Ariella Coler-Reilly

HTLV-1 induces a Th1-like state in CD4 + CCR4 + T cells

Human T-lymphotropic virus type 1 (HTLV-1) is linked to multiple diseases, including the neuroinflammatory disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T cell leukemia/lymphoma. Evidence suggests that HTLV-1, via the viral protein Tax, exploits CD4+ T cell plasticity and induces transcriptional changes in infected T cells that cause suppressive CD4+CD25+CCR4+ Tregs to lose expression of the transcription factor FOXP3 and produce IFN-γ, thus promoting inflammation. We hypothesized that transformation of HTLV-1-infected CCR4+ T cells into Th1-like cells plays a key role in the pathogenesis of HAM/TSP. Here, using patient cells and cell lines, we demonstrated that Tax, in cooperation with specificity protein 1 (Sp1), boosts expression of the Th1 master regulator T box transcription factor (T-bet) and consequently promotes production of IFN-γ. Evaluation of CSF and spinal cord lesions of HAM/TSP patients revealed the presence of abundant CD4+CCR4+ T cells that coexpressed the Th1 marker CXCR3 and produced T-bet and IFN-γ. Finally, treatment of isolated PBMCs and CNS cells from HAM/TSP patients with an antibody that targets CCR4+ T cells and induces cytotoxicity in these cells reduced both viral load and IFN-γ production, which suggests that targeting CCR4+ T cells may be a viable treatment option for HAM/TSP.

Positive feedback loop via astrocytes causes chronic inflammation in virus-associated myelopathy

Human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a rare neurodegenerative disease characterized by chronic inflammation in the spinal cord. We hypothesized that a positive feedback loop driven by chemokines may be responsible for the chronic inflammation in HAM/TSP. We aimed to determine the identity of these chemokines, where they are produced, and how they drive chronic inflammation in HAM/TSP. We found that patients with HAM/TSP have extraordinarily high levels of the chemokine CXCL10 (also known as IP-10) and an abundance of cells expressing the CXCL10-binding receptor CXCR3 in the cerebrospinal fluid. Histological analysis revealed that astrocytes are the main producers of CXCL10 in the spinal cords of patients with HAM/TSP. Co-culture of human astrocytoma cells with CD4+ T cells from patients with HAM/TSP revealed that astrocytes produce CXCL10 in response to IFN-γ secreted by CD4+ T cells. Chemotaxis assays results suggest that CXCL10 induces migration of peripheral blood mononuclear cells to the central nervous system and that anti-CXCL10 neutralizing antibody can disrupt this migration. In short, we inferred that human T-lymphotropic virus type 1-infected cells in the central nervous system produce IFN-γ that induces astrocytes to secrete CXCL10, which recruits more infected cells to the area via CXCR3, constituting a T helper type 1-centric positive feedback loop that results in chronic inflammation.

CSF CXCL10, CXCL9, and Neopterin as Candidate Prognostic Biomarkers for HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis

Background Human T-lymphotropic virus type 1 (HTLV-1) -associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a rare chronic neuroinflammatory disease. Since the disease course of HAM/TSP varies among patients, there is a dire need for biomarkers capable of predicting the rate of disease progression. However, there have been no studies to date that have compared the prognostic values of multiple potential biomarkers for HAM/TSP. Methodology/Principal Findings Peripheral blood and cerebrospinal fluid (CSF) samples from HAM/TSP patients and HTLV-1-infected control subjects were obtained and tested retrospectively for several potential biomarkers, including chemokines and other cytokines, and nine optimal candidates were selected based on receiver operating characteristic (ROC) analysis. Next, we evaluated the relationship between these candidates and the rate of disease progression in HAM/TSP patients, beginning with a first cohort of 30 patients (Training Set) and proceeding to a second cohort of 23 patients (Test Set). We defined “deteriorating HAM/TSP” as distinctly worsening function (≥3 grades on Osames Motor Disability Score (OMDS)) over four years and “stable HAM/TSP” as unchanged or only slightly worsened function (1 grade on OMDS) over four years, and we compared the levels of the candidate biomarkers in patients divided into these two groups. The CSF levels of chemokine (C-X-C motif) ligand 10 (CXCL10), CXCL9, and neopterin were well-correlated with disease progression, better even than HTLV-1 proviral load in PBMCs. Importantly, these results were validated using the Test Set. Conclusions/Significance As the CSF levels of CXCL10, CXCL9, and neopterin were the most strongly correlated with rate of disease progression, they represent the most viable candidates for HAM/TSP prognostic biomarkers. The identification of effective prognostic biomarkers could lead to earlier detection of high-risk patients, more patient-specific treatment options, and more productive clinical trials.

Pathogenesis of Hand-Foot Syndrome induced by PEG-modified liposomal Doxorubicin

PEGL-DOX is an excellent treatment for recurrent ovarian cancer that rarely causes side-effects like cardiotoxicity or hair loss, but frequently results in Hand-Foot Syndrome (HFS). In severe cases, it can become necessary to reduce the PEGL-DOX concentration or the duration of the drug therapy, sometimes making it difficult to continue treatment. In this study, we prepared an animal model to compare the effects of DOX versus PEGL-DOX, and we noticed that only treatment with PEGL-DOX resulted in HFS, which led us to conclude that extravasation due to long-term circulation was one of the causes of HFS. In addition, we were able to show that the primary factor leading to the skin-specific outbreaks in the extremities was the appearance of reactive oxygen species (ROS) due to interactions between DOX and the metallic Cu(II) ions abundant in skin tissue. ROS directly disturb the surrounding tissue and simultaneously induce keratinocyte-specific apoptosis. Keratinocytes express the thermoreceptor TRPM2, which is thought to be able to detect ROS and stimulate the release of chemokines (IL-8, GRO, Fractalkine), which induce directed chemotaxis in neutrophils and other blood cells. Those cells and the keratinocytes then undergo apoptosis and simultaneously release IL-1β, IL-1α, and IL-6, which brings about an inflammatory state. In the future, we plan to develop preventative as well as therapeutic treatments by trapping the ROS.

Mogamulizumab, an Anti-CCR4 Antibody, Targets Human T-Lymphotropic Virus Type 1–infected CD8+ and CD4+ T Cells to Treat Associated Myelopathy

BACKGROUND Human T-lymphotropic virus type 1 (HTLV-1) can cause chronic spinal cord inflammation, known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Since CD4(+)CCR4(+) T cells are the main HTLV-1 reservoir, we evaluated the defucosylated humanized anti-CCR4 antibody mogamulizumab as a treatment for HAM/TSP. METHODS We assessed the effects of mogamulizumab on peripheral blood mononuclear cells from 11 patients with HAM/TSP. We also studied how CD8(+) T cells, namely CD8(+) CCR4(+) T cells and cytotoxic T lymphocytes, are involved in HTLV-1 infection and HAM/TSP pathogenesis and how they would be affected by mogamulizumab. RESULTS Mogamulizumab effectively reduced the HTLV-1 proviral load (56.4% mean reduction at a minimum effective concentration of 0.01 µg/mL), spontaneous proliferation, and production of proinflammatory cytokines, including interferon γ (IFN-γ). Like CD4(+)CCR4(+) T cells, CD8(+)CCR4(+) T cells from patients with HAM/TSP exhibited high proviral loads and spontaneous IFN-γ production, unlike their CCR4(-) counterparts. CD8(+)CCR4(+) T cells from patients with HAM/TSP contained more IFN-γ-expressing cells and fewer interleukin 4-expressing cells than those from healthy donors. Notably, Tax-specific cytotoxic T lymphocytes that may help control the HTLV-1 infection were overwhelmingly CCR4(-). CONCLUSIONS We determined that CD8(+)CCR4(+) T cells and CD4(+)CCR4(+) T cells are prime therapeutic targets for treating HAM/TSP and propose mogamulizumab as a new treatment.

HTLV-1 induces a Th1-like state in CD4+ CCR4+ T cells that produces an inflammatory positive feedback loop via astrocytes in HAM/TSP

The main feature of Human T-lymphotropic virus type I (HTLV-1) -associated myelopathy/tropical spastic paraparesis (HAM/TSP) pathogenesis is a virus-induced hyperactive immune response that produces chronic inflammation in the central nervous system (CNS), but the mechanism by which HTLV-1 deregulates the immune response is unknown. We recently reported a high frequency of HTLV-1-infected CCR4+ cells, including regulatory T cells. We showed that HTLV-1 induces a Th1-like state in these CCR4+ cells via T-bet expression. We have also found that CXCL10 plays an important role in a positive feedback loop that maintains inflammation in the CNS. Astrocytes, which were found to be the main producers of CXCL10 in the CNS, are another key player in the loop. In short, we postulate that infected CCR4+ Th1-like T cells produce interferon-γ, which stimulates astrocytes to produce CXCL10. We now have a much better understanding of the molecular mechanisms at play in HAM/TSP pathogenesis.

Mogamulizumab (Anti-CCR4) in HTLV-1–Associated Myelopathy

BACKGROUND Human T‐lymphotropic virus type 1 (HTLV‐1) causes the debilitating neuroinflammatory disease HTLV‐1–associated myelopathy–tropical spastic paraparesis (HAM–TSP) as well as adult T‐cell leukemia–lymphoma (ATLL). In patients with HAM–TSP, HTLV‐1 infects mainly CCR4+ T cells and induces functional changes, ultimately causing chronic spinal cord inflammation. We evaluated mogamulizumab, a humanized anti‐CCR4 monoclonal antibody that targets infected cells, in patients with HAM–TSP. METHODS In this uncontrolled, phase 1–2a study, we assessed the safety, pharmacokinetics, and efficacy of mogamulizumab in patients with glucocorticoid‐refractory HAM–TSP. In the phase 1 dose‐escalation study, 21 patients received a single infusion of mogamulizumab (at doses of 0.003 mg per kilogram of body weight, 0.01 mg per kilogram, 0.03 mg per kilogram, 0.1 mg per kilogram, or 0.3 mg per kilogram) and were observed for 85 days. Of those patients, 19 continued on to the phase 2a study and received infusions, over a period of 24 weeks, of 0.003 mg per kilogram, 0.01 mg per kilogram, or 0.03 mg per kilogram at 8‐week intervals or infusions of 0.1 mg per kilogram or 0.3 mg per kilogram at 12‐week intervals. RESULTS The side effects of mogamulizumab did not limit administration up to the maximum dose (0.3 mg per kilogram). The most frequent side effects were grade 1 or 2 rash (in 48% of the patients) and lymphopenia and leukopenia (each in 33%). The dose‐dependent reduction in the proviral load in peripheral‐blood mononuclear cells (decrease by day 15 of 64.9%; 95% confidence interval [CI], 51.7 to 78.1) and inflammatory markers in cerebrospinal fluid (decrease by day 29 of 37.3% [95% CI, 24.8 to 49.8] in the CXCL10 level and of 21.0% [95% CI, 10.7 to 31.4] in the neopterin level) was maintained with additional infusions throughout the phase 2a study. A reduction in spasticity was noted in 79% of the patients and a decrease in motor disability in 32%. CONCLUSIONS Mogamulizumab decreased the number of HTLV‐1–infected cells and the levels of inflammatory markers. Rash was the chief side effect. The effect of mogamulizumab on clinical HAM–TSP needs to be clarified in future studies. (Funded by the Japan Agency for Medical Research and Development and the Ministry of Health, Labor, and Welfare; UMIN trial number, UMIN000012655.)

Treatment of rheumatoid arthritis with biologics may exacerbate HTLV-1-associated conditions: A case report

Rationale: There are roughly 5 to 10 million persons infected with human T-lymphotropic virus type 1 (HTLV-1) worldwide, and the safety of treating this population with biologics remains poorly understood. Patient concerns and diagnosis: An HTLV-1-infected 66-year-old female with HTLV-1 uveitis (HU) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Her HU had been in remission and her HAM/TSP symptoms had been managed effectively with oral steroids for years. However, she developed severe rheumatoid arthritis (RA) after failing to respond well to conventional anti-rheumatic agents. Interventions: She was administered two intravenous 8mg/kg doses of the biologic tocilizumab. Outcomes: Subsequently, her RA symptoms resolved, but she suffered a recurrence of HU and exacerbation of HAM/TSP symptoms. When she was switched back to steroid-based treatment, HU and HAM symptoms both improved, but RA symptoms again worsened. Finally, an attempt to substitute the biologic abatacept and reduce the steroids failed when HAM/TSP symptoms again became aggravated. Lessons: To the best of our knowledge, this represents the first report worldwide of a biologic aggravating HTLV-1-associated conditions. This report suggests that caution is advised when using biologics to treat HTLV-1-infected patients, though further research is required to clarify the situation.

Patient satisfaction survey for HAM-net registrants

Patient registries can foster communication between doctors and patients who have rare diseases. In order to succeed in the long term, the managers of the registry must work to raise the satisfaction of the registrants. We conducted a satisfaction survey for the HTLV-1 associated myelopathy (HAM) patient registry known as “HAM-net.” Based on the data we collected, we made several alterations, mainly to the newsletter and website. This year we repeated the survey to determine if our alterations were beneficial or not by assessing changes in satisfaction levels. We surveyed 368 patients registered to HAM-net, inquiring about their general impression of HAM-net, the requisite telephone interviews, the newsletter, and the website. The response rate was 74.7%, and 198 registrants responded to the satisfaction survey both times. The number of individuals satisfied with HAM-net in general improved from 63.6% to 77.3% of registrants. More specifically, satisfaction with the newsletter rose dramatically but no significant change was observed for the website. Therefore we concluded that focusing on the newsletter is currently the best way to improve patient satisfaction. For example, we deduced that it is beneficial to increase the volume and quality of the articles. On the other hand, we could not demonstrate that frequently updating the website was beneficial to the patients. We inferred that the website must be improved to be more appealing and useful to the patients. In this study, we showed that properly investigating patient satisfaction using a detailed questionnaire can produce the data necessary to improve patient satisfaction levels. The best way to preserve a good relationship with the registered patients in the long term is to prioritize understanding the patients’ needs and continuously work to improve their satisfaction.

Humanized anti CCR4 antibody KW0761 targets HTLV-1 infected CD4+ CCR4+ and CD8+CCR4+ T cells to treat HAM/TSP

Human T-lymphotropic virus type I (HTLV-1) can cause HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T cell leukemia/lymphoma (ATL). Since the prognosis for HAM/TSP patients is extremely poor, there is a strong demand for a novel therapeutic strategy, especially one which would effectively reduce HTLV-1 proviral load, which is well-correlated with disease prognosis. CD4+CCR4+ T cells are the main HTLV-1 reservoir, and the defucosylated humanized anti-CCR4 antibody KW0761 has been approved in Japan as a treatment for ATL. KW0761 strongly binds to Fcγ receptor IIIa (FcγRIIIa) on natural killer cells and elicits powerful antibody-dependent cellular cytotoxicity (ADCC) against the CCR4+ cells. In this study, we evaluated KW0761 as a treatment for HAM/TSP using primarily ex vivo cell cultures. In addition, given that KW0761 would also target CD8+CCR4+ T cells, we sought to determine how this would likely affect HAM/TSP patients by elucidating the role of CD8+CCR4+ T cells in HAM/TSP pathogenesis. When applied to cultures of PBMCs from HAM/TSP patients (n=11), KW0761 effectively reduced HTLV-1 proviral load (56.4% mean reduction at 0.01μg/mL), spontaneous proliferation, and production of pro-inflammatory cytokines including IFN-γ. Like CD4+CCR4+ T cells, CD8+CCR4+ T cells from HAM/TSP patients exhibited high proviral loads and spontaneous IFN-γ production, unlike their CCR4-counterparts. CD8+CCR4+ T cells from HAM/TSP patients contained more IFN-γ+ cells and less IL-4+ cells than those from healthy donors. Notably, Tax-specific cytotoxic T lymphocytes that may help control the HTLV-1 infection were overwhelmingly CCR4-. In conclusion, we determined that CD8+CCR4+ T cells as well as CD4+CCR4+ T cells are prime therapeutic targets for treating HAM/TSP, and that KW0761 shows promise as a new treatment. Based on the results of this study, we have begun conducting an investigator -led Phase I/IIa clinical trial to test the safety and efficacy of KW0761 on HAM/TSP patients (UMIN000012655).