bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation of macrophage cytostatic effector mechanisms during acute graft-versus-host disease: release of intracellular iron and nitric oxide–mediated cytostasis
Authors: Nestel Frederick P. , Greene Robert N. , Kichian Krikor , Ponka Premysl , Lapp Wayne S. 
Published: October 2019

AbstractDuring acute graft-versus-host disease (GVHD) the activation of macrophages (Mφ) is mediated by 2 signals, interferon (IFN)-γ and bacteria-derived lipopolysaccharide (LPS). A cascade of inflammatory responses that includes the release of mediators of tissue injury follows Mφ activation. Among the tissues characteristically targeted during acute GVHD are epithelial tissues of the skin and gastrointestinal tract that normally undergo continuous proliferation and are therefore sensitive to cytostatic processes. We have investigated whether Mφ can mediate cytostatic mechanisms capable of interrupting cell proliferation during acute GVHD. GVHD was induced in nonirradiated C57BL/6XAF1 (B6AF1) mice by the injection of 60 × 106 (acute GVHD) or 30 × 106 (nonlethal GVHD) C57BL/6 (B6) lymphoid cells. Mφ from animals undergoing acute GVHD could be triggered by normally insignificant quantities of LPS to mediate a cytostatic effect on target cells, resulting in the complete shutdown of cellular proliferation. The same amounts of LPS had no effect on Mφ from normal or syngeneically transplanted animals. Mφ mediated the release of significant quantities of intracellular iron from target cells undergoing cytostasis. Reversal of cytostasis occurred following inhibition of nitric oxide (NO) production by NG-monomethyl-L-arginine (NMMA). Production of NO by LPS-triggered Mφ reflected the severity of GVHD. NO release increased significantly during acute GVHD but was only transiently increased during nonlethal GVHD. The results provide evidence that, as a result of activation during acute GVHD, Mφ produce NO and induce the release of iron from target cells, resulting in a potent cytostatic effect that inhibits cellular proliferation.
Cell–cell contact between marrow stromal cells and myeloma cells via VCAM-1 and α4β1-integrin enhances production of osteoclast-stimulating activity
Authors: Michigami Toshimi , Shimizu Nobuaki , Williams Paul J. , Niewolna Maria , Dallas Sarah L. , Mundy Gregory R. , Yoneda Toshiyuki 
Published: October 2019

Abstract
Myeloma is a unique hematologic malignancy that exclusively homes in the bone marrow and induces massive osteoclastic bone destruction presumably by producing cytokines that promote the differentiation of the hematopoietic progenitors to osteoclasts (osteoclastogenesis). It is recognized that neighboring bone marrow stromal cells influence the expression of the malignant phenotype in myeloma cells. This study examined the role of the interactions between myeloma cells and neighboring stromal cells in the production of osteoclastogenic factors to elucidate the mechanism underlying extensive osteoclastic bone destruction. A murine myeloma cell line 5TGM1, which causes severe osteolysis, expresses α4β1-integrin and tightly adheres to the mouse marrow stromal cell line ST2, which expresses the vascular cell adhesion molecule-1 (VCAM-1), a ligand for α4β1-integrin. Co-cultures of 5TGM1 with primary bone marrow cells generated tartrate-resistant acid phosphatase-positive multinucleated bone-resorbing osteoclasts. Co-cultures of 5TGM1 with ST2 showed increased production of bone-resorbing activity and neutralizing antibodies against VCAM-1 or α4β1-integrin inhibited this. The 5TGM1 cells contacting recombinant VCAM-1 produced increased osteoclastogenic and bone-resorbing activity. The activity was not blocked by the neutralizing antibody to known osteoclastogenic cytokines including interleukin (IL)-1, IL-6, tumor necrosis factor, or parathyroid hormone-related peptide. These data suggest that myeloma cells are responsible for producing osteoclastogenic activity and that establishment of direct contact with marrow stromal cells via α4β1-integrin/VCAM-1 increases the production of this activity by myeloma cells. They also suggest that the presence of stromal cells may provide a microenvironment that allows exclusive colonization of myeloma cells in the bone marrow.
Chimeric Fv-ζ or Fv-ε receptors are not sufficient to induce activation or cytokine production in peripheral T cells
Authors: Brocker Thomas 
Published: October 2019

AbstractIn current clinical trials, chimeric antibody-like receptors fused to signaling domains derived from TCR-ζ or Fc(ε)RIγ-chain are tested for their ability to lyse tumor cells in vivo. In this study, the function of primary T cells expressing such receptors has been investigated in transgenic mice. These receptors cannot induce proliferation of resting T cells or trigger the production of optimal amounts of cytokines. It is further demonstrated that an initial low presence of cytokine message and protein is disappearing rather fast, whereas the triggering of endogenous TCR/CD3 in the same cells leads to normal prolonged cytokine production. The direct clinical relevance of these findings is further underlined by the increased in vivo tumor rejection by T cells expressing chimeric receptors in presence of exogenous interleukin-2. Therefore, adoptive T-cell therapy using primary T cells transfected with single chain receptors might benefit substantially from the accompanying administration of cytokines.
Vertical transmission of HCV is related to maternal peripheral blood mononuclear cell infection
Authors: Azzari Chiara , Resti Massimo , Moriondo Maria , Ferrari Roberto , Lionetti Paolo , Vierucci Alberto 
Published: October 2019

Abstract
Infection of peripheral blood mononuclear cells (PBMNCs) has been demonstrated to be a crucial event in the vertical transmission of viruses, and it is known that hepatitis C virus (HCV) can infect PBMNCs. The relationship between vertical transmission of HCV and the presence of positive and negative strands of HCV-RNA in the PBMNCs of HCV-carrier mothers was investigated using reverse transcriptase–polymerase chain reaction (RT-PCR). During the study, 13 consecutive mothers who transmitted infection to their offspring and 53 consecutive mothers who did not were examined. The positive strand of HCV-RNA was identified in the PBMNCs of all mothers who transmitted the infection and in 13 of 53 mothers who did not (P &lt; 10−6). The HCV-RNA−strand was found in 5 of 13 mothers who transmitted the infection, and the strand was not found in the mothers who did not transmit the infection (P = .0001). Neither maternal PBMNC infection nor HCV transmission to the offspring was significantly related to the viral genotype or to the maternal viral load. These data show that maternal PBMNC infection by HCV and viral replicative activity in PBMNCs are important factors in the transmission of HCV from mother to child. The mechanism through which HCV infection of PBMNC favors vertical transmission of the virus is still incompletely understood.
Phosphatase inhibition promotes antiapoptotic but not proliferative signaling pathways in erythropoietin-dependent HCD57 cells
Authors: Lawson Amy E. , Bao Haifeng , Wickrema Amittha , Jacobs-Helber Sarah M. , Sawyer Stephen T. 
Published: October 2019

AbstractErythropoietin (EPO) allows erythroid precursors to proliferate while protecting them from apoptosis. Treatment of the EPO-dependent HCD57 murine cell line with 70 μmol/L orthovanadate, a tyrosine phosphatase inhibitor, resulted in both increased tyrosine protein phosphorylation and prevention of apoptosis in the absence of EPO without promoting proliferation. Orthovanadate also delayed apoptosis in primary human erythroid progenitors. Thus, we investigated what survival signals were activated by orthovanadate treatment. Expression of Bcl-XL and BAD phosphorylation are critical for the survival of erythroid cells, and orthovanadate in the absence of EPO both maintained expression levels of antiapoptotic Bcl-XLand induced BAD phosphorylation at serine 112. Orthovanadate activated JAK2, STAT1, STAT5, the phosphatidylinositol-3 kinase (PI-3 kinase) pathway, and other signals such as JNK and p38 without activating the EPO receptor, JAK1, Tyk2, Vav, STAT3, and SHC. Neither JNK nor p38 appeared to have a central role in either apoptosis or survival induced by orthovanadate. Treatment with cells with LY294002, an inhibitor of PI-3 kinase activity, triggered apoptosis in orthovanadate-treated cells, suggesting a critical role of PI-3 kinase in orthovanadate-stimulated survival. Mitogen-activated protein kinase (MAPK) was poorly activated by orthovanadate, and inhibition of MAPK with PD98059 blocked proliferation without inducing apoptosis. Thus, orthovanadate likely acts to greatly increase JAK/STAT and PI-3 kinase basal activity in untreated cells by blocking tyrosine protein phosphatase activity. Activated JAK2/STAT5 then likely acts upstream of Bcl-XL expression and PI-3 kinase likely promotes BAD phosphorylation to protect from apoptosis. In contrast, MAPK/ERK activity correlates with only EPO-dependent proliferation but is not required for survival of HCD57 cells.
MgcRacGAP is involved in the control of growth and differentiation of hematopoietic cells
Authors: Kawashima Toshiyuki , Hirose Koichi , Satoh Takaya , Kaneko Azusa , Ikeda Yasuo , Kaziro Yoshito , Nosaka Tetsuya , Kitamura Toshio 
Published: October 2019

AbstractIn a search for key molecules that prevent murine M1 leukemia cells from undergoing interleukin (IL)-6–induced differentiation into macrophages, we isolated an antisense complementary DNA (cDNA) that encodes full-length mouse MgcRac-GTPase-activating protein (GAP) through functional cloning. Forced expression of this antisense cDNA profoundly inhibited IL-6–induced differentiation of M1 cells into macrophage lineages. We also isolated a full-length human MgcRacGAP cDNA, which encodes an additional N-terminal polypeptide of 105 amino acid residues compared with the previously published human MgcRacGAP. In human HL-60 leukemic cells, overexpression of the full-length form of human MgcRacGAP alone induced growth suppression and macrophage differentiation associated with hypervacuolization and de novo expression of the myelomonocytic marker CD14. Analyses using a GAP-inactive mutant and 2 deletion mutants of MgcRacGAP indicated that the GAP activity was dispensable, but the myosin-like domain and the cysteine-rich domain were indispensable for growth suppression and macrophage differentiation. The present results indicated that MgcRacGAP plays key roles in controlling growth and differentiation of hematopoietic cells through mechanisms other than regulating Rac GTPase activity.
Interleukin-9 enhances interleukin-5 receptor expression, differentiation, and survival of human eosinophils
Authors: Gounni Abdelilah Soussi , Gregory Bernard , Nutku Esra , Aris Fadi , Latifa Koussih , Minshall Eleanor , North Janet , Tavernier Jan , Levit Roy , Nicolaides Nick , Robinson Douglas , Hamid Qutayba 
Published: October 2019

AbstractInterleukin-9 (IL-9) has been implicated in the pathogenesis of allergic disorders. To examine the interaction between IL-9 and eosinophils, we evaluated mature peripheral blood eosinophils for their expression of the specific α-subunit of the IL-9 receptor (IL-9R–α). The expression of IL-9R–α by human eosinophils was detected at the messenger RNA (mRNA) and protein levels by reverse transcriptase–polymerase chain reaction (RT-PCR), flow cytometry, and immunocytochemical analysis, respectively. Functional analyses demonstrated that recombinant human (rh)IL-9 inhibited in vitro peripheral blood human eosinophil apoptosis in a concentration-dependent manner. We then examined the role of IL-9 in eosinophil differentiation using the human cord blood CD34+cells and human promyelocytic leukemia cells (HL-60). The addition of IL-9 to CD34+ cells cultured in IL-3 and IL-5 enhanced eosinophil development, and IL-9 alone induced the expression of IL-5R–α. IL-9 also up-regulated the IL-5R–α chain cell surface expression during terminal eosinophil differentiation of the HL-60 cell line. Our findings suggest that IL-9 may potentiate in vivo eosinophil function by increasing their survival and IL-5–mediated differentiation and maturation. Taken together, these results suggest a mechanism by which IL-9 potentiates airway and tissue eosinophilia.
Phosphatidylinositol-3 kinase regulates p21ras activation during IgE-mediated stimulation of human basophils
Authors: Miura Katsushi , MacGlashan Donald W. 
Published: October 2019

AbstractCross-linking of IgE or a bacterial product (f-Met-Leu-Phe; FMLP) induces the release of leukotriene C4 (LTC4) and histamine in human basophils. However, the signaling mechanisms in human basophils are only partially understood. It has been demonstrated that extracellular signal-regulated kinases (ERK1/2) specifically regulate the pathway for LTC4 generation, but not for histamine release and interleukin-4 production. More recent studies have suggested that tyrosine kinase (syk)-mediated phosphorylation of shc is responsible for the ras-ERK cascade via the formation of shc-Grb2-Sos2 following stimulation with anti-IgE antibody, but not FMLP, in human basophils. However, while characterizing the role of phosphatidylinositol (PI)-3 kinase in signaling pathways leading to basophil mediator release, it was noted that this pathway might also regulate p21ras activation. Anti-IgE antibody, but not FMLP, resulted in phosphorylation of p85 (regulatory subunit of PI3 kinase), suggesting activation of PI3 kinase. Inhibition of PI3 kinase by selective inhibitor (LY294002) abolished anti-IgE antibody- but not FMLP-induced phosphorylation of MEK1 (MAPK kinase/ERK kinase) and ERKs while inhibiting LTC4 generation as well as histamine release. IgE-mediated activation of ras (upstream of MEK-ERK) was also inhibited. But, further upstream, phosphorylation of syk and of shc and inducible association between shc and Grb2 were not affected. Furthermore, the IgE-mediated cytosolic calcium response ([Ca++]i) was also diminished. These results suggest that functional responses may be dependent on the activity of PI3 kinase, which regulates at least 2 important signaling pathways: by regulating activation of ras for the MEK-ERK pathway and the increase in [Ca++]i.
CGP57148B (STI-571) induces differentiation and apoptosis and sensitizes Bcr-Abl–positive human leukemia cells to apoptosis due to antileukemic drugs
Authors: Fang Guofu , Kim Caryn Naekyung , Perkins Charles L. , Ramadevi Nimmanapalli , Winton Elliott , Wittmann Sylvie , Bhalla Kapil N. 
Published: October 2019

Abstract
The differentiation and apoptosis-sensitizing effects of the Bcr-Abl–specific tyrosine kinase inhibitor CGP57148B, also known as STI-571, were determined in human Bcr-Abl–positive HL-60/Bcr-Abl and K562 cells. First, the results demonstrate that the ectopic expression of the p185 Bcr-Abl fusion protein induced hemoglobin in the acute myeloid leukemia (AML) HL-60 cells. Exposure to low-dose cytosine arabinoside (Ara-C; 10 nmol/L) increased hemoglobin levels in HL-60/Bcr-Abl and in the chronic myeloid leukemia (CML) blast crisis K562 cells, which express the p210 Bcr-Abl protein. As compared with HL-60/neo, HL-60/Bcr-Abl and K562 cells were resistant to apoptosis induced by Ara-C, doxorubicin, or tumor necrosis factor-α (TNF-α), which was associated with reduced processing of caspase-8 and Bid protein and decreased cytosolic accumulation of cytochrome c (cyt c). Exposure to CGP57148B alone increased hemoglobin levels and CD11b expression and induced apoptosis of HL-60/Bcr-Abl and K562 cells. CGP57148B treatment down-regulated antiapoptotic XIAP, cIAP1, and Bcl-xL, without affecting Bcl-2, Bax, Apaf-1, Fas (CD95), Fas ligand, Abl, and Bcr-Abl levels. CGP57148B also inhibited constitutively active Akt kinase and NFκB in Bcr-Abl–positive cells. Attenuation of NFκB activity by ectopic expression of transdominant repressor of IκB sensitized HL-60/Bcr-Abl and K562 cells to TNF-α but not to apoptosis induced by Ara-C or doxorubicin. Importantly, cotreatment with CGP57148B significantly increased Ara-C– or doxorubicin-induced apoptosis of HL-60/Bcr-Abl and K562 cells. This was associated with greater cytosolic accumulation of cyt c and PARP cleavage activity of caspase-3. These in vitro data indicate that combinations of CGP57148B and antileukemic drugs such as Ara-C may have improved in vivo efficacy against Bcr-Abl–positive acute leukemia.
Bcr/Abl activates transcription of theBcl-X gene through STAT5
Authors: Gesbert Franck , Griffin James D. 
Published: October 2019

AbstractSeveral tyrosine kinase oncogenes have been associated with myeloproliferative diseases, including Bcr/Abl, Tel/Abl, Tel/Jak2, and Tel/PDGFR. One target molecule shared by these oncogenes is known to be STAT5. We generated sublines of Ba/F3 cells in which either wild-type STAT5 or a constitutively active mutant of STAT5 (STAT5-1*6) were expressed under the control of a tetracycline-inducible promoter. These cell lines were compared with a Ba/F3 cell line in which the expression of p210Bcr/Abl was made inducible by a similar promoter. Before induction, all cells were dependent on interleukin 3 (IL-3) for growth and survival. Both STAT5-1*6 and Bcr/Abl enhanced viability and induced proliferation in the absence of IL-3. We found that the proviability protein Bcl-XL, but not Bcl-2, was induced by both p210Bcr/Abl and STAT5-1*6. Using a Bcl-X gene promoter construct fused to a luciferase complementary DNA (cDNA), both p210Bcr/Abl and STAT5-1*6 were shown to induce transcription of Bcl-X. The increase in transcription of the Bcl-X promoter and the increase in Bcl-X protein, due to p210Bcr/Abl, were blocked by expression of a dominant negative STAT5 mutant. Interestingly, however, STAT5-1*6 required the continued presence of IL-3 to cause a significant increase in Bcl-XL protein, whereas p210Bcr/Abl did not need IL-3. Studies with enzyme inhibitors suggest that the extra signal supplied by IL-3 may be supplied by the PI3K pathway. Overall, these data suggest that constitutively activated STAT5 can increase viability and proliferation of Ba/F3 cells. This may contribute to, but is not likely sufficient for, the enhanced viability associated with Bcr/Abl transformation.
Implantation of bone marrow beneath the kidney capsule results in transfer not only of functional stroma but also of hematopoietic repopulating cells
Authors: Varas Florencio , Grande Teresa , Ramı́rez Angel , Bueren Juan A. 
Published: October 2019

Abstract
Renal ossicles are ossified structures developed after the implantation of a bone marrow (BM) plug beneath the kidney capsule. The authors have investigated the origin of the hematopoietic cells in murine renal ossicles by conducting sex-mismatched implants into Ly-5 congenic mice. BM plugs from transgenic mice provided additional genotypic tracers. Flow cytometry analyses on nonadherent cells from long-term cultures established with ossicles excised at 17 to 40 weeks postimplantation evidenced the presence of 5% to 70% of donor-derived myeloid cells. The genetic analysis of the day 12 colony-forming unit (CFU-S12) population in ossicles excised at 10 to 40 weeks postimplantation revealed that 16% to 93% of the colonies were of donor origin. Moreover, we describe for the first time the presence of long-term repopulating cells of donor origin in ossicles excised at 10 to 19 weeks postimplantation.
Mutations in the gene encoding neutrophil elastase in congenital and cyclic neutropenia
Authors: Dale David C. , Person Richard E. , Bolyard Audrey Anna , Aprikyan Andrew G. , Bos Cindy , Bonilla Mary Ann , Boxer Laurence A. , Kannourakis George , Zeidler Cornelia , Welte Karl , Benson Kathleen F. , Horwitz Marshall 
Published: October 2019

Abstract
Congenital neutropenia and cyclic neutropenia are disorders of neutrophil production predisposing patients to recurrent bacterial infections. Recently the locus for autosomal dominant cyclic neutropenia was mapped to chromosome 19p13.3, and this disease is now attributable to mutations of the gene encoding neutrophil elastase (the ELA2 gene). The authors hypothesized that congenital neutropenia is also due to mutations of neutrophil elastase. Patients with congenital neutropenia, cyclic neutropenia, or Shwachman-Diamond syndrome were referred to the Severe Chronic Neutropenia International Registry. Referring physicians provided hematologic and clinical data. Mutational analysis was performed by sequencing polymerase chain reaction (PCR)-amplified genomic DNA for each of the 5 exons of the neutrophil ELA2 gene and 20 bases of the flanking regions. RNA from bone marrow mononuclear cells was used to determine if the affected patients expressed both the normal and the abnormal transcript. Twenty-two of 25 patients with congenital neutropenia had 18 different heterozygous mutations. Four of 4 patients with cyclic neutropenia and 0 of 3 patients with Shwachman-Diamond syndrome had mutations. For 5 patients with congenital neutropenia having mutations predicted to alter RNA splicing or transcript structure, reverse transcriptase-PCR showed expression of both normal and abnormal transcripts. In cyclic neutropenia, the mutations appeared to cluster near the active site of the molecule, whereas the opposite face was predominantly affected by the mutations found in congenital neutropenia. This study indicates that mutations of the gene encoding neutrophil elastase are probably the most common cause for severe congenital neutropenia as well as the cause for sporadic and autosomal dominant cyclic neutropenia.
Probability in transcriptional regulation and its implications for leukocyte differentiation and inducible gene expression
Authors: Hume David A. 
Published: October 2019

AbstractThe phenotype of individual hematopoietic cells, like all other differentiated mammalian cells, is determined by selective transcription of a subset of the genes encoded within the genome. This overview summarizes the recent evidence that transcriptional regulation at the level of individual cells is best described in terms of the regulation of the probability of transcription rather than the rate. In this model, heterogeneous gene expression among populations of cells arises by chance, and the degree of heterogeneity is a function of the stability of the mRNA and protein products of individual genes. The probabilistic nature of transcriptional regulation provides one explanation for stochastic phenomena, such as stem cell lineage commitment, and monoallelic expression of inducible genes, such as lymphokines and cytokines.