Human T-cell Lymphotropic Virus Research Articles

Rare Case Report of Adult T-Cell Leukemia / Lymphoma (ATLL), in the City of Macau- Rio Grande Do Norte; Brazil

Introduction:Adult T-cell leukemia / lymphoma (ATLL) is a rare type of malignant haemopathy with the Human T-Cell Lymphotropic Virus type I (HTLV-1) as its etiologic agent. The clinical picture includes skin lesions, hypercalcemia, elevated lactate dehydrogenase (LDH), adenomegaly, myelopathy and leukocytosis with atypical TCD4 lymphocytes.Objective:To report a case of a patient from the city of Macau-RN, with ATLL, presenting skin lesions, weight loss (> 13%), leukocytosis and supraclavicular lymph node enlargement. Case Description: Male patient, bricklayer, 67-year-old, hypertensive, was admitted to a hospital in Natal-RN, with severe itching, diffuse exanthematic skin lesions for 13 days, adynamia, associated with progressive, weight loss (P: 73Kg, 63Kg -13.6%), hyporexia, feverish (37.8 ° C), insidious and progressive drowsiness. Physical examination showed palpable lymphadenomegaly in the right supraclavicular chain, 1 cm, mobile and painless. Painful abdomen on deep palpation in the right hypochondrium and left iliac fossa, moderate hepatosplenomegaly. The blood count showed leukocytosis with the presence of atypical lymphocytes with convoluted nucleus (Flow-Cell), Creatinine (6.81), urea 349, hyperuricemia (14.9 mg / dL), hypercalcemia (12.8), LDH (723), Alkaline phosphatase (1388) GGT (183). Abdominal, kidney and urinary tract ultrasound revealed acute pancreatitis with signs of saponification (steatonecrosis of peripancreatic fat) and bilateral acute parenchymal nephropathy, respectively. The transthoracic echocardiogram identified aortic and mitral valve sclerosis. Immunophenotyping by flow cytometry found lymphoproliferative disease of mature TCD4 + cells, and the diagnosis of ATLL was confirmed by the serological reagent for HTLV-1. From then on, adequate treatment for ATLL was started with reversion of the clinical period, currently being followed up on an outpatient basis.Conclusions:The multiprofessional performance with accurate clinical investigation associated and specific laboratory exams such as immunophenotyping by flow cytometry and serological tests are essential for the early diagnosis and treatment of ATLL, a rare entity in the state of Rio Grande do Norte., Brazil and that high mortality when not diagnosed and treated early. Disclosures No relevant conflicts of interest to declare.

Adult T-Cell Leukemia/Lymphoma: A Cohort of 41 Cases Recorded in the Brazilian T-Cell Project

Introduction:Adult T cell Leukemia/Lymphoma (ATLL) is a mature T-Cell-neoplasm related to human T-cell lymphotropic virus type 1 (HTLV-1) infection that shows variable clinical presentation and adverse prognosis with shorter overall survival (OS) when compared to other peripheral T-cell lymphomas (PTCL). Previous epidemiological studies estimated cumulative incidence in endemic regions around the world. In Brazil, mainly due to its vast dimension, data collection has limitations and is subject to bias. In April 2015 theBrazilianT-cell longitudinal project initiative was launched. One of the primary purposes was the collection of epidemiological and clinical data from the most frequent subtypes of newly diagnosed PTCL. Among them, 41 cases of ATLL were recorded. Objectives:The aim of this study is to describe clinical features, frequency and overall survival (OS) of 41 cases of ATLL registered in the ongoingBrazilianT-Cell Project. Methods:This is an ambispective observational study design collecting baseline characteristics, clinical features including date of diagnosis, clinical subtypes, B symptoms, performance status, Ann-Arbor staging, HTLV-1 status, number of sites, nodal and extra nodal presentation and types of skin lesions, peripheral blood counts and biochemical tests, front-line treatment and best response after first-line treatment. REDcap Platform has been used to collect and store data and for descriptive analysis the IBM-SPSS version 24 was applied. Kaplan-Meier method estimated the OS, whereas Log-Rank tests to compare its curves. OS period was calculated from diagnosis date until death or last seen date, and event was death by any cause. Results:Out of 281 cases of PTCL registered so far, 41 were ATLL cases. The median age was 50 years (34-88), 25 (64%) female; a higher incidence of lymphoma subtype was observed (46%), followed by acute (29%), chronic (17%) and smoldering (8%). Most of the patients (85%) had advanced-stage disease (III-IV, Ann-Arbor) and 56% had B symptoms (Table 1); 73% received chemotherapy with anthracycline-based regimens (46.5% CHOEP; 33.5% CHOP; 20% others) whereas 17% were managed with immunotherapy and antiviral therapy. The overall response rate was 30%; no response or progression 46%; stable disease 9% and 15% no data available yet (Table 2). Median follow-up was 13 months and 25 months for 41% of alive patients. Two year OS was 39% (95%CI: 23-55%) (Figure 1). Smoldering and Chronic subtypes showed better OS when compared with acute and lymphoma (100% smoldering, 86% chronic; 30% lymphoma type and 13% acuteP=0.04) (Figure 2). The multivariate Cox Regression analysis found male gender (HR 10.9 95%CI: 3.0-39.7, P<0.0001) and albumin (HR 0.23 Beta -1.45 95%CI: 0.10-0.55, P=0.001) as significant prognostic factors for OS. Discussion:ATLL prognosis remains poor regardless of the type of treatment regimen and may be associated with the high incidence of lymphoma and acute subtypes, as well as advanced stage disease presentation. Despite the high number of cases seen in southeastern region of Brazil, it is important to emphasize there are still limited data from other regions. Albeit the sample size is small, these findings confirmed literature review data so far, with poor overall survival in a short time and gender and albumin as predictors of OS in the multivariate analysis. Conclusion:This study highlights the poor prognosis associated with ATLL. Moreover, it seems relevant to expand this study to all Brazilian regions. Hence, the need for early diagnosis and new treatment strategies, able to reduce mortality is warranted, that could possibly change the nature and spectrum of disease. Disclosures Federico: Spectrum:Consultancy, Membership on an entity's Board of Directors or advisory committees;Sandoz:Consultancy, Membership on an entity's Board of Directors or advisory committees;Cephalon/Teva:Research Funding;Mundipharma s.r.l.:Research Funding;Celgene:Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Millennium/Takeda:Research Funding;Roche:Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Takeda:Consultancy, Membership on an entity's Board of Directors or advisory committees.

Clinical Features and Outcome of HTLV-1 Carriers Diagnosed with Hodgkin Lymphoma in Peru: A Matched Cohort Study

Background: The human T-cell lymphotropic virus type 1 (HTLV-1) is an oncogenic retrovirus that affects CD4+ T-cell lymphocytes and is the cause for adult T-cell leukemia/lymphoma (ATLL), an aggressive peripheral T-cell neoplasm. Hodgkin-like ATLL subtype is a unique entity usually indistinguishable from Hodgkin lymphoma (HL) in the setting of HTLV-1 infection. HTLV-1 proviral integration and TCR Cb1 gene rearrangement testing are often necessary to differentiate both entities. However, less is known on HTLV-1 carriers diagnosed with HL (HTLV-1+ HL). We aim to compare survival outcomes between HTLV-1+ HL and matched controls treated at the National Cancer Institute in Peru. Methods: We reviewed medical records of patients diagnosed and managed for HL at the National Cancer Institute (Instituto Nacional de Enfermedades Neoplasicas, INEN) in Lima-Peru between 2002 and 2019. All patients should have had serologic evaluation for HTLV-1 infection at the time of diagnosis and should have had no suspicion (or confirmation) of a T-cell neoplasm during pathological examination. To investigate the impact of HTLV-1 infection on survival, we matched HTLV-1+ HL cases to HTLV-1-negative HL patients (controls) based on age, sex, cancer staging, and comorbidities. Treatment responses were assessed according to the Lugano criteria. Survival curves (event-free and overall survival) were estimated using the Kaplan-Meier method and compared with the Log-rank test. Multivariate Cox regression analysis was fitted and reported as Hazard Ratios (HR) with a 95% confidence interval (95% CI). Results: A total of 68 HL patients were identified and had sufficient data for analysis. Twenty cases had HTLV-1+ HL and 48 HTLV-1-negative HL. Table 1 summarizes the clinical features and outcomes of HL patients. In all patients the median age at diagnosis was 55 years with a female/male ratio of 1:1. Histological subtypes of HL were not statistically different among both groups with mixed cellularity as the most common subtype (HTLV-1+ HL 50% vs. HTLV-1-negative HL 38%), followed by nodular sclerosis (HTLV-1+ HL 15% vs. 31%), lymphocyte-rich (HTLV-1+ HL 15% vs. 15%), and nodular lymphocyte-predominant (HTLV-1+ HL 5% vs. 4%). ECOG performance status ≤2, advanced-stage disease (III-IV), presence of B symptoms, and presence of extranodal disease at the time of diagnosis were not different in both groups. Co-infections were presented in 5 (7.4%) HL patients (1 strongyloidiasis and 3 tuberculosis in the HTLV-1+ HL group, and 1 tuberculosis in the HTLV-1 negative HL group). All HTLV-1-negative HL patients were treated with first-line ABVD regimen compared to 18 (90%) HTLV-1+ HL patients; the remaining HTLV-1+ HL patients received involved-field radiation (n=1) and best supportive care (n=1). HTLV-1+ HL patients had inferior response rates (complete and partial response) compared to the matched control group (CR: 60% vs. 71%, and PR: 15% vs. 27%, respectively, p=0.015). At a median follow-up of 5-years, the overall survival was 55% in HTLV-1+ HL versus 67% in the matched control group (aHR: 1.39, 95%CI [0.6-3.4], p=0.47) (Figure 1). In the multivariate analysis, HTLV-1 infection was not a significant prognostic factor for worse event-free or overall survival. Relapsed rates were not different between both groups (HTLV-1+ HL 25% vs. 20.8%), however, more deaths were seen in the HTLV-1+ HL group (60% vs. 35%) but this was not statistically significant. Conclusion: To the best of our knowledge, this is the first case series describing the characteristics and outcome of HTLV-1 carriers diagnosed with HL. We found lower response rates to conventional treatment in HTLV-1+ HL patients compared to HTLV-1 negative individuals. However, long-term outcomes and relapsed rates were not different among groups. Further investigation is needed to confirm the potential impact of HTLV-1 infection in HL outcome. Disclosures No relevant conflicts of interest to declare.

Abstract PO-21: Investigating the role of exosomes derived from chemotherapy-resistant leukemia cells as mediators of cellular plasticity

Abstract Adult T-cell leukemia/lymphoma (ATLL) is a type of cancer with aggressive and rapid progression and has been linked to infection with the human T-cell lymphotropic virus type 1 (HTLV-1). Standard treatment consists of chemotherapy, radiation therapy, and stem-cell transplant, but the development of chemoresistance is common. Despite major advances in understanding the pathogenesis of the disease, patients who do not respond or achieve only transient responses remain a challenge for clinicians. Exosomes are small extracellular vesicles (30-150 nm in diameter) involved in intercellular communication and biologic material transference (including mRNA, miRNA, lipids, and metabolites) between the cells. Exosomes are an emerging key to understanding cancer cell communication and signaling pathway activation during the chemoresistance process. Our hypothesis is that exosomes secreted by chemoresistant (CR) ATLL cells can drive phenotypic changes in nonresistant ATLL cells. For this purpose, we induced chemoresistance using the CHOP protocol (dexamethasone, doxorubicin, and vincristine cocktail) in Jurkat cells (human acute T-cell leukemia/lymphoma). We determined IC50 values as 1 nM of dexamethasone, 0.05 μM of doxorubicin, and 1 nM of vincristine. Acquisition of chemoresistance was demonstrated by increased cell viability after treatment using IC50 of drugs cocktail. We found that Jurkat-CR have slower doubling time compared to respective naïve cells, 26 hours and 21 hours to CR-Jurkat and naïve, respectively. Exosomes derived from the putative chemoresistant were isolated and used to treat their respective naïve cells. There was an increase in cell proliferation after the exosome's treatment comparing to control for Jurkat (P<0.0035). However, there was no difference in proliferation comparing the treatment using exosomes derived from naïve cells and those derived from CR cells (P=0.91). The cell proliferation was higher after 78 hours of exosomes' treatment (P<0.001). Those results are preliminary data. Despite the differences in proliferation related to exosomes treatment, further experiments are required to prove our initial hypothesis. Citation Format: Taismara Garnica, Jéssika Lesbon, Arina Rochetti, Chantell Payton, Rhona Muirhead, Lisa Pang, David Argyle, Juliano da Silveira, Heidge Fukumasu. Investigating the role of exosomes derived from chemotherapy-resistant leukemia cells as mediators of cellular plasticity [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-21.

Single Institutional Experience on Cutaneous Manifestation of Adult T-cell Leukemia/Lymphoma - Potential Diagnostic Pitfall

Abstract Introduction/Objective Adult T-cell Leukemia/Lymphoma (ATLL) is an aggressive peripheral T-cell neoplasm caused by the human T-cell lymphotropic virus-1 (HTLV1). Approximately half of the patients diagnosed with ATLL have heterogeneous cutaneous manifestations and 1/3 of those patients have skin changes e.g. rashes, papules, and nodules at initial presentation. There is clinical and morphologic overlap between ATLL and other cutaneous T-cell neoplasms such as Cutaneous T-Cell Lymphoma/mycosis fungoides (CTCL/MF) which could pose a potential diagnostic challenge. Methods A retrospective study was conducted using PathNet system to search for HTLV1 positive ATLL patients. Clinicopathologic features of the patients with cutaneous involvement were analyzed. Results Total 31 patients with ATLL were identified. Nine patients (29%, median 54.5 years, range 47-67 years, male: female ratio 2:7) showed skin manifestations, and the cutaneous involvement with ATLL was confirmed by skin biopsy. Five (55.5%, 5/9) cases were initially misdiagnosed as CTCL/MF. Among the 5 patients, 2 presented with skin rash or diffuse erythematous patch/plaque before developing generalized lymphadenopathy or overt circulating atypical lymphocytosis; 2 developed severe pruritic rash with erythematous skin changes resembling Sezary syndrome; and 1 patient had folliculotrophic MF diagnosed 12 years before. Notably, atypical lymphocytosis (0.46- 41.19/µL) occurred in 3 of the 4 remaining cases. In addition, eight of the 9 patients displayed a variable level of CD3+/CD4+/ CD25strong+ abnormal T-cells on flow cytometry. A low-level bone marrow involvement (2-10%) was found in 8 of 9 cases. Elevated calcium levels were identified in 3 of 9 cases (33%). There were 7 of 8 patients (87.5%) who developed generalized lymphadenopathy when diagnosis of ATLL was rendered. Conclusion In patients with cutaneous manifestations, features including hypercalcemia, atypical lymphocytosis, lymphadenopathy, CD3/CD4/strong CD25 coexpression, and bone marrow involvement should prompt a test for HTLV1. Early diagnosis of ATLL can initiate proper treatment and improve patient clinical outcomes.

Restoration of ceramide de novo synthesis by the synthetic retinoid ST1926 as it induces adult T-cell leukemia cell death.

Ceramide (Cer) is a bioactive cellular lipid with compartmentalized and tightly regulated levels. Distinct metabolic pathways lead to the generation of Cer species with distinguishable roles in oncogenesis. Deregulation of Cer pathways has emerged as an important mechanism for acquired chemotherapeutic resistance. Adult T-cell leukemia (ATL) cells are defective in Cer synthesis. ATL is an aggressive neoplasm that develops following infection with human T-cell lymphotropic virus-1 (HTLV-1) where the viral oncogene Tax contributes to the pathogenesis of the disease. ATL cells, resistant to all-trans-retinoic acid, are sensitive to pharmacologically achievable concentrations of the synthetic retinoid ST1926. We studied the effects of ST1926 on Cer pathways in ATL cells. ST1926 treatment resulted in early Tax oncoprotein degradation in HTLV-1-treated cells. ST1926 induced cell death and a dose- and time-dependent accumulation of Cer in malignant T cells. The kinetics and degree of Cer production showed an early response upon ST1926 treatment. ST1926 enhanced de novo Cer synthesis via activation of ceramide synthase CerS(s) without inhibiting dihydroceramide desaturase, thereby accumulating Cer rather than the less bioactive dihydroceramide. Using labeling experiments with the unnatural 17-carbon sphinganine and measuring the generated Cer species, we showed that ST1926 preferentially induces the activities of a distinct set of CerS(s). We detected a delay in cell death response and interruption of Cer generation in response to ST1926 in Molt-4 cells overexpressing Bcl-2. These results highlight the potential role of ST1926 in inducing Cer levels, thus lowering the threshold for cell death in ATL cells.

Enhanced efficacy of JAK1 inhibitor with mTORC1/C2 targeting in smoldering/chronic adult T cell leukemia

Adult T-cell leukemia (ATL) is an aggressive T-cell lymphoproliferative malignancy of regulatory T lymphocytes (Tregs), caused by human T-cell lymphotropic virus 1 (HTLV-1). Interleukin 2 receptor alpha (IL-2Rα) is expressed in the leukemic cells of smoldering/chronic ATL patients, leading to constitutive activation of the JAK/STAT pathway and spontaneous proliferation. The PI3K/AKT/mTOR pathway also plays a critical role in ATL cell survival and proliferation. We previously performed a high-throughput screen that demonstrated additive/synergistic activity of Ruxolitinib, a JAK1/2 inhibitor, with AZD8055, an mTORC1/C2 inhibitor. However, effects of unintended JAK2 inhibition with Ruxolitinib limits it therapeutic potential for ATL patients, which lead us to evaluate a JAK1-specific inhibitor. Here, we demonstrated that Upadacitinib, a JAK-1 inhibitor, inhibited the proliferation of cytokine-dependent ATL cell lines and the expression of p-STAT5. Combinations of Upadacitinib with either AZD8055 or Sapanisertib, mTORC1/C2 inhibitors, showed anti-proliferative effects against cytokine-dependent ATL cell lines and synergistic effect with reducing tumor growth in NSG mice bearing IL-2 transgenic tumors. Importantly, the combination of these two agents inhibited ex vivo spontaneous proliferation of ATL cells from patients with smoldering/chronic ATL. Combined targeting of JAK/STAT and PI3K/AKT/mTOR pathways represents a promising therapeutic intervention for patients with smoldering/chronic ATL.

Polyploid Giant Cancer Cells, a Hallmark of Oncoviruses and a New Therapeutic Challenge.

Tumors are renowned as intricate systems that harbor heterogeneous cancer cells with distinctly diverse molecular signatures, sizes and genomic contents. Among those various genomic clonal populations within the complex tumoral architecture are the polyploid giant cancer cells (PGCC). Although described for over a century, PGCC are increasingly being recognized for their prominent role in tumorigenesis, metastasis, therapy resistance and tumor repopulation after therapy. A shared characteristic among all tumors triggered by oncoviruses is the presence of polyploidy. Those include Human Papillomaviruses (HPV), Epstein Barr Virus (EBV), Hepatitis B and C viruses (HBV and HCV, respectively), Human T-cell lymphotropic virus-1 (HTLV-1), Kaposi's sarcoma herpesvirus (KSHV) and Merkel polyomavirus (MCPyV). Distinct viral proteins, for instance Tax for HTLV-1 or HBx for HBV have demonstrated their etiologic role in favoring the appearance of PGCC. Different intriguing biological mechanisms employed by oncogenic viruses, in addition to viruses with high oncogenic potential such as human cytomegalovirus, could support the generation of PGCC, including induction of endoreplication, inactivation of tumor suppressors, development of hypoxia, activation of cellular senescence and others. Interestingly, chemoresistance and radioresistance have been reported in the context of oncovirus-induced cancers, for example KSHV and EBV-associated lymphomas and high-risk HPV-related cervical cancer. This points toward a potential linkage between the previously mentioned players and highlights PGCC as keystone cancer cells in virally-induced tumors. Subsequently, although new therapeutic approaches are actively needed to fight PGCC, attention should also be drawn to reveal the relationship between PGCC and oncoviruses, with the ultimate goal of establishing effective therapeutic platforms for treatment of virus-associated cancers. This review discusses the presence of PGCCs in tumors induced by oncoviruses, biological mechanisms potentially favoring their appearance, as well as their consequent implication at the clinical and therapeutic level.

Trends and epidemiological analysis of hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and human T-cell lymphotropic virus among Iranian blood donors: strategies for improving blood safety

BackgroundBlood transfusion is associated with potential risks of transfusion-transmitted infections (TTIs). Different strategies are needed to monitor blood safety and screen the donors’ efficacy, such as evaluation of the prevalence and trends of TTIs. This study was conducted to evaluate the prevalence and trends of TTIs, including hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV 1/2), and the impact of the donors’ characteristics such as age, sex, and donor status on the prevalence of TTIs in blood donors in seven large provinces of Iran from 2010 to 2018.MethodsThis study was conducted on the data collected from all blood donations in seven Iranian Blood Transfusion Centers including Ardabil, Alborz, Guilan, West Azarbaijan, North, Razavi, and South Khorasan from April 2010 to March 2018. Demographic characteristics, number of donations, donor status, and screening and confirmatory serological results of all blood donations were collected from Iranian Blood Transfusion Organizations (IBTO) national database. The prevalence and trend of HBV, HCV, HIV, and HTLV 1/2 infections were reported according to the donation year and donor’s characteristics.ResultsThe analysis of the prevalence and trend of TTIs in 3,622,860 blood donors showed a significant decreasing trend in first-time and regular donors. Additionally, compared to first- time donors, regular donors made safer blood donations with lower risks of HBV, HIV, HCV and HTLV 1/2 (P < 0.0001). Although the prevalence of HTLV 1/2 and HBV was higher in females, TTIs had a significant decreasing trend in males and females. Finally, it was found that the prevalence of HBV and HTLV 1/2 increased with age up to 40–49 years and then decreased thereafter.ConclusionsThe decreasing trends of TTIs in Iranian donors during 9 years may indicate that the various strategies implemented by IBTO have been effective in recent years. Other factors such as a decrease in the prevalence of specific TTIs in the general population might have also contributed to these declines.

Cryo-EM structure of the deltaretroviral intasome in complex with the PP2A regulatory subunit B56\u03b3

Human T-cell lymphotropic virus type 1 (HTLV-1) is a deltaretrovirus and the most oncogenic pathogen. Many of the ~20 million HTLV-1 infected people will develop severe leukaemia or an ALS-like motor disease, unless a therapy becomes available. A key step in the establishment of infection is the integration of viral genetic material into the host genome, catalysed by the retroviral integrase (IN) enzyme. Here, we use X-ray crystallography and single-particle cryo-electron microscopy to determine the structure of the functional deltaretroviral IN assembled on viral DNA ends and bound to the B56γ subunit of its human host factor, protein phosphatase 2 A. The structure reveals a tetrameric IN assembly bound to two molecules of the phosphatase via a conserved short linear motif. Insight into the deltaretroviral intasome and its interaction with the host will be crucial for understanding the pattern of integration events in infected individuals and therefore bears important clinical implications.

Status of humoral and cellular immune markers in human T-cell lymphotropic virus type 1 (HTLV-1) asymptomatic carriers in northeastern Iran, Mashhad.

It is estimated that about 10-20 million peoples are infected with human T-cell leukemia virus type 1 (HTLV-1) around the world and suffered from HTLV-related diseases. The present study was aimed to evaluate the cellular immunity, T-cell activation, humoral immunity, and inflammatory response hallmarks which affect HTLV-1-associated disease progression. A total of 78 participants were included in the study, comprising 39 HTLV-1 asymptomatic careers (ACs) and 39 healthy controls. The HTLV-proviral load (PVL) was determined via real-time PCR technique, and anti-HTLV antibody, sIL2R, sCD30, Neoptrin, hs-CRP, IgE, anti-VCA, anti-EBNA, and anti-EA were assessed by ELISA method. Mean PVL in ACs was 352.7 ± 418.7 copies/104 PBMCs. A significant higher level of sIL-2R was observed in ACs (P < 0.0001). Anti-VCA antibody titer in ACs and healthy controls was 80.72 ± 105.95 and 156.05 ± 130.71, respectively (P = 0.007). Intriguingly, suppression in ACs immune response was not observed. Resultantly, HTLV-1 infection has no effect on the humoral immune response in ACs but greater T-cell activation and function cellular responses were detected. Finally, more studies on various immune markers in adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients are greatly needed to illuminate the association of ACs' immune status with the development of the related diseases.

Human T-cell lymphotropic virus HBZ and tax mRNA expression are associated with specific clinicopathological features in adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is caused by human T-cell leukemia virus type 1 (HTLV-1). HTLV-1-associated mRNA, including HBZ and tax, is deeply involved in the pathogenesis of ATLL. Using 88 ATLL tissue samples, we performed in situ mRNA analysis of HBZ and tax, and investigated its association with clinicopathological characteristics of ATLL. The median value of HBZ signals (/1000 ATLL cells) was 795.2 (range: 0.4-4013.1) and of tax signals (/1000 ATLL cells) was 5.1 (range: 0.1-891.2). The low-expression HBZ group displayed significant increase in the number of skin lesion (P = 0.0283). The high-expression tax group displayed significant increase in the number of PD-1-positive tumor-infiltrating lymphocytes (P < 0.0001). In addition, we identified patients with very high-expression of tax signals (400 or more signals/1000 ATLL cells). These patients displayed significant reductions in the expression of HLA class I (P = 0.0385) and β2M (P = 0.0124). Moreover, these patients displayed significantly poor overall survival (median survival time [MST] 7.7 months, 95% confidence interval [CI] [4.7-NA]), compared with the survival in patients with less than 400 tax signals (MST 22.6 months, 95% CI [13.7-41.7]) (P = 0.0499). These results suggest that Tax-mediated treatment of ATLL should be performed carefully in the high-expression tax group. More detailed studies could elucidate the clinicopathological significance of HBZ and tax mRNA expressions in ATLL.

Post-translational modifications of hnRNP A1 differentially modulate retroviral IRES-mediated translation initiation.

The full-length mRNAs of the human immunodeficiency virus type-1 (HIV-1), the human T-cell lymphotropic virus type-1 (HTLV-1), and the mouse mammary tumor virus (MMTV) harbor IRESs. The activity of the retroviral-IRESs requires IRES-transacting factors (ITAFs), being hnRNP A1, a known ITAF for the HIV-1 IRES. In this study, we show that hnRNP A1 is also an ITAF for the HTLV-1 and MMTV IRESs. The MMTV IRES proved to be more responsive to hnRNP A1 than either the HTLV-1 or the HIV-1 IRESs. The impact of post-translational modifications of hnRNP A1 on HIV-1, HTLV-1 and MMTV IRES activity was also assessed. Results show that the HIV-1 and HTLV-1 IRESs were equally responsive to hnRNP A1 and its phosphorylation mutants S4A/S6A, S4D/S6D and S199A/D. However, the S4D/S6D mutant stimulated the activity from the MMTV-IRES to levels significantly higher than the wild type hnRNP A1. PRMT5-induced symmetrical di-methylation of arginine residues of hnRNP A1 enabled the ITAF to stimulate the HIV-1 and HTLV-1 IRESs while reducing the stimulatory ability of the ITAF over the MMTV IRES. We conclude that retroviral IRES activity is not only dependent on the recruited ITAFs but also relies on how these proteins are modified at the post-translational level.

HLA-B*35 as a new marker for susceptibility to human T-cell lymphotropic virus type 1 (HTLV-1) Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) in patients living in Argentina

BackgroundHuman T-cell lymphotropic virus type 1 (HTLV-1) is the etiological agent of HTLV associated myelopathy/ Tropical Spastic Paraparesis (HAM/TSP) and Adult T cell leukemia/lymphoma (ATLL), in around 2–5% of the infected individuals. Host genetic background might play a role in disease progression. Several previous studies across many countries report HLA haplotype to be one such factor. Here, we sequenced HLA-A, -B and -C of 66 individuals by Sequence-Based Typing (SBT), and compared the frequency of different alleles among ATLL patients, HAM/TSP patients, asymptomatic carriers and non-infected individuals living in Argentina.ResultsThe frequency of HLA-A, -B and -C alleles largely matched that of the general population in Argentina. We identified HLA-A*02, HLA-B*35 and HLA-C*07 as associated to protection from ATLL (p = 0.031), susceptibility to HAM/TSP (p < 0.001) and susceptibility to ATLL (p = 0.017), respectively. We also found a strong correlation between high proviral load (PVL) and disease (p = 0.008), but were unable to identify any particular allele associated with high or low PVL.ConclusionsWe have found HLA-A*02, HLA-B*35 and HLA-C*07 to be associated to protection from ATLL (HLA-A*02) and susceptibility to HAM/TSP (HLA-B*35) or to ATLL (HLA-C*07), respectively. Whereas HLA-A*02 protection from ATLL has already been extensively described in other regions of the world, this is the first report that links HLA-B*35 and an increased susceptibility to HAM/TSP. As for HLA-C*07 it has previously been associated to susceptibility to HAM/TSP in other countries but in our population it has been linked to ATLL.

Dynamic Scenario in HTLV-I Infection

In this article we present a model that describes the emerging dynamic scenario of infection with the human T-cell lymphotropic virus (HTLV-I). In this model we incorporate the phase of latency in the infection of the CD4+ lymphocytes, the immune response mediated by CD8+ T lymphocytes and the possible appearance of adult T-cell leukemia (ATL). The proposed model is a six-dimensional, non-linear system of ordinary differential equations that describes the dynamic interactions among different cell types. Several types of biological implications are discussed.

Is the human T-cell lymphotropic virus type 2 in the process of endogenization into the human genome?

Human T-cell lymphotropic virus type 2 (HTLV-2) infection has been shown to be endemic among intravenous drug users in parts of North America, Europe and Southeast Asia and in a number of Amerindian populations. Despite a 65% genetic similarity and common host humoral response, the human T-cell lymphotropic viruses type 1 (HTLV-1) and 2 display different mechanisms of host interaction and capacity for disease development. While HTLV-1 pathogenicity is well documented, HTLV-2 etiology in human disease is not clearly established. From an evolutionary point of view, its introduction and integration into the germ cell chromosomes of host species could be considered as the final stage of parasitism and evasion from host immunity. The extraordinary abundance of endogenous viral sequences in all vertebrate species genomes, including the hominid family, provides evidence of this invasion. Some of these gene sequences still retain viral characteristics and the ability to replicate and hence are potentially able to elicit responses from the innate and adaptive host immunity, which could result in beneficial or pathogenic effects. Taken together, this data may indicate that HTLV-2 is more likely to progress towards endogenization as has happened to the human endogenous retroviruses millions of years ago. Thus, this intimate association (HTLV-2/human genome) may provide protection from the immune system with better adaptation and low pathogenicity.

An exploration of cancer-related mortality attributable to infections in Italy

Abstract Background Previous attempts estimated the impact of infectious agents on cancer incidence in Italy, but the burden of carcinogenic infections on cancer mortality remains unknown. Therefore, we aimed to conduct a preliminary analysis in order to estimate this burden at country level. Methods We applied the global, regional, or national population attributable fractions for Helicobacter pylori, hepatitis B virus (HBV), hepatitis C virus (HCV), high-risk human papillomavirus (HPV) types, Epstein-Barr virus (EBV), human herpesvirus type 8 (HHV-8), and human T-cell lymphotropic virus type 1 (HTLV-1) - all microorganisms ranked as group 1 carcinogenic agents in human beings by the International Agency for Research on Cancer - to 2015 cancer-related deaths recorded according to the 10th International Classification of Diseases coding system in Italy. Results We estimated a total of 14,120 deaths attributable to carcinogenic infections, being 8.3% of the total of cancer-related deaths (n = 170,339). 58.8% of those occurred in men. H. pylori, HCV, HBC, and HPV accounted for 96.4% of the whole mortality burden attributable to carcinogenic infections in both sexes. H. pylori was responsible for 8,116 (57.5%) deaths due to gastric carcinoma (non-cardia and non-Hodgkin lymphoma). Hepatitis-related liver cancer accounted for a total 4,372 deaths: 3,812 due to HCV infection and 560 to HBV. Cancers related to HPV infection represented the third most frequent cause of deaths due to carcinogenic infections in women. Conclusions We estimated that one out of 12 cancer deaths in Italy was attributable to an infection sustained by carcinogenic agents. Such mortality burden is potentially avoidable, given that these infections are both potentially preventable and treatable. Thus, these estimates provide actionable metric of the burden for the implementation of specific public health measures. Further analyses will provide more accurate estimates of this disease burden. Key messages In Italy, one out of 12 cancer-related deaths is attributable to infections sustained by preventable or treatable carcinogenic agents. These estimates provide metric of carcinogenic infections for the implementation of specific public health measures to avert the related mortality burden.

Targeting aberrant DNA hypermethylation as a driver of ATL leukemogenesis by using the new oral demethylating agent OR-2100

AbstractAdult T-cell leukemia-lymphoma (ATL) is an aggressive hematological malignancy of CD4+ T cells transformed by human T-cell lymphotropic virus-1 (HTLV-1). Most HTLV-1–infected individuals are asymptomatic, and only 3% to 5% of carriers develop ATL. Here, we describe the contribution of aberrant DNA methylation to ATL leukemogenesis. HTLV-1–infected T-cells and their uninfected counterparts were separately isolated based on CADM1 and CD7 expression status, and differentially methylated positions (DMPs) specific to HTLV–infected T cells were identified through genome-wide DNA methylation profiling. Accumulation of DNA methylation at hypermethylated DMPs correlated strongly with ATL development and progression. In addition, we identified 22 genes downregulated because of promoter hypermethylation in HTLV-1–infected T cells, including THEMIS, LAIR1, and RNF130, which negatively regulate T-cell receptor (TCR) signaling. Phosphorylation of ZAP-70, a transducer of TCR signaling, was dysregulated in HTLV-1–infected cell lines but was normalized by reexpression of THEMIS. Therefore, we hypothesized that DNA hypermethylation contributes to growth advantages in HTLV-1–infected cells during ATL leukemogenesis. To test this idea, we investigated the anti-ATL activities of OR-1200 and OR-2100 (OR21), novel decitabine (DAC) prodrugs with enhanced oral bioavailability. Both DAC and OR21 inhibited cell growth, accompanied by global DNA hypomethylation, in xenograft tumors established by implantation of HTLV-1–infected cells. OR21 was less hematotoxic than DAC, whereas tumor growth inhibition was almost identical between the 2 compounds, making it suitable for long-term treatment of ATL patient-derived xenograft mice. Our results demonstrate that regional DNA hypermethylation is functionally important for ATL leukemogenesis and an effective therapeutic target.

Phylogenetic dating analysis of HTLV-1 from Chile suggests transmissions events related to ancient migrations and contemporary expansion

•Human T-cell lymphotropic virus type 1 (HTLV-1) is a globally-spread virus. It is estimated that there are about 5–10 million infected people in the world. HTLV is endemic in Chile, with higher seroprevalence among indigenous people. However, little is known about HTLV-1 genetic diversity, its introduction and dispersion in this country. To gain insights into these issues, a phylogenetic dating analysis was conducted based on Chilean and closed related long terminal repeat sequences. The time tree reconstruction showed that the introduction of HTLV-1aA occurred several times in Chile. It was hypothesized that these introductions took place at least in two different historical moments: (i) during the ancient human migrations and (ii) during/after the European colonization of South America. The present study contributes toward understanding the evolutionary history of HTLV-1 in Chile and South America.

Human T-cell lymphotropic virus type-1 infection associated with sarcopenia: community-based cross-sectional study in Goto, Japan.

Sarcopenia is characterized by a progressive skeletal muscle disorder that involves the loss of muscle mass and low muscle strength, which contributes to increased adverse outcomes. Few studies have investigated the association between chronic infection and sarcopenia. This study aimed to examine the association between human T-cell lymphotropic virus type-1 (HTLV-1) and sarcopenia. We conducted a cross-sectional study and enrolled 2,811 participants aged ≥ 40 years from a prospective cohort study in Japanese community dwellers during 2017–2019. Sarcopenia was defined as low appendicular skeletal muscle mass and low handgrip strength. The association between HTLV-1 seropositivity and sarcopenia was assessed using multivariable logistic regression. Odds ratio (OR) and 95% confidence interval (CI) of sarcopenia were analysed using HTLV-1 seropositivity. We adjusted for age, sex, body mass index, physical activity, systolic blood pressure, glycated haemoglobin, low-density lipoprotein cholesterol, and smoking and drinking status. Of 2,811 participants, 484 (17.2%) HTLV-1 infected participants were detected. HTLV-1 infection was significantly associated with sarcopenia (adjusted OR 1.46, 95% CI 1.03–2.07, P = 0.034). HTLV-1 was associated with sarcopenia among community-dwelling adults. Active surveillance and early detection of asymptomatic HTLV-1 infection might be beneficial to reinforce countermeasures to inhibit the progress of HTLV infection-associated sarcopenia.