Adult T-cell Leukemia/lymphoma Patients Research Articles

Abstract 3965: A cytolytic effector CD8+ T cell response is associated with remission in adult T-cell leukemia/lymphoma

Abstract Introduction: Adult T-cell leukemia/lymphoma (ATLL) is a rare blood cancer that develops in 3-5% of human T-lymphotropic virus-1 (HTLV1) carriers when the combination of viral oncoproteins and somatic mutations lead to malignant transformation of HTLV1 infected CD4+ T cells. ATLL has the worst overall survival among peripheral T cell lymphomas and remains a fatal disease despite efforts to improve outcomes over the last 35 years. First-line combination chemotherapy rarely achieves a durable response and two immune-modulating treatments (α-CCR4 and α-PD-1 monoclonal antibodies) failed in clinical trials. These findings highlight an urgent need to improve our understanding of the functional state of host immunity in ATLL patients. A host immune response against HTLV1 is pivotal in preventing ATLL development. Malignant ATLL cells can escape immune surveillance by preventing antigen presentation and engaging immune checkpoints. The prospect of an ATLL clone inducing systemic suppression was suggested in the literature but has not been directly examined. Furthermore, HTLV1-specific CD8+ cytotoxic T lymphocytes (CTLs) play an important role during viral latency, yet it remains unknown if they play a clinically relevant role during ATLL treatment. Methodology: In this work, we hypothesized that malignant ATLL cells will exhibit a suppressive immune phenotype and that effective therapeutic interventions will augment anti-ATLL CTLs to promote durable remission. We implemented an immune profiling approach to analyze PBMC samples from ATLL patients. Specifically, we developed a powerful 30-marker spectral flow panel to discriminate malignant ATLL cells from non-transformed lymphocytes (T, B, and NK cells) and monitor the expression of key transcription factors and markers associated with proliferation, cytolysis, and exhaustion. We analyzed diagnostic samples from the Montefiore-Einstein ATLL Biobank and samples collected during a phase 2 clinical trial aimed to assess the efficacy of a promising Belinostat/Zidovudine/Interferon-α combination therapy against ATLL (NCT02737046). Results: Our findings reveal that malignant ATLL cells exhibit an immune phenotype associated with robust immunosuppression and yet distinct from other suppressive immune cells (i.e., regulatory T cells). Additionally, we discovered that ATLL patient samples contained a unique population of phenotypically exhausted CD8+ T cells, the proportion of which was drastically reduced in patients under remission. Remarkably, a decrease in this exhausted subset correlated with the expansion of highly cytolytic CD8+ CTLs. Conclusion: Altogether, our findings suggest that ATLL cells may drive CD8+ CTLs into exhaustion to achieve immune evasion and that a robust anti-ATLL CTL response actively contributes to a remission state. Citation Format: Erik Guillen, Eric Liu, Yanhua Wang, Aditi Shastri, Alejandro Sica, Amit Verma, Xingxing Zhang, Juan Carlos Ramos, Hilda Ye, Gregoire Lauvau. A cytolytic effector CD8+ T cell response is associated with remission in adult T-cell leukemia/lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3965.

Development of Innate-Immune-Cell-Based Immunotherapy for Adult T-Cell Leukemia-Lymphoma.

γδ T cells and natural killer (NK) cells have attracted much attention as promising effector cell subsets for adoptive transfer for use in the treatment of malignant and infectious diseases, because they exhibit potent cytotoxic activity against a variety of malignant tumors, as well as virus-infected cells, in a major histocompatibility complex (MHC)-unrestricted manner. In addition, γδ T cells and NK cells express a high level of CD16, a receptor required for antibody-dependent cellular cytotoxicity. Adult T-cell leukemia-lymphoma (ATL) is caused by human T-lymphotropic virus type I (HTLV-1) and is characterized by the proliferation of malignant peripheral CD4+ T cells. Although several treatments, such as chemotherapy, monoclonal antibodies, and allogeneic hematopoietic stem cell transplantation, are currently available, their efficacy is limited. In order to develop alternative therapeutic modalities, we considered the possibility of infusion therapy harnessing γδ T cells and NK cells expanded using a novel nitrogen-containing bisphosphonate prodrug (PTA) and interleukin (IL)-2/IL-18, and we examined the efficacy of the cell-based therapy for ATL in vitro. Peripheral blood samples were collected from 55 patients with ATL and peripheral blood mononuclear cells (PBMCs) were stimulated with PTA and IL-2/IL-18 for 11 days to expand γδ T cells and NK cells. To expand NK cells alone, CD3+ T-cell-depleted PBMCs were cultured with IL-2/IL-18 for 10 days. Subsequently, the expanded cells were examined for cytotoxicity against ATL cell lines in vitro. The proportion of γδ T cells in PBMCs was markedly low in elderly ATL patients. The median expansion rate of the γδ T cells was 1998-fold, and it was 12-fold for the NK cells, indicating that γδ T cells derived from ATL patients were efficiently expanded ex vivo, irrespective of aging and HTLV-1 infection status. Anti-CCR4 antibodies enhanced the cytotoxic activity of the γδ T cells and NK cells against HTLV-1-infected CCR4-expressing CD4+ T cells in an antibody concentration-dependent manner. Taken together, the adoptive transfer of γδ T cells and NK cells expanded with PTA/IL-2/IL-18 is a promising alternative therapy for ATL.

Whole-genome CRISPR screening identifies molecular mechanisms of PD-L1 expression in adult T-cell leukemia/lymphoma

AbstractAdult T-cell leukemia/lymphoma (ATLL) is an aggressive T-cell malignancy with a poor prognosis and limited treatment options. Programmed cell death ligand 1(PD-L1) is recognized to be involved in the pathobiology of ATLL. However, what molecules control PD-L1 expression and whether genetic or pharmacological intervention might modify PD-L1 expression in ATLL cells are still unknown. To comprehend the regulatory mechanisms of PD-L1 expression in ATLL cells, we performed unbiased genome-wide clustered regularly interspaced short palindromic repeat (CRISPR) screening in this work. In ATLL cells, we discovered that the neddylation-associated genes NEDD8, NAE1, UBA3, and CUL3 negatively regulated PD-L1 expression, whereas STAT3 positively did so. We verified, in line with the genetic results, that treatment with the JAK1/2 inhibitor ruxolitinib or the neddylation pathway inhibitor pevonedistat resulted in a decrease in PD-L1 expression in ATLL cells or an increase in it, respectively. It is significant that these results held true regardless of whether ATLL cells had the PD-L1 3' structural variant, a known genetic anomaly that promotes PD-L1 overexpression in certain patients with primary ATLL. Pevonedistat alone showed cytotoxicity for ATLL cells, but compared with each single modality, pevonedistat improved the cytotoxic effects of the anti–PD-L1 monoclonal antibody avelumab and chimeric antigen receptor (CAR) T cells targeting PD-L1 in vitro. As a result, our work provided insight into a portion of the complex regulatory mechanisms governing PD-L1 expression in ATLL cells and demonstrated the in vitro preliminary preclinical efficacy of PD-L1–directed immunotherapies by using pevonedistat to upregulate PD-L1 in ATLL cells.

Examining Adult T-Cell Leukemia/Lymphoma in the United States: A Hospital Based Study of Demographics and Survival Outcomes Focused on Hispanics

BACKGROUND: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive neoplasm of mature CD4(+) T-cells caused by infection by Human T-lymphotropic virus type1 (HTLV-1) ( Arch Pathol Lab Med PMID: 24476526). ATLL affects 5% of those infected by HTLV-1, mainly in Africa, the Caribbean, Japan, and South America ( Rev Assoc Med Bras (1992) PMID: 27925051). In the United States (US) it is usually seen in immigrants from these regions ( Arch Pathol Lab Med PMID: 24476526). While there are treatment options for ATLL, it is often refractory to conventional chemotherapy and in general has a poor prognosis ( Actas Dermosifiliogr (Engl Ed) PMID: 29685460, Cancer Treat Res PMID: 30596217). Considering its poor outcomes and unique epidemiology, more information is needed regarding its effect in Hispanics (HI) vs Non-hispanics (NH) in the US. METHODS: Data were analyzed on ATLL patients in the US reported to the National Cancer Database (NCDB) between 2004 and 2019. Demographic and treatment characteristics were compared between ethnic groups. Kaplan-Meier and Cox regression analyses were used to compare overall survival (OS) between HI and NH populations. Multivariate analysis and propensity score matching was performed with adjustment for age, stage, comorbidity score, and insurance status, type of facility and great circle distance. RESULTS Of the 3073 ATLL patients studied between 2004 and 2019, 9% were HI, and 87% NH. In both groups, most here male with 65% of HI and 66% of NH. At diagnosis, HI patients were younger with a median age of 35 years vs. 42 years in NH (p<0.001). HI patients were more likely to be <65 at diagnosis 89% vs 83% (p=0.044). Most HI and NH patients identified as white (86% vs 68%), followed by black (4% vs 25%). Private insurance was the most common type in both groups (50% vs 57%), followed by government sponsored insurance (33% vs 36%). HI had a higher rate of being uninsured 12% vs 6% (p<0.001). Regarding Census Median Income (2008-2012), the most prevalent bracket for HI was $48,000 - $62,000 (28%), compared to NH $63,000+ (33%). HI were more likely to have an income of less than $38,000 (21% vs 18%) (p=0.512). HI also tended to live closer to their hospital (Great Circle Distance), with a median of 8.0 miles, vs NH at median of 11.6 miles (p=0.001). On survival analysis; the survival probability at 2, 5 and 10 years of HI vs NH were (64% vs 58%), (53% vs 48%), and (51% vs 43%), respectively. The median survival (MS) time was 3.7 years for NH and not reached for HI. The overall survival (OS) difference favoring HI was marginal and non-statistically significant (p=0.067). Independently, on multivariate analysis, NH ethnicity was not associated with worse OS (HR 1.25, CI 0.9-1.74, p=0.18). Interestingly, the propensity matched analysis demonstrated significant MS difference between HI vs NH (median 1.84 vs. 1.53 years). CONCLUSION Although the difference in OS in this study between HI and NH was not significant, there is a trend in the data showing increased survivability among HI despite patients in this group being more likely to be uninsured or in a lower income bracket. One possible explanation is that HI tended to present at an earlier age when compared to NH. It is evident that more data is needed to increase the power of these findings. Therefore, further study into the disease differences between these two groups, early detection, tumor markers, and targeted treatments will be necessary to improve the overall poor prognosis of this aggressive disease.

Clinical Outcomes of Tucidinostat Therapy for Relapsed/Refractory Adult T-Cell Leukemia-Lymphoma (ATL) in Clinical Practice

【Objective】 Tucidinostat, approved for relapsed/refractory adult T-cell leukemia-lymphoma (ATL) treatment in June 2021 in Japan, demonstrated an objective response rate (ORR) of 30.4%, progression-free survival (PFS) of 1.7 months (95% CI: 0.8-7.4), and overall survival (OS) of 7.9 months (95% CI: 2.3-18.0) in a phase IIb trial for 23 cases of relapsed/refractory adult T-cell leukemia-lymphoma (ATL) in Japan. We report the treatment results of this agent in Miyazaki Prefecture. 【Methods】 We retrospectively analyzed the treatment results of relapsed/refractory ATL patients who received Tucidinostat at 6 facilities within the Miyazaki prefecture, and HTLV-1 endemic area in southwest Japan, after its approval. All clinical procedures for patients were part of routine care, and the requirement for written patient consent was waived by the committee in view of the retrospective nature of this study. Approved study protocols were presented on the web site in an opt-out format, ensuring patients had the right to refuse participation in the study. In accordance with these protocols, clinical information was then collected. 【Results】 From October 2021 to July 2023, Tucidinostat was administered to 24 cases of relapsed/refractory ATL. The median age at the start of administration was 72.5 (41-85), with 13 cases of the acute type, 7 cases of the lymphoma type, and 4 cases of poor-prognosis chronic type. The median number of prior treatment regimens was 2 (1-4), with 19 cases of multi-drug combination chemotherapy, 18 cases of mogamulizumab, and 5 cases of oral chemotherapy. There were no cases of transplantation. The period from prior treatment to Tucidinostat administration was 3.2 months (0-27.5 months), and the disease stage at the start of Tucidinostat administration was relapse in 7 cases and refractory in 17 cases. The starting dose was 40mg/day (twice a week) in 19 cases and 20mg/day (twice a week) in 4 cases, with a median number of total treatment courses of 3 (1-20). Of the 24 cases,19 had their dose reduced or treatment suspended because of myelosuppression. The best treatment response was complete response(CR) in 5 cases, parcial response (PR) in 8 cases, Stable Disease(SD) in 8 cases, with an efficacy rate (CR/PR) of 54.2%. The PFS after the start of treatment was 3.7 months (1.8-7.8), and the OS after the start of treatment was 8.6 months. The reason for discontinuation of administration were progression disease in 15 cases, intolerance in 1 case (skin rash in 1 case), and severe complications in 1 case (cryptococcal meningitis). In the Cox proportional hazards model analysis, considering the clinical characteristics at the initiation of Tucidinostat, the initial sIL-2R level negatively impacted PFS. PFS was then stratified using an sIL-2R cutoff of 5000 U/mL, showing a Median Survival Time (MST) of PFS: 0.65 months for those below the cutoff versus 0.15 months for those above it, p=0.006 (log-rank).“A similar trend was observed for OS (Median OS: not reached vs. 0.53 months, p=0.032 (log-rank)). 【Conclusion】 In relapsed/refractory ATL, Tucidinostat achieved treatment results similar to those in the phase IIb trial in clinical practice. In particular, for cases with an sIL2-R value of less than 5000, it was suggested that Tucidinostat may be a meaningful treatment option.

Outcomes of Allogeneic Transplantation for Adult T-Cell Leukemia/Lymphoma in Adolescents and Young Adult (AYA) and Young Patients

Introduction Allogeneic hematopoietic stem cell transplantation (allo-HSCT) provides a durable remission for patients with adult T-cell leukemia/lymphoma (ATL). Reduced-intensity regimens (RIC) have been increasingly used in ATL patients due to their old age and higher non-relapse mortality. However, the role of RIC regimen has not been fully evaluated among ATL patients aged <50 years. We here conducted a nationwide study to evaluate the prognostic impact of conditioning intensity on the post-transplant outcomes in ATL patients aged <50 years. Methods The clinical data of patients aged <50 years who underwent their first allo-HSCT between January 2001 and December 2020 were collected from the Transplant Registry Unified Management Program of the Japan Society for Hematopoietic Cell Transplantation. Cox proportional hazards regression models were used to evaluate variables potentially affecting overall survival (OS), graft-versus-host disease (GVHD)- and relapse-free survival (GRFS), and chronic GVHD-free survival (CRFS). Fine and Gray proportional hazards models were used to evaluate variables potentially affecting cumulative incidences of relapse (CIR) and non-relapse mortality (NRM). CIR and NRM were estimated using cumulative incidence curves to accommodate competing events. A two-sided P-value ≤0.05 was considered to be significant. To examine the effect modification, a threshold for P interaction <0.10 was used to indicate significant differences across prespecified subgroups. Results This study included 73 and 330 patients who were <40 years old (adolescents and young adults [AYA] patients) and 40-49 years old (young patients), respectively. In AYA patients, the median age at HSCT was 36 years (range, 20-39). RIC regimen was used in 16 out of 57 AYA patients (21.9%), and in 74 out of 330 young patients (22.4%) (P=1.000). There was no significant difference of the patient characteristics regarding comorbidity, performance status at HSCT, disease status, clinical subtype, and donor type. The estimated 3-year OS rates were 61.8% and 43.1% in AYA and young patients, respectively (P=0.005); the estimated 3-year CRFS rates were 35.8% and 22.6% in AYA and young patients, respectively (P=0.008); and the estimated 3-year GRFS rates were 26.7% and 15.1% in AYA and young patients, respectively (P=0.006). The estimated 3-year CIR were 36.3% and 39.3% in AYA and young patients, respectively (P=0.407); and the estimated 3-year NRM were 17.0% and 23.4% in AYA and young patients, respectively (P=0.113). In addition, the use of RIC regimen was associated with lower NRM than that of MAC regimen (P=0.015), but there was no significant difference of OS, CRFS, GRFS, and CIR between MAC and RIC regimens. The multivariate analyses revealed that young patients were significantly associated with worse OS (Hazard ratio (HR) [95% confidential interval], 1.62 [1.10-2.39]; P=0.015), CRFS (HR, 1.51 [1.10-2.06]; P=0.010), and GRFS (HR, 1.49 [1.11-1.99]; P=0.008) than AYA patients. The utilization of RIC regimen was significantly associated with lower NRM (HR, 0.46 [0.24-0.86]; P=0.015). To find the optimal selection of conditioning intensity (MAC vs. RIC) by patient's age, we next evaluated the effect modification. In the subgroup analysis, there was significant interaction of conditioning intensity with patient's age (P interaction=0.002) in NRM but not in OS, CRFS, GRFS, and CIR. Among AYA patients, the estimated 1-year NRM were 12.5% and 18.8% in MAC and RIC regimens, respectively (P=0.085). Among young patients, the estimated 1-year NRM were 23.5% and 8.2% in MAC and RIC regimens, respectively (P<0.001). Conclusion The present study clarified that AYA patients exhibited better post-transplant outcomes than young patients, indicating the prognostic value of patient's age in ATL patients aged <50 years. Moreover, no significant differences were observed in OS, CRFS, GRFS, and CIR between RIC and MAC regimens, but the utilization of RIC regimen would reduce the risk of non-relapse death among young patients. These facts suggested that RIC regimen could be an alternative option for ATL patients aged 40-49 years.

Single-Cell RNA Sequencing Revealed the YY1/EZH2/MLH1 Axis As a Possible Therapeutic Target of Intractable Adult T-Cell Leukemia

Background: Due to clinical heterogeneity of adult T-cell leukemia/lymphoma (ATL) and its diverse genetic abnormality, common therapeutic targets of ATL remains unclear. Whereas the YY1/EZH2 axis regulates global epigenetic modification of genes in ATL, its downstream target genes have not been fully elucidated. Meanwhile, DNA mismatch repair proteins may be targeted in ATL. Here we explored underlying molecular axes for ATL progression through comprehensive single-cell RNA-sequencing (sc-RNA-seq). Methods: Peripheral blood of 42 ATL patients and asymptomatic HTLV-1 carriers in addition to two cell lines of ATL43T and ED+ were subjected to the following analyses. Molecular markers associated with their clinical phenotypes were extracted through sc-RNA-seq analysis. Expression levels of DNA mismatch repair proteins (MLH1, MSH2) and target molecules were validated by flow cytometry. Finally, their function was verified through lentiviral shRNA-dependent knockdown and molecular-targeting reagents. Results: While the frequencies of CADM1+ cells among CD4+ T cells were generally correlated with HTLV-1 proviral loads (R = 0.76, p < 0.001), substantial CADM1+ cells were detected but did not increase in some long-remitted cases; thus, CADM1+ cells are biologically heterogeneous. sc-RNA-seq of CADM1+ cells of four ATL cases identified a cluster of CD48-deficient cells. in silico promoter analysis of the cluster extracted a transcription factor YY1 as a candidate for common master regulators. EZH2 and the putative driver genes (CELF2, PTPRC, CBLB, ATXN1, IKZF2) were identified as differentially expressed genes (DEGs) in the cluster. The EZH2-overexpressed cluster was increased in acute-type ATL compared with remitted ATL and smoldering-type ATL. Interestingly, the cluster increased moderately in the other smoldering-type ATL, which required UVB irradiation due to intractable skin lesion. Given that YY1 and EZH2 were up-regulated in acute-type ATL, the cluster may represent tumor aggressiveness. Furthermore, biphasic expression of YY1/EZH2 was observed in 2 acute-type ATL, which indicates that the EZH2 high ATL cells confer malignant signature. In-house analysis on microarray dataset GSE55851 specified the MLH1 associated with YY1/EZH2. MLH1 within CADM1+ fraction was down-regulated in ATL patients with remission (n = 7) but maintained in progressive ATL (n = 6) (p < 0.05). Lentiviral shYY1 knockdown resulted in down-regulation of MLH1 in both ATL43T and ED+ (p < 0.01). The EZH1/2 inhibitor valemetostat down-regulated EZH2 (p = 0.018) and MLH1 (p = 0.014) in primary ATL cells. Finally, knockdown of either YY1 or MLH1 suppressed proliferation of ATL43T and ED+ (p < 0.0001). Conclusions: Our findings indicate that down-regulation of MLH1 through YY1/EZH2 inhibition plays a key role in the treatment of aggressive ATL.

Anti-HTLV-1 immunity combined with proviral load as predictive biomarkers for adult T-cell leukemia-lymphoma.

Human T-cell leukemia virus type 1 (HTLV-1) establishes chronic infection in humans and induces a T-cell malignancy called adult T-cell leukemia-lymphoma (ATL) and several inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Persistent HTLV-1 infection is established under the pressure of host immunity, and therefore the immune response against HTLV-1 is thought to reflect the status of the disease it causes. Indeed, it is known that cellular immunity against viral antigens is suppressed in ATL patients compared to HAM/TSP patients. In this study, we show that profiling the humoral immunity to several HTLV-1 antigens, such as Gag, Env, and Tax, and measuring proviral load are useful tools for classifying disease status and predicting disease development. Using targeted sequencing, we found that several carriers whom this profiling method predicted to be at high risk for developing ATL indeed harbored driver mutations of ATL. The clonality of HTLV-1-infected cells in those carriers was still polyclonal; it is consistent with an early stage of leukemogenesis. Furthermore, this study revealed significance of anti-Gag proteins to predict high risk group in HTLV-1 carriers. Consistent with this finding, anti-Gag cytotoxic T lymphocytes (CTLs) were increased in patients who received hematopoietic stem cell transplantation and achieved remission state, indicating the significance of anti-Gag CTLs for disease control. Our findings suggest that our strategy that combines anti-HTLV-1 antibodies and proviral load may be useful for prediction of the development of HTLV-1-associated diseases.

Therapeutic approaches for HTLV-1-associated adult T-cell leukemia/lymphoma: a comprehensive review.

Adult T-cell leukemia/lymphoma (ATLL), an infrequent malignancy resultant from human T-cell lymphotropic virus type I (HTLV-1), exhibits a spectrum of phenotypes, encompassing acute, smoldering, lymphomatous, and chronic variants, each bearing distinct clinical presentations. The preponderant acute manifestation is characterized by hypercalcemia, systemic manifestations, organomegaly, and dermatological eruptions. Conversely, the chronic phenotype is typified by lymphocytosis and/or cutaneous eruptions, while smoldering ATLL assumes an asymptomatic course. Immunocompromise afflicts ATLL patients, heightening their vulnerability to opportunistic infections that frequently intricately intertwine with disease progression. Therefore, an early diagnosis is crucial to manage the disease appropriately. While conventional chemotherapeutic regimens have shown limited success, especially in acute and lymphoma types, recent studies suggest that allogeneic stem cell transplantation might enhance treatment results because it has shown promising outcomes in some patients. Novel therapeutics, such as interferon and monoclonal antibodies, have also shown promise, but more research is needed to confirm their efficacy. Moreover, the identification of biomarkers for ATLL and genetic changes in HTLV-1 infected cells has led to the development of targeted therapies that have shown remarkable success in clinical trials. These targeted therapies have the potential to offer a more personalized approach to the treatment of ATLL. The aim of our review is to elaborate on conventional and novel therapies and the efficiency of mentioned treatments.

CDK9 Inhibitor Induces Apoptosis, Autophagy, and Suppression of Tumor Growth in Adult T-Cell Leukemia/Lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is a hematopoietic malignancy with a poor prognosis that develops in approximately 5% of human T-cell leukemia virus type 1 (HTLV-1) carriers. Cyclin-dependent kinase 9 (CDK9), together with Cyclin T, forms a transcription elongation factor, positive transcription elongation factor b (P-TEFb). P-TEFb promotes transcriptional elongation by phosphorylating the second serine (Ser2) of the seven amino acid repeat sequence in the C-terminal domain of RNA polymerase II (RNAP II). CDK9 inhibitors suppress cell proliferation by inducing apoptosis in chronic lymphocytic leukemia and breast cancer but there are no reports on autophagy of CDK9 inhibitors. Here, we investigated the effect of LY2857785, a novel CDK9 selective inhibitor, on cell death in ATL-related cell lines in vitro, freshly isolated cells from ATL patients ex vivo, and on ATL tumor xenografts in NOD/SCID mice in vivo. LY2857785 significantly reduced cell viability and induced apoptosis, as shown by annexin V-positive cells, cleaved poly(ADP-ribose) polymerase (PARP), and cleaved caspase-3, and suppressed the levels of anti-apoptotic protein myeloid cell leukemia-1 (MCL-1). LY2857785 decreased RNAP II Ser2 phosphorylation and downstream c-Myc protein levels. Interestingly, LY2857785 also increased microtubule-associated proteins 1A/1B light chain 3B (LC3)-II binding to autophagosome membranes. Furthermore, LY2857785 decreased the viability of freshly isolated ATL cells and induced apoptosis. Finally, LY2857785 significantly decreased the growth of ATL tumor xenografts. These results suggest that LY2857785 induces cell death of ATL cells by MCL-1-dependent apoptosis and autophagy and has anti-tumor activity.

Differential modulation of IL-4, IL-10, IL-17, and IFN-γ production mediated by IgG from Human T-lymphotropic virus-1 (HTLV-1) infected patients on healthy peripheral T (CD4+, CD8+, and γδ) and B cells.

Human T-lymphotropic virus 1 (HTLV-1) infected individuals remain as asymptomatic carriers (ACs) or can develop the chronic neurological disorder HTLV-1-associated myelopathy/Tropical Spastic Paraparesis (HAM/TSP) or the adult T-cell leukemia/lymphoma (ATLL), and the immunological mechanisms involved in this pathologies need to be elucidated. Recently, it has been demonstrated that induced or naturally developed IgG repertoires obtained from different groups of donors, grouped by immune status, can modulate human T and B cell functions. Here we aimed to evaluate if the IgG obtained from HTLV-1-infected ACs, HAM/TSP, and ATLL patients can differentially modulate the production of cytokines by human T and B cells. With this purpose, we cultured PBMCs with IgG purified from ACs, HAM/TSP, or ATLL donors and evaluated the frequency and intracellular cytokine production by flow cytometry. Our results indicate that IgG from HAM/TSP patients could induce an augment of IL-17-producing CD4+ T cells, reduce the frequency of IL-4-producing CD4+ T cells, increase IFN-γ-producing CD8+ T cells, and reduce IL-4-producing CD8+ T cells. IgG from ATLL could reduce the frequency of IL-4-producing CD4+ T cells, similarly to IgG from HAM/TSP /TSP, and could reduce the frequency of IFN-γ-producing γδT cells without influence on IL-17- and IL4-producing γδT and could reduce the frequency of IL-10- producing B cells. Finally, IgG from both HAM/TSP and ATLL patients could reduce the frequency of IFN-γ producing B cells. In conclusion, these results suggest that these preparations are active, partly overlapping in their effects, and able to elicit distinct effects on target populations.

Adult T-cell leukemia/lymphoma in HTLV-1 non-endemic regions

BackgroundHTLV-1 infection is a neglected disease, despite producing neurological and lymphoproliferative severe illnesses and affect over 10 million people worldwide. Roughly 5% of HTLV-1 carriers develop Adult T-cell leukemia/lymphoma (ATLL), one of the most aggressive hematological malignancies. MethodsA national HTLV-1 register exists since 1989 in Spain, a non-endemic country with a large migrant flow from Latin America and Equatorial Africa, where HTLV-1 is endemic. The main features of all patients diagnosed with ATLL in Spain up to date are reported. ResultsA total of 451 cases of HTLV-1 infection had been reported in Spain until the end of year 2022. ATLL had been diagnosed in 35 (7.8%). The current average incidence of ATLL in Spain is of two cases per year. Women represent 57% of ATLL patients. Mean age at diagnosis was 47 years-old. Roughly 57% were Latin Americans and 26% Africans. At diagnosis, the majority presented with acute or lymphoma clinical forms. Survival was shorter than one year in most of them.Mean HTLV-1 proviral load was significantly greater in ATLL patients than in asymptomatic HTLV-1 carriers (2,305 vs 104 copies/104 PBMC). HTLV-1 subtyping in 6 ATLL patients found the 1a transcontinental variant (n = 4) and the Japanese variant (n = 2). All ATLL patients were negative for HIV-1, did not develop HTLV-1-associated myelopathy and were not transplant recipients. ConclusionThe rate of ATLL is very low in Spain and mostly associated to migrants from HTLV-1 endemic regions. Given the poor clinical outcome of ATLL, HTLV-1 testing should be performed at least once in all migrants coming from HTLV-1 endemic countries and in natives who have lived in or had sex partners from such regions.

Investigating the effect of MAP2K1 gene (MEK1) in MAPK pathway in the induction of adult T-cell leukemia/lymphoma (ATLL).

HTLV-1 is responsible for two important diseases, HAM/TSP and ATLL. Approximately 10 to 20 million people are infected with HTLV-1 worldwide. Identifying altered genes in different cancers is crucial for finding potential treatment strategies. One of the proteins of the RAS/MAPK signaling pathway is MEK1, which is made from the MAP2K1 gene. The effects of the MAP2K1 gene on the MAPK signaling pathway are not yet fully elucidated. The current study aims to determine the MAP2K1 gene mutations and the level of MAP2K1 gene expression in ATLL patients compared to healthy individuals. Ten ATLL and 10 healthy control individuals were investigated in this study. We used ELISA test to screen anti-HTLV-I antibodies and PCR for confirmation of infection. Then, we extracted total RNA from fresh whole blood, and cDNA was synthesized. The expression levels of the MAP2K1 gene were examined by qRT-PCR, and to check possible mutations in the MAP2K1 gene; all samples were sequenced and analyzed by BioEdite Software. MAP2K1 gene expression in the ATLL group was significantly higher than in the healthy control (P=0.001). The mutational sequencing analysis showed nucleotide 212 (S→R) change and identification mutations at different nucleotides that were entirely different from the nucleotide mutations defined in the UniProt database. These results could be a perspective in the prevention, prognosis, and targeted treatment of diseases in which the MAP2K1 gene plays a vital role.

HTLV-1 Hbz protein, but not hbz mRNA secondary structure, is critical for viral persistence and disease development.

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic cause of adult T-cell leukemia/lymphoma (ATL) and encodes a viral oncoprotein (Hbz) that is consistently expressed in asymptomatic carriers and ATL patients, suggesting its importance in the development and maintenance of HTLV-1 leukemic cells. Our previous work found Hbz protein is dispensable for virus-mediated T-cell immortalization but enhances viral persistence. We and others have also shown that hbz mRNA promotes T-cell proliferation. In our current studies, we evaluated the role of hbz mRNA on HTLV-1-mediated immortalization in vitro as well as in vivo persistence and disease development. We generated mutant proviral clones to examine the individual contributions of hbz mRNA, hbz mRNA secondary structure (stem-loop), and Hbz protein. Wild-type (WT) and all mutant viruses produced virions and immortalized T-cells in vitro. Viral persistence and disease development were also evaluated in vivo by infection of a rabbit model and humanized immune system (HIS) mice, respectively. Proviral load and sense and antisense viral gene expression were significantly lower in rabbits infected with mutant viruses lacking Hbz protein compared to WT or virus with an altered hbz mRNA stem-loop (M3 mutant). HIS mice infected with Hbz protein-deficient viruses showed significantly increased survival times compared to animals infected with WT or M3 mutant virus. Altered hbz mRNA secondary structure, or loss of hbz mRNA or protein, has no significant effect on T-cell immortalization induced by HTLV-1 in vitro; however, the Hbz protein plays a critical role in establishing viral persistence and leukemogenesis in vivo.

Gene expression and TCR amino acid sequences selected by HLA-A02:01-restricted CTLs specific to HTLV-1 in ATL patients.

Adult T-cell leukaemia/lymphoma (ATL) is an aggressive malignancy of peripheral T cells caused by human T-cell lymphotropic virus type-1 (HTLV-1). Tax is the most important regulatory protein for HTLV-1. We aimed to reveal a unique amino acid sequence (AA) of complementarity-determining region 3 (CDR3) of the T-cell receptor (TCR)β and TCRα chains of HLA-A*02:01-restricted Tax11-19 -specific cytotoxic T cells (Tax-CTLs). The gene expression profiles (GEP) of Tax-CTLs were assessed by the next-generation sequence (NGS) method with SMARTer technology. Tax-CTLs seemed to be oligoclonal, and their gene compositions were skewed. The unique motifs of 'DSWGK' in TCRα and 'LAG' in TCRβ at CDR3 were observed in almost all patients. Tax-CTL clones harbouring the 'LAG' motif with BV28 had a higher binding score than those without either of them, besides a higher binding score associated with longer survival. Tax-CTLs established from a single cell showed killing activities against Tax-peptide-pulsed HLA-A2+ T2 cell lines. GEP of Tax-CTLs revealed that genes associated with immune response activity were well preserved in long-term survivors with stable status. These methods and results can help us better understand immunity against ATL, and should contribute to future studies on the clinical application of adoptive T-cell therapies.

Zidovudine and Interferon Alfa based regimens for the treatment of adult T-cell leukemia/lymphoma (ATLL): a systematic review and meta-analysis

BackgroundATLL (Adult T-Cell Leukemia/Lymphoma) is an aggressive hematological malignancy. This T-cell non-Hodgkin lymphoma, caused by the human T-cell leukemia virus type 1 (HTLV-1), is challenging to treat. There is no known treatment for ATLL as of yet. However, it is recommended to use Zidovudine and Interferon Alfa-based regimens (AZT/IFN), chemotherapy, and stem cell transplant. This study aims to review the outcome of patients with different subtypes of ATLL treated with Zidovudine and Interferon Alfa-based regimens.MethodsA systematic search was carried out for articles evaluating outcomes of ATLL treatment by AZT/IFN agents on human subjects from January 1, 2004, until July 1, 2022. Researchers assessed all studies regarding the topic, followed by extracting the data. A random-effects model was used in the meta-analyses.ResultsWe obtained fifteen articles on the AZT/IFN treatment of 1101 ATLL patients. The response rate of the AZT/IFN regimen yielded an OR of 67% [95% CI: 0.50; 0.80], a CR of 33% [95% CI: 0.24; 0.44], and a PR of 31% [95% CI: 0.24; 0.39] among individuals who received this regimen at any point during their treatment. Our subgroup analyses’ findings demonstrated that patients who received front-line and combined AZT/IFN therapy responded better than those who received AZT/IFN alone. It is significant to note that patients with indolent subtypes of disease had considerably higher response rates than individuals with aggressive disease.ConclusionIFN/AZT combined with chemotherapy regimens is an effective treatment for ATLL patients, and its use in the early stages of the disease may result in a greater response rate.

A contemporary national population-based analysis of demographics and outcomes of Hispanics with adult T-cell leukemia/lymphoma in the US.

e18771 Background: Adult T-cell Leukemia/Lymphoma (ATL) is a malignancy caused by the human T-cell leukemia virus type I with heterogenous clinical course (Blood Adv PMID29545256 J Clin Exp Hematop PMID34937829). There are endemic regions, but emigration has increased its incidence in the United States (US) (Hematol Oncol Clin North AmPMID2834087). There is a need to recognize trends and ethnic patterns to better understand this malignancy (J Oncol Pract PMID28796966 Blood Adv PMID29545256). This is the first national population-based analysis evaluating ethnic differences for HI diagnosed with ATL in the US. Methods: Data were analyzed on ATL patients in the US reported to the Surveillance, Epidemiology, and End Results (SEER) database between 2000-2018. Demographic, clinical and survival patterns were analyzed. Kaplan-Meier and Cox regression analyses were used when appropriate. Multivariate analysis and propensity score matching were performed with adjustment for age, stage and B-symptoms. Results: 598 patients (HI=65, NH=533) were diagnosed with ATL. Male sex predominated in in both. HI were diagnosed at a younger median age, 52 years (y) vs 63y for NH [p<0.001]. Most of HI presented in the age bracket of 40-60y, while NH were identified between 60-80y [p <0.001]. Regarding race, most of HI and NH were whites 82% vs 52% respectively, however, for NH Blacks and Asian/Pacific Islander were noted to be representative in the sample [p <0.001]. The majority of HI were diagnosed between 2010-2014, however for NH, same incidence was reported from 2005-2009 and 2010-2014 [p = 0.107]. For both group the presence of B symptoms was predominantly unknown. The median survival for HI was 1.5y vs 0.8y for NH. The survival probability at 2, 5 and 10y for HI corresponded to 0.474, 0.341 and 0.238, while for NH it was 0.347, 0.244 and 0.153, respectively. The OS probability at 10y had no statistically significant difference but a tendency favoring HI [p = 0.053]. On multivariate analysis, when adjusted for age, those patients who were older than 80y and between 60-80 y, had worse OS compared to those younger than 60y, with Hazard Ratio of 3.9 (95% CI: 2.7 – 5.6) and 1.7 (95% CI: 1.2 – 2.2), respectively. Conclusions: This national population-based study identified similar OS in HI diagnosed with ATL in the US. The median survival time was noted to be higher for HI and the OS had a tendency favoring this group; however, findings are not yet significant. This association should be further analyzed as there may be unique oncologic response in this ethnic minority. HI may have remarkable immunologic reaction to infection due to oncogenic viruses plus the creation of a distinct tumor microenvironment. Recognizing clinical trends and identifying genetic predictors may assist in constructing more accurate prognostic indices to deliver targeted therapy.

Diagnosis and management of adult T‐cell leukemia/lymphoma in a Brazilian Cohort. T‐cell Brazil Project

Introduction: Adult T-cell leukemia/lymphoma (ATL) is a peripheral T-cell malignancy caused by human T-cell leukemia virus type I (HTLV-1), endemic in some areas of the world, such as Brazil. Between 3% and 5% of HTLV-1-infected individuals develop ATL after a long latency. The clinical features are heterogeneous and classified into acute, lymphoma, chronic and smoldering types. Acute and lymphoma types are defined as aggressive whereas the others as indolent ATL. On April 2017, the T-cell Brazil project was launched. Methods: Ambispective observational study design collected 90 ATL patients from 606 registered cases in the T-Cell Brazil Project. Its main goal is to describe demographic and clinical features, analyze the overall and progression-free survival (OS and PFS), and try to identify factors that could influence them. REDcap Platform has been used to collect and store data, and the IBM-SPSS version 24 for statistical analysis. Results: The median age was 50 years (23–88), 59% female; 50% was lymphoma subtype, followed by 33% acute (both aggressive), 12% chronic and 5% smoldering (indolent); 87% had advanced stage disease (III-IV, Ann Arbor), 57% had B symptoms and 11% had Central Nervous System involved. Both indolent and aggressive had elevated serum LDH levels. 25% received chemotherapy plus immunotherapy, whilst 46% took chemotherapy alone with anthracycline-based regimens (46% CHOEP; 33% CHOP; 21% others). The best response (complete plus partial) after 1st line of treatment reached 50%; 31% had no response or progression; 13% was undetermined due early death; 5% were on treatment, and 1% had stable disease (without treatment). Median follow-up was ten months (0–78) and 18 months for 35% of alive cases. OS for 24 months was 34% (95% CI: 24%–44%), whereas 24-month PFS was 20% (95% CI: 12%–28%). Indolent presented better OS and PFS when compared with Aggressive; 86% versus 33%, P = 0.001 for OS and 45% versus 12%, P = 0.002 for PFS. Public medical care had worst OS and PFS than private (P = 0.14 and P = 0.05). The multivariate Cox Regression for OS resulted hypoalbuminemia - albumin <3.5 g/dL (HR 2.13 CI95% 1.10–4.12, P = 0.024) plus LDH twice the normal value (HR 2.49 CI95% 1.17–5.32, P = 0.018) as predictors. And for PFS were male (HR 1.83 CI95% 1.03–3.24, P = 0.037), ECOG > 1 (HR 2.01 CI95% 1.10–3.70, P = 0.023) and hypoalbuminemia (HR 3.35 CI95% 1.82–6.17, P < 0.0001). The research was funded by: Educational Support by Takeda Keyword: aggressive T-cell non-Hodgkin lymphoma No conflicts of interests pertinent to the abstract.

Mechanisms of Innate Immune Sensing of HTLV-1 and Viral Immune Evasion.

Human T lymphotropic virus-1 (HTLV-1) was the first identified oncoretrovirus, which infects and establishes a persistent infection in approximately 10-20 million people worldwide. Although only ~5% of infected individuals develop pathologies such as adult T-cell leukemia/lymphoma (ATLL) or a neuroinflammatory disorder termed HTLV-1-asssociated myelopathy/tropical spastic paraparesis (HAM/TSP), asymptomatic carriers are more susceptible to opportunistic infections. Furthermore, ATLL patients are severely immunosuppressed and prone to other malignancies and other infections. The HTLV-1 replication cycle provides ligands, mainly nucleic acids (RNA, RNA/DNA intermediates, ssDNA intermediates, and dsDNA), that are sensed by different pattern recognition receptors (PRRs) to trigger immune responses. However, the mechanisms of innate immune detection and immune responses to HTLV-1 infection are not well understood. In this review, we highlight the functional roles of different immune sensors in recognizing HTLV-1 infection in multiple cell types and the antiviral roles of host restriction factors in limiting persistent infection of HTLV-1. We also provide a comprehensive overview of intricate strategies employed by HTLV-1 to subvert the host innate immune response that may contribute to the development of HTLV-1-associated diseases. A more detailed understanding of HTLV-1-host pathogen interactions may inform novel strategies for HTLV-1 antivirals, vaccines, and treatments for ATLL or HAM/TSP.

Adult T-cell leukemia and lymphoma in French Guiana: a retrospective analysis with real-life data from 2009 to 2019

Adult T-cell leukemia/lymphoma (ATL), one of the most aggressive cancers in the world, occurs in 5% of the 10 million people living with HTLV-1 worldwide. French Guiana, a French overseas territory in South America, is one of the highest endemic areas of HTLV-1 worldwide. Here, we describe the demographic and clinical characteristics and outcome of ATL in this area. We retrospectively collected data from all patients diagnosed between 2009 and 2019. Patients were distributed according to Shimoyama's classification. Prognostic factors were explored through univariate analysis. Over the 10-year study period, 41 patients with a median age of 54 years at diagnosis were identified, among whom 56% were women. Sixteen (39%) patients were Maroons, a cultural group descendant of the runaway enslaved Africans from former Dutch Guiana. Among the study population, 23 (56%) had an acute type, 14 (34%) a lymphoma type, and one and one chronic and primary cutaneous tumour, respectively. First-lines of treatment included either chemotherapy or Zidovudine combined with pegylated interferon alpha. The 4-year overall survival was 11.4% for the entire population with 0% and 11% for lymphoma and acute forms, respectively. The median progression-free survival was 93 and 115 days for the acute and lymphoma groups (p=0.37), respectively. Among the twenty-nine patients who died, 8 (28%) died of toxicity, 7 (24%) died of disease progression and the cause of death remained unknown in 14 (48%) patients. Due to the overall poor prognosis, no significant prognostic factors could be identified. This study provides real-life data from ATL patients in French Guiana, a remote territory in a middle-income region. Patients, mostly Maroons, presented with a younger age and the prognosis was worse than expected compared to Japanese patients. None.