Distinct gene expression signatures induced by viral transactivators of different HTLV-1 subgroups that confer a different risk of HAM/TSP.

BACKGROUND: Among human T cell leukemia virus type 1 (HTLV-1)-infected individuals, there is an association between HTLV-1 tax subgroups (subgroup-A or subgroup-B) and the risk of HAM/TSP in the Japanese population. To investigate the role of HTLV-1 subgroups in viral pathogenesis, we studied the functional difference in the subgroup-specific viral transcriptional regulators Tax and HBZ using microarray analysis, reporter gene assays, and evaluation of viral-host protein-protein interaction. RESULTS: (1) Transcriptional changes in Jurkat Tet-On human T-cells that express each subgroup of Tax or HBZ protein under the control of an inducible promoter revealed different target gene profiles; (2) the number of differentially regulated genes induced by HBZ was 2-3 times higher than that induced by Tax; (3) Tax and HBZ induced the expression of different classes of non-coding RNAs (ncRNAs); (4) the chemokine CXCL10, which has been proposed as a prognostic biomarker for HAM/TSP, was more efficiently induced by subgroup-A Tax (Tax-A) than subgroup-B Tax (Tax-B), in vitro as well as in unmanipulated (ex vivo) PBMCs obtained from HAM/TSP patients; (5) reporter gene assays indicated that although transient Tax expression in an HTLV-1-negative human T-cell line activated the CXCL10 gene promoter through the NF-κB pathway, there was no difference in the ability of each subgroup of Tax to activate the CXCL10 promoter; however, (6) chromatin immunoprecipitation assays showed that the ternary complex containing Tax-A is more efficiently recruited onto the promoter region of CXCL10, which contains two NF-κB binding sites, than that containing Tax-B. CONCLUSIONS: Our results indicate that different HTLV-1 subgroups are characterized by different patterns of host gene expression. Differential expression of pathogenesis-related genes by subgroup-specific Tax or HBZ may be associated with the onset of HAM/TSP.

Detection of human T lymphotropic virus type-I bZIP factor and tax in the salivary glands of Sjögren's syndrome patients.

OBJECTIVES: To detect HTLV-I bZIP factor (HBZ), tax and relevant molecules in labial salivary glands (LSGs) from patients with Sjögren's syndrome (SS). METHODS: The expressions of HBZ and tax in T cell lines and LSGs were analysed by in situ hybridization (ISH) or real time PCR. The expressions of forkhead box P3 (Foxp3) and p65 in immunohistochemistry were quantified. RESULTS: After specificity of ISH probes was determined in 5 T cell lines, in LSGs from an adult T-cell leukemia (ATL) patient and 3 HTLV-I-associated myelopathy (HAM)-SS patients, both HBZ and tax signals were detected in infiltrating mononuclear cells (MNCs) and ducts, and HBZ and tax were dominantly expressed in MNCs of ATL and HAM-SS, respectively. HBZ was dominantly observed in LSGs from 8 HTLV-I asymptomatic carrier (AC)-SS patients; faint expression of HBZ was observed in LSGs from 5 HTLV-I-seronegative SS patients. No cell adhesion molecule 1(CADM1) expressed in LSGs from the ATL patient. Although Foxp3 expression was observed in LSG MNCs of all of the SS patients, the ATL patient's expression was significantly greater than that of the AC-SS (p<0.01) and HTLV-I-seronegative SS (p<0.01) patients. The Foxp3 expression was similar in ATL and HAMSS, but significantly higher in HAM-SS than AC-SS (p<0.05). p65 was expressed in LSG MNC nuclei from all SS patients and co-expressed with Foxp3. The expressions of Foxp3 in ducts differed according to HTLV-I infection. CONCLUSIONS: These results suggest that HBZ-mediated Foxp3 expression is partly associated with the pathogenesis of HTLV-I-seropositive SS.

Prosultiamine for treatment of lower urinary tract dysfunction accompanied by human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis.

OBJECTIVES: To evaluate oral prosultiamine treatment in patients with overactive bladder accompanied by human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis. METHODS: This was a prospective, single-center, open-label study. Patients received oral prosultiamine (300 mg) once daily in the morning, and the overactive bladder symptom score and urine levels of overactive bladder-related biomarkers (nerve growth factor/creatinine and adenosine triphosphate/creatinine) 12 weeks after the initial administration were compared with the baseline values. In addition, the urodynamic parameters, including involuntary detrusor contraction and detrusor sphincter dyssynergia, were evaluated before and after treatment. RESULTS: A total of 16 patients were recruited for this clinical study. In the overactive bladder symptom score, night-time frequency, urgency and the total score improved after oral prosultiamine treatment (P = 0.028, 0.001 and 0.004, respectively). Both urinary nerve growth factor/creatinine and adenosine triphosphate/creatinine levels decreased significantly after the treatment (P = 0.004 and 0.017, respectively). Urodynamic studies showed that the maximum cystometric capacity increased significantly after the treatment. However, the symptoms disappeared because of the treatment in six of 10 patients with involuntary detrusor contraction (60%) and three of seven patients with detrusor sphincter dyssynergia (42.9%). There were no serious adverse events. CONCLUSIONS: The changes in urodynamic parameters and urine levels of overactive bladder-related markers suggest that oral prosultiamine is a safe and effective treatment for overactive bladder with human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis.

Tumor necrosis factor alpha inhibitors have no effect on a human T-lymphotropic virus type-I (HTLV-I)-infected cell line from patients with HTLV-I-associated myelopathy.

BACKGROUND: While tumor necrosis factor alpha (TNF-α) inhibitors (TNFi) and other biologics are very effective against autoimmune diseases, they can also cause infectious diseases. Therefore, it is important to clarify whether the TNFi sometimes used to treat patients with rheumatoid arthritis (RA) complicated with human T-lymphotropic virus type-I (HTLV-I) infection have the unintended side effect of promoting HTLV-I proliferation. METHODS: We used the HTLV-I-infected cell line HCT-5, derived from spinal fluid cells of a patient with HTLV-I associated myelopathy, to evaluate the production of cytokines and chemokines, TNF-α receptor (TNFR), the expression of HTLV-I associated genes, the HTLV-I proviral load (PVL), the expression of HTLV-I structural protein, and apoptosis. We used Jurkat cells as a control. RESULTS: Supernatants of HCT-5 showed time-dependent elevations of IL-6, RANTES and ICAM-1. HCT-5 supernatants treated with infliximab, adalimumab, etanercept (ETN), golimumab and certolizumab pegol showed no significant differences in the levels of these molecules compared to the control. Neither TNFR1 nor TNFR2 expression was altered by any TNFi treatment, relative to phosphate-buffered saline (PBS) treatment, with the exception that TNFR2 was significantly decreased and internalized in HCT-5 cells by ETN treatment. The HTLV-I associated genes Tax and HBZ and the PVL levels were not significantly changed. Immunofluorescence staining of HCT-5 for an HTLV-I-associated protein, GAG, was also not significantly different between any of the TNFi treatments and the PBS treatment. DNA ladders as an index of apoptosis were not detected. Apoptotic cells were not increased by the addition of any TNFi. CONCLUSIONS: In vitro, TNFi did not affect the cytokine profiles, expression of associated genes and proteins, proviral load or apoptosis of HCT-5 cells. The results suggested that TNFi treatment of RA patients complicated with HTLV-I might have no effect on HTLV-I infection.

The CC chemokine ligand (CCL) 1, upregulated by the viral transactivator Tax, can be downregulated by minocycline: possible implications for long-term treatment of HTLV-1-associated myelopathy/tropical spastic paraparesis.

BACKGROUND: Chemokine (C-C motif) ligand 1 (CCL1) is produced by activated monocytes/ macrophages and T-lymphocytes, and acts as a potent attractant for Th2 cells and a subset of T-regulatory (Treg) cells. Previous reports have indicated that CCL1 is overexpressed in adult T-cell leukemia cells, mediating an autocrine anti-apoptotic loop. Because CCL1 is also known as a potent chemoattractant that plays a major role in inflammatory processes, we investigated the role of CCL1 in the pathogenesis of human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP). RESULTS: The results showed that: (1) CCL1 was preferentially expressed in HAM/TSP-derived HTLV-1-infected T-cell lines, (2) CCL1 expression was induced along with Tax expression in the Tax-inducible T-cell line JPX9, (3) transient Tax expression in an HTLV-1-negative T-cell line activated the CCL1 gene promoter, (4) plasma levels of CCL1 were significantly higher in patients with HAM/TSP than in HTLV-1-seronegative patients with multiple sclerosis and HTLV-1-infected asymptomatic healthy carriers, and (5) minocycline inhibited the production of CCL1 in HTLV-1-infected T-cell lines. CONCLUSIONS: The present results suggest that elevated CCL1 levels may be associated with the pathogenesis of HAM/TSP. Although further studies are required to determine the in vivo significance, minocycline may be considered as a potential candidate for the long-term treatment of HAM/TSP via its anti-inflammatory effects, which includes the inhibition of CCL1 expression.

Distribution, Innervation, and Cellular Organization of Taste Buds in the Sea Catfish, Plotosus japonicus.

The gustatory system of the sea catfish Plotosus japonicus, like that of other catfishes, is highly developed. To clarify the details of the morphology of the peripheral gustatory system of Plotosus, we used whole-mount immunohistochemistry to investigate the distribution and innervation of the taste buds within multiple organs including the barbels, oropharyngeal cavity, fins (pectoral, dorsal, and caudal), and trunk. Labeled taste buds could be observed in all the organs examined. The density of the taste buds was higher along the leading edges of the barbels and fins; this likely increases the chance of detecting food. In all the fins, the taste buds were distributed in linear arrays parallel to the fin rays. Labeling of nerve fibers by anti-acetylated tubulin antibody showed that the taste buds within each sensory field are innervated in different ways. In the barbels, large nerve bundles run along the length of the organ, with fascicles branching off to innervate polygonally organized groups of taste buds. In the fins, nerve bundles run along the axis of fin rays to innervate taste buds lying in a line. In each case, small fascicles of fibers branch from large bundles and terminate within the basal portions of the taste buds. Serotonin immunohistochemistry demonstrated that most of the taste buds in all the organs examined contained disk-shaped serotonin-immunopositive cells in their basal region. This indicates a similar organization of the taste buds, in terms of the existence of serotonin-immunopositive basal cells, across the different sensory fields in this species.

Reevaluation for clinical manifestations of HTLV-I-seropositive patients with Sjögren's syndrome.

BACKGROUND: The aim of the study was to reassess the prevalence and characteristics of human T lymphotropic virus type I (HTLV-I)-associated Sjögren's syndrome (SS) and SS in HTLV-I-associated myelopathy (HAM) based on the American European Consensus Group (AECG) criteria in HTLV-I endemic area, Nagasaki prefecture. METHODS: The 349 patients who underwent a minor salivary gland biopsy (MSGB) for suspected SS were retrospectively classified by AECG classification criteria and divided with or without anti-HTLV-I antibody. RESULTS: The HTLV-I data-available 294 patients were investigated. One hundred-seventy patients were classified as SS and 26.5 % were HTLV-I-seropositive. We have included 26 patients with HTLV-I-associated myelopathy (HAM) and 38.5 % were classified as having SS. The prevalences of ANA and anti-SS-A/Ro antibody of HAM + SS were significantly low compared to the HTLV-I asymptomatic carriers (AC) with SS and the HTLV-I-seronegative SS patients, although lacrimal dysfunction tended to be high in HAM + SS and significantly high in AC + SS patients compared with the patients with HTLV-I-seronegative SS. The focus scores of MSGB in the HAM + SS patients were similar to those of the AC + SS patients and the HTLV-I-seronegative patients with SS. Among the MSGB-positive patients, there was a low prevalence of ANA in the HAM + SS patients. Similar results were obtained in case of anti-SS-A/Ro or SS-B/La antibody. CONCLUSION: In HTLV-I endemic area, high prevalence of anti-HTLV-I antibody among SS as well as the characteristics of HAM + SS and AC + SS was still determined by AECG classification criteria.

Pentosan polysulfate treatment ameliorates motor function with increased serum soluble vascular cell adhesion molecule-1 in HTLV-1-associated neurologic disease.

The main therapeutic strategy against human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) characterized by lower extremity motor dysfunction is immunomodulatory treatment, with drugs such as corticosteroid hormone and interferon-α, at present. However, there are many issues in long-term treatment with these drugs, such as insufficient effects and various side effects. We now urgently need to develop other therapeutic strategies. The heparinoid, pentosan polysulfate sodium (PPS), has been safely used in Europe for the past 50 years as a thrombosis prophylaxis and for the treatment of phlebitis. We conducted a clinical trial to test the effect of subcutaneous administration of PPS in 12 patients with HAM/TSP in an open-labeled design. There was a marked improvement in lower extremity motor function, based on reduced spasticity, such as a reduced time required for walking 10 m and descending a flight of stairs. There were no significant changes in HTLV-I proviral copy numbers in peripheral blood contrary to the inhibitory effect of PPS in vitro for intercellular spread of HTLV-I. However, serum soluble vascular cell adhesion molecule (sVCAM)-1 was significantly increased without significant changes of serum level of chemokines (CXCL10 and CCL2). There was a positive correlation between increased sVCAM-1and reduced time required for walking 10 m. PPS might induce neurological improvement by inhibition of chronic inflammation in the spinal cord, through blocking the adhesion cascade by increasing serum sVCAM-1, in addition to rheological improvement of the microcirculation. PPS has the potential to be a new therapeutic tool for HAM/TSP.

Efficacy of prosultiamine treatment in patients with human T lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis: results from an open-label clinical trial.

BACKGROUND: Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic myelopathy characterized by motor dysfunction of the lower extremities and urinary disturbance. Immunomodulatory treatments are the main strategy for HAM/TSP, but several issues are associated with long-term treatment. We conducted a clinical trial with prosultiamine (which has apoptotic activity against HTLV-I-infected cells) as a novel therapy in HAM/TSP patients. METHODS: We enrolled 24 HAM/TSP patients in this open-label clinical trial. Prosultiamine (300 mg, orally) was administered once daily for 12 weeks. We monitored changes in the motor function of the lower extremities and urinary function as well as copy numbers of the HTLV-I provirus in peripheral blood mononuclear cells (PBMCs). RESULTS: Improvement in the motor function of the lower extremities based on a reduction in spasticity (for example, decrease in time required for walking and descending a flight of stairs) was observed. In an urodynamic study (UDS), bladder capacity and detrusor pressure and then maximum flow rate increased significantly. Detrusor overactivity and detrusor-sphincter dyssynergia improved in 68.8% and 45.5% of patients observed at pretreatment, respectively. Improvement in UDS corresponded with improvements in the score of nocturia-quality of life questionnaire. HTLV-I proviral copy numbers in PBMCs decreased significantly (approximately 15.4%) compared with pretreatment levels. CONCLUSIONS: These data suggest that prosultiamine can safely improve motor dysfunction of the lower extremities and urinary disturbance as well as reduce HTLV-I provirus levels in peripheral blood. It therefore has potential as a new therapeutic tool for HAM/TSP patients. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) number, UMIN000005969. Please see related commentary: http://www.biomedcentral.com/1741-7015/11/183.

HTLV-I virological and histopathological analysis in two cases of anti-centromere-antibody-seropositive Sjögren's syndrome.

INTRODUCTION: The aim of this study was to show the clinical and pathological characteristics of anti-centromere-antibody (ACA)-seropositive Sjögren's syndrome (SS) in two anti-human T-cell leukemia virus type I (HTLV-I)-seropositive patients. METHODS: One patient was an HTLV-I carrier whereas the other was diagnosed with HTLV-I-associated myelopathy (HAM). Background data including serum HTLV-I titers, viral loads, and cytokine profiles were recorded. Azocarmine with aniline blue (Azan)-Mallory staining and immunohistochemistry of the labial salivary glands (LSGs) and a muscle biopsy specimen from the HAM patient were performed. RESULTS: Serum transforming growth factor beta (TGF-ß), tumor necrosis factor alpha (TNF-α), and HTLV-I viral load were high in the HAM-SS patient compared with the HTLV-I carrier. Fibrous change in LSG was prominent in the HAM-SS patient. Although TGF-ß expression was similar in the two patients, expression of HTLV-I-related proteins including p12, p28, group-specific antigen (GAG), and nuclear factor kappa-B (NF-κB) in the LSG were dominantly detected in the HAM-SS patient. Frequency of TGF-ß staining in HTLV-I-seropositive SS patients without ACA, HTLV-I-seronegative SS patients with ACA, and HTLV-I-seronegative SS patients without ACA was lower than that of the previous two patients. CONCLUSION: A high HTLV-I viral load in situ is supposed to promote the production of cytokines, especially TGF-ß, resulting in the fibrous change of LSG in ACA-seropositive SS patients.

HAM/TSP Pathogenesis: The Transmigration Activity of HTLV-1-Infected T Cells into Tissues.

Slowly progressive spastic paraparesis with bladder dysfunction, the main clinical feature of human T-cell leukemia virus-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), is induced by chronic inflammation in the spinal cord, mainly the lower thoracic cord. A long-standing bystander mechanism, such as the destruction of surrounding tissues by inflammatory cytokines, etc., induced under the interaction between infiltrated HTLV-1-infected CD4+ T cells and HTLV-1-specific CD8+ cytotoxic T cells, has been considered implicated for the induction of chronic inflammation. As this bystander mechanism is triggered conceivably by the transmigration of HTLV-1-infected CD4+ T cells to the spinal cord, heightened transmigrating activity of HTLV-1-infected CD4+ T cells to the spinal cord might play a crucial role as the first responder in the development of HAM/TSP. This review evaluated the functions of HTLV-1-infected CD4+ T cells in HAM/TSP patients as the prerequisite for the acquisition of the activity such as adhesion molecule expression changes, small GTPases activation, and expression of mediators involved in basement membrane disruption. The findings suggest that HTLV-1-infected CD4+ T cells in HAM/TSP patients have enough potential to facilitate transmigration into the tissues. Future HAM/TSP research should clarify the molecular mechanisms leading to the establishment of HTLV-1-infected CD4+ T cells as the first responder in HAM/TSP patients. In addition, a regimen with an inhibitory activity against the transmigration of HTLV-1-infected CD4+ T cells into the spinal cord might be recommended as one of the therapeutic strategies against HAM/TSP patients.

High-power γ-ray flash generation in ultraintense laser-plasma interactions.

When high-intensity laser interaction with matter enters the regime of dominated radiation reaction, the radiation losses open the way for producing short pulse high-power γ-ray flashes. The γ-ray pulse duration and divergence are determined by the laser pulse amplitude and by the plasma target density scale length. On the basis of theoretical analysis and particle-in-cell simulations with the radiation friction force incorporated, optimal conditions for generating a γ-ray flash with a tailored overcritical density target are found.

Advantage of higher-avidity CTL specific for Tax against human T-lymphotropic virus-1 infected cells and tumors.

Strong CTL response can be observed and associated with the control of proviral load in human T-lymphotropic virus type 1 (HTLV-1) infection. However, there are few details with regard to how HTLV-1 specific CTLs work against HTLV-1 infected cells and adult T-cell leukemia cells (ATLs). In this study, using Tax-specific CTL lines with high- and low-functional avidity developed from HLA-A2-transgenic mice, we showed that higher avidity CTLs specific for Tax expressing larger numbers of TCRs and better binding strength to the antigen-HLA-A2 complex are much more efficient at eliminating HTLV-1 infected cells and, in particular, ATL tumor cells with the ability of recognizing a latent level of Tax product detected only with a real-time PCR. These findings suggest that such higher avidity CTLs specific for Tax in HTLV-1 could be responsible for preventing the development of HTLV-1 infection by detecting trace amount of antigens.

Efficient generation of Xe K-shell x rays by high-contrast interaction with submicrometer clusters.

The interaction between a 25 TW laser and Xe clusters at a peak intensity of 1 × 10¹9 W/cm² has been investigated. Xe K-shell x rays, whose energies are approximately 30 keV, were clearly observed with a hard x-ray CCD at 3.4 MPa. Moreover, we studied the yield of the Xe K-shell x rays by changing the pulse duration of the laser at a constant laser energy and found that the pulse duration of 40 fs is better than that of 300 fs for generating Xe K-shell x rays.

Intravesical injection of onabotulinumtoxinA in neurogenic overactive bladder patients with human T-cell leukemia virus type 1-associated myelopathy: A single-institution case series.

INTRODUCTION: Neurogenic overactive bladder is a main feature of human T-cell leukemia virus type 1-associated myelopathy/tropical spastic paraparesis. We successfully performed intravesical onabotulinumtoxinA therapy for refractory neurogenic overactive bladder due to human T-cell leukemia virus type 1-associated myelopathy/tropical spastic paraparesis. CASE PRESENTATION: We retrospectively reviewed four neurogenic overactive bladder patients with human T-cell leukemia virus type 1-associated myelopathy/tropical spastic paraparesis who underwent bladder wall injections of onabotulinumtoxinA from April to October 2020. All patients were female. Their median age was 66 (range, 63-71) years. They were previously treated with ß3-adrenergic receptor agonists or anticholinergic drugs alone or in combination for ≥12 weeks. However, insufficient results were obtained. After 4 weeks of intravesical onabotulinumtoxinA therapy, overactive bladder symptoms improved and maximum cystometric capacity increased in all cases. CONCLUSION: Intravesical onabotulinumtoxinA therapy may be useful for treating refractory overactive bladder due to human T-cell leukemia virus type 1-associated myelopathy/tropical spastic paraparesis.

Antitumor effects of chloroquine/hydroxychloroquine mediated by inhibition of the NF-κB signaling pathway through abrogation of autophagic p47 degradation in adult T-cell leukemia/lymphoma cells.

Adult T-cell leukemia/lymphoma (ATLL) originates from human T-cell leukemia virus type 1 (HTLV-1) infection due to the activation of the nuclear factor-κB (NF-κB) signaling pathway to maintain proliferation and survival. An important mechanism of the activated NF-κB signaling pathway in ATLL is the activation of the macroautophagy (herafter referred to as autophagy in the remainder of this manuscript)-lysosomal degradation of p47 (NSFL1C), a negative regulator of the NF-κB pathway. Therefore, we considered the use of chloroquine (CQ) or hydroxychloroquine (HCQ) (CQ/HCQ) as an autophagy inhibitor to treat ATLL; these drugs were originally approved by the FDA as antimalarial drugs and have recently been used to treat autoimmune diseases, such as systemic lupus erythematosus (SLE). In this paper, we determined the therapeutic efficacy of CQ/HCQ, as NF-κB inhibitors, in ATLL mediated by blockade of p47 degradation. Administration of CQ/HCQ to ATLL cell lines and primary ATLL cells induced cell growth inhibition in a dose-dependent manner, and the majority of cells underwent apoptosis after CQ administration. As to the molecular mechanism, autophagy was inhibited in CQ-treated ATLL cells, and activation of the NF-κB pathway was suppressed with the restoration of the p47 level. When the antitumor effect of CQ/HCQ was examined using immunodeficient mice transplanted with ATLL cell lines, CQ/HCQ significantly suppressed tumor growth and improved the survival rate in the ATLL xenograft mouse model. Importantly, HCQ selectively induced ATLL cell death in the ATLL xenograft mouse model at the dose used to treat SLE. Taken together, our results suggest that the inhibition of autophagy by CQ/HCQ may become a novel and effective strategy for the treatment of ATLL.

Inhibitory effect of HTLV-1 infection on the production of B-cell activating factors in established follicular dendritic cell-like cells.

INTRODUCTION: The low frequency of ectopic germinal center in labial salivary glands of patients with human T-cell leukemia virus type 1 (HTLV-1) antibody-positive Sjögren's syndrome (SS) suggests that HTLV-1 has some effects on follicular dendritic cells (FDCs). METHODS: We used flow cytometry, immunofluorescence, and enzyme-linked immunosorbent assays (ELISAs) to investigate the direct effect of HTLV-1 on B-cell activating factors produced by established FDC like cells obtained from excised human tonsils. We then measured the serum B-cell activating factor (BAFF) and C-X-C motif ligand (CXCL) 13 concentrations of the HTLV-1-seropositive SS patients and the HTLV-1-seronegative SS patients by ELISA. RESULTS: Among the 31 isolated specimens, 22 showed morphological characteristics of FDCs. Day 2-cultured specimens showed expressions of CD14, CD23, CD40, intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1. After 2 weeks, 12 of these specimens expressed ICAM-1, FDC, and fibroblast cell marker. Intracellular BAFF and CXCL13 were constitutively expressed regardless of stimulation. After direct coculture with the HTLV-1-infected T-cell line HCT-5 or MT-2, the BAFF and CXCL13 expressions on the FDC-like cells were decreased in accord with the increased number of HCT-5 and MT-2 cells with styliform change and without HTLV-1 Gag protein expression. Interferons upregulated the concentration of BAFF (but not CXCL13) in the culture supernatant, which showed a declining trend under the presence of HCT-5 or MT-2. The serum concentrations of BAFF and CXCL13 in the HTLV-1-seropositive SS patients were lower than those of the HTLV-1 seronegative SS patients. CONCLUSIONS: HTLV-1 partially inhibited the BAFF and CXCL13 expressions of established FDC-like cells.

Tocilizumab has no direct effect on cell lines infected with human T-cell leukemia virus type 1.

OBJECTIVE: It remains unclear whether human T-cell leukemia virus type 1 (HTLV-1) infection influences therapeutic responses in patients with rheumatic diseases and whether immunosuppressive treatments increase the risk of HTLV-1-related complications in HTLV-1 carriers with rheumatic diseases. We examined the effects of tocilizumab (TCZ), an interleukin (IL)-6 receptor antagonist, on two HTLV-1-infected T-cell lines (HCT-5 and MT-2) in vitro. METHODS: We evaluated production of cytokines and chemokines, expression of HTLV-I associated genes, HTLV-1 proviral load (PVL), expression of HTLV-1 structural proteins, and apoptosis. RESULTS: There were no significant differences in cytokine and chemokine levels in the culture supernatants of HCT-5 and MT-2 cells treated with phosphate-buffered saline (PBS) or TCZ. No significant differences were detected in mRNA abundance of Tax or HBZ, PVL, expression of the HTLV-1 structural protein GAG, or apoptosis among HCT-5 and MT-2 cells treated with PBS or TCZ. CONCLUSIONS: TCZ had no effect the cytokine profiles, HTLV-1 gene and protein expression, PVL, or apoptosis in HTLV-1-infected T-cell lines. Thus, TCZ treatment has no effect on HTLV-1 infection in vitro.

High-energy ions from near-critical density plasmas via magnetic vortex acceleration.

Ultraintense laser pulses propagating in near-critical density plasmas generate magnetic dipole vortex structures. In the region of decreasing plasma density, the vortex expands both in forward and lateral directions. The magnetic field pressure pushes electrons and ions to form a density jump along the vortex axis and induces a longitudinal electric field. This structure moves together with the expanding dipole vortex. The background ions located ahead of the electric field are accelerated to high energies. The energy scaling of ions generated by this magnetic vortex acceleration mechanism is derived and corroborated using particle-in-cell simulations.

Stationary solutions of equations of motion for a radiating charged particle including a radiation reaction effect.

For a radiating charged particle, the radiation reaction force plays an important role in determining its motion. Several formulas have been proposed to describe the radiation reaction force. Stationary solutions of the Lorentz-Abraham-Dirac (LAD), Mo-Papas, Landau-Lifshitz, and Ford-O'Connell equations are obtained and compared for a charged particle under a static magnetic and a rotating electric field. The behaviors of the obtained solutions look quite similar. The relative differences of the Lorentz factor, calculating the values using the LAD equation compared to the other equations, are evaluated; these values are shown to be less than 10^{-6} in the regime where classical radiation reactions are applicable.