bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stromal cell-derived factor-1α stimulates tyrosine phosphorylation of multiple focal adhesion proteins and induces migration of hematopoietic progenitor cells: roles of phosphoinositide-3 kinase and protein kinase C
Authors: Wang Jian-Feng , Park In-Woo , Groopman Jerome E. 
Published: October 2019

AbstractThe stromal cell-derived factor-1 (SDF-1) is an alpha chemokine that binds to the CXCR4 receptor. Knock-out studies in mice demonstrate that this ligand-receptor pair is essential in hematopoiesis. One function of SDF-1 appears to be the regulation of migration of hematopoietic progenitor cells. We previously characterized signal transduction pathways induced by SDF-1 in human hematopoietic progenitors and found tyrosine phosphorylation of focal adhesion components, including the related adhesion focal tyrosine kinase (RAFTK), the adaptor molecule p130 Cas, and the cytoskeletal protein paxillin. To better understand the functional role of signaling molecules connecting the CXCR4 receptor to the process of hematopoietic migration, we studied SDF-1–mediated pathways in a model hematopoietic progenitor cell line (CTS), as well as in primary human bone marrow CD34+cells. We observed that several other focal adhesion components, including focal adhesion kinase (FAK) and the adaptor molecules Crk and Crk-L, are phosphorylated on SDF-1 stimulation. Using a series of specific small molecule inhibitors, both protein kinase C (PKC) and phosphoinositide-3 kinase (PI-3K) appeared to be required for SDF-1–mediated phosphorylation of focal adhesion proteins and the migration of both CTS and primary marrow CD34+ cells, whereas the mitogen-activated protein kinases ERK-1 and -2 were not. These studies further delineate the molecular pathways mediating hematopoietic progenitor migration and response to an essential chemokine, SDF-1.
Improved muscle-derived expression of human coagulation factor IX from a skeletal actin/CMV hybrid enhancer/promoter
Authors: Hagstrom J. Nathan , Couto Linda B. , Scallan Ciaran , Burton Melissa , McCleland Mark L. , Fields Paul A. , Arruda Valder R. , Herzog Roland W. , High Katherine A. 
Published: October 2019

AbstractHemophilia B is caused by the absence of functional coagulation factor IX (F.IX) and represents an important model for treatment of genetic diseases by gene therapy. Recent studies have shown that intramuscular injection of an adeno-associated viral (AAV) vector into mice and hemophilia B dogs results in vector dose–dependent, long-term expression of biologically active F.IX at therapeutic levels. In this study, we demonstrate that levels of expression of approximately 300 ng/mL (6% of normal human F.IX levels) can be reached by intramuscular injection of mice using a 2- to 4-fold lower vector dose (1 × 1011 vector genomes/mouse, injected into 4 intramuscular sites) than previously described. This was accomplished through the use of an improved expression cassette that uses the cytomegalovirus (CMV) immediate early enhancer/promoter in combination with a 1.2-kilobase portion of human skeletal actin promoter. These results correlated with enhanced levels of F.IX transcript and secreted F.IX protein in transduced murine C2C12 myotubes. Systemic F.IX expression from constructs containing the CMV enhancer/promoter alone was 120 to 200 ng/mL in mice injected with 1 × 1011vector genomes. Muscle-specific promoters performed poorly for F.IX transgene expression in vitro and in vivo. However, the incorporation of a sequence from the -skeletal actin promoter containing at least 1 muscle-specific enhancer and 1 enhancer-like element further improved muscle-derived expression of F.IX from a CMV enhancer/promoter-driven expression cassette over previously published results. These findings will allow the design of a clinical protocol for therapeutic levels of F.IX expression with lower vector doses, thus enhancing efficacy and safety of the protocol.
Cloning of PRV-1, a novel member of the uPAR receptor superfamily, which is overexpressed in polycythemia rubra vera
Authors: Temerinac Snežana , Klippel Steffen , Strunck Elisabeth , Röder Sabine , Lübbert Michael , Lange Winand , Azemar Marc , Meinhardt Gerold , Schaefer Hans-Eckart , Pahl Heike L. 
Published: October 2019

AbstractPolycythemia vera (PV) is a clonal stem cell disorder characterized by hyperproliferation of the erythroid, myeloid, and megakaryocytic lineages. Although it has been shown that progenitor cells of patients with PV are hypersensitive to several growth factors, the molecular pathogenesis of this disease remains unknown. To investigate the molecular defects underlying PV, we used subtractive hybridization to isolate complementary DNAs (cDNAs) differentially expressed in patients with PV versus normal controls. We isolated a novel gene, subsequently named PRV-1, which is highly expressed in granulocytes from patients with PV (n = 19), but not detectable in normal control granulocytes (n = 21). Moreover, PRV-1 is not expressed in mononuclear cells from patients with chronic myelogenous leukemia (n = 4) or acute myelogenous leukemia (n = 5) or in granulocytes from patients with essential thrombocythemia (n = 4) or secondary erythrocytosis (n = 4). Northern blot analysis showed that PRV-1 is highly expressed in normal human bone marrow and to a much lesser degree in fetal liver. It is not expressed in a variety of other tissues tested. Although PRV-1 is not expressed in resting granulocytes from normal controls, stimulation of these cells with granulocyte colony-stimulating factor induces PRV-1 expression. The PRV-1 cDNA encodes an open reading frame of 437 amino acids, which contains a signal peptide at the N-terminus and a hydrophobic segment at the C-terminus. In addition, PRV-1 contains 2 cysteine-rich domains homologous to those found in the uPAR/Ly6/CD59/snake toxin-receptor superfamily. We therefore propose that PRV-1 represents a novel hematopoietic receptor.
Cloning of the human platelet F11 receptor: a cell adhesion molecule member of the immunoglobulin superfamily involved in platelet aggregation
Authors: Sobocka Malgorzata B. , Sobocki Tomasz , Banerjee Probal , Weiss Cipora , Rushbrook Julie I. , Norin Allen J. , Hartwig John , Salifu Moro O. , Markell Mariana S. , Babinska Anna , Ehrlich Yigal H. , Kornecki Elizabeth 
Published: October 2019

AbstractThis study demonstrates that the human platelet F11 receptor (F11R) functions as an adhesion molecule, and this finding is confirmed by the structure of the protein as revealed by molecular cloning. The F11R is a 32-/35-kd protein duplex that serves as the binding site through which a stimulatory monoclonal antibody causes platelet aggregation and granule secretion. A physiological role for the F11R protein was demonstrated by its phosphorylation after the stimulation of platelets by thrombin and collagen. A pathophysiological role for the F11R was revealed by demonstrating the presence of F11R-antibodies in patients with thrombocytopenia. Adhesion of platelets through the F11R resulted in events characteristic of the action of cell adhesion molecules (CAMs). To determine the structure of this protein, we cloned the F11R cDNA from human platelets. The predicted amino acid sequence demonstrated that it is an integral membrane protein and an immunoglobulin superfamily member containing 2 extracellular C2-type domains. The structure of the F11R as a member of a CAM family of proteins and its activity in mediating adhesion confirm each another. We conclude that the F11R is a platelet-membrane protein involved in 2 distinct processes initiated on the platelet surface. The first is antibody-induced platelet aggregation and secretion that are dependent on both the FcγRII and the GPIIb/IIIa integrin and that may be involved in pathophysiological processes associated with certain thrombocytopenias. The second is an F11R-mediated platelet adhesion that is not dependent on either the FcγRII or the fibrinogen receptor and that appears to play a role in physiological processes associated with platelet adhesion and aggregation.
Tracing uptake of C3dg-conjugated antigen into B cells via complement receptor type 2 (CR2, CD21)
Authors: Hess Michael W. , Schwendinger Michael G. , Eskelinen Eeva-Liisa , Pfaller Kristian , Pavelka Margit , Dierich Manfred P. , Prodinger Wolfgang M. 
Published: October 2019

AbstractElectron microscopy was used to study the internalization and delivery of ligands for complement receptor type 2 (CR2, CD21) to endocytic compartments of B-lymphoblastoid Raji cells. Opsonized antigen was mimicked with purified C3dg conjugated to colloidal gold. C3dg-gold bound specifically to the cell surface in a time-dependent manner, and preincubation of the cells with a monoclonal antibody blocking the CR2 ligand-binding site completely inhibited any C3dg-gold binding. Notably, the binding of C3d-gold was confined to cell surface protrusions, eg, microvilli. C3dg-gold was apparently internalized through coated pits located at the bases of microvilli and could be traced to different compartments of the endocytic pathway. The morphologic characteristics and intracellular distribution of these multivesicular or multilaminar structures were compatible with those of compartments known to harbor major histocompatibility complex (MHC) class II molecules. Immunolabeling showed that the internalized C3dg-gold colocalized with MHC class II in these structures. These data provide the first ultrastructural evidence that complement-coated antigens are endocytosed by antigen-nonspecific B cells by CR2 and are delivered to the compartments in which peptide loading for antigen presentation occurs. They support the notion that CR2 may play a role in antigen presentation by B cells regardless of B-cell receptor specificity.
Vascular endothelial growth factor and interleukin-6 in paracrine tumor-stromal cell interactions in multiple myeloma
Authors: Dankbar Berno , Padró Teresa , Leo Regine , Feldmann Birgit , Kropff Martin , Mesters Rolf M. , Serve Hubert , Berdel Wolfgang E. , Kienast Joachim 
Published: October 2019

AbstractVascular endothelial growth factor (VEGF), a multifunctional cytokine, potently stimulates angiogenesis including tumor neovascularization. Although well established in solid tumors, the role of VEGF in bone marrow neoangiogenesis and paracrine tumor-stromal cell interactions in lymphohematopoietic malignancies has not been fully elucidated. In multiple myeloma (MM), marrow neovascularization parallels disease progression. This parallel prompted us to investigate the expression and secretion of VEGF by myeloma cells and its potential effects in myeloma-marrow stroma interactions. The biologically active splice variants VEGF165 and VEGF121 were expressed and secreted by myeloma cell lines and plasma cells isolated from the marrow of patients with MM. As shown by immunocytochemistry or RT-PCR, myeloma cells did not express or weakly expressed the VEGF receptors FLT-1 and FLK-1/KDR, indicating that autocrine stimulation is unlikely. In contrast, FLK-1/KDR was abundantly expressed by marrow stromal cells. Therefore, we studied the effects of VEGF on marrow stroma, focusing on the secretion of interleukin-6 (IL-6), a potent growth factor for myeloma cells and an inhibitor of plasma cell apoptosis. Exposure of stromal and microvascular endothelial cells to recombinant human (rh) VEGF165 or VEGF121 induced a time- and dose-dependent increase in IL-6 secretion (14- to 27-fold at 50 ng/mL after 24 hours, P &lt; .001). Conversely, rhIL-6 stimulated VEGF expression and secretion in myeloma cell lines (40%-60%; P &lt; .05) and to a variable degree (up to 5.3-fold; P &lt; .005) in plasma cells purified from the marrow of patients with MM. This mutual stimulation suggests paracrine interactions between myeloma and marrow stromal cells triggered by VEGF and IL-6.
The Ikaros gene, a central regulator of lymphoid differentiation, fuses to the BCL6 gene as a result of t(3;7)(q27;p12) translocation in a patient with diffuse large B-cell lymphoma
Authors: Hosokawa Yoshitaka , Maeda Yumiko , Ichinohasama Ryo , Miura Ikuo , Taniwaki Masafumi , Seto Masao 
Published: October 2019

AbstractThe BCL6 gene, isolated from the breakpoints of 3q27-associated chromosomal translocations, has been implicated in diffuse large B-cell lymphomas (DLBL). Here we describe the molecular characterization of novel t(3;7)(q27;p12) translocations in 2 patients with DLBL. Molecular genetic analysis of the breakpoint area involving BCL6 revealed the presence of the Ikaros gene, a central regulator of lymphoid differentiation that had been mapped to human chromosome 7 band p13-p11.1. As a molecular consequence of the translocation, the 5′ regulatory region of the BCL6 gene was replaced by the putative 5′ regulatory region of theIkaros gene, probably leading to deregulated expression of theBCL6 gene throughout B-cell differentiation. Reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) analyses of a patient sample established that the t(3;7)(q27;p12) results in fusion of the Ikaros andBCL6 genes. This study provides the first evidence that the Ikaros gene is rearranged in human hematopoietic malignant disorders.
Rapid selection of antigen-specific T lymphocytes by retroviral transduction
Authors: Koehne Guenther , Gallardo Humilidad F. , Sadelain Michel , O'Reilly Richard J. 
Published: October 2019

AbstractInfusions of donor peripheral blood T cells can induce durable remissions of Epstein-Barr virus (EBV) lymphomas complicating marrow grafts, but they contain alloreactive T cells capable of inducing graft-versus-host disease. EBV-specific T-cell lines or clones avoid this problem but require 30 to 40 days of culture to establish. To accelerate the generation of EBV-specific T cells, we tested whether retroviral vectors, which only integrate in dividing cells, could be used to transduce and select antigen-reactive T cells early after sensitization to autologous EBV-transformed B cells. T cells were transduced with a dicistronic retroviral vector, NIT, which encodes low-affinity nerve growth factor receptor as an immunoselectable marker and herpes simplex virus thymidine kinase as a suicide gene, at different time points after sensitization. EBV-specific cytotoxic T lymphocyte precursor (CTLp) frequencies in purified NIT+T-cell fractions transduced on day 8 of culture were comparable to those of EBV-specific T-cell lines cultured for 30 days or more. Alloreactive CTLp frequencies were markedly reduced in the NIT+ fraction relative to the untransduced T-cell population. NIT+ fractions transduced on day 8 possessed more CD4+ T cells than the cell lines at day 30 and exhibited the same selective pattern of reactivity against immunodominant antigens presented by specific HLA alleles. In contrast, T cells transduced with NIT 5 days after stimulation with mitogen and interleukin-2 were relatively depleted of T cells specific for autologous EBV-transformed cells. Thus, retroviral vectors may be used for rapid selection of viral antigen-reactive T cells depleted of alloreactive T cells.
Transfer of tissue factor from leukocytes to platelets is mediated by CD15 and tissue factor
Authors: Rauch Ursula , Bonderman Diana , Bohrmann Bernd , Badimon Juan J. , Himber Jacques , Riederer Markus A. , Nemerson Yale 
Published: October 2019

AbstractWe describe thrombogenic tissue factor (TF) on leukocyte-derived microparticles and their incorporation into spontaneous human thrombi. Polymorphonuclear leukocytes and monocytes transfer TF+particles to platelets, thereby making them capable of triggering and propagating thrombosis. This phenomenon calls into question the original dogma that vessel wall injury and exposure of TF within the vasculature to blood is sufficient for the occurrence of arterial thrombosis. The transfer of TF+ leukocyte-derived particles is dependent on the interaction of CD15 and TF with platelets. Both the inhibition of TF transfer to platelets by antagonizing the interaction CD15 with P-selectin and the direct interaction of TF itself suggest a novel therapeutic approach to prevent thrombosis.
Impaired antigen presentation by human monocytes during endotoxin tolerance
Authors: Wolk Kerstin , Döcke Wolf-Dietrich , von Baehr Volker , Volk Hans-Dieter , Sabat Robert 
Published: October 2019

AbstractEndotoxin tolerance (ET) has been described as a temporary alteration in the lipopolysaccharide (LPS) response of monocytic cells after an initial LPS exposure with respect to the production of soluble immunomodulators. Apart from the LPS response, monocytic cells play an important role in initiation of the specific immune response as antigen-presenting cells. This study investigated the capacity of human blood monocytes to induce T-cell stimulation in ET. First, the expression of monocyte surface molecules, important for T-cell interaction, was analyzed by flow cytometry. In vitro priming of peripheral blood mononuclear cells with LPS clearly down-regulates major histocompatibility complex class II molecules and the costimulatory molecule CD86. Both changes were dependent on the endogenous interleukin (IL)-10 and less so on the transforming growth factor-β. In contrast, other accessory molecules on monocytes were only marginally down-regulated (CD58), were not significantly changed during ET (CD40), or even remained up-regulated after initial LPS priming (CD54, CD80). Second, an impact of these phenotypic alterations on the accessory function of monocytes was observed. This was manifested as diminished T-cell proliferation and interferon (IFN)-γ release in response to the presence of different recall antigens. Neutralizing IL-10 during LPS priming prevented the diminished T-cell IFN-γ production but had little effect on T-cell proliferation. These data confirm that ET is an appropriate model of the monocyte functional state in immunoparalysis, which is frequently observed in patients after septic shock, trauma, or major surgery.
T-cell progenitor function during progressive human immunodeficiency virus-1 infection and after antiretroviral therapy
Authors: Clark Dawn R. , Repping Sjoerd , Pakker Nadine G. , Prins Jan M. , Notermans Daan W. , Wit Ferdinand W. N. M. , Reiss Peter , Danner Sven A. , Coutinho Roel A. , Lange Joep M. A. , Miedema Frank 
Published: October 2019

AbstractImpairment of T-cell renewal has been proposed as contributing to CD4+ T-cell depletion in persons infected with human immunodeficiency virus-1. We analyzed the T-cell development capacity of progenitors using fetal thymus organ culture. Those who progressed to AIDS had a dramatic loss in T-cell development capacity shortly after seroconversion. In contrast, long-term nonprogressors retained progenitor capacity 8 years after seroconversion. Approximately 70% of patients experienced an improvement in T-cell development capacity after receiving 6 months of potent antiretroviral therapy. Improvement in T-cell development in fetal thymus organ culture correlated with an increase in the number of naive CD4+ T cells in peripheral blood. Numbers of progenitors in blood and bone marrow after seroconversion or during therapy did not correlate with the change observed in T-cell development capacity. These data provide evidence that HIV-1 infection can interfere with T-cell renewal at the level of the progenitor cell. Interference with T-cell renewal may contribute to CD4+ T-cell depletion.
Detection of clonotypic IGH and TCR rearrangements in the neonatal blood spots of infants and children with B-cell precursor acute lymphoblastic leukemia
Authors: Yagi Tomohito , Hibi Shigeyoshi , Tabata Yasuhiro , Kuriyama Kikuko , Teramura Tomoko , Hashida Tetsuo , Shimizu Yoshitaka , Takimoto Tetsuya , Todo Shinjiro , Sawada Tadashi , Imashuku Shinsaku 
Published: October 2019

AbstractAn attractive hypothesis is that in utero exposure of hematopoietic cells to oncogenic agents can induce molecular changes leading to overt acute lymphoblastic leukemia (ALL) in infants and perhaps older children as well. Although supported by studies of identical infant twins with concordant leukemia, and of nontwined patients withMLL gene rearrangements, this concept has not been extended to the larger population of B-lineage ALL patients who lack unique nonconstitutive mutations or abnormally rearranged genes. We therefore sought to demonstrate a prenatal origin for 7 cases of B-cell precursor ALL (either CD10+ or CD10−) that had been diagnosed in infants and children 14 days to 9 years of age. Using a polymerase chain reaction–based assay, we identified the same clonotypic immunoglobulin heavy-chain complementarity determining region or T-cell receptor VD2-DD3 sequences in the neonatal blood spots (Guthrie card) and leukemic cell DNAs of 2 infants with CD10− ALL and 2 of the 5 older patients with CD10+ ALL. Nucleotide sequencing showed a paucity of N or P regions and shortened D germ line and conserved J sequences, indicative of cells arising from fetal hematopoiesis. Our findings strongly suggest a prenatal origin for some cases of B-cell precursor ALL lacking specific clonotypic abnormalities.
Sulfated glycoconjugates enhance CD36-dependent adhesion ofPlasmodium falciparum–infected erythrocytes to human microvascular endothelial cells
Authors: McCormick Christopher John , Newbold Christopher I. , Berendt Anthony R. 
Published: October 2019

AbstractA novel adhesive pathway that enhances the adhesion ofPlasmodium falciparum-infected erythrocytes (IEs) to endothelial cells has been identified. The sulfated glycoconjugates heparin, fucoidan, dextran sulfate 5000, and dextran sulfate 500 000 caused a dramatic increase in adhesion of IEs to human dermal microvascular endothelial cells. The same sulfated glycoconjugates had little effect on IE adhesion to human umbilical vein endothelial cells, a CD36-negative cell line. The effect was abolished by a monoclonal antibody directed against CD36, suggesting that enhanced adhesion to endothelium is dependent on CD36. No effect was observed on adhesion to purified platelet CD36 cells immobilized on plastic. The same sulfated glycoconjugates enhanced adhesion of infected erythrocytes to COS cells transfected with CD36, and this was inhibited by the CD36 monoclonal antibody. These findings demonstrate a role for sulfated glycoconjugates in endothelial adherence that may be important in determining the location and magnitude of sequestration through endogenous carbohydrates. In addition, they highlight possible difficulties that may be encountered from the proposed use of sulfated glycoconjugates as antiadhesive agents in patients with severe malaria.