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Project description:TCRαβ CD8 large granular lymphocyte (LGL) leukemia is a rare heterogeneous hematological disorder with a chronic disease course that mostly affects elderly. It is generally accepted that LGL cells arise as a consequence of chronic antigenic stimulation and inflammation and thrive because of dysregulation of mainly the STAT3 but also to some extent the ERK pathway, which are constitutively activated. In approximately 40% of patients this is due to STAT3 activating mutations, but for the other 60% it remains to be elucidated, why the STAT3 pathway is chronically activated. miRNAs are one of the most potent regulators in health and disease and are also linked with various leukemias. Therefore, we hypothesized that aberrant miRNA expression could contribute to dysregulation of the STAT3 pathway. miRNA sequencing in LGL leukemia cases and aged-matched healthy control TEMRA cells revealed overexpression of miRNA181a. Furthermore, gene set enrichment analysis (GSEA) of miRNA181a implicated its involvement in the STAT3 and ERK1/2 pathways. Phosphoflow analysis of STAT3, ERK1/2 in miR181a-transfected human CD8 T cells revealed that miR181a overexpression results in STAT3 and ERK1/2 phosphorylation. By using TL1, a human T-LGL cell line model, we have now established that miR181a is the common actor in T-LGL leukemia, driving STAT3 activation by SOCS3 inhibition in LGL leukemia patients. Additionally, miR181a induces ERK1/2 phosphorylation by inhibition of DUSP6. Taken together, our data show that miR181a is the missing link to explain why STAT3-unmutated patients show hyperactive STAT3.
2021-12-01 | GSE159878 | GEO
Project description:TCRαβ CD8 large granular lymphocyte (LGL) leukemia is a rare heterogeneous hematological disorder with a chronic disease course that mostly affects elderly. It is generally accepted that LGL cells arise as a consequence of chronic antigenic stimulation and inflammation and thrive because of dysregulation of mainly the STAT3 but also to some extent the ERK pathway, which are constitutively activated. In approximately 40% of patients this is due to STAT3 activating mutations, but for the other 60% it remains to be elucidated, why the STAT3 pathway is chronically activated. miRNAs are one of the most potent regulators in health and disease and are also linked with various leukemias. Therefore, we hypothesized that aberrant miRNA expression could contribute to dysregulation of the STAT3 pathway. miRNA sequencing in LGL leukemia cases and aged-matched healthy control TEMRA cells revealed overexpression of miRNA181a. Furthermore, gene set enrichment analysis (GSEA) of miRNA181a implicated its involvement in the STAT3 and ERK1/2 pathways. Phosphoflow analysis of STAT3, ERK1/2 in miR181a-transfected human CD8 T cells revealed that miR181a overexpression results in STAT3 and ERK1/2 phosphorylation. By using TL1, a human T-LGL cell line model, we have now established that miR181a is the common actor in T-LGL leukemia, driving STAT3 activation by SOCS3 inhibition in LGL leukemia patients. Additionally, miR181a induces ERK1/2 phosphorylation by inhibition of DUSP6. Taken together, our data show that miR181a is the missing link to explain why STAT3-unmutated patients show hyperactive STAT3.
2021-12-01 | GSE159819 | GEO
Project description:T-LGL cells arise as a consequence of chronic antigenic stimulation and inflammation and thrive because of constitutive activation of the STAT3 and ERK pathway. Notably, in 40% of patients, constitutive STAT3 activation is due to STAT3 activating mutations, whereas in 60% this is unknown. As miRNAs are amongst the most potent regulators in health and disease, we hypothesized that aberrant miRNA expression could contribute to dysregulation of these pathways. miRNA sequencing in T-LGL leukemia cases and aged-matched healthy control TEMRA cells revealed overexpression of miR-181a. Furthermore, geneset enrichment analysis (GSEA) of downregulated targets of miR-181a implicated involvement in regulating STAT3 and ERK1/2 pathways. Flow cytometric analyses showed increased SOCS3+ and DUSP6+ T-LGL cells upon miR-181a inhibition. In addition, miR-181a-transfected human CD8+ T cells showed increased basal STAT3 and ERK1/2 phosphorylation. By using TL1, a human T-LGL cell line, we could show that miR-181a is an actor in T-LGL leukemia, driving STAT3 activation by SOCS3 inhibition and ERK1/2 phosphorylation by DUSP6 inhibition and verified this mechanism in an independent cell line. In addition, miR-181a inhibition resulted in a higher sensitivity to FAS-mediated apoptosis. Collectively, our data show that miR-181a could be the missing link to explain why STAT3-unmutated patients show hyperactive STAT3.
| S-EPMC8979821 | biostudies-literature
Project description:miR181a is a novel key player in the STAT3 mediated survival network of TCRab CD8+ T-LGL leukemia
| PRJNA670710 | ENA
Project description:miR181a is a novel key player in the STAT3 mediated survival network of TCRab CD8+ T-LGL leukemia [RNA-Seq]
| PRJNA670520 | ENA
Project description:miR181a is a novel key player in the STAT3 mediated survival network of TCRab CD8+ T-LGL leukemia [sRNA-Seq]
| PRJNA670802 | ENA
Project description:Vaccines against SARS-CoV-2 are the most effective measure against the COVID-19 pandemic. The safety profile of mRNA vaccines in patients with rare diseases has not been assessed systematically in the clinical trials, as these patients were typically excluded. This report describes the occurrence of agranulocytosis within days following the first dose of an mRNA-1273 vaccination against COVID-19 in a previously healthy older adult. The patient was diagnosed with a suspected STAT3 wild-type T-cell large granular lymphocytic leukaemia (T-LGL). Neutropenia was successfully treated with IVIG, glucocorticoids, and G-CSF. In vitro experiments aimed at elucidating the pathways potentially causing the mRNA vaccine-associated neutropenia indicated that the mRNA, but not the adenoviral Ad26.COV2.S vector vaccine, triggered strong IL-6/STAT3 activation in vitro, resulting in excessive T-cell activation and neutrophil degranulation in the patient but not in controls. mRNA-1273 activated TLR-3 suggesting TLR mediated IL-6/STAT3 pathway activation. To complete the primary series of COVID-19 immunization, we used a single dose of Ad26.COV2.S vector vaccine without reoccurrence of neutropenia. The T-LGL clone remained stable during the follow-up of more than 12 months without ongoing therapy. Our data suggest that switching the immunization platform may be a reasonable approach in subjects with rare associated hematologic side effects due to excess STAT3-mediated stimulation following mRNA vaccination. Using in vitro testing before re-administration of a (COVID) vaccine also has relevance for other rare immune events after (mRNA) vaccination.
| S-EPMC9933345 | biostudies-literature
Project description:Large granular lymphocyte (LGL) leukemia is characterized by a clonal expansion of either CD3(+) cytotoxic T or CD3(-) NK cells. Prominent clinical features of T-LGL leukemia include neutropenia, anemia and rheumatoid arthritis (RA). The terminal effector memory phenotype (CD3(+)/CD45RA(+)/CD62L(-)CD57(+)) of T-LGL suggests a pivotal chronic antigen-driven immune response. LGL survival is then promoted by platelet-derived growth factor and interleukin-15, resulting in global dysregulation of apoptosis and resistance to normal pathways of activation-induced cell death. These pathogenic features explain why treatment of T-LGL leukemia is based on immunosuppressive therapy. The majority of these patients eventually need treatment because of severe or symptomatic neutropenia, anemia, or RA. No standard therapy has been established because of the absence of large prospective trials. The authors use low-dose methotrexate initially for T-LGL leukemia patients with neutropenia and/or RA. We recommend either methotrexate or oral cyclophosphamide as initial therapy for anemia. If treatment is not successful, patients are switched to either the other agent or cyclosporine. The majority of patients experience an indolent clinical course. Deaths infrequently occur because of infections related to severe neutropenia. As there are no curative therapeutic modalities for T-LGL leukemia, new treatment options are needed.
| S-EPMC3062292 | biostudies-literature
Project description:BackgroundT-large granular lymphocyte (T-LGL) leukemia is a rare clonal lymphoproliferative disorder, which has a favorable prognosis. There are different complications between Asian and Western patients diagnosed with LGL leukemia. In Asians, pure red cell aplasia (PRCA) is the most common hematological compatible clinical feature of LGL leukemia, whereas in Western patients, rheumatoid arthritis and neutropenia are more commonly seen. Herein, a rare case of T-LGL leukemia associated PRCA was reported.Case descriptionA 72-year-old man, presenting with anemia and leukopenia, was admitted to hospital. The bone marrow (BM) smear revealed that erythroid series were suppressed with only 4%, mature lymphocytes constituting up to 23% of the marrow cells. The results of T-cell receptor (TCR) arrangement revealed mutations in the TCR-β and TCR-γ genes. Further, STAT3 mutation (p. [D661Y; N664T] and p.N647I), TNFAIP3 mutation (p.L48fs), and KMT2D mutation (p.E5291K) were confirmed. The patient was diagnosed with CD8+ TCRαβ T-LGL leukemia-associated PRCA, harboring STAT3, TNFAIP3 and KMT2D mutation. The BM smear, immunophenotype, gene rearrangement and karyotype were consistent with those of the first diagnosis. Cyclosporine A (CyA) based regimens were effective, even in a cessation of discontinued treatment. The patient refused BM-related examinations and has remained in hematological complete remission (CR) until the time of writing (at least 3 years).ConclusionsThe administration of CyA yielded a CR in this case. However, the standard therapy for T-LGL leukemia-associated PRCA is not clear, and more prospective studies are needed to ascertain the underlying mechanism of pathogenesis.
| S-EPMC10174971 | biostudies-literature
Project description:T-cell large granular lymphocyte (LGL) leukemia is characterized by clonal expansion of CD3(+)CD8(+) cells. Leukemic LGLs correspond to terminally differentiated effector-memory cytotoxic T lymphocytes (CTLs) that escape Fas-mediated activation-induced cell death (AICD) in vivo. The gene expression signature of peripheral blood mononuclear cells from 30 LGL leukemia patients showed profound dysregulation of expression of apoptotic genes and suggested uncoupling of activation and apoptotic pathways as a mechanism for failure of AICD in leukemic LGLs. Pathway-based microarray analysis indicated that balance of proapoptotic and antiapoptotic sphingolipid-mediated signaling was deregulated in leukemic LGLs. We further investigated sphingolipid pathways and found that acid ceramidase was constitutively overexpressed in leukemic LGLs and that its inhibition induced apoptosis of leukemic LGLs. We also showed that S1P(5) is the predominant S1P receptor in leukemic LGLs, whereas S1P(1) is down-regulated. FTY720, a functional antagonist of S1P-mediated signaling, induced apoptosis in leukemic LGLs and also sensitized leukemic LGLs to Fas-mediated death. Collectively, these results show a role for sphingolipid-mediated signaling as a mechanism for long-term survival of CTLs. Therapeutic targeting of this pathway, such as use of FTY720, may have efficacy in LGL leukemia.
| S-EPMC2481553 | biostudies-literature