bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of polymorphonuclear leukocyte phagocytosis by myosin light chain kinase after activation of mitogen-activated protein kinase
Authors: Mansfield Pamela J. , Shayman James A. , Boxer Laurence A. 
Published: October 2019

AbstractPolymorphonuclear leukocyte (PMNL) phagocytosis mediated by FcγRII proceeds in concert with activation of the mitogen-activated protein (MAP) kinase, extracellular signal-regulated kinase ERK2. We hypothesized that myosin light chain kinase (MLCK) could be phosphorylated and activated by ERK, thereby linking the MAP kinase pathway to the activation of cytoskeletal components required for pseudopod formation. To explore this potential linkage, PMNLs were challenged with antibody-coated erythrocytes (EIgG). Peak MLCK activity, 3-fold increased over controls, occurred at 4 to 6 minutes, corresponding with the peak rate of target ingestion and ERK2 activity. The MLCK inhibitor ML-7 (10 μmol/L) inhibited both phagocytosis and MLCK activity to basal values, thereby providing further support for the linkage between the functional response and the requirement for MLCK activation. The MAPK kinase (MEK) inhibitor PD098059 inhibited phagocytosis, MLCK activity, and ERK2 activity by 80% to 90%. To directly link ERK activation to MLCK activation, ERK2 was immunoprecipitated from PMNLs after EIgG ingestion. The isolated ERK2 was incubated with PMNL cytosol as a source of unactivated MLCK and with MLCK substrate; under these conditions ERK2 activated MLCK, resulting in phosphorylation of the MLCK substrate or of the myosin light chain itself. Because MLCK activates myosin, we evaluated the effect of directly inhibiting myosin adenosine triphosphatase using 2,3-butanedione monoxime (BDM) and found that phagocytosis was inhibited by more than 90% but MLCK activity remained unaffected. These results are consistent with the interpretation that MEK activates ERK, ERK2 then activates MLCK, and MLCK activates myosin. MLCK activation is a critical step in the cytoskeletal changes resulting in pseudopod formation.
Polarization and interaction of adhesion molecules P-selectin glycoprotein ligand 1 and intercellular adhesion molecule 3 with moesin and ezrin in myeloid cells
Authors: Alonso-Lebrero José L. , Serrador Juan M. , Domı́nguez-Jiménez Carmen , Barreiro Olga , Luque Alfonso , del Pozo Miguel A. , Snapp Karen , Kansas Geoffrey , Schwartz-Albiez Reinhard , Furthmayr Heinz , Lozano Francisco , Sánchez-Madrid Francisco 
Published: October 2019

AbstractIn response to the chemoattractants interleukin 8, C5a,N-formyl-methionyl-leucyl-phenylalanine, and interleukin 15, adhesion molecules P-selectin glycoprotein ligand 1 (PSGL-1), intercellular adhesion molecule 3 (ICAM-3), CD43, and CD44 are redistributed to a newly formed uropod in human neutrophils. The adhesion molecules PSGL-1 and ICAM-3 were found to colocalize with the cytoskeletal protein moesin in the uropod of stimulated neutrophils. Interaction of PSGL-1 with moesin was shown in HL-60 cell lysates by isolating a complex with glutathione S-transferase fusions of the cytoplasmic domain of PSGL-1. Bands of 78- and 81-kd were identified as moesin and ezrin by Western blot analysis. ICAM-3 and moesin also coeluted from neutrophil lysates with an anti-ICAM-3 immunoaffinity assay. Direct interaction of the cytoplasmic domains of ICAM-3 and PSGL-1 with the amino-terminal domain of recombinant moesin was demonstrated by protein-protein binding assays. These results suggest that the redistribution of PSGL-1 and its association with intracellular molecules, including the ezrin-radixin-moesin actin-binding proteins, regulate functions mediated by PSGL-1 in leukocytes stimulated by chemoattractants.
X-linked genetic factors regulate hematopoietic stem-cell kinetics in females
Authors: Christensen Kaare , Kristiansen Marianne , Hagen-Larsen Heidi , Skytthe Axel , Bathum Lise , Jeune Bernard , Andersen-Ranberg Karen , Vaupel James W. , Ørstavik Karen Helene 
Published: October 2019

Abstract
X inactivation makes females mosaics for 2 cell populations, usually with an approximate 1:1 distribution. Skewing of this distribution in peripheral blood cells is more common among elderly women.1–3 The depletion of hematopoietic stem cells followed by random differentiation may explain the acquired skewing with age.4 However, an animal model suggests that selection processes based on X-linked genetic factors are involved.5 We studied peripheral blood cells from 71 monozygotic twin pairs aged 73 to 93 years and from 33 centenarians, and we found that with age, 1 of the cell populations becomes predominant for most women. We also observed a strong tendency for the same cell line to become predominant in 2 co-twins. This suggests that X-linked genetic factors influence human hematopoietic stem cell kinetics. The fact that females have 2 cell lines with different potentials could be one of the reasons women live longer than men.
Structure of the activation domain of the GM-CSF/IL-3/IL-5 receptor common β-chain bound to an antagonist
Authors: Rossjohn Jamie , McKinstry William J. , Woodcock Joanna M. , McClure Barbara J. , Hercus Timothy R. , Parker Michael W. , Lopez Angel F. , Bagley Christopher J. 
Published: October 2019

AbstractHeterodimeric cytokine receptors generally consist of a major cytokine-binding subunit and a signaling subunit. The latter can transduce signals by more than 1 cytokine, as exemplified by the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2 (IL-2), and IL-6 receptor systems. However, often the signaling subunits in isolation are unable to bind cytokines, a fact that has made it more difficult to obtain structural definition of their ligand-binding sites. This report details the crystal structure of the ligand-binding domain of the GM-CSF/IL-3/IL-5 receptor β-chain (βc) signaling subunit in complex with the Fab fragment of the antagonistic monoclonal antibody, BION-1. This is the first single antagonist of all 3 known eosinophil-producing cytokines, and it is therefore capable of regulating eosinophil-related diseases such as asthma. The structure reveals a fibronectin type III domain, and the antagonist-binding site involves major contributions from the loop between the B and C strands and overlaps the cytokine-binding site. Furthermore, tyrosine421 (Tyr421), a key residue involved in receptor activation, lies in the neighboring loop between the F and G strands, although it is not immediately adjacent to the cytokine-binding residues in the B-C loop. Interestingly, functional experiments using receptors mutated across these loops demonstrate that they are cooperatively involved in full receptor activation. The experiments, however, reveal subtle differences between the B-C loop and Tyr421, which is suggestive of distinct functional roles. The elucidation of the structure of the ligand-binding domain of βc also suggests how different cytokines recognize a single receptor subunit, which may have implications for homologous receptor systems.
Development of lentiviral vectors for gene therapy for human diseases
Authors: Buchschacher Gary L. , Wong-Staal Flossie 
Published: October 2019

Abstract
Retroviral vectors derived from murine retroviruses are being used in several clinical gene therapy trials. Recently, progress has been made in the development of vectors based on the lentivirus genus of retroviruses, which ironically includes a major human pathogen, human immunodeficiency virus (HIV). As these vector systems for clinical gene transfer are developed, it is important to understand the rationale behind their design and development. This article reviews the fundamental features of retrovirus replication and of the elements necessary for development of a retroviral vector system, and it discusses why vector systems based on HIV or other lentiviruses have the potential to become important tools in clinical gene therapy.
Identification and characterization of a bipotent (erythroid and megakaryocytic) cell precursor from the spleen of phenylhydrazine-treated mice
Authors: Vannucchi Alessandro Maria , Paoletti Francesco , Linari Silvia , Cellai Cristina , Caporale Roberto , Ferrini Pierluigi Rossi , Sanchez Massimo , Migliaccio Giovanni , Migliaccio Anna Rita 
Published: October 2019

Abstract
We have identified a cell population expressing erythroid (TER-119) and megakaryocyte (4A5) markers in the bone marrow of normal mice. This population is present at high frequency in the marrows and in the spleens involved in the erythroid expansion that occurs in mice recovering from phenylhydrazine (PHZ)-induced hemolytic anemia. TER-119+/4A5+ cells were isolated from the spleen of PHZ-treated animals and were found to be blast-like benzidine-negative cells that generate erythroid and megakaryocytic cells within 24-48 hours of culture in the presence of erythropoietin (EPO) or thrombopoietin (TPO). TER-119+/4A5+ cells represent a late bipotent erythroid and megakaryocytic cell precursors that may exert an important role in the recovery from PHZ-induced anemia.
Weak D alleles express distinct phenotypes
Authors: Wagner Franz F. , Frohmajer Alexander , Ladewig Birgit , Eicher Nicole I. , Lonicer Cornelie B. , Müller Thomas H. , Siegel Manfred H. , Flegel Willy A. 
Published: October 2019

AbstractThe weak D phenotype is caused by many different RHD alleles encoding aberrant RhD proteins, raising the possibility of distinct serologic phenotypes and of anti-D immunizations in weak D. We reported 6 new RHD alleles, D category III type IV, DIM, and the weak D types 4.1, 4.2.1, 4.2.2, and 17. The immunohematologic features of 18 weak D types were examined by agglutination and flow cytometry with more than 50 monoclonal anti-D. The agglutination patterns of the partial D phenotypes DIM, DIII type IV, and DIVtype III correlated well with the D epitope models, those of the weak D types showed no correlation. In flow cytometry, the weak D types displayed type-specific antigen densities between 70 and 4000 RhD antigens per cell and qualitatively distinct D antigens. A Rhesus D similarity index was devised to characterize the extent of qualitative changes in aberrant D antigens and discriminated normal D from all tested partial D, including D category III. In some rare weak D types, the extent of the alterations was comparable to that found in partial Ds that were prone to anti-D immunization. Four of 6 case reports with anti-D in weak D represented auto-anti-D. We concluded that, in contrast to previous assumptions, most weak D types, including prevalent ones, carry altered D antigens. These observations are suggestive of a clinically relevant potential for anti-D immunizations in some, but not in the prevalent weak D types, and were used to derive an improved transfusion strategy in weak D patients.
The elusive factor Xa receptor: failure to detect transcripts that correspond to the published sequence of EPR-1
Authors: Zaman Guido J. R. , Conway Edward M. 
Published: October 2019

AbstractThe coagulation protease factor Xa induces cellular responses implicated in cardiovascular and inflammatory disease. Effector-cell protease receptor 1 (EPR-1) is a functionally characterized receptor of factor Xa, and the EPR-1complementary DNA (cDNA) was published. Remarkably, the cDNA encoding an inhibitor of apoptosis, survivin, is reportedly identical to that ofEPR-1 except for a few nucleotide differences and its orientation opposite to EPR-1. To isolate the EPR-1cDNA and gene, we surveyed gene databases for expressed sequence tags (ESTs) that could be derived from EPR-1. All ESTs with strong homology to EPR-1/survivin were derived from survivinand could not encode EPR-1. By polymerase chain reaction and Southern blot hybridization, EPR-1 was not detectable in the human or murine genome, but survivin was. Our data suggest that EPR-1 is either highly cell-specific or the published EPR-1 cDNA includes sequences from clones derived from survivin messenger RNA. The means by which factor Xa mediates its cellular effects requires further evaluation.
CD4 T lymphocytes are primed to express Fas ligand by CD4 cross-linking and to contribute to CD8 T-cell apoptosis via Fas/FasL death signaling pathway
Authors: Tateyama Masaki , Oyaizu Naoki , McCloskey Thomas W. , Than Soe , Pahwa Savita 
Published: October 2019

AbstractCD4 molecules serve as coreceptors for the T-cell receptor (TCR)/CD3 complex that are engaged coordinately with TCR and facilitate antigen-specific T-cell activation leading to interleukin 2 (IL-2) production and proliferation. However, cross-ligation of CD4 molecules prior to TCR stimulation has been shown to prime CD4 T cells to undergo apoptosis. Although in vivo and in vitro experiments have implicated the involvement of Fas/FasL interaction in this CD4 cross-linking (CD4XL)-induced apoptosis, detailed mechanisms to account for cell death induction have not been elucidated. In the present study, we demonstrate that CD4XL in purified T cells not only led to Fas up-regulation but also primed CD4 T cells to express FasL upon CD3 stimulation and rendered the T cells susceptible to Fas-mediated apoptosis. Notably, in addition to CD4+ T cells, CD4XL-induced sensitization for apoptosis was observed in CD8+ T cells as well and was associated with Bcl-x down-modulation. Both CD4 and CD8 T-cell subsets underwent apoptosis following cell–cell contact with FasL+ CD4 T cells. CD28 costimulation abrogated CD4XL/CD3-induced apoptosis with restoration of IL-2 production and prevented Bcl-x down-modulation. As CD4 molecules are the primary receptors for human immunodeficiency virus 1 (HIV-1), we conclude that HIV-1 envelope mediated CD4XL can lead to the generation of FasL-expressing CD4+ T cells that can lead to apoptosis of CD4 as well as CD8 T cells. These findings implicate a novel mechanism for CD8 T-cell depletion in HIV disease.
Oxidative stress interferes with cancer chemotherapy: inhibition of lymphoma cell apoptosis and phagocytosis
Authors: Shacter Emily , Williams Joy A. , Hinson Roger M. , Sentürker Sema , Lee Yang-ja 
Published: October 2019

Abstract
Many antineoplastic drugs kill tumor cells by inducing apoptosis. This highly controlled mechanism of cell death is thought to be physiologically advantageous because apoptotic cells are removed by phagocytosis before they lose their permeability barrier, thus preventing induction of an inflammatory response to the dying cells. In contrast, necrotic cells lyse and release their contents into the extracellular space, thus inducing inflammation. In this report, we examine the effects of oxidative stress on chemotherapy-induced cell killing. We find that H2O2 inhibits the ability of 4 different chemotherapy drugs (VP-16, doxorubicin, cisplatin, and AraC) to induce apoptosis in human Burkitt lymphoma cells. H2O2 shifts the form of cell death from apoptosis to pyknosis/necrosis, which occurs after a significant delay compared with chemotherapy-induced apoptosis. It can also lower the degree of cell killing by these drugs. These effects of H2O2 can be prevented by the antioxidant agents Desferal, Tempol, and dimethylsulfoxide. Phagocytosis by monocyte-derived macrophages of VP-16–treated lymphoma cells is also inhibited by H2O2. Cells killed with H2O2 (with or without VP-16) do ultimately undergo phagocytosis, but this occurs only after they have lost their permeability barrier. Thus, membrane-intact apoptotic cells are recognized and phagocytosed by monocyte-derived macrophages, but membrane-intact pyknotic/necrotic cells are not. The results suggest that chemotherapy-induced apoptosis and phagocytosis of cancer cells may be enhanced by including certain antioxidant agents in the treatment protocol.
ESOP-1, a secreted protein expressed in the hematopoietic, nervous, and reproductive systems of embryonic and adult mice
Authors: Kato Keizo , Morrison Aline M. , Nakano Toru , Tashiro Kei , Honjo Tasuku 
Published: October 2019

AbstractTo isolate soluble factors expressed in early phases of hematopoietic differentiation, we applied the signal sequence trap method to the in vitro murine hematopoietic differentiation system, in which ES cells are cocultured with OP-9 stroma cells. This strategy allowed us to isolate cDNA for a secreted protein, ESOP-1, of 160 amino acids, the sequence of which shows 64% identity with human ESOP-1/MD-2. ESOP-1 mRNA was highly expressed in the mouse embryos at 7.5 days after coitus. Expression of the ESOP-1 mRNA and protein was shown in the embryonic and adult hematopoietic system. In addition, the ESOP-1 protein was found in the yolk sac–blood islands, the developing nervous system, and the adult reproductive system. These results suggest that ESOP-1 may play some roles in the development or maintenance of hematopoietic, nervous, and reproductive systems.
Oral isobutyramide reduces transfusion requirements in some patients with homozygous β-thalassemia
Authors: Reich Susanne , Bührer Christoph , Henze Günter , Ohlendorf Dieter , Mesche Michael , Sinha Pranav , Kage Andreas , Müller Christian , Vetter Barbara , Kulozik Andreas E. 
Published: October 2019

Abstract
The butyrate derivative isobutyramide (IBT) increases fetal hemoglobin (HbF) in patients with β-hemoglobinopathies, but little is known about its usefulness for prolonged therapeutic use. We treated 8 patients with transfusion-dependent β-thalassemia with 350 mg/kg of body weight per day of oral IBT for 126 to 384 days. During the trial period, the hemoglobin level was maintained between 85 g/L (range 82-87 g/L) (pretransfusion) and 115 g/L (range 110-119 g/L) (post-transfusion) (median, interquartile range), corresponding to 4-week transfusion intervals in all patients during the pretreatment phase. Adverse effects (bitter taste, epigastric discomfort) did not cause discontinuation of IBT. HbF increased in all patients from 3.1% (range 1.9%-4.8%) to 6.0% (range 3.3%-8.7) (P = .0017), while free Hb dropped from 0.48 g/L (range 0.39-0.81 g/L) to 0.19 g/L (range 0.16-0.24 g/L) (P &lt; .0001). Transfusion intervals were consistently extended to 8 or 9 weeks in 1 patient, resulting in a decrease of daily iron load from 455 μg/kg per day (range 451-459 μg/kg per day) before therapy to 211μg/kg per day (range 203-286 μg/kg per day) during the 12-month treatment period. Prolongation of transfusion intervals achieved by IBT was less consistent in another patient, whose parenteral iron load nevertheless decreased from 683 μg/kg per day (range 618-748 μg/kg per day) to 542 μg/kg per day (340-596 μg/kg per day). In the other 6 patients, no prolongation of transfusion intervals was achieved. Response to treatment was associated with high pretreatment HbF (&gt; 4.5%), high parental HbF, and increased erythropoietin levels (&gt; 150 IU/L). We conclude that IBT prolongs transfusion intervals and reduces parenteral iron burden in some patients with transfusion-dependent β-thalassemia.
Fibrinogen Alès: a homozygous case of dysfibrinogenemia (γ-Asp330 →Val) characterized by a defective fibrin polymerization site “a”
Authors: Lounes Karim Chabane , Soria Claudine , Mirshahi Shah Sultan , Desvignes Pierre , Mirshahi Massoud , Bertrand Olivier , Bonnet Pierre , Koopman Jaap , Soria Jeannette 
Published: October 2019

AbstractCongenital homozygous dysfibrinogenemia was diagnosed in a man with a history of 2 thrombotic strokes before age 30. His hemostatic profile was characterized by a dramatically prolonged plasma thrombin clotting time, and no clotting was observed with reptilase. Complete clotting of the abnormal fibrinogen occurred after a prolonged incubation of plasma with thrombin. The release of fibrinopeptides A and B by thrombin and of fibrinopeptide A by reptilase were both normal. Thrombin-induced fibrin polymerization was impaired, and no polymerization occurred with reptilase. The polymerization defect was characterized by a defective site “a,” resulting in an absence of interaction between sites A and a, indicated by the lack of fragment D1 (or fibrinogen) binding to normal fibrin monomers depleted in fibrinopeptide A only (Des-AA fm). By SDS-PAGE, the defect was detected on the γ-chain and in its fragment D1. The molecular defect determined by analysis of genomic DNA showed a single base change (A→T) in exon VIII of the γ-chain. The resulting change in the amino acid structure is γ 330 aspartic acid (GAT) → valine (GTT). It is concluded that the residue γ-Asp330 is essential for the normal functioning of the polymerization site a on the fibrinogen γ-chain.
Cytoskeletal regulation of the platelet glycoprotein Ib/V/IX–von Willebrand factor interaction
Authors: Mistry Nayna , Cranmer Susan L. , Yuan Yuping , Mangin Pierre , Dopheide Sacha M. , Harper Ian , Giuliano Simon , Dunstan Dave E. , Lanza Francois , Salem Hatem H. , Jackson Shaun P. 
Published: October 2019

AbstractShear-induced binding of von Willebrand factor (vWf) to the platelet glycoprotein (GP) Ib/V/IX complex plays a key role in initiating platelet adhesion and aggregation at sites of vascular injury. This study demonstrated that pretreating human platelets with inhibitors of actin polymerization, cytochalasin D or latrunculin B, dramatically enhances platelet aggregation induced by vWf. The effects of these inhibitors were specific to the vWf-GPIbα interaction because they enhanced vWf-induced aggregation of Glanzmann thrombasthenic platelets and Chinese hamster ovary (CHO) cells transfected with GPIb/V/IX. Moreover, cytochalasin D enhanced the extent of platelet aggregation induced by high shear stress (5000 s−1) and also lowered the shear threshold required to induce aggregation from 3000 s−1 to as low as 500 s−1. Studies of CHO cells expressing GPIbα cytoplasmic tail truncation mutants that failed to bind actin-binding protein-280 (deletion of residues 569-610 or 535-568) demonstrated that the linkage between GPIb and actin-binding protein-280 was not required for vWf-induced actin polymerization, but was critical for the enhancing effects of cytochalasin D on vWf-induced cell aggregation. Taken together, these studies suggest a fundamentally important role for the cytoskeleton in regulating the adhesive function of GPIb/V/IX.
Therapeutic efficacy of FcγRI/CD64-directed bispecific antibodies in B-cell lymphoma
Authors: Honeychurch Jamie , Tutt Alison L. , Valerius Thomas , Heijnen Ingmar A. F. M. , Van de Winkel Jan G. J. , Glennie Martin J. 
Published: October 2019

AbstractCD64 (FcγRI) receptors represent highly potent trigger molecules for activated polymorphonuclear cells (PMN) and mediate lysis of a range of tumors in the presence of appropriate monoclonal antibodies. An huCD64 transgenic mouse model designed to analyze the therapeutic activity of a panel of bispecific F(ab')2(BsAb) in retargeting granulocyte–colony-stimulating factor (G-CSF)–activated PMN against syngeneic B-cell lymphomas is reported. This model allows careful analysis of the individual elements of the therapeutic process. BsAb were directed against immunoglobulin-idiotype (Id), major histocompatibility class II (MHC II), or CD19 on the tumors and huCD64 on the effectors. In vitro cytotoxicity assays and in vivo tumor tracking showed that, provided effectors were activated with G-CSF, all 3 derivatives destroyed and cleared lymphoma cells, with (huCD64 × MHC II) proving by far the most cytotoxic in vitro. However, though all derivatives delivered some survival advantage, only the [huCD64 × Id] BsAb provided long-term protection to tumor-bearing animals. These results demonstrate that CD64-recruited cytotoxic effectors operate in vivo but that the (huCD64 × Id) conferred an additional anti-tumor function essential for long-term protection. T-cell depletion studies demonstrated that this extra therapeutic activity with [huCD64 × Id] was totally dependent on CD4 and CD8 T cells and that mice, once “cured” with BsAb, were resistant to tumor rechallenge. These findings indicate that CD64 is an effective trigger molecule for delivering cytokine-activated PMN against tumor in vivo and that, provided tumor targets are selected appropriately, CD64-based BsAb can establish long-term T-cell immunity.