bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Interleukin-3 and Other Growth Factors on α4β1 Integrin-Mediated Adhesion and Migration of Human Hematopoietic Progenitor Cells
Authors: Schofield Karen P. , Rushton Graham , Humphries Martin J. , Dexter T. Michael , Gallagher John T. 
Published: October 2019

AbstractThe mechanisms by which hematopoietic progenitor cells are normally anchored in stromal niches and yet can be mobilized by specific growth factors are poorly understood. It is likely, however, that integrins and their extracellular matrix (ECM) ligands play a key role in this process, and recent evidence suggests that integrin function is modulated by signals originating from activated growth factor receptors. We have now examined this further by studying the role of growth factors on α4β1 integrin-mediated adhesion of human CD34+ hematopoietic progenitor cells to specific recombinant fibronectin fragments coated onto tissue culture dishes. Cells were prepared from cord blood and peripheral blood harvests. During a 30-minute adhesion assay a mean of 74% of CD34 cells attached to the so-called H120 fragment of fibronectin, which contains the strongest α4β1 integrin-binding sequence. The level of cell adhesion was significantly reduced by low concentrations of interleukin-3 (IL-3) (2.5 to 10 ng/mL), whereas stem cell factor (SCF ) and granulocyte colony-stimulating factor (G-CSF ) at these concentrations did not affect adherence of the cells. Migratory behavior of CD34 cells was examined using fibronectin fragments adsorbed onto a Transwell filter. The H120 fragment supported much higher levels of cell migration than the H0 fragment of fibronectin, which contains a weak α4β1 integrin binding sequence. Over a 16-hour assay, migration of peripheral blood progenitor cells was increased slightly by SCF and by G-CSF. However, a marked stimulation was observed with IL-3, which significantly increased migration. Similar effects were noted with cord blood cells, although a small proportion of cells were able to migrate in the absence of growth factors. These results indicate that there is a highly selective and functional link between the α4β1 integrin and IL-3/IL-3–receptor that could affect the position of stem and progenitor cells in the marrow stroma and influence their growth and development.
FcγRIII-Mediated Regulation of Hematopoiesis in Murine Bone Marrow Cells by Interleukin-3 and CD95 (Fas/Apo-1)
Authors: Yoshikawa Hideshi , Sakihama Toshiko , Nakajima Yasuo , Tasaka Kachio 
Published: October 2019

AbstractThe interleukin-3 (IL-3)–dependent murine bone marrow–derived cell line FDC-P2/185-4 (185-4) undergoes apoptosis when IL-3 is withdrawn from culture medium. Previous results from our studies indicated that a high concentration of aggregated mouse IgG prevented apoptosis of 185-4 cells through FcγRIII by an autocrine mechanism, producing IL-3. But after 24 hours, 185-4 cells expressed CD95 (Fas/Apo-1) on their surfaces on stimulation via FcγRIII. In addition, this CD95 was functional and apoptosis was induced by anti-CD95 monoclonal antibody (MoAb). We investigated how these conflicting effects were induced by FcγRIII stimulation within the context of cell survival and death. The results showed that IL-3 was induced by calcium ionophore and that the IL-3 induced by FcγRIII stimulation was blocked by EGTA or FK506, but not by staurosporine (protein kinase C [PKC] inhibitor), indicating the important role of calcium-calcineurin in this system. On the other hand, the CD95 expression induced by FcγRIII stimulation was blocked by staurosporine, but not by EGTA or FK506, and phorbol myristate acetate (PMA) induced CD95 expression in the same manner as FcγRIII, indicating the involvement of PKC in the CD95 expression induced by FcγRIII stimulation. Thus, FcγRIII-mediated stimulation even while promoting immediate survival of the bone marrow cells, also triggers mechanisms that will facilitate their eventual deletion at the end of the response. These results suggest that a balance between cell survival and death is maintained to avoid unlimited cell growth caused by FcγRIII-ligand interaction in hematopoiesis during inflammation.
In Vitro Negative Selection of Viral Superantigen-Reactive Thymocytes by Thymic Dendritic Cells
Authors: Ferrero Isabel , Anjuère Fabienne , Robson MacDonald H. , Ardavı́n Carlos 
Published: October 2019

AbstractIntrathymic expression of endogenous mouse mammary tumor virus (MMTV)–encoded superantigens (SAg) induces the clonal deletion of T cells bearing SAg-reactive T-cell receptor (TCR) Vβ elements. However, the identity of the thymic antigen-presenting cells (APC) involved in the induction of SAg tolerance remains to be defined. We have analyzed the potential of dendritic cells (DC) to mediate the clonal deletion of Mtv-7-reactive TCR αβ P14 transgenic thymocytes in an in vitro assay. Our results show that both thymic and splenic DC induced the deletion of TCR transgenic double positive (DP) thymocytes. DC appear to be more efficient than splenic B cells as negatively selecting APC in this experimental system. Interestingly, thymic and splenic DC display a differential ability to induce CD4+SP thymocyte proliferation. These observations suggest that thymic DC may have an important role in the induction of SAg tolerance in vivo.
Long-Term Malignant Hematopoiesis in Human Acute Leukemia Bone Marrow Biopsies Implanted in Severe Combined Immunodeficiency Mice
Authors: Legrand Faezeh , Khazaal Ibrahim , Peuchmaur Michel , Fenneteau Odile , Cavé Hélène , Rohrlich Pierre , Vilmer Etienne , Péault Bruno 
Published: October 2019

Abstract
Bone marrow (BM) trephine biopsies from 15 pediatric patients with acute lymphoid (ALL) or myeloid (AML) leukemia were engrafted subcutaneously into severe combined immunodeficiency (SCID) mice conditioned by 200 cGy total-body irradiation. Implants were harvested 5 to 19 weeks later for histologic, cytologic, and/or flow cytometric analysis of the residing marrow. Eighteen of 19 grafts contained viable human leukemic cells to various extents as assessed by one or more of these methods. Thirteen of 14 implants analyzed by flow cytometry included high numbers of tumor cells, accounting for 85% to 100% of the total nucleated cells in seven of them. Histologically, engrafted marrow samples exhibited areas of blastic infiltration, and tumor-specific gene rearrangements were retrieved in long-term engrafted biopsies. Importantly, engrafted mice remained perfectly healthy even 5 months posttransplantation, and no human tumor cell dissemination was detected in the hematolymphoid and nonhematopoietic tissues at the time of autopsy. These results demonstrate that human malignant hematopoiesis can be sustained long-term in its original, intact marrow stromal environment transplanted in appropriately conditioned immunodeficient mice.
The Hemoglobin-Deficit Mouse: Analysis of Phenotype and Hematopoiesis in the Transplant Model
Authors: Bloom Michael L. , Simon-Stoos Karen L. 
Published: October 2019

Abstract
The mouse mutant hemoglobin deficit (gene symbol hbd ) is characterized by a severe microcytic anemia that is inherited in an autosomal-recessive manner. To assess the mutation's effect on hematopoiesis, unfractionated bone marrow (BM) from either a mutant C57BL6/J-hbd/hbd, Gpi1b/Gpi1b (phenotype symbol HBD), or normal C57BL6/J -+hbd/+hbd, Gpi1b/Gpi1b mouse was injected intravenously into irradiated congenic C57BL6/J-+hbd/+hbd, Gpi1a/Gpi1a, Igha/Igha, Thy1a/Thy1a mice. The congenic recipients of mutant or normal marrow obtained complete red blood cell (RBC) and leukocyte reconstitution, with the exception of one recipient of HBD marrow. After 24 weeks posttransplantation, the normal recipients of HBD marrow obtained a microcytic anemia similar to the donor. These results suggest that the HBD phenotype is caused by a BM defect. We observed that the erythroid lineage derived from donor HBD marrow repopulated more slowly than the normal marrow at 4 weeks posttransplantation. To determine if this difference was a result of an erythropoietic defect, competitive repopulation was performed using either mutant or normal marrow competed against normal congenic marrow. For the erythroid lineage, no significant contribution from HBD marrow was observed. To assess if the RBC block was based on a deficiency of myeloid progenitors, both in vitro and in vivo assays were performed: absolute numbers of bone progenitors were increased, suggesting that the defect results in a late block to erythroid differentiation.
In Vitro Generation of Allospecific Human CD8+ T Cells of Tc1 and Tc2 Phenotype
Authors: Halverson David C. , Schwartz Gretchen N. , Carter Charles , Gress Ronald E. , Fowler Daniel H. 
Published: October 2019

AbstractWe have previously shown that allospecific murine CD8+ T cells of the Tc1 and Tc2 phenotype could be generated in vitro, and that such functionally defined T-cell subsets mediated a graft-versus-leukemia (GVL) effect with reduced graft-versus-host disease (GVHD). To evaluate whether analogous Tc1 and Tc2 subsets might be generated in humans, CD8+ T cells were allostimulated in the presence of either interleukin-12 (IL-12) and transforming growth factor-beta (TGF-β) (Tc1 culture) or IL-4 (Tc2 culture). Tc1-type CD8 cells secreted the type I cytokines IL-2 and interferon gamma (IFN-γ), whereas Tc2-type cells primarily secreted the type II cytokines IL-4, IL-5, and IL-10. Both cytokine-secreting populations effectively lysed tumor targets when stimulated with anti–T-cell receptor (TCR) antibody; allospecificity of Tc1- and Tc2-mediated cytolytic function was demonstrated using bone marrow–derived stimulator cells as targets. In addition, both Tc1 and Tc2 subsets were capable of mediating cytolysis through the fas pathway. We therefore conclude that allospecific human CD8+ T cells of Tc1 and Tc2 phenotype can be generated in vitro, and that these T-cell populations may be important for the mediation and regulation of allogeneic transplantation responses.
Effect of Diagnosis (Refractory Anemia With Excess Blasts, Refractory Anemia With Excess Blasts in Transformation, or Acute Myeloid Leukemia [AML]) on Outcome of AML-Type Chemotherapy
Authors: Estey Elihu , Thall Peter , Beran Miloslav , Kantarjian Hagop , Pierce Sherry , Keating Michael 
Published: October 2019

Abstract
In current medical practice, patients with refractory anemia with excess blasts in transformation (RAEB-t), and especially patients with RAEB, receive chemotherapy regimens (AML Rx) administered to patients with acute myeloid leukemia (AML) less often than do patients with AML. These entities are distinguished primarily by marrow blast percentage (5% to 19% RAEB, 20% to 29% RAEB-t, and ≥30% AML). The poor prognosis of many RAEB or RAEB-t patients, if untreated, led us to give them AML Rx using the same plan as for AML. The purpose of this analysis was to see if diagnosis (RAEB, RAEB-t, or AML) affected outcome. We treated 372 patients with AML (acute promyelocytic leukemia [APL] excluded), 106 with RAEB-t, and 52 with RAEB. AML Rx produced a 62% complete remission (CR) rate in RAEB, essentially identical to the rates in RAEB-t and AML, but event-free survival (EFS) from CR and from start of treatment (start of Rx), as well as overall survival, were poorer in RAEB than in AML or RAEB-t, with AML and RAEB-t being identical. However, patients with RAEB or RAEB-t were more likely to have poor prognostic characteristics, in particular complex abnormalities involving chromosomes 5 and/or 7. Multivariate analyses indicated that, when considered together with cytogenetics and other patient characteristics, a diagnosis of RAEB rather than AML or RAEB-t had no effect on EFS from start of Rx, EFS from CR, survival, or achievement of CR. These analyses suggested a trend for patients with RAEB-t to have better EFS from start of Rx than patients with AML or RAEB (P = .08; relative risk, 0.80; 95% confidence interval, 0.62 to 1.03), but there were no differences with respect to the other outcomes. Our data suggest that the propriety of administering AML Rx to patients with RAEB or RAEB-t who have poor prognosis without treatment is identical to the propriety of treating AML in this fashion. Deterrents to standard AML Rx in these patients could justifiably include cytogenetics, age, etc, but not a diagnosis of RAEB or RAEB-t per se.
The Human Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF ) Receptor Exists as a Preformed Receptor Complex That Can Be Activated by GM-CSF, Interleukin-3, or Interleukin-5
Authors: Woodcock Joanna M. , McClure Barbara J. , Stomski Frank C. , Elliott Michael J. , Bagley Christopher J. , Lopez Angel F. 
Published: October 2019

AbstractThe granulocyte-macrophage colony-stimulating factor (GM-CSF ) receptor is expressed on normal and malignant hematopoietic cells as well as on cells from other organs in which it transduces a variety of functions. Despite the widespread expression and pleiotropic nature of the GM-CSF receptor, little is known about its assembly and activation mechanism. Using a combination of biochemical and functional approaches, we have found that the human GM-CSF receptor exists as an inducible complex, analogous to the interleukin-3 (IL-3) receptor, and also as a preformed complex, unlike the IL-3 receptor or indeed other members of the cytokine receptor superfamily. We found that monoclonal antibodies to the GM-CSF receptor α chain (GMRα) and to the common β chain of the GM-CSF, IL-3, and IL-5 receptors (βc ) immunoprecipitated both GMRα and βc from the surface of primary myeloid cells, myeloid cell lines, and transfected cells in the absence of GM-CSF. Further association of the two chains could be induced by the addition of GM-CSF. The preformed complex required only the extracellular regions of GMRα and βc , as shown by the ability of soluble βc to associate with membrane-anchored GMRα or soluble GMRα. Kinetic experiments on eosinophils and monocytes with radiolabeled GM-CSF, IL-3, and IL-5 showed association characteristics unique to GM-CSF. Significantly, receptor phosphorylation experiments showed that not only GM-CSF but also IL-3 and IL-5 stimulated the phosphorylation of GMRα-associated βc . These results indicate a pattern of assembly of the heterodimeric GM-CSF receptor that is unique among receptors of the cytokine receptor superfamily. These results also suggest that the preformed GM-CSF receptor complex mediates the instantaneous binding of GM-CSF and is a target of phosphorylation by IL-3 and IL-5, raising the possibility that some of the biologic activities of IL-3 and IL-5 are mediated through the GM-CSF receptor complex.
Mice Lacking Both Granulocyte Colony-Stimulating Factor (CSF) and Granulocyte-Macrophage CSF Have Impaired Reproductive Capacity, Perturbed Neonatal Granulopoiesis, Lung Disease, Amyloidosis, and Reduced Long-Term Survival
Authors: Seymour John F. , Lieschke Graham J. , Grail Dianne , Quilici Cathy , Hodgson George , Dunn Ashley R. 
Published: October 2019

AbstractMice lacking granulocyte colony-stimulating factor (G-CSF) are neutropenic with reduced hematopoietic progenitors in the bone marrow and spleen, whereas those lacking granulocyte-macrophage colony-stimulating factor (GM-CSF) have impaired pulmonary homeostasis and increased splenic hematopoietic progenitors, but unimpaired steady-state hematopoiesis. These contrasting phenotypes establish unique roles for these factors in vivo, but do not exclude the existence of additional redundant functions. To investigate this issue, we generated animals lacking both G-CSF and GM-CSF. In the process of characterizing the phenotype of these animals, we further analyzed G-CSF– and GM-CSF–deficient mice, expanding the recognized spectrum of defects in both. G-CSF–deficient animals have a marked predisposition to spontaneous infections, a reduced long-term survival, and a high incidence of reactive type AA amyloidosis. GM-CSF–deficient mice have a modest impairment of reproductive capacity, a propensity to develop lung and soft-tissue infections, and a similarly reduced survival as in G-CSF–deficient animals. The phenotype of mice lacking both G-CSF and GM-CSF was additive to the features of the constituent genotypes, with three novel additional features: a greater degree of neutropenia among newborn mice than in those lacking G-CSF alone, an increased neonatal mortality rate, and a dominant influence of the lack of G-CSF on splenic hematopoiesis resulting in significantly reduced numbers of splenic progenitors. In contrast to newborn animals, adult mice lacking both G-CSF and GM-CSF exhibited similar neutrophil levels as G-CSF–deficient animals. These findings demonstrate that the additional lack of GM-CSF in G-CSF–deficient animals further impairs steady-state granulopoiesis in vivo selectively during the early postnatal period, expand the recognized roles of both G-CSF and GM-CSF in vivo, and emphasize the utility of studying multiply deficient mouse strains in the investigation of functional redundancy.
Cytoplasmic Localization of a Functionally Active Fanconi Anemia Group A–Green Fluorescent Protein Chimera in Human 293 Cells
Authors: Kruyt Frank A.E. , Waisfisz Quinten , Dijkmans Lonneke M. , Hermsen Mario A.J.A. , Youssoufian Hagop , Arwert Fré , Joenje Hans 
Published: October 2019

Abstract
Hypersensitivity to cross-linking agents and predisposition to malignancy are characteristic of the genetically heterogeneous inherited bone marrow failure syndrome, Fanconi anemia (FA). The protein encoded by the recently cloned FA complementation group A gene, FAA, has been expected to localize in the nucleus as based on the presence of sequences homologous to a bipartite nuclear localization signal (NLS) and a leucine repeat motif. In contrast to this expectation, we show here that a functionally active FAA-green fluorescent protein (GFP) hybrid resides in the cytoplasmic compartment of human kidney 293 cells. In accordance with this finding, disruption of the putative NLS by site-directed mutagenesis failed to affect both subcellular localization and the capacity to complement hypersensitivity to the cross-linking agent mitomycin C in FA-A lymphoblasts. Furthermore, the N-terminal part of FAA with the putative NLS at amino acid position 18 to 35 showed no nuclear translocation activity when fused to GFP, while the first 115 N-terminal amino acids appeared to be indispensable for the complementing activity in FA-A cells. Similarly, mutagenesis studies of the putative leucine repeat showed that, even though this region of the protein is important for complementing activity, this activity does not depend on an intact leucine zipper motif. Finally, fusion of the NLS motif derived from the SV40 large T antigen to FAA could not direct the hybrid protein into the nucleus of 293 cells, suggesting that FAA is somehow maintained in the cytoplasm via currently unknown mechanisms. Thus, like the first identified FA protein, FAC, FAA seems to exert its function in the cytoplasmic compartment suggesting FA proteins to be active in a yet to be elucidated cytoplasmic pathway that governs hematopoiesis and protects against genomic instability.
Induction of Apoptosis Without Differentiation by Retinoic Acid in PLB-985 Cells Requires the Activation of Both RAR and RXR
Authors: Monczak Yury , Trudel Michel , Lamph William W. , Miller Wilson H. 
Published: October 2019

AbstractRetinoic acid (RA) induces differentiation, followed by apoptosis in acute promyelocytic leukemia (APL) cells, both in vitro and in patients. One problem in understanding these mechanisms is to distinguish molecular events leading to differentiation from those leading to apoptosis. We have identified a leukemic cell line, PLB-985, where RA directly induces apoptosis with no morphologic, genetic, or cell-surface marker evidence of differentiation. These cells differentiate following dimethyl sulfoxide (DMSO), but not RA, treatment. Two-color flow cytometry showed no alteration of the cell cycle after RA treatment, and cell-surface marker analysis of CD11a, CD11b, and CD13 showed no modulation typical of differentiating cells. RNA expression of myeloblastin and transglutaminase, genes regulated by RA-induced differentiation in NB4 cells, was unchanged by RA treatment. Instead, RA induced apoptosis, as shown by typical apoptotic morphological features, genomic DNA laddering, and positive labeling in the TUNEL assay. We found that induction of apoptosis in this model requires a different pattern of retinoid receptor binding and transcriptional activation than is seen in APL cells. As previously described, treatment with retinoid receptor-selective ligands showed that stimulation of RAR alone is sufficient to induce differentiation and apoptosis in NB4 cells, and that stimulation of RXR has no effect on the parameters analyzed. In PLB-985 cells, on the other hand, apoptosis was induced only upon costimulation of both RAR and RXR. Stimulation of either receptor alone had no effect on the cells. Consistent with these findings, bcl-2 RNA and protein levels were downregulated after stimulation of both RAR and RXR, but not with an RAR-specific ligand alone, as in NB4 cells. The expression of several other bcl-2 family members (bcl-X, ich-1, bax, bag, and bak ) and retinoid receptors (RARα, RXRα, and RXRβ) was not affected by treatment with RAR- and/or RXR-activating retinoids; RARβ RNA was undetectable before and after retinoid treatment. Thus, our cell model provides a useful tool in determining the genetic events mediating apoptosis as a response to RA, unobscured by events implicated in differentiation.
Generation of Virtually Pure and Potentially Proliferating Dendritic Cells From Non-CD34 Apheresis Cells From Patients With Multiple Myeloma
Authors: Tarte Karin , Lu Zhao Yang , Fiol Genevieve , Legouffe Eric , Rossi Jean-François , Klein Bernard 
Published: October 2019

AbstractDefects in immune response are often reported in patients with multiple myeloma (MM). Because dendritic cells (DCs) are key effectors in promoting cellular immunity and are potential vectors for immunotherapy, we have evaluated the ability of MM patients' apheresis cells to generate DCs in short-term cultures. We report here the obtaining of a virtually pure population of DCs (89.7% ± 6%, n = 18) after culturing adherent apheresis cells for 7 days with granulocyte-macrophage colony-stimulating factor (GM-CSF ) and interleukin-4 (IL-4). These cells exhibited all the phenotypic characteristics (CD1a+, HLA-DR+, CD80+, CD40+, CD14−) and the MLR stimulating capacity of mature DCs. The number of DCs reached 12.1% of the initial apheresis cell number put into culture. As DC precursors involved in this model were CD34− cells, the unabsorbed cells resulting from clinical-grade CD34 purification were a reliable source of DCs, even after freezing. The proliferation of DC precursors could be increased 10-fold by adding IL-3 and tumor necrosis factor-α together with GM-CSF and IL-4. Thus, CD34− apheresis cells from patients with MM offer an interesting source for generating pure, functional, and potentially proliferating DCs.
Successful Reconstitution of Human Hematopoiesis in the SCID-hu Mouse by Genetically Modified, Highly Enriched Progenitors Isolated From Fetal Liver
Authors: Humeau Laurent , Chabannon Christian , Firpo Meri T. , Mannoni Patrice , Bagnis Claude , Roncarolo Maria-Grazia , Namikawa Reiko 
Published: October 2019

Abstract
Highly purified CD34++CD38−Lin− hematopoietic progenitors isolated from human fetal liver were infected with the murine retroviral vector, MFG nls-LacZ, which encodes a modified version of the Escherichia coli β-galactosidase gene. Progenitors that were cocultured with the packaging cell line could reconstitute human bone marrow or thymus implanted in SCID-hu mice. Expression of the β-galactosidase gene was observed in primitive and committed clonogenic progenitors, mature myeloid, B-lineage cells, and T-lineage cells for up to 4 months after injection into SCID-hu mice. Furthermore, hematopoietic reconstitution by genetically modified progenitor cells could be achieved by the injection of the cells generated from as few as 500 CD34++CD38−Lin− cells, suggesting efficient retroviral gene transfer into fetal liver progenitors.