Search results for "Eloi"

Immune Therapy of Lympho-Hemopoietic Malignancies.

2017

Myeloid cell heterogeneity in lung cancer: implication for immunotherapy

2020

Lung is a specialized tissue where metastases from primary lung tumors takeoff and those originating from extra-pulmonary sites land. One commonality characterizing these processes is the supportive role exerted by myeloid cells, particularly neutrophils, whose recruitment is facilitated in this tissue microenvironment. Indeed, neutrophils have important part in the pathophysiology of this organ and the key mechanisms regulating neutrophil expansion and recruitment during infection can be co-opted by tumor cells to promote growth and metastasis. Although neutrophils dominate the myeloid landscape of lung cancer other populations including macrophages, dendritic cells, mast cells, basophils …

Acute myeloid leukemia (AML)-reactive cytotoxic T lymphocyte clones rapidly expanded from CD8(+) CD62L((high)+) T cells of healthy donors prevent AML…

2008

Objective Current in vitro techniques for isolating leukemia-reactive cytotoxic T lymphocytes (CTLs) from healthy donors are of relatively low efficiency and yield responder populations with unknown biological significance. This study aimed at the development of a more reliable approach, allowing generation and expansion of acute myeloid leukemia (AML)-reactive CTLs using primary in vitro stimulation. Materials and Methods We established allogeneic mini-mixed lymphocyte-leukemia cultures (mini-MLLCs) by stimulating donor CD8 + T cells with human leukocyte antigen (HLA) class I–matched AML blasts in microtiter plates. Before culture, CD8 + T cells were separated into CD62L (high)+ and CD62L …

STAT5 is crucial to maintain leukemic stem cells in acute myelogenous leukemias induced by MOZ-TIF2.

2012

Abstract MOZ-TIF2 is a leukemogenic fusion oncoprotein that confers self-renewal capability to hematopoietic progenitor cells and induces acute myelogenous leukemia (AML) with long latency in bone marrow transplantation assays. Here, we report that FLT3-ITD transforms hematopoietic cells in cooperation with MOZ-TIF2 in vitro and in vivo. Coexpression of FLT3-ITD confers growth factor independent survival/proliferation, shortens disease latency, and results in an increase in the number of leukemic stem cells (LSC). We show that STAT5, a major effector of aberrant FLT3-ITD signal transduction, is both necessary and sufficient for this cooperative effect. In addition, STAT5 signaling is essent…

Role of SHP2 for FLT3-dependent proliferation and transformation in 32D cells.

2008

Fms-like tyrosine kinase 3 (FLT3) is a class III receptor tyrosine kinase, which plays a role in proliferation and differentiation of B-cell progenitors, myelomonocytic and dendritic cells, as well as in the maintenance of pluripotent hematopoietic stem cells (reviewed in Stirewalt and Radich,1and Schmidt-Arras et al.2). Recently, FLT3 has received much attention as an important oncoprotein. Mutations in FLT3 that lead to constitutive activation are among the most common molecular lesions found in acute myeloid leukemia.3 The most prevalent type of mutations result in internal tandem duplications (ITD) of amino-acid stretches in the juxtamembrane domain of FLT3. FLT3-ITD is constitutively a…

SOCS2 controls proliferation and stemness of hematopoietic cells under stress conditions and its deregulation marks unfavorable acute leukemias

2015

Abstract Hematopoietic stem cells (HSC) promptly adapt hematopoiesis to stress conditions, such as infection and cancer, replenishing bone marrow–derived circulating populations, while preserving the stem cell reservoir. SOCS2, a feedback inhibitor of JAK–STAT pathways, is expressed in most primitive HSC and is upregulated in response to STAT5-inducing cytokines. We demonstrate that Socs2 deficiency unleashes HSC proliferation in vitro, sustaining STAT5 phosphorylation in response to IL3, thrombopoietin, and GM-CSF. In vivo, SOCS2 deficiency leads to unrestricted myelopoietic response to 5-fluorouracil (5-FU) and, in turn, induces exhaustion of long-term HSC function along serial bone marro…

3054 – MONOCYTE SUBSET PRODUCTION DURING AGING

2020

A growing body of evidence suggests that monocytes are more heterogenous than previously appreciated and that monocyte subsets play distinct roles in both health and disease. We have previously demonstrated that two separate pathways of monocyte production by granulocyte-monocyte progenitors (GMPs) and monocyte-dendritic cell progenitors (MDPs) yield functionally distinct monocyte subsets in mouse bone marrow. GMPs produce classical monocytes with neutrophil-like properties, and MDPs yield classical monocytes that give rise to monocyte-derived DCs (moDCs). We also showed that Toll-like receptor agonists differentially promote production of these monocyte subsets during emergency monopoiesis…

Engraftment of low numbers of pediatric acute lymphoid and myeloid leukemias into NOD/SCID/IL2Rcγnull mice reflects individual leukemogenecity and hi…

2013

Although immortalized cell lines have been extensively used to optimize treatment strategies in cancer, the usefulness of such in vitro systems to recapitulate primary disease is limited. Therefore, the design of in vivo models ideally utilizing patient-derived material is of critical importance. In this regard, NOD.Cg-Prkdc(scid) IL2rg(tmWjl) /Sz (NSG) mice have been reported to provide superior engraftment rates. However, limited data exist on the validity of such a model to constitute a surrogate marker for clinical parameters. We studied primary and serial engraftment on more than 200 NSG mice with 54 primary pediatric B cell precursor acute lymphatic leukemia (B-ALL), myeloid leukemia …

MLL-Rearranged Leukemia Is Dependent on Aberrant H3K79 Methylation by DOT1L

2011

SummaryThe histone 3 lysine 79 (H3K79) methyltransferase Dot1l has been implicated in the development of leukemias bearing translocations of the Mixed Lineage Leukemia (MLL) gene. We identified the MLL-fusion targets in an MLL-AF9 leukemia model, and conducted epigenetic profiling for H3K79me2, H3K4me3, H3K27me3, and H3K36me3 in hematopoietic progenitor and leukemia stem cells (LSCs). We found abnormal profiles only for H3K79me2 on MLL-AF9 fusion target loci in LSCs. Inactivation of Dot1l led to downregulation of direct MLL-AF9 targets and an MLL translocation-associated gene expression signature, whereas global gene expression remained largely unaffected. Suppression of MLL translocation-a…

Baseline circulating myeloid-derived suppressor cells subpopulations, neutrophils/lymphocytes ratio, and response to PD-1/PD-L1 inhibitor in non-smal…

2020

e15042 Background: Inhibitors of immune checkpoint PD-1/PD-L1 (ICI) have become a care standard in non-small cell lung cancer (NSCLC). Despite promising results, some patients cannot take advantage of immunotherapy effects. Nowadays, neither predictive nor prognostic circulating biomarkers have been found in order to select patients or to predict response to ICI. Myeloid-derived suppressor cells (MDSC) are potent immunity suppressors and may represent both a potential prognostic and a predictive biomarker. We aimed to assess the role of pretreatment circulating MDSC subpopulations on ICI outcomes in NSCLC patients. Methods: 86 NSCLC patients treated with ICI and 10 healthy donors in 3 cent…