Human T-lymphotropic virus 1 (HTLV-1) is the etiologic agent of adult cell leukemia/lymphoma (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). One of the major questions in HTLV-1 studies is related to the understanding of causes that lead to different clinical manifestations. However, it is well known that the viral genes tax and HTLV-1 basic leucine zipper factor (HBZ) are related to viral infectivity and the development of neurological and hematological diseases. Currently, there is evidence that HTLV-1 infected cells can release small extracellular vesicles (sEVs) involved in the mechanisms of viral particles spreading. Therefore, we evaluated the expression levels of tax and HBZ viral transcripts in serum-derived sEVs from HTLV-1 carriers, as well as the role of these vesicles in the modulation of the immune response. Three HAM/TSP carriers presented detectable levels of tax and HBZ transcripts in sEVs and were positively correlated to the proviral load (PVL) in peripheral blood mononuclear cells (PBMCs). The viral transcripts were only detectable in individuals with a PVL higher than 6,000/105 PBMCs. Additionally, it was observed that HBZ presented a 2–12-folds increase over tax expression units. Gene expression and secretory protein analysis indicated that PBMCs from blood donors and HTLV-1 carriers exposed to increasing doses of tax+ HBZ+ sEVs showed a dose-dependent increase in interferon (IFN)-γ and interleukin (IL)-8 transcripts and proteins. Interestingly, the increase in IL-8 levels was close to those seen in HTLV-1-infected PBMCs with high PVL. Taken together, these findings indicate that the expression of viral transcripts in serum-derived sEVs of HTLV-1 carriers is related to the PVL presented by the infected individual. Additionally, tax+ HBZ+ sEVs can induce the production of inflammatory cytokines in patients with low PVL, which may be related to the development of symptoms in HTLV-1 infection.

Evaluation of antioxidant status and oxidative stress markers in HTLV-1 infected individuals: correlation with the severity of virus-induced complications.

Introduction. Human T-cell lymphotropic virus type 1 (HTLV-1), a well-known member of the retroviridae family, potentially causes serious outcomes including adult T-cell leukaemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM-TSP). Oxidative stress plays a key role in progression and clinical exacerbation of several chronic infections. We have previously shown a reduction in serum total antioxidant capacity (TAC) during HTLV-1 infection and this study was set out to investigate the reasons for TAC reduction.Hypothesis/Gap Statement. Oxidant/antioxidant imbalance during HTLV-1 infection may result from disruptions in oxidant levels or antioxidant defence system.Aim. This study aimed to analyse the key enzymes and oxidant molecules playing important roles in virus-induced oxidative stress.Methodology. We measured serum activities of the major antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) as well as serum concentrations of the main oxidant markers: nitric oxide (NO) and malondialdehyde (MDA). Totally 40 HTLV-1 infected patients and 40 healthy controls were enrolled in this study. The patient group consisted of chronic carriers and patients with HAM-TSP (N=20).Results. The current study found that serum levels of MDA and NO were significantly higher in patient groups particularly in HAM-TSP patients (P<0.05). In addition, a reductive trend was observed in the serum activities of CAT, SOD, and GPX in HTLV-1 infected patients compared with healthy controls (P<0.05).Conclusion. Reduced activities of CAT, SOD, and GPX antioxidant enzymes along with the observed elevated concentrations of oxidant molecules may contribute to oxidative stress and worse outcomes during HTLV-1 infection.

Current Perspectives in Human T-Cell Leukemia Virus Type 1 Infection and Its Associated Diseases.

Human T-cell leukemia virus type 1 (HTLV-1) is a replication-competent human retrovirus associated with two distinct types of diseases: a malignancy of mature CD4+ T cells called adult T-cell leukemia-lymphoma (ATL) and a chronic inflammatory central nervous system disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It was the first human retrovirus ever associated with a human cancer. Although most HTLV-1-infected individuals remain asymptomatic for life, a subpopulation develops ATL or HAM/TSP. Although the factors that cause these different manifestations of HTLV-1 infection are not fully understood, accumulating evidence suggests that the complex virus-host interactions, as well as the host immune response against HTLV-1 infection, appear to regulate the development of HTLV-1-associated diseases. This review outlines and discusses the current understanding, ongoing developments, and future perspectives of HTLV-1 research.

Regulation of HTLV-1 transformation.

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.

Clinical and Public Health Implications of Human T-Lymphotropic Virus Type 1 Infection.

Human T-lymphotropic virus type 1 (HTLV-1) is estimated to affect 5 to 10 million people globally and can cause severe and potentially fatal disease, including adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The burden of HTLV-1 infection appears to be geographically concentrated, with high prevalence in discrete regions and populations. While most high-income countries have introduced HTLV-1 screening of blood donations, few other public health measures have been implemented to prevent infection or its consequences. Recent advocacy from concerned researchers, clinicians, and community members has emphasized the potential for improved prevention and management of HTLV-1 infection. Despite all that has been learned in the 4 decades following the discovery of HTLV-1, gaps in knowledge across clinical and public health aspects persist, impeding optimal control and prevention, as well as the development of policies and guidelines. Awareness of HTLV-1 among health care providers, communities, and affected individuals remains limited, even in countries of endemicity. This review provides a comprehensive overview on HTLV-1 epidemiology and on clinical and public health and highlights key areas for further research and collaboration to advance the health of people with and at risk of HTLV-1 infection.

Cognitive screening in HTLV-1-infected people using a self-perceived memory score and auditory P300.

The HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is the most common neurological manifestation associated with human T-cell lymphotropic virus type-1 (HTLV-1) infection. Although cognitive impairment has been highlighted in the spectrum of HTLV-1 neurological manifestations, it may go unnoticed in those who do not spontaneously report it. We aimed at evaluating the applicability of a self-perceived memory score (SMS) and the cognitive event-related potential (P300) for early detection of cognitive impairment in HTLV-1-infected people. The SMS was measured by a 0-10 point numeric scale combined with a sad-happy face rating scale. The higher the number, the better was the SMS. The P300 was obtained through an oddball paradigm with a mental counting task. The participants were 15 (21.4%) individuals with HAM/TSP, 20 (28.6%) HTLV-1 asymptomatic carriers, and 35 (50%) seronegative controls. We found that SMS (p < 0.001) and P300 latency (p < 0.001) got progressively worse from the seronegative controls to the asymptomatic carriers and then to the HAM/TSP. The results that indicated cognitive impairment were SMS < 7.2 points and P300 latency > 369.0ms. The HAM/TSP group showed the highest prevalence of altered P300 (80%) and SMS (87%). Interestingly, the asymptomatic group also presented significantly higher prevalence of altered SMS (60%) and P300 (35%) when compared to controls (< 10%). The frequency of cognitive impairment was 16 times higher in the HTLV-1 asymptomatic group and 69 times higher in the HAM/TSP group when compared to controls. The use of SMS in the medical consultation was a useful and easy-to-apply method to screen HTLV-1-infected subjects for everyday memory complaints.

Identification of hub genes and molecular pathways in human T-lymphotropic virus type 1 associated diseases using protein-protein interactions networks.

Background and Objectives:Human T-lymphotropic virus type 1 (HTLV-1) is the cause of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The present study aims to analyze gene expression patterns in ATL and HAM/TSP.Materials and Methods:Microarray gene expression profiling of T-lymphocytes from HTLV-1 associated disease and healthy control were obtained from Gene Expression Omnibus (GEO). Several bioinformatics tools were used to identify differentially expressed genes (DEGs). Among the generated DEGs, we constructed protein-protein interaction (PPI) between HAM/TSM and ATL in comparison to asymptomatic carriers (ACs). Subsequently, gene ontology (GO) and topological analysis were performed.Results:We found that the majority of DEGs in ATL and HAM/TSP were importantly implicated in immune response categories. The nodes and edges number of normal-AC, AC-ATL and ATL-HAM/TSP PPIs were 168 and 145, 116 and 97, and 275 and 327, respectively. Based on the topological analyses of protein-protein interaction networks, APP (Amyloid Beta Precursor Protein) was detected as a critical player in progression of HTLV-1 disease.Conclusion:Dysregulation of immune response associated transcripts play a critical role in HTLV-1 disease progression. Immune response associated genes may be biomarker for prognosis in cancer development and therapeutic targets.

Forefront studies on human T‐cell leukemia virus type 1‐associated myelopathy/tropical spastic paraparesis

AbstractHuman T‐cell leukemia virus type 1 can cause human T‐cell leukemia virus type 1‐associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T‐cell leukemia/lymphoma in some infected individuals. HAM/TSP is a rare progressive neurological disease characterized by spastic spinal paralysis. The developments in previous research have identified many aspects of the disease pathology. However, the disease is rarely cured, and the aims of treatment remain controlling long‐term progression. This study intends to describe the pathophysiology and treatments for HAM/TSP elucidated from recent studies and the HAM/TSP patient registry.

Integration of gene co-expression analysis and multi-class SVM specifies the functional players involved in determining the fate of HTLV-1 infection toward the development of cancer (ATLL) or neurological disorder (HAM/TSP).

Human T-cell Leukemia Virus type-1 (HTLV-1) is an oncovirus that may cause two main life-threatening diseases including a cancer type named Adult T-cell Leukemia/Lymphoma (ATLL) and a neurological and immune disturbance known as HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). However, a large number of the infected subjects remain as asymptomatic carriers (ACs). There is no comprehensive study that determines which dysregulated genes differentiate the pathogenesis routes toward ATLL or HAM/TSP. Therefore, two main algorithms including weighted gene co-expression analysis (WGCNA) and multi-class support vector machines (SVM) were utilized to find major gene players in each condition. WGCNA was used to find the highly co-regulated genes and multi-class SVM was employed to identify the most important classifier genes. The identified modules from WGCNA were validated in the external datasets. Furthermore, to find specific modules for ATLL and HAM/TSP, the non-preserved modules in another condition were found. In the next step, a model was constructed by multi-class SVM. The results revealed 467, 3249, and 716 classifiers for ACs, ATLL, and HAM/TSP, respectively. Eventually, the common genes between the WGCNA results and classifier genes resulted from multi-class SVM that also determined as differentially expressed genes, were identified. Through these step-wise analyses, PAIP1, BCAS2, COPS2, CTNNB1, FASLG, GTPBP1, HNRNPA1, RBBP6, TOP1, SLC9A1, JMY, PABPC3, and PBX1 were found as the possible critical genes involved in the progression of ATLL. Moreover, FBXO9, ZNF526, ERCC8, WDR5, and XRCC3 were identified as the conceivable major involved genes in the development of HAM/TSP. These genes can be proposed as specific biomarker candidates and therapeutic targets for each disease.

Human T-Cell Leukemia Virus Type 1 Envelope Protein: Post-Entry Roles in Viral Pathogenesis.

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.

Work ability and associated factors in people living with human T-cell leukemia virus type 1

ABSTRACTBackground: Infection with the human T-lymphotropic virus type 1 (HTLV-1) affects an estimated 10-15 million people worldwide. However, knowledge of the impact of HTLV-1 infection on work ability is lacking. This study aimed to measure the frequency and identify factors associated with poor work ability in patients living with HTLV-1. Methods: This cross-sectional study included 207 individuals infected with HTLV-1 who attended the University Hospital in Salvador, Bahia, Brazil. HTLV-1 antibodies were detected in the participants’ blood by enzyme-linked immunosorbent assay (ELISA) and confirmed by western blotting. Participants answered a questionnaire on sociodemographic data, personal habits, clinical data, health-related quality of life, and work ability, evaluated using the work ability index questionnaire. A Poisson regression model with a robust variance estimate was used to identify the factors associated with the prevalence of poor work ability.Results: Patients mean age was 55.2, ranging from 19 to 84 years, 73.0% were females, 100% had monthly family income less than US$ 394, and 33.8% presented HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). No individual was classified as having excellent work ability. Poor work ability prevalence was strongly associated (prevalence ratio; 95% confidence interval [CI]) with sedentarism (1.30; 1.03-1.65), neurological symptoms (1.25; 1.02-1.52), and low physical (0.95; 0.94-0.96) and mental (0.98; 0.97-0.99) component summaries of health-related quality of life.Conclusions: Poor work ability among people living with HTLV-1 is associated with sedentarism, neurologic symptoms, and low health-related quality of life.

Computed tomography with 6-year follow-up demonstrates the evolution of HTLV-1 related lung injuries: A cohort study.

Previous observational studies have demonstrated the development of pulmonary impairments in human T-lymphotropic virus type 1 (HTLV-1) infected individuals. The main observed lesions due to chronic inflammation of viral infection in situ are bronchiectasis and lung-scarring injuries. This lung inflammation may be the causal agent of restrictive and obstructive lung diseases, primarily in tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP-HAM) patients. We conducted a prospective cohort study to compare spirometry and high-resolution computed tomography (HRCT) findings among 28 HTLV-1-carrier patients over the course of 6 years (2014-2019) (male/female: 7/21; mean age: 54.7 ± 9.5, range: 41-68 years). Chest HRCT exams revealed the development and evolution of lung lesions related to TSP-HAM: including centrilobular nodules, parenchymal bands, lung cysts, bronchiectasis, ground-glass opacity, mosaic attenuation, and pleural thickening. Spirometry exams showed maintenance of respiratory function, with few alterations in parameters suggestive of obstructive and restrictive disorders primarily in individuals with lung lesions and TSP-HAM. The findings of the present study indicate that pulmonary disease related to HTLV-1 is a progressive disease, with development of new lung lesions, mainly in individuals with TSP-HAM. To improve clinical management of these individuals, we recommend that individuals diagnosed with PET-MAH undergo pulmonary evaluation.

Hypovitaminosis D Is Associated with Higher Levels of Inflammatory Cytokines and with HAM/TSP in HTLV-Infected Patients.

Recent studies have shown the effects of vitamin D on host response to infectious diseases. Some studies detected a high prevalence of hypovitaminosis D in HIV-infected patients, but scarce information exists for HTLV-1 infection. We conducted a cross-sectional study to evaluate the frequency of hypovitaminosis D in HTLV-1 patients and its relationship with their immune response in HTLV-infected patients and in age- and gender-matched controls at a Brazilian rehabilitation hospital. We compared vitamin D, interleukin-6 (IL-6), tumoral necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) levels across groups. Logistic regression was utilized to assess the association between hypovitaminosis D and cytokine levels. We enrolled 161 HTLV-infected subjects (129 HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients, 32 asymptomatic HTLV carriers) and equal number of HTLV-negative controls. We observed a significantly higher prevalence of hypovitaminosis D in patients with HAM/TSP than in HTLV asymptomatic carriers (p < 0.001), or controls (p < 0.001). HAM/TSP patients also had higher levels of IL-6 and IFN-γ than asymptomatic carriers. Patients with HAM/TSP and hypovitaminosis D had higher levels of TNF-α than asymptomatic HTLV carriers. These findings suggest hypovitaminosis D plays a role in HAM/TSP pathogenesis, and it needs to be evaluated in further studies.

Following the Clues: Usefulness of Biomarkers of Neuroinflammation and Neurodegeneration in the Investigation of HTLV-1-Associated Myelopathy Progression.

Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurodegenerative disease due to axonal damage of the corticospinal secondary to an inflammatory response against infected T-cells. In the present work, we aimed to evaluate biomarkers of neurodegeneration and neuroinflammation in the definition of HAM/TSP prognosis. Neurofilament light (NfL) and phosphorylated heavy (pNfH) chains, total Tau protein, cellular prion protein (PrPc), inflammatory chemokines, and neopterin were quantified in paired cerebrospinal fluid (CSF) and serum samples from HAM/TSP patients (n=21), HTLV-1 asymptomatic carriers (AC) (n=13), and HTLV-1 seronegative individuals with non-inflammatory non-degenerative neurological disease (normal-pressure hydrocephalus) (n=9) as a control group. HTLV-1 proviral load in peripheral blood mononuclear cells and the expression of chemokine receptors CCR4, CCR5, and CXCR3 in infected CD4+ T-cells (HTLV-1 Tax+ cells) were also assessed. CSF levels of Tau, NfL, and pNfH were similar between groups, but PrPc and neopterin were elevated in HAM/TSP patients. Most individuals in the control group and all HTLV-1 AC had CSF/serum neopterin ratio < 1.0, and two-thirds of HAM/TSP patients had ratio values > 1.0, which positively correlated with the speed of disease progression and pNfH levels, indicating active neuroinflammation. HAM/TSP patients showed high serum levels of CXCR3-binding chemokines (CXCL9, CXCL10, and CXCL11) and elevated CSF levels of CCL2, CCL3, CCL4, CCL17, CXCL5, CXCL10, and CXCL11. Indeed, CXCL10 concentration in CSF of HAM/TSP patients was 5.8-fold and 8.7-fold higher in than in HTLV-1 AC and controls, respectively, and correlated with CSF cell counts. HAM/TSP patients with typical/rapid disease progression had CSF/serum CXCL10 ratio > 1.0 and a higher frequency of CXCR3+Tax+CD4+ T-cells in blood, which indicated a positive gradient for the migration of infected cells and infiltration into the central nervous system. In conclusion, the slow progression of HAM/TSP abrogates the usefulness of biomarkers of neuronal injury for the disease prognosis. Thus, markers of inflammation provide stronger evidence for HAM/TSP progression, particularly the CSF/serum neopterin ratio, which may contribute to overcome differences between laboratory assays.

Polymorphisms in HTLV-1 Tax-responsive elements in HTLV-1-associated myelopathy/tropical spastic paraparesis patients are associated with reduced proviral load but not with disease progression.

Human T-lymphotropic virus type 1 (HTLV-1) provirus expression is mainly directed by Tax-responsive elements (TRE) within the long terminal repeats (LTR). Mutations in TRE can reduce provirus expression and since a high proviral load (PVL) is a risk factor for the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), we evaluated polymorphisms in the 5' LTR and the association with PVL and disease progression. HTLV-1 LTR and tax sequences derived from asymptomatic carriers (AC) and HAM/TSP patients followed in a longitudinal study were analysed according to PVL and clinical severity. Individuals infected with HTLV-1 presenting the canonical TRE, considering strain ATK-1 as the consensus, displayed sustained higher PVL. By contrast, an LTR A125G mutation in TRE was associated with slightly reduced PVL only in HAM/TSP patients, although it did not influence the speed of disease progression. Moreover, this polymorphism was frequent in Latin American strains of the HTLV-1 Cosmopolitan Transcontinental subtype. Therefore, polymorphisms in the 5' TRE of HTLV-1 may represent one of the factors influencing PVL in HAM/TSP patients, especially in the Latin American population. Indeed, higher PVL in the peripheral blood has been associated with an increased inflammatory activity in the spinal cord and to a poorer prognosis in HAM/TSP. However, this event was not associated with TRE polymorphisms.

Clinical course of neurogenic bladder dysfunction in human T-cell leukemia virus type-1-associated myelopathy/tropical spastic paraparesis: a nationwide registry study in Japan

BackgroundMost patients with human T-cell leukemia virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) develop neurogenic bladder dysfunction. However, longitudinal changes and treatment effects remain poorly understood. This study aimed to characterize the clinical course of urinary dysfunction in this population.MethodsThis prospective observational study included 547 patients enrolled in HAM-net, a nationwide registry for HAM/TSP in Japan. Urinary dysfunction severity was evaluated using the HAM/TSP-bladder dysfunction symptom score (HAM-BDSS) and the HAM/TSP-bladder dysfunction severity grade (HAM-BDSG). These specific measures were recently developed for assessing urinary dysfunction in HAM/TSP. We analyzed longitudinal changes over a 6-year follow-up period, associations between urinary and gait dysfunction, and treatment efficacy of urinary catheterization and mirabegron (a β3-adrenergic agonist for overactive bladder symptoms).ResultsThe mean (standard deviation [SD]) age and disease duration at enrollment were 61.9 (10.7) years and 16.6 (11.6) years, respectively, and 74.6% of patients were women. Only 8.0% were free from urinary symptoms (HAM-BDSG 0), 65.4% had urinary symptoms or were on medication (HAM-BDSG I), and 23.2% and 3.3% used intermittent and indwelling catheters (HAM-BDSG II and III), respectively. HAM-BDSG and BDSS were worse in patients with greater gait dysfunction (p < 0.001 for both). During the 6-year follow-up, 66.7% of patients with HAM-BDSG 0 developed new urinary symptoms. Of those with HAM-BDSG I at enrollment, 10.8% started using urinary catheters. Importantly, HAM-BDSS significantly improved after initiating catheterization (mean [SD] change, − 8.93 [10.78], p < 0.001). The number of patients receiving mirabegron increased in the fourth year. Multivariable linear regression analysis significantly associated mirabegron with improvement in HAM-BDSS (− 5.82, 95% confidence interval − 9.13 to − 2.51, p = 0.001).ConclusionsUrinary dysfunction affected 92% of patients and progressed over the 6-year follow-up. Urinary symptoms were more severe in patients with poorer gait function. Urinary catheterization and mirabegron were effective in relieving symptoms. Effective utilization of real-world data is key to establishing evidence for rare diseases, such as HAM/TSP.

Dysregulation of immune gene expression profiles during HTLV-1 infection

BackgroundHuman T-lymphotropic virus type 1 (HTLV-1) is the main cause of adult T cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The aim of this study was to evaluate the dysregulation of immune genes that may be involved in the pathogenesis of ATLL using microarray datasets. MethodThe gene expression profiles of ATLL cases (GSE19080) were obtained from GEO database. Next, the quality and reliability of data were evaluated by MetaQC, and the expression data in each group were normalized by affy package. Subsequently, the R package MetaDE was applied for the analysis of differentially expressed genes (DEGs). Using STRING database, protein-protein interaction network (PPIN) was constructed for hub DEGs. Finally, online servers including STRING, Enrichr, and KEGG pathway were applied for gene enrichment and interpretation of the results. Results65 significant hub DEGs were divided in three groups, normal health, asymptomatic carrier and ATLL patients. The PPIN analysis between hub DEGs was carried out by STRING. Enrichment analysis revealed that the hub DEGs were involved in various pathways such as apoptosis, proliferation of T cell, Ras signaling, MAPK signaling, NF-κB signaling, integrin signaling, P53 signaling, angiogenesis, tissue invasion, and DNA damage process. ConclusionAccording to the present study, HTLV-1 appears to cause inflammation by enhancing cell proliferation. During the HTLV-1 infection, dysregulation of immune genes such as IL-10, TGF-β, JAK, BCL2, etc. result in immortalization of HTLV-1-infected CD4+ T cells, and eventually progression to ATLL.

Evaluation of interleukin-32 and cyclooxygenase-2 expression in HAM/TSP patients and HTLV-1 asymptomatic carriers.

Objective(s):HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neuroinflammatory disorder associated with HTLV-1. Cytokines and inflammatory mediators have a major role in forming inflammation in HAM/TSP patients. This study aimed to measure the levels of IL-32, a proinflammatory cytokine associated with autoinflammatory disorders, and also cyclooxygenase -2 (COX-2) as a key mediator of inflammatory pathways in HAM/TSP patients and HTLV-1 asymptomatic carriers (ACs).Materials and Methods:Peripheral blood monocyte cells (PBMCs) were isolated from HAM/TSP patients, ACs, and healthy controls (HCs), and DNA and RNA were extracted to evaluate HTLV-1 proviral load (PVL) and expression of IL-32 and COX-2, using real-time PCR. Serum levels of IL-32 were determined by using an ELISA assay.Results:The expression level of IL-32 was significantly higher in ACs compared with HAM/TSP patients and HCs (P<0.0001 and P>0.05, respectively). There were no statistically significant differences in the expression levels of Cox-2 and protein levels of IL-32 between the study groups. HTLV-1 PVL was higher in HAM/TSP patients compared with ACs.Conclusion: Results showed increased mRNA levels of IL-32 in ACs. Since HTLV-1 PVL in ACs is lower than in HAM/TSP patients, it could be concluded that IL-32 might be an HTLV-1 inhibitor that seems to control virus replication. Despite the difference in IL-32 mRNA levels between study groups, no statistically significant differences were observed in IL-32 serum levels. Also, there were no significant differences in COX-2 expression.

Highly Sensitive Viral RNA-Seq Is a Powerful Tool to Analyze the Viral Transcripts in HTLV-1-Infected Individuals

IntroductionHuman T-cell leukemia virus type 1 (HTLV-1) is a retrovirus which causes two major pathologies in infected individuals, Adult T-cell leukemia-lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). There are tens of thousands of different infected clones in asymptomatic HTLV-1 carriers (AC) and each clone can be identified by the viral integration site. Monoclonal integration of HTLV-1 provirus is observed in the host genomic DNA in ATL cells, suggesting that these originate from a single virus-infected clone. It is well known that Tax and HBZ, encoded in the sense and antisense strands of HTLV-1 provirus, respectively, have the ability to induce oncogenesis. The question is how a certain infected clone, among various different ones, becomes a malignant clone. One hypothesis is that a malignant clone may express viral gene transcripts, associated with oncogenesis, more abundantly than a non-malignant clone. Another hypothesis is that HTLV-1 integration may induce an abnormal transcript in the host cell, such as the aberrant expression of the host gene nearby the integration site or the generation of a chimeric transcript between the virus and the host. To analyze HTLV-1 transcript or explore the presence of virus-host chimeric transcripts efficiently, we aimed to establish a method with higher resolution than the conventional RNA-seq by using DNA probe targeting for the entire HTLV-1 sequence. And then, we applied the protocol to characterize the pattern of transcription from HTLV-1 provirus and analyzed virus-host chimeric transcripts in patients' samples.MethodsTo check the efficiency and possible bias of the highly sensitive viral RNA-seq analysis, we analyzed viral transcript of an HTLV-1-infected clone, TBX-4B. Subsequently, mRNA-seq was performed with PBMCs from 6 AC, 4 HAM/TSP, and 5 ATL patients. After cDNA libraries synthesis, HTLV-1 sequences were enriched by the probe-based capture method as we reported previously for DNA-seq (Miyazato et al, Sci Rep 2016). The enriched libraries were sequenced in an Illumina NextSeq device.ResultsWe analyzed HTLV-1 transcript of a virus-infected T-cell clone both before and after the enrichment by viral-specific DNA probes. The proportion of viral sequences within the total number of reads was significantly increased from 0.05% to 80.62% (1600-fold) by the enrichment method. We found that most of the viral regions were significantly and similarly enriched by the additional enrichment step, suggesting the DNA probe-based enrichment of HTLV-1 sequences is applicable to RNA-seq. Next, we applied the protocol to analyze PBMC samples from HTLV-1-infected individuals. The results showed that the level of anti-sense HTLV-1 transcription was significantly higher than that of the sense transcription, not only in ATL patients, which is consistent with previous reports by other groups, but also in AC and HAM/TSP patients. Average proportion of sense and antisense signals were 3.42% and 96.46%, respectively. Even after the enrichment step, tax expression, a sense viral transcript, was undetectable in most of the samples except for one AC and one ATL patient, while an anti-sense transcript HBZ was detectable in all infected individuals. There was no significant difference in the expression level of HBZ between different clinical states. We identified more abundant virus-host chimeric transcripts in ATL samples than in HAM/TSP patients or AC. In ATL cases, HTLV-1 generated chimeric transcripts with the following host genes, HSD17B11, COLEC12, AHSA2, EEF2, TAOK1, KIAA0100, and KIF1B . The presence of abundant chimeric transcripts was validated by RT-PCR.DiscussionWe have established a highly sensitive viral RNA-seq for HTLV-1 transcript analysis. That significantly increased the sensitivity of detection of proviral and chimeric transcripts between virus and the host genome. The result was not consistent with the hypothesis that a malignant clone may express viral gene transcripts more abundantly than a non-malignant clone. Thus, the presence of chimeric transcripts could play a role in cell proliferation and help us reveal the mechanism of clonal selection for HTLV-1-infected cells. We are now going to analyze virus-host chimeric transcripts detected by the high sensitive RNA-seq in more patients' samples to clarify their association with oncogenesis. [Display omitted] DisclosuresYamano:Daiichi Sankyo: Research Funding; Ono Pharma: Research Funding. Utsunomiya:Celgene: Honoraria; Novartis Pharma: Honoraria; Roche Diagnostics: Honoraria; Japan Blood Products Organization: Honoraria; Daiichi Sankyo: Honoraria; Kyowa Hakko Kirin: Honoraria, Research Funding; Astellas Pharma: Honoraria; Chugai Pharma: Honoraria; Bristol-Myers Squibb: Honoraria; Siemens: Honoraria; Nippon Shinyaku: Honoraria; HUYA Bioscience International: Honoraria; Pfizer: Honoraria.

Molecular characterization of HTLV-1 genomic region hbz from patients with different clinical conditions.

The human T-cell lymphotropic virus type-1 (HTLV-1) is associated with severe pathologies, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), adult T-cell leukemia-lymphoma (ATLL), and infective dermatitis associated with the HTLV-1 (IDH). Interestingly, HTLV-1 infection does not necessarily imply the development of pathological processes and it is unknown why some patients remainasymptomatic carriers (AC). Despite some mutations in the HTLV-1 genome appear to influence the outcome of HTLV-1, there are few studies that characterizemolecularly the hbz region. This study aimed to perform the molecular characterization of hbz gene isolated from patients with different clinical outcomes. A total of 15 sequences were generated and analyzed with 571 sequences previously published. The analises showed that the R119Q mutation seems to be related to HTLV-1 clinical conditionssince the frequency of this HBZ mutation is significantly different in comparison between AC with HAM/TSP and ATLL. The R119Q mutation is possibly a protective factor as the frequency is higher in AC sequences.