The expression of the novel cytotoxic protein granzyme M by large granular lymphocytic leukaemias of both T-cell and NK-cell lineage: an unexpected finding with implications regarding the pathobiology of these disorders

Large granular lymphocyte leukemia: a clonal disorder with autoimmune manifestations

Large granular lymphocyte (LGL) leukemia is a rare lymphoproliferative disorder characterized by an expansion of clonal T or natural killer lymphocytes. Neutropenia-related infections and anemia represent the main manifestations. LGL leukemia is frequently associated with autoimmune disorders such as rheumatoid arthritis, Sjögren's syndrome, autoimmune endocrinopathies, vasculitis, or autoimmune cytopenia. Recent advances in the phenotypic and molecular characterization of LGL clones have underscored the pivotal role of a chronic antigenic stimulation and a dysregulation of the Jak/STAT signaling pathway in the pathophysiology linking leukemic-cell expansion and autoimmunity. In more than half of patients, there is a somatic STAT3 mutation. The disease is characterized by an indolent course, but approximately half of all patients will eventually require therapy. The first-line treatment for LGL leukemia is historically based on immunosuppressive agents (methotrexate, cyclophosphamide, or cyclosporine). However, cytokines blocking molecules or Jak/STAT inhibitors represent a new conceptual therapeutic approach for LGL leukemia. In this review, we present an overview of the spectrum of LGL proliferations, potential links between LGL expansion and autoimmunity, and therapeutic approaches.

Pre-treatment [18F]FDG PET/CT for assessing bone marrow involvement and prognosis in patients with newly diagnosed peripheral T-cell lymphoma

PURPOSE

To explore the value of [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in assessing bone marrow involvement (BMI) and prognosis in newly diagnosed peripheral T-cell lymphomas (PTCLs) before treatment.

METHODS

This retrospective study included 201 eligible PTCLs who received pre-bone marrow biopsy (BMB) and PET/CT. The status of bone marrow (BM) by PET was assessed using a visual examination and a quantitative index (the maximal standardized uptake value [SUVmax] of BM divided by the SUVmax of the liver [M/L]).

RESULTS

Totally 148 patients had no evidence of BMI by PET or BMB; BMI was detected by both methods in 16 patients. The sensitivity and specificity of PET/CT for patients with confirmed BMI by BMB were 43.2% and 90.2%, respectively (κ =  0.353). In addition, 25 patients assessed by PET/CT staging (having stage I to II disease) had no evidence of BMI detected by both PET/CT and BMB. Image-guided biopsy was also recommended when PET/CT showed a focal FDG uptake outside the iliac crest. Survival analysis revealed that BMB was significant for overall survival (OS) (P = 0.020) while M/L for both progression free survival (P = 0.002) and OS (P < 0.001). In multivariate analysis, M/L (HR 1.825, 95% CI 1.071-3.110, P = 0.027) was an independent prognostic factor for OS. There were no statistical differences at the genetic level about BMI confirmed by PET or BMB.

CONCLUSION

PET/CT has a complementary role in assessing BMI and an ability to predict prognosis in PTCL patients.

A modern view of LGL leukemia

ABSTRACT

Large granular lymphocytic leukemia (LGLL) is a rare lymphoproliferative chronic disorder characterized by expansion of either T or natural killer (NK) cytotoxic cells. In contrast to Epstein-Barr virus-induced aggressive NK-LGLL, chronic T-LGLL and NK-LGLL are indolent diseases affecting older patients with a median age of 66.5 years. LGLL is frequently associated with autoimmune disorders, most frequently rheumatoid arthritis. An auto-/alloantigen is tentatively implicated in disease initiation. Large granular lymphocyte expansion is then triggered by proinflammatory cytokines such as interleukin-15, macrophage inflammatory protein 1 (MIP-1), and RANTES (regulated upon activation, normal T cell expressed, and secreted). This proinflammatory environment contributes to deregulation of proliferative and apoptotic pathways. After the initial description of the JAK-STAT pathway signaling activation in the majority of patients, recurrent STAT3 gain-of-function mutations have been reported. The JAK-STAT pathway plays a key role in LGL pathogenesis by promoting survival, proliferation, and cytotoxicity. Several recent advances have been made toward understanding the molecular landscapes of T- and NK-LGLL, identifying multiple recurrent mutations affecting the epigenome, such as TET2 or KMT2D, and cross talk with the immune microenvironment, such as CCL22. Despite an indolent course, published series suggest that the majority of patients eventually need treatment. However, it is noteworthy that many patients may have a long-term observation period without ever requiring therapy. Treatments rely upon immunosuppressive drugs, namely cyclophosphamide, methotrexate, and cyclosporine. Recent advances have led to the development of targeted approaches, including JAK-STAT inhibitors, cytokine targeting, and hypomethylating agents, opening new developments in a still-incurable disease.

Large Granular Lymphocytic Leukemia: Clinical Features, Molecular Pathogenesis, Diagnosis and Treatment

Large granular lymphocytic (LGL) leukemia is a lymphoproliferative disorder characterized by persistent clonal expansion of mature T- or natural killer cells in the blood via chronic antigenic stimulation. LGL leukemia is associated with specific immunophenotypic and molecular features, particularly STAT3 and STAT5 mutations and activation of the JAK-STAT3, Fas/Fas-L and NF-κB signaling pathways. Disease-related deaths are mainly due to recurrent infections linked to severe neutropenia. The current treatment is based on immunosuppressive therapies, which frequently produce unsatisfactory long-term responses, and for this reason, personalized approaches and targeted therapies are needed. Here, we discuss molecular pathogenesis, clinical presentation, associated autoimmune disorders, and the available treatment options, including emerging therapies.

Withania somnifera (L.) Dunal (Ashwagandha) for the possible therapeutics and clinical management of SARS-CoV-2 infection: Plant-based drug discovery and targeted therapy

Coronavirus disease 2019 (COVID-19) pandemic has killed huge populations throughout the world and acts as a high-risk factor for elderly and young immune-suppressed patients. There is a critical need to build up secure, reliable, and efficient drugs against to the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Bioactive compounds of Ashwagandha [Withania somnifera (L.) Dunal] may implicate as herbal medicine for the management and treatment of patients infected by SARS-CoV-2 infection. The aim of the current work is to update the knowledge of SARS-CoV-2 infection and information about the implication of various compounds of medicinal plant Withania somnifera with minimum side effects on the patients' organs. The herbal medicine Withania somnifera has an excellent antiviral activity that could be implicated in the management and treatment of flu and flu-like diseases connected with SARS-CoV-2. The analysis was performed by systematically re-evaluating the published articles related to the infection of SARS-CoV-2 and the herbal medicine Withania somnifera. In the current review, we have provided the important information and data of various bioactive compounds of Withania somnifera such as Withanoside V, Withanone, Somniferine, and some other compounds, which can possibly help in the management and treatment of SARS-CoV-2 infection. Withania somnifera has proved its potential for maintaining immune homeostasis of the body, inflammation regulation, pro-inflammatory cytokines suppression, protection of multiple organs, anti-viral, anti-stress, and anti-hypertensive properties. Withanoside V has the potential to inhibit the main proteases (Mpro) of SARS-CoV-2. At present, synthetic adjuvant vaccines are used against COVID-19. Available information showed the antiviral activity in Withanoside V of Withania somnifera, which may explore as herbal medicine against to SARS-CoV-2 infection after standardization of parameters of drug development and formulation in near future.

Intersection Between Large Granular Lymphocyte Leukemia and Rheumatoid Arthritis

Large granular lymphocyte (LGL) leukemia, a rare hematologic malignancy, has long been associated with rheumatoid arthritis (RA), and the diseases share numerous common features. This review aims to outline the parallels and comparisons between the diseases as well as discuss the potential mechanisms for the relationship between LGL leukemia and RA. RA alone and in conjunction with LGL leukemia exhibits cytotoxic T-cell (CTL) expansions, HLA-DR4 enrichment, RA-associated autoantibodies, female bias, and unknown antigen specificity of associated T-cell expansions. Three possible mechanistic links between the pathogenesis of LGL leukemia and RA have been proposed, including LGL leukemia a) as a result of longstanding RA, b) as a consequence of RA treatment, or c) as a driver of RA. Several lines of evidence point towards LGL as a driver of RA. CTL involvement in RA pathogenesis is evidenced by citrullination and granzyme B cleavage that modifies the repertoire of self-protein antigens in target cells, particularly neutrophils, killed by the CTLs. Further investigations of the relationship between LGL leukemia and RA are warranted to better understand causal pathways and target antigens in order to improve the mechanistic understanding and to devise targeted therapeutic approaches for both disorders.

COVID-19: Targeting Proteases in Viral Invasion and Host Immune Response

An acute respiratory disorder (COVID-19) that accelerated across the globe has been found to be caused by a novel strain of coronaviruses (SARS-CoV-2). The absence of a specific antiviral drug or vaccination has promoted the development of immediate therapeutic responses against SARS-CoV-2. As increased levels of plasma chemokines and, cytokines and an uncontrolled influx of inflammatory cells were observed in lethal cases, it was concluded that the severity of the infection corresponded with the imbalanced host immunity against the virus. Tracing back the knowledge acquired from SERS and MERS infections, clinical evidence suggested similar host immune reactions and host ACE2 receptor-derived invasion by SARS-CoV-2. Further studies revealed the integral role of proteases (TMPRSS2, cathepsins, plasmin, etc.) in viral entry and the immune system. This review aims to provide a brief review on the latest research progress in identifying the potential role of proteases in SARS-CoV-2 viral spread and infection and combines it with already known information on the role of different proteases in providing an immune response. It further proposes a multidisciplinary clinical approach to target proteases specifically, through a combinatorial administration of protease inhibitors. This predictive review may help in providing a perspective to gain deeper insights of the proteolytic web involved in SARS-CoV-2 viral invasion and host immune response.

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.

T-Cell Large Granular Lymphocytic Leukemia - Case Reports

SUMMARY – T-cell large granular lymphocytic leukemia (T-LGLL) is an uncommon but probably underdiagnosed disease caused by clonal proliferation of large granular lymphocytes. Diagnosis is typically based on the high number of morphologically characteristic lymphoid cells and finding of an abnormal immunophenotype by flow cytometry. Because of its relatively indolent clinical behavior, observation is often an appropriate therapy. Here we present a case of a 53-year-old male admitted to the hospital because of abdominal pain. Blood examination revealed mild mycrocitic anemia and multiplied lactate dehydrogenase level. Abdominal ultrasound showed splenomegaly of 16 cm, with no lymphadenopathy. Fine needle aspiration of bone marrow revealed hypocellular marrow with 50% of atypical lymphoid cells. There were 81% of atypical medium sized granular lymphocytes with irregularly shaped nuclei in peripheral blood, so the cytologic diagnosis was lymphoproliferative process. Bone marrow biopsy showed nodular and interstitial proliferation of small, partially atypical T lymphocytic cells positive for CD2, CD3, CD5, CD8, granzyme and TIA, and negative for hairy cell markers, CD10, MUM 1, bcl 1, CD4 and CD56. The finding was consistent with T-LGLL. Due to splenomegaly, the patient was treated with cyclosporine and gradually reduced dose of corticosteroids, leading to regression of splenomegaly and normalization of lactate dehydrogenase level.

STAT3 mutation and its clinical and histopathologic correlation in T-cell large granular lymphocytic leukemia

Although T-cell large granular lymphocytic leukemia (T-LGLL) is a clinically indolent disorder, patients with moderate to severe cytopenia require therapeutic intervention. The recent discovery of STAT3 mutations has shed light on the genetic basis of T-LGLL pathogenesis. However, the association of STAT3 mutational status with patients' clinical, histopathologic, and other laboratory features has not been thoroughly evaluated in T-LGLL. In this study, STAT3 mutations were identified in 18 of 36 patients with T-LGLL (50%), including Y640F (12/18, 66.7%), N647I (3/18, 16.7%), E638Q (1/18, 5.6%), I659L (1/18, 5.6%), and K657R (1/18, 5.6%). Interestingly, pure red cell aplasia was seen exclusively in T-LGLL patients without STAT3 mutations (6/15 in the wild-type STAT3 group versus 0/13 in the mutant STAT3 group; P = .02); these patients also were the only responders to T-LGLL therapy (mainly cyclophosphamide) in wild-type STAT3 group. Patients harboring STAT3 mutations were more prone to rheumatoid arthritis (4/13 versus 0/15 in the wild-type STAT3 group; P = .04), frequently requiring therapy for neutropenia/neutropenia-associated infections, and demonstrated good therapeutic responses to methotrexate. No significant differences were seen in complete blood count, flow cytometric immunophenotypic features, T-cell receptor γ V-J rearrangement repertoire, and bone marrow biopsy morphology among the STAT3-mutation and wild-type groups other than significantly larger tumor burden in patients with STAT3 mutations. The distinct disease association and therapeutic responses observed in patients with mutant and wild-type STAT3 warrant further investigation to elucidate the underlying mechanisms. They also highlight the importance of identifying STAT3 mutational status in patients with T-LGLL, which may aid in clinical therapeutic choice.

Large granular lymphocytic leukemia. Current diagnostic and therapeutic approaches and novel treatment options

INTRODUCTION

Large granular lymphocytic leukemia (LGLL) is a low grade lymphoproliferative disorder characterized by the clonal proliferation of large granular lymphocytes (LGL) and recognised by the WHO. The diagnosis and management of these patients is challenging due to the limited information from prospective studies. Guidelines for front-line therapy have not been established. The prognosis is favourable with median overall survivals greater than 10 years. Areas covered: This manuscript is a review of the clinical features, diagnosis, pathogenesis and, in particular, the various available therapeutic options for this rare lymphoid leukemia. A systematic literature search using electronic PubMed database has been carried out. Expert commentary: A watch and wait strategy without therapeutic intervention is recommended in asymptomatic patients. The immunomodulators methotrexate, cyclophosphamide and cyclosporin are the most commonly used drugs in the routine practice with responses ranging from 50 to 65% and without evidence of cross-resistance among them. Purine analogs such as 2´deoxycoformycin and fludarabine alone or in combination may be indicated in patients with bulky and/or widespread disease. Trials using monoclonal antibodies such as Alemtuzumab and agents targeting the disrupted JAK/STAT pathway in LGLL such as JAK-3 inhibitors are promising particularly in a relapse setting.

The pathogenesis and treatment of large granular lymphocyte leukemia

Large granular lymphocyte (LGL) leukemia is a spectrum of rare lymphoproliferative diseases of T lymphocytes and natural killer cells. These diseases frequently present with splenomegaly, neutropenia, and autoimmune diseases like rheumatoid arthritis. LGL leukemia is more commonly of a chronic, indolent nature; however, rarely, they have an aggressive course. LGL leukemia is thought to arise from chronic antigen stimulation, which drives long-term cell survival through the activation of survival signaling pathways and suppression of pro-apoptotic signals. These include Jak-Stat, Mapk, Pi3k-Akt, sphingolipid, and IL-15/Pdgf signaling. Treatment traditionally includes immunosuppression with low dose methotrexate, cyclophosphamide, and other immunosuppressive agents; however, prospective and retrospective studies reveal very limited success. New studies surrounding Jak-Stat signaling suggest this may reveal new avenues for LGL leukemia therapeutics.

A case of CD4(+)T-cell large granular lymphocytic leukemia

We report here a case of a 59-yr-old man with CD4⁺ T-cell large granular lymphocytic leukemia (T-LGL). Peripheral blood examination indicated leukocytosis (45×10⁹ cells/L) that consisted of 34% neoplastic lymphoid cells. Other laboratory results indicated no specific abnormalities except for serum antinuclear antibody titer (1:640), glucose (1.39 g/L), and hemoglobin A1c (7.7%) levels. Computed tomography indicated multiple small enlarged lymph nodes (<1 cm in diameter) in both the axillary and inguinal areas, a cutaneous nodule (1.5 cm in diameter) in the left suboccipital area, and mild hepatosplenomegaly. Bone marrow examination revealed hypercellular marrow that consisted of 2.4% neoplastic lymphoid cells. The neoplastic lymphoid cells exhibited a medium size, irregularly shaped nuclei, a moderate amount of cytoplasm, and large granules in the cytoplasm. Immunohistochemical analysis indicated CD3⁺, CD4⁺, T-cell receptor βF1⁺, granzyme B⁺, and TIA1⁺. Flow cytometric analysis of the neoplastic lymphoid cells revealed CD3+, cytoplasmic CD3⁺, CD4⁺, and CD7⁺. Cytogenetic analysis indicated an abnormal karyotype of 46,XY,inv(3)(p21q27),t(12;17)(q24.1;q21),del(13)(q14q22)[2]/46,XY[28]. The patient was diagnosed with CD4⁺ T-LGL and received chemotherapy (10.0 mg methotrexate). This is the second case of CD4⁺ T-LGL that has been reported in Korea.

Orphan granzymes find a home

Cytotoxic lymphocytes are armed with granules that are released in the granule-exocytosis pathway to kill tumor cells and virus-infected cells. Cytotoxic granules contain the pore-forming protein perforin and a family of structurally homologues serine proteases called granzymes. While perforin facilitates the entry of granzymes into a target cell, the latter initiate distinct apoptotic routes. Granzymes are also implicated in extracellular functions such as extracellular matrix degradation, immune regulation, and inflammation. The family of human granzymes consists of five members, of which granzyme A and B have been studied most extensively. Recently, elucidation of the specific characteristics of the other three human granzymes H, K, and M, also referred to as orphan granzymes, have started. In this review, we summarize and discuss what is currently known about the biology of the human orphan granzymes.

Transcriptional signatures of Itk-deficient CD3+, CD4+ and CD8+ T-cells

BACKGROUND

The Tec-family kinase Itk plays an important role during T-cell activation and function, and controls also conventional versus innate-like T-cell development. We have characterized the transcriptome of Itk-deficient CD3+ T-cells, including CD4+ and CD8+ subsets, using Affymetrix microarrays.

RESULTS

The largest difference between Itk-/- and Wt CD3+ T-cells was found in unstimulated cells, e.g. for killer cell lectin-like receptors. Compared to anti-CD3-stimulation, anti-CD3/CD28 significantly decreased the number of transcripts suggesting that the CD28 co-stimulatory pathway is mainly independent of Itk. The signatures of CD4+ and CD8+ T-cell subsets identified a greater differential expression than in total CD3+ cells. Cyclosporin A (CsA)-treatment had a stronger effect on transcriptional regulation than Itk-deficiency, suggesting that only a fraction of TCR-mediated calcineurin/NFAT-activation is dependent on Itk. Bioinformatic analysis of NFAT-sites of the group of transcripts similarly regulated by Itk-deficiency and CsA-treatment, followed by chromatin-immunoprecipitation, revealed NFATc1-binding to the Bub1, IL7R, Ctla2a, Ctla2b, and Schlafen1 genes. Finally, to identify transcripts that are regulated by Tec-family kinases in general, we compared the expression profile of Itk-deficient T-cells with that of Btk-deficient B-cells and a common set of transcripts was found.

CONCLUSION

Taken together, our study provides a general overview about the global transcriptional changes in the absence of Itk.