bluuebunny/crossref_metadata_2025_split huggingface dataset:
Granulocytic Differentiation of Normal Hematopoietic Precursor Cells Induced by Transcription Factor PU.1 Correlates With Negative Regulation of the c-myb Promoter
Authors: Bellon Teresa , Perrotti Danilo , Calabretta Bruno 
Published: October 2019

AbstractNumerous transcription factors allow hematopoietic cells to respond to lineage- and stage-specific cytokines and/or to act as their effectors. The transcription factors PU.1 and c-Myb are essential for hematopoiesis, most likely acting at distinct stages of differentiation, but sharing a common set of target genes. To determine whether PU.1 and c-Myb are functionally interrelated, murine bone marrow (BM) cells and 32Dcl3 murine myeloid precursor cells were infected with a retrovirus carrying a PU.1 cDNA and assessed for myeloid colony formation and for granulocytic differentiation, respectively. Compared with noninfected normal BM cells or to cells infected with an empty virus, hematopoietic precursor cells expressing PU.1 formed an increased number of interleukin-3 (IL-3) and granulocyte colony-stimulating factor (G-CSF )–stimulated colonies. Moreover, granulocytic differentiation of 32Dcl3 cells constitutively expressing PU.1 was accelerated, as indicated by morphology and by expression of differentiation markers. Downregulation of c-Myb protein levels by expression of an antisense c-myb construct was also associated with a faster kinetics of 32Dcl3 granulocytic differentiation. Sequence analysis of the 5′ flanking region of the c-myb gene revealed a consensus PU box at position +16 to +21 able to specifically interact in electrophoretic mobility shift assays with either bacterially synthesized PU.1 protein or whole cell extracts from differentiated 32Dcl3 cells. Transient expression of PU.1 in cotransfection assays in different cell lines resulted in inhibition of chloramphenicol acetyl transferase activity driven by different segments of the c-myb promoter. Moreover, such an effect was dependent on an intact PU box. Thus, the ability of PU.1 to potentiate terminal myeloid differentiation appears to involve downregulation of c-myb expression, an essential step during differentiation of hematopoietic precursor cells.
Fas-Fas Ligand–Based Interactions Between Tumor Cells and Tumor-Specific Cytotoxic T Lymphocytes: A Lethal Two-Way Street
Authors: Zeytun Ahmet , Hassuneh Mona , Nagarkatti Mitzi , Nagarkatti Prakash S. 
Published: October 2019

AbstractIn the current study, we investigated the repercussions of the interaction between tumor cells (LSA) and the tumor-specific cytotoxic T lymphocyte (CTL) (PE-9) when both expressed Fas and Fas ligand (FasL). The CTL clone, PE-9, expressed high levels of Fas and FasL upon activation through the T-cell receptor (TCR). Furthermore, the activated PE-9 cells used both perforin- and FasL-based pathways to kill Fas-positive (Fas+) LSA tumor cells. Interestingly, LSA tumor cells also constitutively expressed FasL but not perforin, and killed Fas+ PE-9 CTLs and Fas+ but not Fas-negative (Fas−) activated T cells and thymocytes, as detected using the JAM test. PE-9 CTLs, cultured for 24 hours in the presence of cell lysates of FasL-bearing LSA cells but not FasL-deficient P815 cells, exhibited significant apoptosis as detected using the TUNEL method. Moreover, another FasL+ T-cell lymphoma line, EL-4, induced apoptosis in Fas+ but not in Fas− T cells in a similar fashion. The current study demonstrates for the first time that not only can the tumor-specific CTL mediate Fas-based killing of tumor cells, but FasL+ tumor cells can kill the Fas+ tumor-specific CTL. Thus, the survival of the tumor or the host may depend on which cell can accomplish this task more efficiently. The current study also suggests that FasL-based killing of CTLs by specific tumor cells may constitute a major limiting factor in successful immunotherapy.
RheothRx (Poloxamer 188) Injection for the Acute Painful Episode of Sickle Cell Disease: A Pilot Study
Authors: Adams-Graves Patricia , Kedar Amos , Koshy Mabel , Steinberg Martin , Veith Robert , Ward Daniel , Crawford Rebekah , Edwards Suzanne , Bustrack James , Emanuele Martin 
Published: October 2019

Abstract
RheothRx (Glaxo Wellcome Inc, Research Triangle Park, NC; poloxamer 188) Injection is a nonionic surfactant with hemorrheologic properties that suggest it may be useful in treating acute painful episodes (vasoocclusive crises) of sickle cell disease (SCD). We conducted a randomized, double-blind, placebo-controlled pilot study to evaluate the safety and efficacy of poloxamer, formulated as RheothRx Injection, in 50 patients with SCD. Patients with moderate to severe painful episodes requiring parenteral analgesics were randomized to receive a 48-hour infusion of either RheothRx or placebo. Pain was assessed every 4 hours. Efficacy endpoints included: (1) painful episode duration, (2) days of hospitalization, (3) quantity of analgesics used, and (4) pain intensity scores. Three subgroups of patients were considered for efficacy analyses based on the actual duration of the study drug infusion and the completeness of pain score data collection. Compared with placebo and depending on the subgroup, RheothRx-treated patients showed a 16% to 45% decrease in duration of painful episodes, a 1- to 2-day reduction in hospital stay, a threefold to fivefold reduction in analgesic requirements, and a 1-point reduction (using a 5-point scale) in average pain intensity scores at 72 hours. RheothRx was well tolerated; no clinically significant differences were observed between treatments with respect to adverse experiences or other safety measures. In addition, there were no differences between treatment groups in the incidence of recurrent painful episodes. In this study, RheothRx significantly reduced total analgesic use and pain intensity and showed trends to shorter duration of painful episodes and total days of hospitalization. In patients with moderate to severe vasoocclusive pain, RheothRx was safe and may offer a therapeutic benefit.
Suppression of Megakaryocyte Colony Growth by Plasma From Foals Infected With Equine Infectious Anemia Virus
Authors: Tornquist Susan J. , Crawford Timothy B. 
Published: October 2019

AbstractFoals infected with equine infectious anemia virus become thrombocytopenic 7 to 20 days after virus inoculation, and within a few days following the onset of detectable viremia. The thrombocytopenia is associated with suppression of platelet production. Possible mediators of suppression of thrombopoiesis include tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β), cytokines that are released during inflammation. To assess effects of plasma or serum from infected foals on megakaryocyte (MK) growth and maturation in vitro, equine low-density bone marrow cells were cultured for clonogenic and ploidy assays. Neutralizing antibodies to TNF-α and TGF-β were added to cultures to determine the contribution of these cytokines to suppression of thrombopoiesis. Plasma from the immediately pre-thrombocytopenia (Pre-Tp) period significantly reduced MK colony numbers. This suppression was partially reversed upon antibody neutralization of plasma TNF-α, TGF-β, or both. There were no differences in ploidy distribution of MK grown in the presence of preinfection serum compared with those grown in the presence of Pre-Tp serum. These results indicate that TNF-α and TGF-β may contribute to suppression of MK proliferation and represent likely factors in the pathogenesis of thrombocytopenia.
Detection and Characterization of Primitive Malignant and Normal Progenitors in Patients With Acute Myelogenous Leukemia Using Long-Term Coculture With Supportive Feeder Layers and Cytokines
Authors: Ailles Laurie E. , Gerhard Brigitte , Hogge Donna E. 
Published: October 2019

Abstract
Analysis of the mitogenic activity of interleukin-3 (IL-3), Steel factor (SF ), and flt-3 ligand (FL) on acute myelogenous leukemia (AML) blasts using the short-term endpoints of proliferation in 3H-thymidine (3H-Tdr) incorporation assays or methylcellulose cultures (colony assays) showed that greater than 90% of samples contained cells that were responsive to one or more of these cytokines. With this information, culture conditions that were known to support normal long-term culture-initiating cells (LTC-IC) were tested, with or without supplements of one or more of these three growth factors, for their ability to support primitive progenitors from 10 cell samples from patients with AML. In all cases cytogenetically abnormal colony forming cells (CFC) were detected after 5 weeks when AML peripheral blood or marrow cells were cocultured on preestablished, normal human marrow feeders (HMF ) and/or Sl/Sl mouse fibroblast feeders and the number of CFC detected in these 5-week-old LTC maintained a linear relationship to the number of input AML cells. Limiting dilution analysis, performed on 6 of the 10 samples, showed the frequency of AML cells initiating LTC (AML LTC-IC) to be 5- to 300-fold lower than the frequency of AML-CFC in the same cell sample, whereas the average number of CFC produced per LTC-IC varied from 1 to 13. Surprisingly, in each case the concentration of cytogenetically normal LTC-IC detected in AML patient blood was at least 10-fold higher than that previously observed in the blood of normal individuals. “Mixed” mouse fibroblast feeders engineered to produce human G-CSF, IL-3, and SF did not enhance detection of AML LTC-IC but did increase the output of cytogenetically normal CFC from LTC of 3 of 4 patient samples. Supplementation of AML LTC with IL-3 and exogenously provided SF and/or FL increased the output of AML-CFC from 5-week-old LTC by greater than or equal to twofold with 5 of 9 patient samples, whereas in one case exogenous addition of FL reduced the output of malignant CFC from LTC. These studies show that conditions that support normal LTC-IC also allow a functionally analogous but rare AML progenitor cell type to be detected. In addition, differences in the responses of normal and leukemic cells to various cytokines active on normal LTC-IC were revealed. Further analysis of these differences may enhance our understanding of leukemogenesis and lead to observations that could be exploited therapeutically.
A Dinucleotide Deletion Results in Defective Membrane Anchoring and Circulating Soluble Glycoprotein Ibα in a Novel Form of Bernard-Soulier Syndrome
Authors: Kenny Dermot , Newman Peter J. , Morateck Patricia A. , Montgomery Robert R. 
Published: October 2019

AbstractThe platelet membrane glycoprotein (GP)Ib-V-IX complex is the receptor for von Willebrand factor and is composed of four membrane-spanning polypeptides: GPIbα, GPIbβ, GPIX, and GPV. A qualitative or quantitative deficiency in the GPIb-V-IX complex on the platelet membrane is the cause of the congenital platelet disorder Bernard-Soulier syndrome (BSS). We describe the molecular basis of a novel variant BSS in a patient in which GPIbα was absent from the platelet surface but present in a soluble form in the plasma. DNA sequence analysis showed a homozygous dinucleotide deletion in the codon for Tyr 508 (TAT) in GPIbα. This mutation (GPIbαΔAT) causes a frame shift that alters the amino acid sequence of GPIbα within its transmembrane region. The hydrophobic nature of the predicted transmembrane region and the cytoplasmic tail at the COOH terminal are altered before reaching a new premature stop codon 38 amino acids short of the wild-type peptide. Although GPIbαΔAT was not detectable on the platelet surface, immunoprecipitation of plasma with specific monoclonal antibodies (MoAbs) identified circulating GPIbα. Transient expression of recombinant GPIbαΔAT in 293T cells also generated a soluble form of the protein. Moreover, when a plasmid encoding GPIbαΔAT was transiently transfected into Chinese hamster ovary (CHO) cells stably expressing the GPβ-IX complex, it failed to be expressed on the cell surface. Thus, a dinucleotide deletion in the codon for Tyr 508 causes a frameshift that alters the amino acid sequence of GPIbα starting within its transmembrane region, changes the hydrophobicity of the normal transmembrane region, and truncates the cytoplasmic domain affecting binding to the cytoskeleton and cytoplasmic proteins. This mutation affects anchoring of the GPIbα polypeptide in platelets and causes the observed BSS phenotype with circulating soluble GPIbα.
Intracellular Signaling Events in CD77-Mediated Apoptosis of Burkitt's Lymphoma Cells
Authors: Taga Samir , Carlier Karine , Mishal Zohair , Capoulade Corinne , Mangeney Marianne , Lécluse Yann , Coulaud Dominique , Tétaud Cécile , Pritchard Linda Louise , Tursz Thomas , Wiels Joëlle 
Published: October 2019

AbstractIn the hematopoietic system CD77, a glycolipid surface antigen, is restricted to group I Burkitt's lymphoma (BL) cell lines and a subset of germinal center B lymphocytes. Recently, we have reported that recombinant B subunits of Verotoxin, which specifically binds to CD77, induce programmed cell death of CD77+ BL cells. Here, we show that an anti-CD77 monoclonal antibody (38.13) immobilized on tissue culture dishes also induces apoptosis, and we have explored the signal transducing events leading to this cell death. We show that ligation of CD77 antigen causes an increase of the intracellular Ca2+ concentration owing to an influx of extracellular Ca2+ through calcium channels. Chelation of extracellular Ca2+ with EGTA partially prevents anti-CD77–induced apoptosis, indicating that this process is probably Ca2+ dependent. We show that the cross-linking of CD77 provokes an increase of intracellular cAMP levels followed by cAMP-dependent protein kinase activation. We report that BL cells produce ceramide when they are exposed to 38.13 but, unexpectedly, without a concomitant decrease in sphingomyelin or CD77 content. Finally, we provide evidence that C2-ceramide, calcium ionophore, and forskolin (which increases intracellular levels of cAMP) independently induce apoptosis of CD77+ BL cells and, moreover, that C2-ceramide and forskolin strongly synergize to cause cell death. The possible role of CD77-mediated apoptosis in the B cell selection that occurs in germinal centers is discussed.
Transforming Growth Factor-β1 Abrogates Fas-Induced Growth Suppression and Apoptosis of Murine Bone Marrow Progenitor Cells
Authors: Dybedal Ingunn , Guan Fengan , Borge Ole Johan , Veiby Ole Petter , Ramsfjell Veslemøy , Nagata Shigekazu , Jacobsen Sten Eirik W. 
Published: October 2019

AbstractFas, a member of the tumor necrosis factor (TNF ) receptor superfamily is a critical downregulator of cellular immune responses. Proinflammatory cytokines like interferon-γ (IFN-γ) and TNF-α can induce Fas expression and render hematopoietic progenitor cells susceptible to Fas-induced growth suppression and apoptosis. Transforming growth factor-β1 (TGF-β1 ) is an essential anti-inflammatory cytokine, thought to play a key role in regulating hematopoiesis. In the present studies we investigated whether TGF-β1 might regulate growth suppression and apoptosis of murine hematopoietic progenitor cells signaled through Fas. In the presence of TNF, activation of Fas almost completely blocked clonogenic growth of lineage-depleted (Lin−) bone marrow (BM) progenitor cells in response to granulocyte-macrophage colony-stimulating factor (GM-CSF ), CSF-1, or a combination of multiple cytokines. Whereas TGF-β1 alone had no effect or stimulated growth in response to these cytokines, it abrogated Fas-induced growth suppression. Single-cell studies and delayed addition of TGF-β1 showed that the ability of TGF-β1 to inhibit Fas-induced growth suppression was directly mediated on the progenitor cells and not indirect through potentially contaminating accessory cells. Furthermore, TGF-β1 blocked Fas-induced apoptosis of Lin− BM cells, but did not affect Fas-induced apoptosis of thymocytes. TGF-β1 also downregulated the expression of Fas on Lin− BM cells. Thus, TGF-β1 potently and directly inhibits activation-dependent and Fas-mediated growth suppression and apoptosis of murine BM progenitor cells, an effect that appears to be distinct from its ability to induce progenitor cell-cycle arrest. Consequently, TGF-β1 might act to protect hematopoietic progenitor cells from enhanced Fas expression and function associated with proinflammatory responses.
Normal Platelets and Megakaryocytes Are Produced In Vivo in the Absence of Thrombopoietin
Authors: Bunting Stuart , Widmer Ramon , Lipari Terry , Rangell Linda , Steinmetz Hope , Carver-Moore Karen , Moore Mark W. , Keller Gilbert-Andre , de Sauvage Frederic J. 
Published: October 2019

Abstract
Thrombopoietin (TPO) has been established as the major regulator of megakaryocyte and platelet production. In vitro and in vivo studies have demonstrated that TPO affects both megakaryocyte proliferation and maturation. In vitro, TPO has been reported to be essential for full development of megakaryocytes and platelets. These studies are in contrast to results observed in vivo in mice deficient in the TPO or c-mpl gene (TPO-/- and c-mpl-/-). Both TPO-/- and c-mpl-/- mice exhibit a 90% reduction in megakaryocyte and platelet levels. But even with this small number of circulating platelets, these mice do not have any excessive bleeding. Ultrastructural analysis indicates that platelets and megakaryocytes present in the knockout mice are morphologically normal. Characterization of platelet function shows that platelets from knockout mice are functionally identical to the wild-type platelets as measured by upregulation of 125I-fibrinogen binding to platelets in response to adenosine diphosphate (ADP) stimulation and by platelet attachment to the immobilized extracellular matrix proteins, collagen and von Willebrand factor (vWF). These results demonstrate that in vivo, TPO is required for the control of megakaryocyte and platelet number but not for their maturation. Other factors with megakaryocytopoietic activity may be able to compensate for the maturational role of TPO and lead to the formation of normal megakaryocytes and platelets in TPO-/- and c-mpl-/- mice.
Anti-CD43 Inhibits Monocyte-Endothelial Adhesion in Inflammation and Atherogenesis
Authors: McEvoy Leslie M. , Jutila Mark A. , Tsao Philip S. , Cooke John P. , Butcher Eugene C. 
Published: October 2019

AbstractRecruitment of blood monocytes into tissues is a central event in the inflammatory response and in atherogenesis. The mechanisms leading to monocyte adhesion and migration through endothelium are not completely defined. We recently reported that MAb L11, against the leukocyte sialomucin CD43, blocks T-lymphocyte binding to lymph node and Peyer's patch high endothelial venules (HEV) and inhibits T-cell extravasation from the blood into organized secondary lymphoid tissues. We have now assessed the ability of L11 to inhibit monocyte-endothelial (EC) interactions and trafficking. L11 blocks binding of WEHI78/24 cells, a murine monocytoid cell line, to inflamed lymph node HEV and inhibits recruitment of monocytes and neutrophils to thioglycollate-inflamed peritoneum. Because monocyte adhesion to the endothelium and diapedesis in lesion-prone regions of the vasculature is among the earliest events in atherogenesis, leading to formation of lipid-laden foam cells, the ability of L11 to block monocyte recognition of aortic endothelial cells was assessed in a novel ex vivo assay of monocyte binding to intact rabbit aortic endothelium. Cholesterol feeding of rabbits induces enhanced aortic adhesiveness for monocytes and WEHI78/24 monocytoid cells, and this adhesion is inhibited by L11. The inhibitory effect of L11 is additive with that of a cocktail of anti–L-selectin and anti-α4 and β2 integrin monoclonal antibodies. Thus, CD43 represents a novel target for manipulation of monocyte recruitment in inflammation and atherogenesis.
A Monocyte Conditioned Medium Is More Effective Than Defined Cytokines in Mediating the Terminal Maturation of Human Dendritic Cells
Authors: Reddy Anita , Sapp Mark , Feldman Mary , Subklewe Marion , Bhardwaj Nina 
Published: October 2019

AbstractMature human dendritic cells can be generated in substantial numbers from nonproliferating progenitors in human blood using a two-step protocol. T cell–depleted mononuclear cells are first cultured with granulocyte-macrophage colony-stimulating factor and interleukin-4 (IL-4) and then exposed to monocyte conditioned medium (MCM). The dendritic cells generated using this approach are rendered terminally mature and are the most potent antigen presenting cells identified to date in humans. We sought to characterize factors in MCM that induce the terminal differentiation of dendritic cells. MCM contained substantial, although varying, quantities of several factors including tumor necrosis factor-α, IL-1β, IL-6, and interferon-α. However, none of the four factors, individually or in various combinations, could fully substitute for the MCM to generate irreversibly differentiated dendritic cells. The yields, percentage of cells expressing the mature phase marker CD83, and mixed leukocyte reaction–stimulatory function were lower when defined cytokines were used in the place of MCM. Therefore, the full maturation of dendritic cells, because it entails changes in many known cell and molecular properties, requires a number of different cytokines that are released in tandem from appropriately stimulated monocytes. We propose that MCM-matured dendritic cells will be the most effective adjuvants for immunotherapy in vivo.
Primary Anaplastic Large-Cell Lymphoma in Adults: Clinical Presentation, Immunophenotype, and Outcome
Authors: Tilly Hervé , Gaulard Philippe , Lepage Eric , Dumontet Charles , Diebold Jacques , Plantier Isabelle , Berger Françoise , Symann Michel , Petrella Tony , Lederlin Pierre , Brière Josette 
Published: October 2019

Abstract
Anaplastic, CD30+, large-cell lymphoma is now a well-recognized pathologic entity that accounts for 2% to 8% of all lymphomas. Recent progress has been made in the understanding of certain biologic features found in anaplastic large-cell lymphoma, but information about its clinical behavior, in comparison to other large-cell lymphomas, is limited. The pathologic review of a large multicenter study of the treatment of aggressive lymphoma identified 146 cases of anaplastic large-cell lymphoma (ALCL) on the basis of morphology and CD30 expression. We compared initial presentation, immunophenotype, and clinical outcome of these cases with those of the 1,695 nonanaplastic diffuse large-cell lymphomas (non-ALCL) included in the same trial. Patients with ALCL were more likely to be male (P = .018) and were younger (P < .0001) than those with non-ALCL. B symptoms were more frequent in ALCL (P = .006). Skin (P < .0001) and lung (P < .05) involvement was also more frequent in ALCL, but frequency of bone marrow involvement was identical (P = .5). Tumor cell phenotype was B in 56 cases (38%), T in 49 cases (34%), and null in 33 cases (22%). Response to chemotherapy (P = .001), event-free survival (P = .006), and overall survival (P = .0004) were better for ALCL than for non-ALCL. Multivariate analyses identified anaplastic character as an independent factor that predicted a longer survival. Tumor cell phenotype did not influence event-free survival (P = .72) or overall survival (P = .83). ALCL in adults is a clinicopathologic entity which, independent of its phenotypic characteristics, has a better outcome than other diffuse large-cell lymphomas.