Dysfunction of immune system in the development of large granular lymphocyte leukemia

Thalidomide-based regimen shows promising efficacy in large granular lymphocytic leukemia: a multicenter phase II study

Large granular lymphocytic leukemia (LGLL) is characterized by the clonal proliferation of cytotoxic T lymphocytes or NK cells. Standard first-line immunosuppressive treatments have limitations, achieving complete remission (CR) rates of up to 50%. Immune system dysregulation is implicated in LGLL. Promising results for thalidomide, an immunomodulatory drug, combined with prednisone and methotrexate (TPM), were observed in our pilot study. This multicenter study evaluated the efficacy and safety of a thalidomide, prednisone, and methotrexate (TPM) regimen in 52 symptomatic, methotrexate- and thalidomide-naive LGLL patients from June 2020 to August 2022. Thalidomide (100 mg daily for up to 24 months), prednisone (0.5-1.0 mg/kg every other day, tapered after 3 months), and methotrexate (10 mg/m2 weekly for up to 12 months) were administered. The primary objective was to determine the CR rate. The median follow-up duration was 29.0 months (range: 4.0-42.0). Forty-seven patients (90.4%) achieved hematological and symptomatic responses. Thirty-nine patients (75.0%) achieved CR. The median time to response was 3.0 months (range: 3.0-9.0). The median progression-free survival was 40.0 months (95% confidence interval (CI): 38.0-42.0), and the median duration of response was 39.0 months (95% CI: 36.1-41.9). The most common adverse event was peripheral neuropathy (24.1%), most of which (84.6%) were grades 1-2. Four patients experienced grade ≥3 adverse events. In conclusion, the TPM regimen was an effective and safe treatment for symptomatic LGLL patients, with a particularly high CR rate. This trial was registered at www.clinicaltrials.gov (#NCT04453345).

Aspergillus flavus with Mycovirus as an Etiologic Factor for Acute Leukemias in Susceptible Individuals: Evidence and Discussion

Several etiologic factors for the development of acute leukemias have been suggested; however, none is applicable to all cases. We isolated a certain mycovirus-containing Aspergillus flavus (MCAF) from the home of a patient with acute lymphoblastic leukemia. Repeated electron microscopic evaluations proved the existence of mycovirus in this organism. According to chemical analysis, this organism does not produce any aflatoxin, possibly due to its infestation with mycoviruses. We reported that using the ELISA technique, forty pediatric patients with acute lymphoblastic leukemia (ALL) uniformly had antibodies to the products of MCAF. In contrast, three separate groups of controls, consisting of normal blood donors, individuals with solid tumors, and patients with sickle cell disease, were negative. In vitro exposure of mononuclear blood cells from patients with ALL, in full remission, to the products of MCAF induced redevelopment of cell surface phenotypes and genetic markers characteristic of ALL. The controls were negative. The incubation of normal and ALL cell lines with the products of MCAF resulted in significant cellular apoptosis, changes in the cell cycle, and the downregulation of transcription factors, including PAX-5 and Ikaros (75 and 55 kDa). Fungi are widespread in nature, and many contain mycoviruses. Normally, an individual inhales 1 to 10 fungal spores per minute, while farmers can inhale up to 75,000 spores per minute. It is known that farmers and foresters, who are more exposed to fungi, have a higher rate of acute leukemia. In contrast, asthmatics, most of whom are allergic to fungal agents, and individuals working in office settings have a lower rate. One of the theories for the development of acute leukemia suggests a genetic predisposition followed by exposure to an infectious agent. With the above findings, we propose that mycovirus-containing Aspergillus flavus may have an etiological role in leukemogenesis in immune-depressed and genetically susceptible individuals.

Clinical features and prognosis of chronic natural killer cell lymphoproliferative disorders

OBJECTIVE

To analyze the current treatment status and prognostic regression of the chronic NK cell lymphoproliferative disorder (CLPD-NK).

METHODS

We retrospectively analyzed the clinical features, treatment and prognosis of 18 patients with CLPD-NK who were treated at our Hospital between September 2016 and September 2022.

RESULTS

Eighteen patients were included: three patients were treated with chemotherapy, five patients underwent immune-related therapy, one patient was treated with glucocorticoids alone, five patients were administered granulocyte colony-stimulating factor, blood transfusion therapy, or anti-infection therapy, followed by observation and follow-up, and four patients were observed without treatment. Fifteen patients survived, including two patients who achieved complete remission (CR) and seven patients who achieved partial remission (PR), of whom one patient progressed to Aggressive NK-cell leukemia (ANKL) and sustained remission after multiple lines of treatment; three patients were not reviewed, of which one patient was still in active disease, three patients developed hemophagocytic syndrome during treatment and eventually died, one of them had positive Epstein-Barr virus (EBV) expression. The 5-years overall survival rate was 83%.

CONCLUSION

Most patients with CLPD-NK have inert progression and a good prognosis, whereas some patients have a poor prognosis after progressing to ANKL and combined with hemophagocytic syndrome. Abnormal NK cells invading the center suggest a high possibility of ANKL development, and immunosuppressants and hormones are effective treatments for this disease.

Effects of senescence on the tumour microenvironment and response to therapy

Cellular senescence is a state of durable cell arrest that has been identified both in vitro and in vivo. It is associated with profound changes in gene expression and a specific secretory profile that includes pro-inflammatory cytokines, growth factors and matrix-remodelling enzymes, referred to as the senescence-associated secretory phenotype (SASP). In cancer, senescence can have anti- or pro-tumour effects. On one hand, it can inhibit tumour progression in a cell autonomous manner. On the other hand, senescence can also promote tumour initiation, progression, metastatic dissemination and resistance to therapy in a paracrine manner. Therefore, despite efforts to target senescence as a potential strategy to inhibit tumour growth, senescent cancer and microenvironmental cells can eventually lead to uncontrolled proliferation and aggressive tumour phenotypes. This can happen either through overcoming senescence growth arrest or through SASP-mediated effects in adjacent tumour cells. This review will discuss how senescence affects the tumour microenvironment, including extracellular matrix remodelling, the immune system and the vascular compartment, to promote tumourigenesis, metastasis and resistance to DNA-damaging therapies. It will also discuss current approaches used in the field to target senescence: senolytics, improving the immune clearance of senescent cells and targeting the SASP.

T-large granular lymphocyte frequencies and correlates in disease states detected by multiparameter flow cytometry in pediatric and young adult population

T-large granular lymphocytes (T-LGL) characterized by dim CD5 staining, although not completely understood, have unique roles in the immune system. Expansion of peripheral blood (PB) clonal T-LGL populations is associated with various entities in adults. We have previously demonstrated clonal T-LGL proliferations in pediatric immune dysregulation/inflammatory/proliferative conditions. However, T-LGL populations have not been studied in broader spectrum pathologies. In this study we evaluated sizes and correlates of T-LGL populations in the pediatric and young adult populations with various disease states. Lymphocytes including T-LGL were investigated retrospectively by reviewing PB multiparameter flow cytometric data with various indications over a 4-year period. Associations with clinical, laboratory findings, and T-LGL population sizes were sought. Among 520 cases reviewed, 240 were females and 280 males with a mean age of 9 years (0-33 years); mean T-LGL population constituted 14% (1-67%) in PB T cells. There were significant differences between T-LGL and CD5-bright, regular T cells. T-LGL correlated with CD8 + /DR + (R = 0.570; P < 0.01) and CD8 + /CD11b + (R = 0.597; P < 0.01) expression, indicating activated cytotoxic phenotype. The highest average T-LGL were seen in bone marrow transplant recipients (23.7%), Evans syndrome (23.7%), lymphoma (20.6%), and acute EBV infection (20.4%) cases, all with underlying immune dysregulation pathologies. In pediatric and young adult patients with different clinical conditions, PB T-LGL constitute an average of 14% of the T cells and have a predominantly activated cytotoxic T cell phenotype. Higher relative presence was seen in cases with an immune dysregulation background. These results may serve as a reference for T-LGL research efforts.

Transient Leukemoid Reaction from T-Cell Large Granular Lymphocytes Post Autologous Stem Cell Transplant in a Patient Affected by Hodgkin Lymphoma

Monoclonal T-cell lymphocytosis has been reported in patients with concomitant autoimmune diseases, viral infections, or immunodeficiencies. Referred to as T-cell large granular lymphocytic leukemia (T-LGLL), most cases cannot identify the triggering cause. Only small case series have been reported in the literature, and no treatment consensus exists. T-cell lymphocytosis may also appear after the transplant of hematopoietic stem cells or solid organs. Rare cases have been reported in patients undergoing autologous stem cell transplant (ASCT) for hematological diseases (including multiple myeloma or non-Hodgkin's lymphoma). Here, we describe the singular case of a patient who underwent ASCT for Hodgkin's lymphoma and displayed the onset of T-LGLL with an uncommonly high number of lymphocytes in peripheral blood and their subsequent spontaneous remission.

A Comparison of the Fifth World Health Organization and the International Consensus Classifications of Mature T-Cell Lymphomas

Peripheral T-cell lymphomas (PTCLs) are a rare subset of non-Hodgkin lymphomas that often carry significant difficulty in diagnosis and classification because of their rarity and biological complexity. Previous editions of the World Health Organization (WHO) classifications of hemopoietic neoplasms in 2001, 2008, and 2017 aimed to standardize hemopoietic neoplasm diagnosis in general. Since then, crucial clinico-pathological, immunophenotypic, and recent molecular discoveries have been made in the field of lymphomas, contributing to refining diagnostic criteria of several diseases, upgrading entities previously defined as provisional, and identifying new entities. In 2022, two different models were proposed to classify hematolymphoid neoplasms: the 5th edition of the WHO classification (WHO-HAEM5) and the International Consensus Classification (ICC). Of note, a common nosography is mandatory to ensure progress in health science and ensure the basis for a real precision medicine. In this article, the authors summarized the main differences with the previous fourth WHO edition and reviewed the main discrepancies between the two newest classifications, as far as PTCLs are concerned.

Epigenome-wide analysis of T-cell large granular lymphocytic leukemia identifies BCL11B as a potential biomarker

BACKGROUND

The molecular pathogenesis of T-cell large granular lymphocytic leukemia (T-LGLL), a mature T-cell leukemia arising commonly from T-cell receptor αβ-positive CD8⁺ memory cytotoxic T cells, is only partly understood. The role of deregulated methylation in T-LGLL is not well known. We analyzed the epigenetic profile of T-LGLL cells of 11 patients compared to their normal counterparts by array-based DNA methylation profiling. For identification of molecular events driving the pathogenesis of T-LGLL, we compared the differentially methylated loci between the T-LGLL cases and normal T cells with chromatin segmentation data of benign T cells from the BLUEPRINT project. Moreover, we analyzed gene expression data of T-LGLL and benign T cells and validated the results by pyrosequencing in an extended cohort of 17 patients, including five patients with sequential samples.

RESULTS

We identified dysregulation of DNA methylation associated with altered gene expression in T-LGLL. Since T-LGLL is a rare disease, the samples size is low. But as confirmed for each sample, hypermethylation of T-LGLL cells at various CpG sites located at enhancer regions is a hallmark of this disease. The interaction of BLC11B and C14orf64 as suggested by in silico data analysis could provide a novel pathogenetic mechanism that needs further experimental investigation.

CONCLUSIONS

DNA methylation is altered in T-LGLL cells compared to benign T cells. In particular, BCL11B is highly significant differentially methylated in T-LGLL cells. Although our results have to be validated in a larger patient cohort, BCL11B could be considered as a potential biomarker for this leukemia. In addition, altered gene expression and hypermethylation of enhancer regions could serve as potential mechanisms for treatment of this disease. Gene interactions of dysregulated genes, like BLC11B and C14orf64, may play an important role in pathogenic mechanisms and should be further analyzed.

Clinical Study of the Relationship between Sjögren Syndrome and T-Cell Large Granular Lymphocytic Leukemia: Single-Center Experience

The relationship between Sjögren syndrome (SS) and T-cell large granular lymphocytic (T-LGL) leukemia remains unclear. In this paper, we report for the first time a large case series of 21 patients with primary and secondary SS associated with T-LGL leukemia. Our results suggest the importance of considering T-LGL leukemia in the diagnostic evaluation of SS patients, particularly when neutropenia occurs. We also postulate that elevated antinuclear antibody titers in patients with T-LGL leukemia indicate the need for the clinical assessment of SS. To assess whether SS affects the frequency of the signal transducer and activator of transcription 3 (STAT3) gene mutations in T-LGL leukemia, we examined STAT3 mutations by next-generation sequencing in two cohorts of patients: with SS-associated T-LGL leukemia and T-LGL leukemia in the setting of rheumatic diseases but without SS. While our results suggest that SS, per se, is not associated with an increased frequency of STAT3 mutations in T-LGL leukemia, further studies are needed to better assess the role of the STAT pathway in the development of concomitant SS and T-LGL leukemia.

LGL Clonal Expansion and Unexplained Cytopenia: Two Clues Don't Make an Evidence

Clonal expansions of large granular lymphocytes (LGL) have been reported in a wide spectrum of conditions, with LGL leukemia (LGLL) being the most extreme. However, the boundaries between LGLL and LGL clones are often subtle, and both conditions can be detected in several clinical scenarios, particularly in patients with cytopenias. The intricate overlap of LGL clonal expansion with other disease entities characterized by unexplained cytopenias makes their classification challenging. Indeed, precisely assigning whether cytopenias might be related to inadequate hematopoiesis (i.e., LGL as a marginal finding) rather than immune-mediated mechanisms (i.e., LGLL) is far from being an easy task. As LGL clones acquire different pathogenetic roles and relevance according to their diverse clinical settings, their detection in the landscape of bone marrow failures and myeloid neoplasms has recently raised growing clinical interest. In this regard, the current availability of different diagnostic techniques, including next generation sequencing, shed light on the relationship between LGL clones and cytopenias, paving the way towards a better disease classification for precision medicine treatments. Herein, we discuss the clinical relevance of LGL clones in the diagnostic algorithm to be followed in patients presenting with cytopenias, offering a foundation for rational management approaches.

Survival and associated comorbidities in inclusion body myositis

OBJECTIVE

To evaluate survival and associated comorbidities in inclusion body myositis (IBM) in a population-based, case-control study.

METHODS

We utilized the expanded Rochester Epidemiology Project medical records-linkage system, including 27 counties in Minnesota and Wisconsin, to identify patients with IBM, other inflammatory myopathies (IIM), and age/sex-matched population-controls. We compared the frequency of various comorbidities and survival among groups.

RESULTS

We identified 50 IBM patients, 65 IIM controls and 294 population controls. Dysphagia was most common in IBM (64%) patients. The frequency of neurodegenerative disorders (dementia/parkinsonism) and solid cancers was not different between groups. Rheumatoid arthritis was the most common rheumatic disease in all groups. A total of 36% of IBM patients had a peripheral neuropathy, 6% had Sjögren's syndrome and 10% had a haematologic malignancy. T-cell large granular lymphocytic leukaemia was only observed in the IBM group. None of the IBM patients had hepatitis B or C, or HIV. IBM patients were 2.7 times more likely to have peripheral neuropathy, 6.2 times more likely to have Sjögren's syndrome and 3.9 times more likely to have a haematologic malignancy than population controls. IBM was associated with increased mortality, with a 10-year survival of 36% from index, compared with 67% in IIM and 59% in population controls. Respiratory failure or pneumonia (44%) was the most common cause of death.

CONCLUSIONS

IBM is associated with lower survival, and higher frequency of peripheral neuropathy, Sjögren's syndrome and haematologic malignancies than the general population. Close monitoring of IBM-related complications is warranted.

CB-LPD, MGUS, T-LGLL, and PRCA: A rare case report of 4 concomitant hematological disorders

RATIONALE

Monoclonal gammopathy of undetermined significance (MGUS) is a clinically asymptomatic clonal plasma cell or lymphoplasmacytic proliferative disorder. Recently, some case reports have described the association of pure red cell aplasia (PRCA) with MGUS, even with a relatively low monoclonal immunoglobulin burden. T large granular lymphocyte leukemia (T-LGLL) is a chronic lymphoproliferative disorder characterized by clonal expansion of T large granular lymphocytes, which is rare in China. There are some reports about T-LGL leukemia in patients with B-cell lymphoma; however, it is very rare that T-LGLL coexists with MGUS and clonal B-cell lymphoproliferative disorders (CB-LPD).

PATIENT CONCERNS

A 77-year-old man was hospitalized because of anemia. He was diagnosed with MGUS, CB-LPD, and PRCA. During the development of the disease, a group of abnormal T lymphocytes was detected by flow cytometry of peripheral blood.

DIAGNOSIS

Combining clinical manifestations with the result of T cell receptor gene rearrangement and immunophenotype, it was consistent with the diagnosis of T large granular lymphocyte leukemia.

INTERVENTIONS

The patient was treat with bortezomib and dexamethasone regimen, Rituximab and sirolimus.

OUTCOMES

The patient was transfusion independent after therapies.

LESSONS

We report a patient with 4 concomitant hematological disorders: T-LGLL, MGUS, CB-LPD, and PRCA, aiming to represent the clinical and flow cytometry characteristics of these concomitant diseases, analyze the mechanism between diseases, and provide a clinical reference.

Large Granular Lymphocyte Expansion in Myeloid Diseases and Bone Marrow Failure Syndromes: Whoever Seeks Finds

Large granular lymphocytes (LGL) are lymphoid cells characterized by either a T-cell or a natural killer phenotype whose expansion may be reactive to toxic, infectious, and neoplastic conditions, or result from clonal selection. Recently, the higher attention to LGL clones led to their detection in many clinical conditions including myeloid neoplasms and bone marrow failures. In these contexts, it is still unclear whether LGL cells actively contribute to anti-stem cell autoimmunity or are only a reaction to dysplastic/leukemic myelopoiesis. Moreover, some evidence exists about a common clonal origin of LGL and myeloid clones, including the detection of STAT3 mutations, typical of LGL, in myeloid precursors from myelodysplastic patients. In this article we reviewed available literature regarding the association of LGL clones with myeloid neoplasms (myelodysplastic syndromes, myeloproliferative neoplasms, and acute myeloid leukemias) and bone marrow failures (aplastic anemia and pure red cell aplasia, PRCA) focusing on evidence of pathogenic, clinical, and prognostic relevance. It emerged that LGL clones may be found in up to one third of patients, particularly those with PRCA, and are associated with a more cytopenic phenotype and good response to immunosuppression. Pathogenically, LGL clones seem to expand after myeloid therapies, whilst immunosuppression leading to LGL depletion may favor leukemic escape and thus requires caution.

Neutropenia and Large Granular Lymphocyte Leukemia: From Pathogenesis to Therapeutic Options

Large granular lymphocyte leukemia (LGLL) is a rare lymphoproliferative disorder characterized by the clonal expansion of cytotoxic T-LGL or NK cells. Chronic isolated neutropenia represents the clinical hallmark of the disease, being present in up to 80% of cases. New advances were made in the biological characterization of neutropenia in these patients, in particular STAT3 mutations and a discrete immunophenotype are now recognized as relevant features. Nevertheless, the etiology of LGLL-related neutropenia is not completely elucidated and several mechanisms, including humoral abnormalities, bone marrow infiltration/substitution and cell-mediated cytotoxicity might cooperate to its pathogenesis. As a consequence of the multifactorial nature of LGLL-related neutropenia, a targeted therapeutic approach for neutropenic patients has not been developed yet; moreover, specific guidelines based on prospective trials are still lacking, thus making the treatment of this disorder a complex and challenging task. Immunosuppressive therapy represents the current, although poorly effective, therapeutic strategy. The recent identification of a STAT3-mediated miR-146b down-regulation in neutropenic T-LGLL patients emphasized the pathogenetic role of STAT3 activation in neutropenia development. Accordingly, JAK/STAT3 axis inhibition and miR-146b restoration might represent tempting strategies and should be prospectively evaluated for the treatment of neutropenic LGLL patients.

STAT3 and STAT5B Mutations in T/NK-Cell Chronic Lymphoproliferative Disorders of Large Granular Lymphocytes (LGL): Association with Disease Features

Simple Summary

STAT3 and STAT5B mutations have been identified in a subset of T and NK large granular lymphocytic leukemia (T/NK-LGLL). The aim of our study was to evaluate the frequency and type of these mutations in all different subtypes of T/NK-LGL expansions (n = 100 patients), as well as to analyze its association with biological and clinical features of the disease. We show for the first time that STAT3/5B mutations were present in all different T/NK-cell LGLL categories here studied; further, STAT3 mutations were associated with overall reduced counts of almost all normal residual populations of immune cells in blood, together with a shorter time-to-therapy vs. wild type T/NK-LGLL. These findings contribute to support the utility of the STAT3 mutation analysis for diagnostic and prognostic purposes in LGLL.

Abstract

STAT3 and STAT5B (STAT3/STAT5B) mutations are the most common mutations in T-cell large granular lymphocytic leukemia (T-LGLL) and chronic lymphoproliferative disorders of NK cells (CLPD-NK), but their clinical impact remains unknown. We investigated the frequency and type of STAT3/STAT5B mutations in FACS-sorted populations of expanded T/NK-LGL from 100 (82 clonal; 6 oligoclonal; 12 polyclonal) patients, and its relationship with disease features. Seventeen non-LGL T-CLPD patients and 628 age-matched healthy donors were analyzed as controls. STAT3 (n = 30) and STAT5B (n = 1) mutations were detected in 28/82 clonal T/NK-LGLL patients (34%), while absent (0/18, 0%) among oligoclonal/polyclonal LGL-lymphocytosis. Mutations were found across all diagnostic subgroups: TCD8⁺-LGLL, 36%; CLPD-NK, 38%; TCD4⁺-LGLL, 7%; Tαβ⁺DP-LGLL, 100%; Tαβ⁺DN-LGLL, 50%; Tγδ⁺-LGLL, 44%. STAT3-mutated T-LGLL/CLPD-NK showed overall reduced (p < 0.05) blood counts of most normal leukocyte subsets, with a higher rate (vs. nonmutated LGLL) of neutropenia (p = 0.04), severe neutropenia (p = 0.02), and cases requiring treatment (p = 0.0001), together with a shorter time-to-therapy (p = 0.0001), particularly in non-Y640F STAT3-mutated patients. These findings confirm and extend on previous observations about the high prevalence of STAT3 mutations across different subtypes of LGLL, and its association with a more marked decrease of all major blood-cell subsets and a shortened time-to-therapy.

Myasthenia Gravis and Large Granular Lymphocytic Leukemia: a rare association

Myasthenia gravis (MG) is an autoimmune neuromuscular junction disorder sometimes observed in hematologic malignancies as a paraneoplastic syndrome. T-cell Large Granular Lymphocytic Leukemia (T-LGLL) is a rare lymphoproliferative clonal frequently associated with autoimmune disorders. Here we report two patients with T-LGLL who developed MG. In both patients the MG was bulbar without generalized weakness and did not involve the thymus. The treatment of T-LGLL led to the resolution of MG symptoms and decrease in acetylcholine receptor antibody titers in both patients suggesting a causative association.

Choroidal Infiltration as First Clinical Manifestation of T-cell Large Granular Lymphocyte (T-LGL) Leukemia

Purpose: To report of a 55-year-old woman suffering from choroidal infiltrates as a first clinical manifestation of T-LGL leukemia. Methods: Retrospective case report. Results: A healthy woman presented with photophobia in both eyes since 1 month. She showed a panuveitis with anterior chamber as well as vitreous cells, creamy-white choroidal lesions in both eyes and a cystoid macular edema in the left eye. Lab testing showed only a moderate lymphocytosis, all other tests, including a pars plana vitrectomy and an anterior chamber tap, were negative. Due to the persistent lymphocytosis, she was referred to the oncologist. A biopsy of the bone marrow revealed T-LGL leukemia. A subsequent biopsy of the choroid showed an infiltration of T-LGL and therefore systemic therapy with cyclophosphamide was started. Conclusions: This is a very rare case describing an involvement of the choroid in T-LGL leukemia.

Advances in the Diagnosis and Treatment of Large Granular Lymphocytic Leukemia

PURPOSE OF REVIEW

The past decade in LGL leukemia research has seen increased pairing of clinical data with molecular markers, shedding new insights on LGL leukemia pathogenesis and heterogeneity. This review summarizes the current standard of care of LGL leukemia, updates from clinical trials, and our congruent improved understanding of LGL pathogenesis.

RECENT FINDINGS

Various clinical reports have identified associations between stem, bone marrow, and solid organ transplants and incidence of LGL leukemia. There is also a potential for underdiagnosis of LGL leukemia within the rheumatoid arthritis patient population, emphasizing our need for continued study. Preliminary results from the BNZ-1 clinical trial, which targets IL-15 along with IL-2 and IL-9 signaling pathways, show some evidence of clinical response. With advances in our understanding of LGL pathogenesis from both the bench and the clinic, exciting avenues for investigations lie ahead for LGL leukemia.

Increased PD-1+Tim-3+ exhausted T cells in bone marrow may influence the clinical outcome of patients with AML

Background

Altered expression of T cell immune inhibitory receptors may result in immunosuppression and associate with the poor prognosis of leukemia patients in which the leukemic bone marrow (BM) microenvironment may contribute to such immunosuppression. We found higher numbers of programmed death-1 (PD-1) + exhausted T cells in peripheral blood (PB) from acute myeloid leukemia (AML) patients. To investigate the leukemic BM influence on immunosuppression, we further compared the distributions of PD-1 and T cell immunoglobulin mucin-3 (Tim-3) and the exhausted T cell phenotype in PB and BM from AML patients and characterized their relationship with clinical outcome.

Methods

PB and BM samples from 15 patients with newly diagnosed AML were collected and analyzed for the expression of PD-1, Tim-3, CD244, and CD57 on CD3+, CD4+, and CD8+ T cells by multicolor flow cytometry.

Results

The proportions of PD-1 + CD3+ and PD-1 + CD8+ T cells were significantly higher in BM compared with PB. Similarly, higher PD-1 + CD244 + CD3+ and PD-1 + CD244 + CD8+ T cells were found in BM, and an increased tendency for PD-1 + CD244 + CD4+ T cells was also detected in this group. In contrast, increased Tim-3 + CD4+/Tim-3 + CD244 + CD4+ T cells were predominant in BM compared with PB, but there was no statistically significant difference in Tim-3 + CD8+ T cells. Moreover, PD-1 and Tim-3 double-positive CD3+/CD4+/CD8+ T cells were significantly increased in the BM group. In addition, a higher proportion of PD-1 + Tim-3 + CD3+ T cells in the BM and PD-1 + Tim-3 + CD4+ T cells in PB was detected in non-complete remission (NCR) compared with complete remission (CR) patients after first-cycle chemotherapy.

Conclusions

Upregulation of PD-1 and Tim-3 and the exhausted phenotype of CD4+ and CD8+ T cells in the BM of AML patients may contribute to mediating the leukemic immunosuppressive microenvironment, and increased PD-1 + Tim-3+ CD8+ T cells may be related to T cell dysfunction in AML, which may influence clinical outcome.

Targeting senescent cells: approaches, opportunities, challenges

Cellular senescence is a hallmark of aging, whose onset is linked to a series of both cell and non-cell autonomous processes, leading to several consequences for the organism. To date, several senescence routes have been identified, which play a fundamental role in development, tumor suppression and aging, among other processes. The positive and/or negative effects of senescent cells are directly related to the time that they remain in the organism. Short-term (acute) senescent cells are associated with positive effects; once they have executed their actions, immune cells are recruited to remove them. In contrast, long-term (chronic) senescent cells are associated with disease; they secrete pro-inflammatory and pro-tumorigenic factors in a state known as senescence-associated secretory phenotype (SASP). In recent years, cellular senescence has become the center of attention for the treatment of aging-related diseases. Current therapies are focused on elimination of senescent cell functions in three main ways: i) use of senolytics; ii) inhibition of SASP; and iii) improvement of immune system functions against senescent cells (immunosurveillance). In addition, some anti-cancer therapies are based on the induction of senescence in tumor cells. However, these senescent-like cancer cells must be subsequently cleared to avoid a chronic pro-tumorigenic state. Here is a summary of different scenarios, depending on the therapy used, with a discussion of the pros and cons of each scenario.

"Locked" cancer cells are more sensitive to chemotherapy

The treatment of metastatic cancer is a great challenging issue throughout the world. Conventional chemotherapy can kill the cancer cells and, whereas, would exacerbate the metastasis and induce drug resistance. Here, a new combinatorial treatment strategy of metastatic cancer was probed via subsequentially dosing dual nanomedicines, marimastat-loaded thermosensitive liposomes (MATT-LTSLs) and paclitaxel nanocrystals (PTX-Ns), via intravenous and intratumoral injection. First, the metastasis was blocked and cancer cells were locked in the tumor microenvironment (TME) by delivering the matrix metalloproteinase (MMP) inhibitor, MATT, to the tumor with LTSLs, downregulating the MMPs by threefold and reducing the degradation of the extracellular matrix. And then, the "locked" cancer cells were efficiently killed via intratumoral injection of the other cytotoxic nanomedicine, PTX-Ns, along with no metastasis and 100% inhibition of tumor growth. This work highlights the importance of the TME's integrity in the chemotherapy duration. We believe this is a generalized strategy for cancer treatment and has potential guidance for the clinical administration.