bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mcl-1, a Bcl-2 Family Member, Delays the Death of Hematopoietic Cells Under a Variety of Apoptosis-Inducing Conditions
Authors: Zhou Ping , Qian Liping , Kozopas Karen M. , Craig Ruth W. 
Published: October 2019

AbstractMcl-1 is a member of the Bcl-2 family that was identified based on increased expression in myeloblastic leukemia cells undergoing differentiation. Mcl-1 was previously found to be similar to Bcl-2 in causing a delay in apoptotic cell death in Chinese hamster ovary cells. The work described here was aimed at determining whether Mcl-1 could also exert such an effect in hematopoietic cells, because endogenous Mcl-1 expression is prominent in the hematopoietic system. A further aim was to assess the effects of Mcl-1 in cells exposed to a variety of cytotoxic stimuli, because Bcl-2 is known to have a broad spectrum of activity. To approach these aims, FDC-P1 murine myeloid progenitor cells were transfected with vectors driving either constitutive or inducible expression of Mcl-1. The introduced Mcl-1 gene was found to cause a prolongation of viability under various conditions that cause apoptotic cell death, including exposure to cytotoxic agents (the chemotherapeutic drug etoposide, calcium ionophore, or UV irradiation) and the withdrawal of required growth factors. In addition, Mcl-1 was found to interact with Bax, a member of the Bcl-2 family that promotes cell death as a homodimer but that can heterodimerize with Bcl-2 to promote cell viability. Although Mcl-1 prolonged cell viability, it did not prevent eventual cell death upon continuous exposure to a cytotoxic agent. Prolongation of viability was maximal when expression of Mcl-1 was induced before the application of the apoptotic stimulus, although some increase occurred if Mcl-1 was induced shortly thereafter and before overt apoptosis. Taken as a whole, these findings provide further parallels between Mcl-1 and Bcl-2, showing that Mcl-1 can interact with Bax in hematopoietic FDC-P1 cells and can prolong cell viability under a variety of cytotoxic conditions.
Formation of Multinucleated Giant Cells In Vitro Is Dependent on the Stage of Monocyte to Macrophage Maturation
Authors: Möst Johannes , Spötl Ludwig , Mayr Gertraud , Gasser Annette , Sarti Alessandra , Dierich Manfred P. 
Published: October 2019

AbstractMultinucleated giant cells (MGC) are a common feature of granulomas that develop during various inflammatory reactions. MGC originate from fusion of monocytes or macrophages, but the exact mechanism of their generation is still unclear. In the present study, we investigated the influence of monocyte to macrophage maturation on the ability of human monocytes/macrophages to fuse with each other. MGC were generated in vitro by stimulation of human peripheral blood monocytes with cytokine containing supernatants. With freshly isolated monocytes, fusion rates of up to 90% were obtained. When monocyte to macrophage maturation was induced by culturing the cells in human serum, fusion rates gradually decreased with advancing time of the preceding culture (corresponding to the stage of differentiation) and almost no MGC formation could be obtained with 8-day-old macrophages. In contrast, fusion rates did not decrease when monocytes had been cultured under serum free conditions before stimulation. When freshly isolated monocytes were added to 1-week cultured macrophages, which had been membrane-labeled with a fluorochrome, fusion between the two populations could be induced. Because the ability for intracellular killing of certain pathogens is reduced in macrophages, fusion with monocytes (newly arriving at the site of inflammation) may represent an attempt to restore this capacity.
Protoporphyria Induced by the Orally Active Iron Chelator 1,2-diethyl-3-hydroxypyridin-4-one in C57BL/10ScSn Mice
Authors: Smith Andrew G. , Clothier Bruce , Francis Jean E. , Gibbs Anthony H. , De Matteis Francesco , Hider Robert C. 
Published: October 2019

AbstractAdministration in the drinking water of the orally-active iron chelator 1,2-diethyl-3-hydroxypyridin-4-one (CP94) to C57BL/10ScSn mice caused the development of hepatic protoporphyria. This was detected after 1 week and continued as long as the chelator was given (15 weeks). The more hydrophilic 1,2-dimethyl- and 1-hydroxyethyl,2-ethyl-analogues (CP20 and CP102) were also tested, but they were both inactive in inducing accumulation of protoporphyrin in the liver. Restriction of in vivo iron supply for ferrochelatase seemed a likely mode of action, but an approximately 30% decrease in activity of this enzyme was also observed when measured in vitro. Extracts of livers from mice given CP20, CP94, and CP102 showed no potential to inhibit mouse ferrochelatase, in contrast to the findings with an extract from mice treated with the known porphyrogenic chemical 4-ethyl - 3 , 5 - diethoxycarbonyl - 2 , 6 - dimethyl - 1 , 4 - dihydropyridine, -indicating that ferrochelatase inhibition did not occur by the formation of an N-ethyl-protoporphyrin derived from metabolism by cytochrome P450. CP20, CP94, CP102, and CP117 (the pivoyl ester of CP102) all caused significant depression of the levels of ferritin-iron and total nonheme iron, but only CP94 caused the significant accumulation of protoporphyrin. Protoporphyria did not occur with iron overloaded C57BL/10ScSn mice or in SWR mice that had elevated basal iron status. Although the protoporphyrin had only a small effect on the total levels of the hemoprotein cytochrome P450 in C57BL/10ScSn mice, the activity of the CYP2B isoforms of cytochrome P450 was actually induced in both strains. The results show that CP94 could cause protoporphyria in individuals of low iron status, perhaps through specifically targeting particular iron pools available to ferrochelatase and by concomitantly stimulating heme synthesis.
A Murine Model for Human Cord Blood Transplantation: Near-Term Fetal and Neonatal Peripheral Blood Cells Can Achieve Long-Term Bone Marrow Engraftment in Sublethally Irradiated Adult Recipients
Authors: Scaradavou Andromachi , Isola Luis , Rubinstein Pablo , Galperin Yelena , Najfeld Vesna , Berlin David , Gordon Jon , Weinberg Rona S. 
Published: October 2019

Abstract
The purposes of the research reported here were first to explore a murine model for human placental and umbilical cord blood transplantation and second to evaluate the engraftment ability of ex vivo cultured hematopoietic cells. Murine near-term fetal and neonatal peripheral blood (FNPB) cells, genetically marked with the human multiple drug resistance transgene (MDR1) were used for syngeneic transplants into sublethally irradiated adult mice. Donor cells were transplanted either fresh and untreated, or after ex vivo culture in the presence of the hematopoietic growth factors recombinant murine stem cell factor, recombinant human interleukin-3 (rHu IL-3), and rHu IL-6, in a liquid culture system. To evaluate, count, and characterize FNPB progenitor cell-derived colonies, neonatal mouse mononuclear cells were cultured directly in methylcellulose with growth factors. To assess their ex vivo expansion ability, FNPB mononuclear cells were first cultured in liquid medium for 3 to 8 days and then transferred to semisolid assay plates. Evaluation of the cell counts after liquid culture showed a 1.4- to 11.6-fold increase, and the numbers of colonies observed in methylcellulose were similar to those produced by fresh FNPB cells. Donor-type engraftment was demonstrated by polymerase chain reaction (PCR) amplification of the human MDR1 transgene in the peripheral blood of all surviving animals (5 of 7 recipients of the fresh, and 3 of 8 recipients of the ex vivo–cultured cells) 2 to 4 months after transplantation. The proportion of donor leukocytes in the peripheral blood of the recipients (chimerism) was evaluated using fluorescence in situ hybridization (FISH) analysis 4 to 6 months after transplantation and ranged from 2% to 26%. In addition, bone marrow cultures were obtained from two recipient animals: one had received fresh-untreated cells and was evaluated 8 months after transplant, the other had received ex vivo cultured cells and was tested 14 months after grafting. The derived hematopoietic colonies were tested by PCR and the transgene was detected, conclusively proving long-term engraftment of donor cells. These results indicate that FNPB transplants can be successfully performed in sublethally irradiated mice with and without ex vivo culture. Long-term donor-type engraftment with sustained chimerism has been demonstrated. Thus, murine neonatal blood grafts can be used as an animal model for cord blood transplantation for gene therapy studies where complete myeloablation is not desirable and partial replacement of defective marrow may be sufficient. Furthermore, the possibility of numerically expanding hematopoietic progenitor cells contained in neonatal blood without affecting their engraftment ability could facilitate use of cord blood grafts in adult recipients.
Development of Antibodies to Fetal Calf Serum With Arthus-Like Reactions in Human Immunodeficiency Virus–Infected Patients Given Syngeneic Lymphocyte Infusions
Authors: Selvaggi Thomas A. , Walker Robert E. , Fleisher Thomas A. 
Published: October 2019

AbstractIn an attempt to restore immune competence to 12 human immunodeficiency virus-1 (HIV-1)–infected patients, lymphocytes from their HIV-1–uninfected identical twin siblings were cultured in medium supplemented with 5% fetal calf serum (FCS), anti-CD3 antibody, and interleukin-2 (100 IU/mL) for 10 days and then infused into the patients. After multiple infusions, at 6- to 8-week intervals, half of the patients developed arthus-like reactions within 4 to 12 hours of infusion consisting of fever <39°C, hypotension, rigors, arthralgias, myalgias, headache, and/or malaise. Preinfusion and postinfusion serum samples were evaluated for the presence of antibodies to FCS using double immunodiffusion. All preinfusion serum samples were negative by this method while 8 of the 12 patients developed antibodies to a single component of FCS after two or more infusions of lymphocytes cultured in FCS-supplemented medium. Prick skin testing to standardized beef extract was negative in all patients. There was a correlation between initial CD4 level and the development of antibodies to FCS (median initial CD4 count in FCS antibody positive patients = 362.0/μL v median initial CD4 count of nonresponders = 135.0/μL). There was no correlation with response to recall antigens in delayed-type hypersensitivity testing. We conclude that selected patients were sensitized to a single component of FCS carried on donor lymphocytes, despite thorough washing of the cells before infusion. The development of antibodies to FCS indicates that immune complex formation could have occurred after the cell infusions, resulting in the arthus-like reactions. These observations suggest that the therapeutic use of human lymphocytes cultured in FCS may expose the recipient to immunogenic substances with possible clinical sequelae.
Involvement of Fas-Mediated Apoptosis in the Inhibitory Effects of Interferon-α in Chronic Myelogenous Leukemia
Authors: Selleri Carmine , Sato Tadatsugu , Del Vecchio Luigi , Luciano Luigia , Barrett A. John , Rotoli Bruno , Young Neal S. , Maciejewski Jaroslaw P. 
Published: October 2019

AbstractInterferon-α (IFN-α) is an established treatment for chronic myelogenous leukemia (CML) in chronic phase, but the mechanism of its antileukemic activity is not clear. One possible mechanism of action might include the induction of apoptosis, and especially Fas-mediated cell killing may play an important role in the elimination of malignant cells. We investigated Fas receptor (Fas-R) expression and the consequences of Fas-R triggering in CML patients. Using two-color flow cytometry, we found a significantly higher number of Fas-R–expressing CD34+ cells in the bone marrow (BM) of CML patients compared with normal subjects. We have previously shown that IFN-γ induces Fas-R expression on CD34+ cells; in this study, we investigated whether IFN-α induces Fas-R expression on CML progenitor cells. Dose-dependent induction of Fas-R expression was observed after IFN-α stimulation of CD34+ cells from CML BM. In methylcellulose culture, IFN-α alone at a therapeutic concentration showed only marginal antiproliferative effects on both normal and CML BM progenitors. In contrast, a Fas-R agonist, the anti-CD95 monoclonal antibody CH11, inhibited colony formation from normal progenitors, and the inhibition was even stronger on CML progenitors. When CML BM cells were cultured in the presence of IFN-α, Fas-R–mediated inhibition of colony growth was potentiated in a dose-dependent fashion, consistent with IFN-α induction of Fas-R expression. This functional effect did not require the presence of accessory cells, since similar results were obtained with purified CD34+ cells. In suspension cultures, we demonstrated that suppression of CML hematopoiesis by IFN-α and Fas-R agonist was exerted through Fas-R–mediated induction of apoptosis. Our findings suggest that the Fas-R/Fas-ligand system might be involved in the immunologic regulation of CML progenitor growth and that its effect can be amplified by IFN-α.
Case-Control Study Suggests a Favorable Impact of TEL Rearrangement in Patients With B-Lineage Acute Lymphoblastic Leukemia Treated With Antimetabolite-Based Therapy: A Pediatric Oncology Group Study
Authors: Rubnitz Jeffrey E. , Shuster Jonathan J. , Land Vita J. , Link Michael P. , Pullen D. Jeanette , Camitta Bruce M. , Pui Ching-Hon , Downing James R. , Behm Frederick G. 
Published: October 2019

Abstract
TEL gene rearrangement is the most common genetic lesion in pediatric acute lymphoblastic leukemia (ALL), occurring in about 25% of B-lineage cases. We previously showed that, among patients treated on St Jude protocols, TEL rearrangement independently conferred an excellent prognosis. To extend these results to patients treated with antimetabolite-based therapy, we performed Southern blot analysis to determine the TEL gene status of 104 cases of B-lineage ALL treated on Pediatric Oncology Group 8602, matched on age, gender, and leukocyte count. There were 52 failures among the 77 patients with germline TEL, compared with only 8 failures among 27 patients in the rearranged group. Based on a two-sided logistic regression analysis, stratified for age (subdivided at 10 years), leukocyte count (subdivided at 50,000), and gender, the estimated odds of failing by 4 years in the germline TEL group is 5.4 times that of the rearranged TEL group, with 95% confidence from 1.9 to 15.6, two-sided P = .0009. Thus, the presence of a rearranged TEL gene is also associated with an improved survival among patients treated with antimetabolite-based therapy. Our results indicate that all newly diagnosed ALL patients should be screened for TEL gene rearrangements and suggest that these patients are candidates for less intensive therapy.
Characterization of cis-Acting Sequences and trans-Acting Signals Regulating Early Growth Response 1 and c-fos Promoters Through the Granulocyte-Macrophage Colony-Stimulating Factor Receptor in BA/F3 Cells
Authors: Watanabe Sumiko , Kubota Hideya , Sakamoto Kathleen M. , Arai Ken-ichi 
Published: October 2019

AbstractHuman granulocyte-macrophage colony-stimulating factor (hGM-CSF ) activates a set of genes such as c-fos, jun, myc, and early growth response gene 1 (egr-1). Studies on BA/F3 cells that express hGM-CSF receptor (hGMR) showed that two different signaling pathways controlled by distinct regions within the β subunit are involved in activation of c-fos/c-jun genes and in c-myc, respectively. However, the region(s) of the β subunit responsible for activation of the egr-1 gene and other regulatory genes has not been identified. We describe here how egr-1 promoter is activated by hGMR through two regions of the β subunit, with these regions being required for activation of the c-fos promoter. Coexpression of dominant negative (dn) Ras (N17ras) or dn JAK2 almost completely suppressed the activation of egr-1 and c-fos promoters. Deletion analysis of egr-1 promoter showed two cis-acting regions responsible for activation by hGM-CSF or mouse interleukin-3 (mIL-3), one between nucleotide positions (nt) −56 and −116, and the other between nt −235 and −480, which contains tandem repeats of the serum response element (SRE) sites. Similar experiments with the c-fos promoter showed that cis-acting regions containing the SRE/AP-1 sites is sufficient for activation by hGM-CSF. Based on these observations, we propose that signaling pathways activating egr-1 and c-fos promoters are controlled by SRE elements, either through the same or overlapping pathways that involve JAK2 and Ras.
Detection of Anaplastic Lymphoma Kinase (ALK) and Nucleolar Protein Nucleophosmin (NPM)-ALK Proteins in Normal and Neoplastic Cells With the Monoclonal Antibody ALK1
Authors: Pulford Karen , Lamant Laurence , Morris Stephan W. , Butler Lisa H. , Wood Katrina M. , Stroud David , Delsol Georges , Mason David Y. 
Published: October 2019

Abstract
The t(2; 5)(p23;q35) translocation, associated with anaplastic large-cell lymphoma (ALCL), results in the production of the nucleolar protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) protein. This report describes an immunocytochemical study of the distribution of ALK and NPM-ALK proteins using a new monoclonal antibody, ALK1, that recognizes a formalin resistant epitope in both the 80-kD NPM-ALK chimeric and the 200-kD normal human ALK proteins. Cytoplasmic and nuclear labeling was seen in the t(2; 5)+ SU-DHL-1 and Karpas 299 cell lines. Normal ALK protein expression was restricted to the central nervous system (in scattered neurons, glial cells, and endothelial cells). Two hundred and thirty-nine cases of lymphoma and 80 nonhematopoietic tumors were immunostained. Antibody ALK1 labeled 53.4% (39 of 73 cases) of CD30+ ALCL. A case of ALCL with a t(1; 2) translocation was ALK1+. Three cases of CD30− ALCL with prominent nucleoli showed a unique pattern of coarse granular cytoplasmic labeling. All other tumors, including Hodgkin's disease and lymphomatoid papulosis, were ALK1−. These results indicate that reliable immunostaining of routine biopsy material for NPM-ALK and ALK proteins is feasible. Such analysis is of diagnostic importance, especially because t(2; 5)+ ALCL cases have a good prognosis with appropriate treatment.
Human Platelets Display High-Affinity Receptors for Thrombopoietin
Authors: Broudy Virginia C. , Lin Nancy L. , Sabath Diana F. , Papayannopoulou Thalia , Kaushansky Kenneth 
Published: October 2019

AbstractThrombopoietin (Tpo) is a major regulator of megakaryopoiesis both in vivo and in vitro. Tpo initiates its biologic effects by binding to the Mpl receptor, which is a member of the hematopoietin receptor family. To define the Tpo binding characteristics of the Mpl receptor, we iodinated purified 70-kD recombinant human Tpo using the Bolton-Hunter reagent. Autoradiographic analysis of 125I-Tpo binding to normal human marrow mononuclear cells showed many grains specifically associated with megakaryocytes; there were no grains specifically associated with myeloblasts or erythroblasts. Equilibrium binding experiments with 125I-Tpo and normal human platelets showed a single class of high-affinity receptors (kd, 190 pmol/L) with approximately 30 Mpl receptors per platelet. Affinity cross-linking with 125I-Tpo showed that the Mpl receptor on platelets is of molecular weight ∼98 kD. Despite their sequence similarity, erythropoietin and Tpo did not cross-compete for binding to BaF3 cells engineered to coexpress Mpl receptor and erythropoietin receptor. Progeny of normal human burst-forming units-erythroid (BFU-E) contained Mpl receptor mRNA, and flow cytometric analysis showed the presence of Mpl receptor protein on the surface of these cells. These data indicate that display of the Mpl receptor is not limited to the megakaryocytic lineage, but also includes progeny of BFU-E. Like receptors for other hematopoietic cytokines, the binding affinity of the Mpl receptor for Tpo is high, with relatively few receptors displayed per cell. These results suggest that the effects of Tpo to speed red blood cell recovery after myelosuppressive therapy in vivo and to enhance colony-forming unit-erythroid generation in vitro may be mediated by direct interaction of Tpo and erythroid progenitor cells.
Efficient In Vivo Marking of Primary CD4+ T Lymphocytes in Nonhuman Primates Using a Gibbon Ape Leukemia Virus-Derived Retroviral Vector
Authors: Bunnell Bruce A. , Metzger Mark , Byrne Ellen , Morgan Richard A. , Donahue Robert E. 
Published: October 2019

AbstractHigh efficiency retroviral-mediated gene transfer to rhesus CD4+ peripheral blood lymphocytes (PBL) was accomplished using an optimized transduction protocol using a gibbon ape leukemia virus (GaLV) envelope-containing packaging cell line PG13. Engineered CD4+ PBL were administered to three nonmyeloablated animals in three or four separate infusions over 9 months. Polymerase chain reaction (PCR) demonstrated in vivo reconstitution of the genetically engineered CD4+ PBL at levels between 1% and 10% of the circulating leukocytes. This level of gene marking indicates that up to 30% of endogenous circulating CD4+ cells can be genetically engineered. The high levels of marked lymphocytes persist for the first 3 weeks following reinfusion then decline to ≤ 0.1% over the next 21 weeks. Lymph node (LN) biopsies were performed to determine if the engineered CD4+ lymphocytes could traffic to lymphoid tissues. Marked lymphocytes were detected in LN biopsies 100 days following reinfusion of the transduced cells. Expression of retroviral vector-derived sequences was detected by reverse transcriptase (RT)-PCR analysis from CD4-enriched lymphocytes that were activated by culturing in the presence of recombinant interleukin-2 (rIL-2). A humoral immune response to fetal bovine serum (FBS) was detected in all animals following the second administration of the culture expanded CD4+ lymphocytes. No antibody response was detected to the neomycin-resistance (NeoR) transgene, the murine retroviral group-specific antigen (gag), or GaLV envelope (env) proteins.
HLA Class II–Mediated Death Is Induced Via Fas/Fas Ligand Interactions in Human Splenic B Lymphocytes
Authors: Truman Jean-Philip , Choqueux Christine , Tschopp Jürg , Vedrenne Jocelyn , Le Deist Françoise , Charron Dominique , Mooney Nuala 
Published: October 2019

AbstractHLA class II molecules, expressed on the surface of antigen-presenting cells, are responsible for the presentation of antigen-derived peptides to CD4+ helper T lymphocytes. Signaling via these molecules initiates the generation of second messengers leading to programed cell death (PCD) of activated B lymphocytes. The present study examined the mechanism of HLA class II–mediated apoptosis and describes the essential role of the molecule Fas and its ligand (FasL). FasL was expressed in B lymphocytes after stimulation via HLA class II or with phorbol esters. Expression of FasL protein was significantly increased in 50% of B lymphocytes after stimulation via HLA class II, and the level of FasL mRNA was also increased either by activation with phorbol esters and ionomycin or by signaling via HLA class II. Although HLA class II signaling did not change the expression of the Fas molecule, it did lead to increased sensitivity to Fas-mediated apoptosis. The crucial role of Fas/FasL interactions was confirmed by the absence of cell death via HLA class II in B cells lacking Fas expression, and by the significant inhibition of HLA class II–mediated apoptosis in the presence of either an antagonistic anti-Fas or anti-FasL antibody. These data demonstrate FasL expression on activated human B lymphocytes and support the idea that antigen presentation could contribute to the regulation of lymphocyte populations via Fas and FasL interactions.