bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Human Actin-Binding Protein Homologue That Binds to Platelet Glycoprotein Ib
Authors: Xu Wen-feng , Xie Zhi-wei , Chung Dominic W. , Davie Earl W. 
Published: October 2019

Glycoprotein (GP)Ib-IX-V is one of the major transmembrane complexes present on the platelet surface. Its extracellular domain binds von Willebrand factor (vWF) and thrombin, while its intracellular domain associates tightly with the cytoskeleton through the actin-binding protein (ABP)-280, also known as filamin. In the present study, a full-length cDNA coding for a human ABP homologue has been cloned and sequenced. This protein was identified by the yeast two-hybrid screening procedure via its interaction with the intracellular domain of GPIb. Initially, a 1.3-kb partial cDNA was isolated from a megakaryocyte-like cell line (K562) cDNA library followed by a full-length cDNA of 9.4 kb that was identified in a human placenta library. The full-length cDNA encoded a protein of 2,578 amino acids with a calculated molecular weight of 276 kD (ABP-276). The amino terminal 248 amino acids contained an apparent actin binding domain followed by 24 tandem repeats each containing about 96 amino acids. The amino acid sequence of the protein shared a high degree of homology with human endothelial ABP-280 (70% identity) and chicken filamin (83% identity). However, the 32 amino acid Hinge I region in ABP-280 that contains a calpain cleavage site conferring flexibility on the molecule, was absent in the homologue. An isoform containing a 24 amino acid insertion with a unique sequence at the missing Hinge I region was also identified (ABP-278). This isoform resulted from alternative RNA splicing. ABP-276 and/or ABP-278 were present in all tissues examined, but the relative amount varied in that some tissue contained both forms, while other tissue contained predominately one or the other.© 1998 by The American Society of Hematology.
Two Signaling Pathways Can Increase Fas Expression in Human Thymocytes
Authors: Moulian Nathalie , Bidault Jocelyne , Planché Claude , Berrih-Aknin Sonia 
Published: October 2019

Fas, a cell surface receptor, can induce apoptosis after cross-linking with its ligand. Fewer than 3% of human thymocytes strongly express Fas. We report that Fas antigen expression can be upregulated by two signaling pathways in vitro, one mediated by anti-CD3 and the other by interleukin-7 + interferon-γ. The two signaling pathways differed in several respects. (1) Fas expression increased in all thymic subsets after cytokine activation, but only in the CD4 lineage after anti-CD3 activation. (2) Fas upregulation was inhibited by cyclosporin A (a calcineurin inhibitor) in anti-CD3–activated but not in cytokine-activated thymocytes. (3) Cycloheximide (a metabolic inhibitor) inhibited Fas upregulation in cytokine-activated thymocytes but not in anti-CD3–activated thymocytes. (4) Cytokine-activated thymocytes were more susceptible than anti-CD3–activated thymocytes to Fas-induced apoptosis, a difference mainly accounted for by CD4+ cells. The nature of the stimulus might thus influence the susceptibility of human thymocytes to Fas-induced apoptosis.© 1998 by The American Society of Hematology.
Tissue Inhibitor of Metalloproteinase (TIMP)-1 Induces Differentiation and an Antiapoptotic Phenotype in Germinal Center B Cells
Authors: Guedez Liliana , Courtemanch Laurel , Stetler-Stevenson Maryalice 
Published: October 2019

Tissue inhibitors of metalloproteinases (TIMPs) have been shown to be multifunctional factors. Contrasting with their enzyme-inhibitory activity, TIMPs also promote cell growth. Previously, we have reported an enhanced expression of TIMP-1 by normal reactive B cells and high-grade lymphomas. In the present study, a series of Burkitt’s lymphoma (BL) cell lines were analyzed for their expression of TIMP-1. TIMP-1 expression correlates with upregulation of activation and survival markers. TIMP-1–negative cells express the phenotype associated with group I BL lines and Epstein-Barr virus (EBV)-negative, nonendemic BLs (CD10+, CD38+, sIg+, and CD77+). However, TIMP-1+ BL lines showed group II/III BL phenotype, downregulation of the above markers, and upregulation and secretion of the activation marker CD23. Also, TIMP-1+ cells have high levels of CD40 expression. To determine whether TIMP-1 is directly involved in the BL phenotype, an EBV-negative BL line JD38 was infected with timp-1–expressing retrovirus and analyzed. In the absence of EBV, upregulation of TIMP-1 is sufficient to induce the same phenotype seen in TIMP-1+, EBV+ BL lines (CD10−, CD38−, sIg−, CD77−, CD23+, CD40 bright). This study not only suggests a role for TIMP-1 in BLs, but also supports its value as a prognostic factor.This is a US government work. There are no restrictions on its use.
On the Role of the Proform-Conformation for Processing and Intracellular Sorting of Human Cathepsin G
Authors: Garwicz Daniel , Lindmark Anders , Persson Ann-Maj , Gullberg Urban 
Published: October 2019

The serine protease cathepsin G is synthesized during the promyelomonocytic stage of neutrophil and monocyte differentiation. After processing, including removal of an amino-terminal propeptide from the catalytically inactive proform, the active protease acquires a mature conformation and is stored in azurophil granules. To investigate the importance of the proform-conformation for targeting to granules, a cDNA encoding a double-mutant form of human preprocathepsin G lacking functional catalytic site and amino-terminal prodipeptide (CatG/Gly201/▵Gly19Glu20) was constructed, because we were not able to stably express a mutant lacking only the propeptide. Transfection of the cDNA to the rat basophilic leukemia RBL-1 and the murine myeloblast-like 32D cl3 cell lines resulted in stable, protein-expressing clones. In contrast to wild-type proenzyme, CatG/Gly201/▵Gly19Glu20 adopted a mature conformation cotranslationally, as judged by the early acquisition of affinity to the serine protease inhibitor aprotinin, appearing before the carboxyl-terminal processing and also in the presence of the Golgi-disrupting agent brefeldin A. The presence of a mature amino-terminus was confirmed by amino-terminal radiosequencing. As with wild-type proenzyme, CatG/Gly201/▵Gly19Glu20 was proteolytically processed carboxyl-terminally and glycosylated with asparagine-linked carbohydrates that were converted into complex forms. Furthermore, it was targeted to granules, as determined by subcellular fractionation. Our results show that the initial proform-conformation is not critical for intracellular sorting of human cathepsin G. Moreover, we demonstrate that double-mutant cathepsin G can achieve a mature conformation before carboxyl-terminal processing of the proform.© 1998 by The American Society of Hematology.
Infusion of Cytotoxic T Cells for the Prevention and Treatment of Epstein-Barr Virus–Induced Lymphoma in Allogeneic Transplant Recipients
Authors: Rooney Cliona M. , Smith Colton A. , Ng Catherine Y.C. , Loftin Susan K. , Sixbey John W. , Gan Yanjun , Srivastava Deo-Kumar , Bowman Laura C. , Krance Robert A. , Brenner Malcolm K. , Heslop Helen E. 
Published: October 2019

Epstein-Barr virus (EBV) causes potentially lethal immunoblastic lymphoma in up to 25% of children receiving bone marrow transplants from unrelated or HLA-mismatched donors. Because this complication appears to stem from a deficiency of EBV-specific cytotoxic T cells, we assessed the safety and efficacy of donor-derived polyclonal (CD4+ and CD8+) T-cell lines as immunoprophylaxis and treatment for EBV-related lymphoma. Thirty-nine patients considered to be at high risk for EBV-induced lymphoma each received 2 to 4 intravenous infusions of donor-derived EBV-specific T lymphocytes, after they had received T-cell–depleted bone marrow from HLA-matched unrelated donors (n = 33) or mismatched family members (n = 6). The immunologic effects of this therapy were monitored during and after the infusions. Infused cells were identified by detection of the neo marker gene. EBV-specific T cells bearing theneo marker were identified in all but 1 of the patients. Serial analysis of DNA detected the marker gene for as long as 18 weeks in unmanipulated peripheral blood mononuclear cells and for as long as 38 months in regenerated lines of EBV-specific cytotoxic T cells. Six patients (15.5%) had greatly increased amounts of EBV-DNA on study entry (>2,000 genome copies/106 mononuclear cells), indicating uncontrolled EBV replication, a complication that has had a high correlation with subsequent development of overt lymphoma. All of these patients showed 2 to 4 log decreases in viral DNA levels within 2 to 3 weeks after infusion and none developed lymphoma, confirming the antiviral activity of the donor-derived cells. There were no toxic effects that could be attributed to prophylactic T-cell therapy. Two additional patients who did not receive prophylaxis and developed overt immunoblastic lymphoma responded fully to T-cell infusion. Polyclonal donor-derived T-cell lines specific for EBV proteins can thus be used safely to prevent EBV-related immunoblastic lymphoma after allogeneic marrow transplantation and may also be effective in the treatment of established disease.© 1998 by The American Society of Hematology.
Proliferation in Monocyte-Derived Dendritic Cell Cultures Is Caused by Progenitor Cells Capable of Myeloid Differentiation
Authors: Cavanagh Lois L. , Saal Russell J. , Grimmett Karen L. , Thomas Ranjeny 
Published: October 2019

Dendritic cells (DC) can be generated by culture of adherent peripheral blood (PB) cells in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). There is controversy as to whether these DC arise from proliferating precursors or simply from differentiation of monocytes. DC were generated from myeloid-enriched PB non-T cells or sorted monocytes. DC generated from either population functioned as potent antigen-presenting cells. Uptake of [3H]-thymidine was observed in DC cultured from myeloid-enriched non-T cells. Addition of lipopolysaccharide or tumor necrosis factor- led to maturation of the DC, but did not inhibit proliferation. Ki67+ cells were observed in cytospins of these DC, and by double staining were CD3−CD19−CD11c−CD40−and myeloperoxidase+, suggesting that they were myeloid progenitor cells. Analysis of the starting population by flow cytometry demonstrated small numbers of CD34+CD33−CD14− progenitor cells, and numerous granulocyte-macrophage colony-forming units were generated in standard assays. Thus, production of DC in vitro from adherent PB cells also enriches for progenitor cells that are capable of proliferation after exposure to GM-CSF. Of clinical importance, the yield of DC derived in the presence of GM-CSF and IL-4 cannot be expanded beyond the number of starting monocytes.© 1998 by The American Society of Hematology.
A Janus Kinase Inhibitor, JAB, Is an Interferon-γ–Inducible Gene and Confers Resistance to Interferons
Authors: Sakamoto Hiroshi , Yasukawa Hideo , Masuhara Masaaki , Tanimura Shyu , Sasaki Atsuo , Yuge Kentaro , Ohtsubo Motoaki , Ohtsuka Akira , Fujita Takasi , Ohta Tsunetaka , Furukawa Yusuke , Iwase Satsuki , Yamada Hisashi , Yoshimura Akihiko 
Published: October 2019

It has been shown that interferons (IFNs) exert their signals through receptor-associated Janus kinases (JAKs) and signal transducers and activators of transcription (STATs). However, molecular mechanism of regulation of IFN signaling has not been fully understood. We have reported novel cytokine-inducible SH2 protein (CIS) and JAK binding protein (JAB) family genes that can potentially modulate cytokine signaling. Here we report that JAB is strongly induced by IFN-γ but not by IFN-β in mouse myeloid leukemia M1 cells and NIH-3T3 fibroblasts. NIH-3T3 cells ectopically expressing JAB but not CIS3 lost responsiveness to the antiviral effect of IFN-β and IFN-γ. M1 leukemic cells stably expressing JAB were also resistant to IFN-γ and IFN-β–induced growth arrest. In both NIH-3T3 and M1 transformants expressing JAB, IFN-γ did not induce tyrosine phosphorylation and DNA binding activity of STAT1. Moreover, IFN-γ–induced activation of JAK1 and JAK2 and IFN-β–induced JAK1 and Tyk2 activation were inhibited in NIH-3T3 JAB transformants. These results suggest that JAB inhibits IFN signaling by blocking JAK activity. We also found that IFN-resistant clones derived from LoVo cells and Daudi cells expressed high levels of JAB without stimulation. In IFN-resistant Daudi cells, IFN-induced STAT1 and JAK phosphorylation was partially reduced. Therefore, overexpression of JAB could be, at least in part, a mechanism of IFN resistance.© 1998 by The American Society of Hematology.
Human Herpesvirus 7 Infection Induces Profound Cell Cycle Perturbations Coupled to Disregulation of cdc2 and Cyclin B and Polyploidization of CD4+ T Cells
Authors: Secchiero Paola , Bertolaso Lucia , Casareto Luca , Gibellini Davide , Vitale Marco , Bemis Kristi , Aleotti Arrigo , Capitani Silvano , Franchini Genoveffa , Gallo Robert C. , Zauli Giorgio 
Published: October 2019

Human herpesvirus 7 (HHV-7) infection of both primary CD4+ T lymphocytes and SupT1 lymphoblastoid T-cell line induced a progressive accumulation of cells exibiting a gap 2/mitosis (G2/M) and polyploid content coupled to an increased cell size. The expression of both cyclin-dependent kinase cdc2 and cyclin B was increased in HHV-7–infected cells with respect to the uninfected ones. Moreover, the simultaneous flow cytometric analysis of cyclin B and DNA content showed that cyclin B expression was not only increased but also unscheduled with respect to its usual cell cycle pattern. However, the levels of kinase activity associated to cdc2 were decreased in HHV-7–infected cells with respect to uninfected cultures. To elucidate the origin of the enlarged HHV-7–infected cells, extensive electron and confocal microscopy analyses were performed. Membrane fusion events associated to cytoplasmic bridges, which characterize the formation of syncytia, were never observed. On the other hand, analysis of serial sections of the same cells strongly suggested that enlarged HHV-7–infected cells contained a single polylobated nucleus. This was confirmed by flow cytometry analysis performed on nuclei isolated from HHV-7–infected cells, which showed multiple peaks with a DNA content >4n. Taken together, these data indicate that giant cells, which represent the hallmark of in vitro HHV-7 infection, arise from single CD4+ T cells undergoing a process of polyploidization.© 1998 by The American Society of Hematology.
IL-2 Adenovector-Transduced Autologous Tumor Cells Induce Antitumor Immune Responses in Patients With Neuroblastoma
Authors: Bowman Laura , Grossmann Michael , Rill Donna , Brown Michael , Zhong Wan-yun , Alexander Barbara , Leimig Thasia , Coustan-Smith Elaine , Campana Dario , Jenkins Jesse , Woods Diane , Kitchingman Geoffrey , Vanin Elio , Brenner Malcolm 
Published: October 2019

In many different murine models, the immunogenicity of tumor cells can be increased by transduction with a range of immunostimulatory genes, inducing an immune response that causes regression of pre-existing unmodified tumor cells. To investigate the relevance of these animal models to pediatric malignancy, we used autologous unirradiated tumor cells transduced with an adenovirus-IL-2 to immunize 10 children with advanced neuroblastoma. In a dose-escalation study, we found that this tumor immunogen induced a moderate local inflammatory response consisting predominantly of CD4+ T lymphocytes, and a systemic response, with a rise in circulating CD25+and DR+ CD3+ T cells. Patients also made a specific antitumor response, manifest by an IgG antitumor antibody and increased cytotoxic T-cell killing of autologous tumor cells. Clinically, five patients had tumor responses after the tumor immunogen alone (one complete tumor response, one partial response, and three with stable disease). Four of these five patients were shown to have coexisting antitumor cytotoxic activity, as opposed to only one of the patients with nonresponsive disease. These results show a promising correlation between preclinical observations and clinical outcome in this disease, and support further exploration of the approach for malignant diseases of children.© 1998 by The American Society of Hematology.
Interleukin-10 Inhibits Erythropoietin-Independent Growth of Erythroid Bursts in Patients With Polycythemia Vera
Authors: Geissler Klaus , Öhler Leopold , Födinger Manuela , Kabrna Eva , Kollars Marietta , Skoupy Sonja , Lechner Klaus 
Published: October 2019

In polycythemia vera (PV) erythroid colonies that grow in vitro in the absence of exogenous erythropoietin (EPO) arise from the abnormal clone that is responsible for overproduction of red blood cells. Although the mechanism of autonomous formation of burst-forming units-erythroid (BFU-E) is not fully understood, a spontaneous release of growth regulatory molecules by PV cells and/or by accessory cells is likely to be involved. Because of its cytokine synthesis inhibiting action, interleukin-10 (IL-10) could be a potentially useful molecule to modulate abnormal erythropoiesis in PV. We studied the effect of recombinant human IL-10 on the EPO-independent growth of erythroid bursts derived from peripheral blood mononuclear cells (PBMNCs) of patients with PV. IL-10 showed a profound, dose-dependent, and specific inhibitory effect on autonomous BFU-E formation. Ten nanograms per milliliter of IL-10 significantly suppressed spontaneous growth of erythroid colonies in methylcellulose in five of five PV patients tested with a mean inhibition by 81% (range, 72-94). To elucidate the possible mechanism of the inhibitory action of IL-10 we further studied the effect of anticytokine antibodies on autonomous BFU-E growth and the ability of exogenous cytokines to restore IL-10–induced suppression of erythroid colony growth. Among a panel of growth regulatory factors tested (granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-3, granulocyte colony-stimulating factor, stem cell factor, and insulin-like growth factor-1) GM-CSF was the only molecule for which both an inhibition of spontaneous BFU-E formation by its respective antibody as well as a significant restimulation of erythroid colonies in IL-10-treated cultures by exogenous addition was found. Moreover, inhibition of GM-CSF production by IL-10 was shown in PV PBMNCs at the mRNA level. Our data indicate that autonomous BFU-E growth in PV can be profoundly inhibited by IL-10 and that this inhibitory effect seems to be at least in part secondary to suppression of endogenous GM-CSF production.© 1998 by The American Society of Hematology.
Impaired Expression of Integrin -4 Subunit in Cultured Mast Cells Derived From Mutant Mice of mi/mi Genotype
Authors: Kim Dae-Ki , Morii Eiichi , Ogihara Hideki , Hashimoto Koji , Oritani Kenji , Lee Young-Mi , Jippo Tomoko , Adachi Shiro , Kanakura Yuzuru , Kitamura Yukihiko 
Published: October 2019

The mi locus encodes a member of the basic-helix-loop-helix-leucine zipper protein family of transcription factors (hereafter called MITF). We have reported that expression of several genes was impaired in cultured mast cells (CMCs) ofmi/mi mice due to a defective transactivation ability of mutant MITF (mi-MITF). Because attachment of mi/mi CMCs to fibroblasts is impaired, we examined the expression of integrin genes in mi/mi CMCs in the present study. Among the integrin genes examined, the expression of integrin 4 subunit was barely detectable in mi/mi CMCs, and the 4 protein was not detected by flow cytometry either. The specific adhesion to vascular cell adhesion molecule-1 (VCAM-1), the ligand for 4 subunit, was observed in +/+ CMCs but not in mi/mi CMCs, indicating that the expression of integrin 4 subunit at a functional level did not occur in mi/mi CMCs. In the promoter region of the 4 subunit gene, there was a CACTTG motif to which normal MITF (+- MITF) bound. The coexpression of +-MITF but not of mi-MITF transactivated the promoter of the 4 subunit gene. The deletion or mutation of the CACTTG motif abolished the transactivation by +-MITF, suggesting that +-MITF directly transactivated the gene encoding 4 subunit of integrin.© 1998 by The American Society of Hematology.
Saturation Mutagenesis of the β Subunit of the Human Granulocyte-Macrophage Colony-Stimulating Factor Receptor Shows Clustering of Constitutive Mutations, Activation of ERK MAP Kinase and STAT Pathways, and Differential β Subunit Tyrosine Phosphorylation
Authors: Jenkins Brendan J. , Blake Timothy J. , Gonda Thomas J. 
Published: October 2019

The high-affinity receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 are heterodimeric complexes consisting of cytokine-specific  subunits and a common signal-transducing β subunit (hβc). We have previously demonstrated the oncogenic potential of this group of receptors by identifying constitutively activating point mutations in the extracellular and transmembrane domains of hβc. We report here a comprehensive screen of the entire hβc molecule that has led to the identification of additional constitutive point mutations by virtue of their ability to confer factor independence on murine FDC-P1 cells. These mutations were clustered exclusively in a central region of hβc that encompasses the extracellular membrane-proximal domain, transmembrane domain, and membrane-proximal region of the cytoplasmic domain. Interestingly, most hβc mutants exhibited cell type-specific constitutive activity, with only two transmembrane domain mutants able to confer factor independence on both murine FDC-P1 and BAF-B03 cells. Examination of the biochemical properties of these mutants in FDC-P1 cells indicated that MAP kinase (ERK1/2), STAT, and JAK2 signaling molecules were constitutively activated. In contrast, only some of the mutant β subunits were constitutively tyrosine phosphorylated. Taken together, these results highlight key regions involved in hβc activation, dissociate hβc tyrosine phosphorylation from MAP kinase and STAT activation, and suggest the involvement of distinct mechanisms by which proliferative signals can be generated by hβc.© 1998 by The American Society of Hematology.
Ultrastructural Analysis of Bone Marrow Hematopoiesis in Mice Transgenic for the Thymidine Kinase Gene Driven by the IIb Promoter
Authors: Poujol Christel , Roux Diana Tronik-Le , Tropel Philippe , Roullot Valérie , Nurden Alan , Marguerie Gérard , Nurden Paquita 
Published: October 2019

Transgenic mice have been generated with expression of the herpes virus thymidine kinase gene directed by a 2.7-kb fragment of the IIb murine promoter of the gene encoding the IIb-subunit of the platelet integrin IIbβ3 (Tropel et al, Blood90:2995, 1997). Administration of ganciclovir (GCV) to these mice resulted not only in an acute cessation of platelet production due to the depletion of the megakaryocytic lineage, but also a decrease in erythrocyte and leukocyte numbers. Immunogold staining on ultrathin frozen sections and electron microscopy has now shown that the remaining population of immature hematopoietic cells contain a high proportion of Sca-1+ and CD34+ cells, with CD45R+ cells of the lymphopoietic lineage being maintained. Stromal cells were also preserved. Blood thrombopoietin levels were high. At 4 days of the recovery phase, Sca-1 and CD34 antigen expression decreased with intense proliferation of cells of the three lineages, with megakaryocyte (MK) progenitors being identified by their positivity for glycoprotein IIb-IIIa. These results suggest that transcriptional activity for the IIb gene promoter was present on pluripotent hematopoietic stem cells. At 6 to 8 days after cessation of GCV, numerous mature MK were observed, some of them with deformed shapes crossing the endothelial barrier through thin apertures. Proplatelet production was visualized in the vascular sinus. After 15 days, circulating platelet levels had increased to approximately 65% of normal. Transgenic IIb-tk mice constitute a valuable model to study in vivo megakaryocytopoiesis.© 1998 by The American Society of Hematology.