bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association Between Ligand-Induced Conformational Changes of Integrin IIbβ3 and IIbβ3-Mediated Intracellular Ca2+ Signaling
Authors: Honda Shigenori , Tomiyama Yoshiaki , Aoki Toshiaki , Shiraga Masamichi , Kurata Yoshiyuki , Seki Jiro , Matsuzawa Yuji 
Published: October 2019

AbstractPlatelet IIbβ3 is a prototypic integrin and plays a critical role in platelet aggregation. Occupancy of IIbβ3 with multivalent RGD ligands, such as fibrinogen, induces both expression of ligand-induced binding sites (LIBS) and IIbβ3 clustering, which are thought to be necessary for outside-in signaling. However, the association between LIBS expression and outside-in signaling remains elusive. In this study, we used various IIbβ3-specific peptidomimetic compounds as a monovalent ligand instead of fibrinogen and examined the association between LIBS expression and outside-in signaling such as IIbβ3-mediated intracellular Ca2+ signaling. Using a set of monoclonal antibodies (MoAbs) against LIBS, we showed that antagonists can be divided into two groups. In group I, antagonists can induce LIBS on both IIb and β3 subunits. In group II, antagonists can induce LIBS on the IIb subunit, but not on the β3 subunit. Inhibition studies suggested that group I and group II antagonists interact with distinct but mutually exclusive sites on IIbβ3. Neither group I nor group II antagonist increased intracellular Ca2+concentrations ([Ca2+]i) in nonactivated platelets. All antagonists at nanomolar concentrations abolished the increase in [Ca2+]i in 0.03 U/mL thrombin-stimulated platelets, which is dependent on both fibrinogen-binding to IIbβ3 and platelet-aggregation. However, only group I antagonists at higher concentrations dose-dependently augmented the [Ca2+]i increase, which is due to aggregation-independent thromboxane A2 production. This increase in [Ca2+]i was not observed in thrombasthenic platelets, which express no detectable IIbβ3. Thus, only the group I antagonists, albeit a monovalent ligand, can initiate IIbβ3-mediated intracellular Ca2+ signaling in the presence of thrombin stimulation. Our findings strongly suggest the association between β3LIBS expression and IIbβ3-mediated intracellular Ca2+ signaling in platelets.
Possible Role of Interleukin-10 (IL-10) and CD40 Ligand Expression in the Pathogenesis of Hypergammaglobulinemia in Human Immunodeficiency Virus Infection: Modulation of IL-10 and Ig Production After Intravenous Ig Infusion
Authors: Müller Fredrik , Aukrust Pål , Nordøy Ingvild , Frøland Stig S. 
Published: October 2019

AbstractThe mechanisms leading to polyclonal hypergammaglobulinemia in patients with human immunodeficiency virus (HIV) infection are not well understood. In light of the important role of interleukin-10 (IL-10) and the interaction between CD40 and CD40 ligand in the normal regulation of B-lymphocyte function and Ig production, we examined these parameters in 24 HIV-infected patients. Both plasma IL-10 levels and the percentage of CD4+ and CD8+lymphocytes expressing CD40 ligand were significantly higher in the patients than in the 10 blood donor controls. Serum IgG correlated positively with circulating IL-10 levels and the percentage of CD4+ lymphocytes expressing CD40 ligand. Furthermore, a single bolus infusion of intravenous Ig (0.4 g/kg) in 8 HIV-infected patients caused a further increase in IL-10 levels in plasma and an increase in both IL-10 and IgG production in peripheral blood mononuclear cell cultures. In another patient group (Wegener’s granulomatosis) receiving a single bolus infusion of intravenous Ig, a similar increase in plasma IL-10 levels was found, suggesting that this may be a general effect of intravenous Ig. In patients with HIV infection, our data suggest that a vicious cycle may be operative where high endogenous Ig levels may enhance IL-10 production that, in turn, leads to higher Ig production.
Thymocyte Contact or Monoclonal Antibody-Mediated Clustering of 3β1 or 6β4 Integrins Activate Interleukin-6 (IL-6) Transcription Factors (NF-κB and NF-IL6) and IL-6 Production in Human Thymic Epithelial Cells
Authors: Ramarli Dunia , Scupoli Maria Teresa , Fiorini Emma , Poffe Ornella , Brentegani Monica , Villa Antonello , Cecchini Germana , Tridente Giuseppe , Marchisio Pier Carlo 
Published: October 2019

AbstractT-cell precursors develop within the thymus in contact with multiple supportive elements, among which thymic epithelial cells (TEC) are known to exert a dominant role in their homing, survival, and functional differentiation. All these functions are supported by cell-cell contacts and cytokine release. Signaling events triggered in lymphoid cells by adhesion to TEC are well characterized, but little is known about the opposite phenomenon. To address this issue, we derived cultures of TEC from human normal thymus. TEC monolayers were cocultured with thymocytes and immunostained with monoclonal antibodies (MoAbs) to integrin  (2, 3, 4, and 6) and β (β1 and β4) chains. Optical and confocal analysis showed that integrins were polarized on TEC at discrete surface locations: 6β4 lined the basal surface of TEC monolayers, whereas 3β1 was found mostly at TEC-TEC contacts; it is noteworthy that both 3β1 and 6β4 became highly enriched also at the boundaries with adherent thymocytes. Functional studies performed with MoAbs anti-β1 and -β4 integrins showed that β1, and, to a much lower extent, β4 heterodimers are involved in the TEC-thymocyte adhesion. Thymocyte contact or MoAb-mediated ligation of 3, 6, β1, and β4 integrins was investigated as a potential inducer of intracellular signaling in TEC. Thymocyte adhesion or cross-linking of MoAbs bound to integrins clustered at the TEC/thymocyte contact sites led to activation of interleukin-6 (IL-6) gene transcription factors, namely NF-IL6 serine phosphorylation and NF-κB nuclear targeting, as well as to increased IL-6 secretion. We propose that integrin clustering occurring during TEC-thymocyte contacts modulates in TEC the gene expression of a cytokine involved in thymocyte growth and functional differentiation.
Efficient and Rapid Induction of a Chronic Myelogenous Leukemia-Like Myeloproliferative Disease in Mice Receiving P210 bcr/abl-Transduced Bone Marrow
Authors: Pear Warren S. , Miller Juli P. , Xu Lanwei , Pui John C. , Soffer Benny , Quackenbush Robert C. , Pendergast Ann Marie , Bronson Roderick , Aster Jon C. , Scott Martin L. , Baltimore David 
Published: October 2019

AbstractExpression of the 210-kD bcr/abl fusion oncoprotein can cause a chronic myelogenous leukemia (CML)-like disease in mice receiving bone marrow cells transduced by bcr/abl-encoding retroviruses. However, previous methods failed to yield this disease at a frequency sufficient enough to allow for its use in the study of CML pathogenesis. To overcome this limitation, we have developed an efficient and reproducible method for inducing a CML-like disease in mice receiving P210 bcr/abl-transduced bone marrow cells. All mice receiving P210 bcr/abl-transduced bone marrow cells succumb to a myeloproliferative disease between 3 and 5 weeks after bone marrow transplantation. The myeloproliferative disease recapitulates many of the hallmarks of human CML and is characterized by high white blood cell counts and extensive extramedullary hematopoiesis in the spleen, liver, bone marrow, and lungs. Use of a retroviral vector coexpressing P210 bcr/abl and green fluorescent protein shows that the vast majority of bcr/abl-expressing cells are myeloid. Analysis of the proviral integration pattern shows that, in some mice, the myeloproliferative disease is clonal. In multiple mice, the CML-like disease has been transplantable, inducing a similar myeloproliferative syndrome within 1 month of transfer to sublethally irradiated syngeneic recipients. The disease in many of these mice has progressed to the development of acute lymphoma/leukemia resembling blast crisis. These results demonstrate that murine CML recapitulates important features of human CML. As such, it should be an excellent model for addressing specific issues relating to the pathogenesis and treatment of this disease.
Oxidative Modification of Low-Density Lipoprotein and Atherogenetic Risk in β-Thalassemia
Authors: Livrea M.A. , Tesoriere L. , Maggio A. , D’Arpa D. , Pintaudi A.M. , Pedone E. 
Published: October 2019

AbstractWe investigated the oxidative state of low-density lipoprotein (LDL) in patients with β-thalassemia to determine whether there was an association with atherogenesis. Conjugated diene lipid hydroperoxides (CD) and the level of major lipid antioxidants in LDL, as well as modified LDL protein, were evaluated in 35 β-thalassemia intermedia patients, aged 10 to 60, and compared with age-matched healthy controls. Vitamin E and β-carotene levels in LDL from patients were 45% and 24% of that observed in healthy controls, respectively. In contrast, the mean amount of LDL-CD was threefold higher and lysil residues of apo B-100 were decreased by 17%. LDL-CD in thalassemia patients showed a strong inverse correlation with LDL vitamin E (r = −0.784; P &lt; .0001), while a negative trend was observed with LDL-β–carotene (r = −0.443; P = .149). In the plasma of thalassemia patients, malondialdehyde (MDA), a byproduct of lipid peroxidation, was increased by about twofold, while vitamin E showed a 52% decrease versus healthy controls. LDL-CD were inversely correlated with plasma vitamin E (r = −0.659; P &lt; .0001) and correlated positively with plasma MDA (r = 0.621; P &lt; .0001). Plasma ferritin was positively correlated with LDL-CD (r = 0.583; P =.0002). No correlation was found between the age of the patients and plasma MDA or LDL-CD. The LDL from thalassemia patients was cytotoxic to cultured human fibroblasts and cytotoxicity increased with the content of lipid peroxidation products. Clinical evidence of mild to severe vascular complications in nine of the patients was then matched with levels of LDL-CD, which were 36% to 118% higher than the mean levels of the patients. Our results could account for the incidence of atherogenic vascular diseases often reported in β-thalassemia patients. We suggest that the level of plasma MDA in β-thalassemia patients may represent a sensitive index of the oxidative status of LDL in vivo and of its potential atherogenicity.
Cytokine Gene Polymorphisms Associating With Severe Acute Graft-Versus-Host Disease in HLA-Identical Sibling Transplants
Authors: Middleton Peter G. , Taylor Penelope R.A. , Jackson Graham , Proctor Stephen J. , Dickinson Anne M. 
Published: October 2019

Abstract
It is now well known that the initial phase of graft-versus-host disease (GVHD) involves cytokine release during preconditioning of the recipient of an allogeneic bone marrow transplant (BMT). Tumor necrosis factor  (TNF), in particular, has been implicated in pathological damage and is released pretransplant due to irradiation and cytotoxic preconditioning regimens. Interleukin-10 (IL-10), a natural immunosuppressant of TNF , may be involved in downregulation of these responses, which may be an individual patient-specific effect. In this study, we determined the genotype for polymorphisms associated with TNF and IL-10 in 80 potential allo-BMT recipients and correlated the genotype with the severity of GVHD in 49 patients for whom clinical data relating to GVHD was available. The widely studied TNF −308 polymorphism does not show any significant associations, but the d3 homozygous allele of the TNFd microsatellite is preferentially associated with grade III/IV GVHD (7 of 11 patients) compared with its occurrence in 8 of 38 patients with grade 0/II GVHD (P = .006). Alleles of the IL-10 −1064 promoter region microsatellite polymorphism that possess greater numbers of dinucleotide (CA) repeats also significantly associate with more severe GVHD. This region has been demonstrated to be important in the regulation of the IL-10 promoter. Eighteen of 38 patients with grade 0-II GVHD possessed alleles with greater numbers (12 or more) of dinucleotide repeats, compared with 9 of 11 cases with grade III-IV GVHD (P &lt; .02). Of the 38 patients with grade 0-II GVHD, 3 of 38 had a both TNFd3/d3 and IL-10 (12-15) genotype, compared with 6 of 11 patients with grade III-IV GVHD (P &lt; .001). There was no association of either the TNFd or IL-10 microsatellite polymorphisms with mortality (P = .43 and .51, respectively). Our results suggest that patient cytokine gene polymorphism genotypes may influence GVHD outcome by affecting cytokine activation during the pretransplant conditioning regimens, and these results are the first to suggest a genetic predisposition to this important transplant-related complication.
Generation of Functional Human Dendritic Cells From Adherent Peripheral Blood Monocytes by CD40 Ligation in the Absence of Granulocyte-Macrophage Colony-Stimulating Factor
Authors: Brossart Peter , Grünebach Frank , Stuhler Gernot , Reichardt Volker L. , Möhle Robert , Kanz Lothar , Brugger Wolfram 
Published: October 2019

AbstractRecently it has been shown that dendritic cells (DC) can develop from peripheral blood monocytes when grown in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). However, it is unclear whether DC can also develop from monocytes in absence of these cytokines. We therefore analyzed the effect of Flt-3 ligand (Flt3L) and of CD40 ligand on the development of human DC from blood monocytes in the absence of GM-CSF. Adherent peripheral blood mononuclear cells (PBMNC) were cultured in the presence of different cytokine combinations and analyzed for the expression of surface molecules and antigen presenting capacity. For functional analyses, cells were tested for their ability to stimulate allogeneic T lymphocytes in a mixed lymphocyte reaction (MLR), to present soluble antigens, and to induce primary HIV-peptide–specific cytotoxic T-cell (CTL) responses in vitro. Furthermore, expression of DC-CK1, a recently identified chemokine with specific expression in DC, and of IL-18 (IGIF), a growth and differentiation factor for Th 1 lymphocytes, was analyzed by reverse-transcription polymerase chain reaction (RT-PCR). In our study, Flt3L alone was not sufficient to generate DC and required addition of IL-4. DC generated with Flt3L and IL-4 underwent maturation after stimulation with tumor necrosis factor- (TNF-) or CD40L, characterized by CD83 expression, upregulation of MHC, adhesion, and costimulatory molecules as well as increased allogeneic proliferative response. In contrast, CD40 ligation alone promoted differentiation of adherent blood monocytes into functional DC in the absence of GM-CSF and IL-4. These cells displayed all phenotypic and functional characteristics of mature DC and were potent stimulatory cells in priming of major histocompatibility complex (MHC) class I–restricted CTL responses against an HIV-peptide, whereas their ability to present soluble protein antigens was reduced. Using a semiquantitative RT-PCR, DC-CK1 and IL-18 transcripts were detected in all generated DC populations, independent of growth factors used. Our findings provide further evidence for the importance of CD40-CD40L interaction for initiation and maintenance of T-cell responses and confirm the emerging concept that blood monocytes provide an additional source of DC depending on external stimuli.
Role of Spontaneous and Interleukin-2–Induced Natural Killer Cell Activity in the Cytotoxicity and Rejection of Fas+and Fas− Tumor Cells
Authors: Bradley Mike , Zeytun Ahmet , Rafi-Janajreh Asimah , Nagarkatti Prakash S. , Nagarkatti Mitzi 
Published: October 2019

AbstractIn the current study, we investigated whether the naive, poly I:C or interleukin-2 (IL-2)–induced natural killer (NK)/lymphokine-activated killer (LAK) cells use perforin and/or Fas ligand (FasL) to mediated cytotoxicity. We correlated these findings with the ability of mice to reject syngeneic Fas+ and Fas− tumor cells either spontaneously or after IL-2 treatment. The spontaneous NK-cell–mediated cytotoxicity was primarily perforin based, whereas the poly I:C and IL-2–induced NK/LAK activity was both FasL and perforin dependent. L1210 Fas+ tumor targets were more sensitive than L1210 Fas− targets to poly I:C and IL-2–induced cytotoxicity in wild-type, gld/gld, and perforin knockout mice. When L1210 Fas+ and Fas– tumor cells were injected subcutaneously (sc) or intraperitoneally into syngeneic mice, Fas− tumor cells caused mortality earlier than Fas+ tumor cells. Also, approximately 20% of the mice injected sc with L1210 Fas+ tumor cells survived the challenge(&gt;60 days), whereas all mice injected similarly with L1210 Fas− tumor cells died. When immunotherapy using IL-2 (10,000 U, three times/d for a week, followed by once/d for an additional week) was attempted in mice injected sc with tumor cells, IL-2 treatment was very effective against mice bearing L1210 Fas+ (40% survival) but not L1210 Fas− (0% survival) tumors. These data correlated with the finding that the LAK cells from IL-2–injected mice caused increased cytotoxicity against L1210 Fas+ when compared with L1210 Fas− targets. Also, L1210 Fas+tumor-bearing mice showed increased tumor-specific cytotoxic T lymphocyte (CTL) activity when compared with those bearing L1210 Fas− tumor cells. Together our studies show for the first time that expression of Fas on tumor targets makes them more immunogenic as well as susceptible to CTL- and IL-2–induced LAK activity. The Fas+ tumor cells are also more responsive to immunotherapy with IL-2.
Hypomethylation Status of CpG Sites at the Promoter Region and Overexpression of the Human MDR1 Gene in Acute Myeloid Leukemias
Authors: Nakayama Masaharu , Wada Morimasa , Harada Taishi , Nagayama Jun , Kusaba Hitoshi , Ohshima Koichi , Kozuru Mitsuo , Komatsu Hirokazu , Ueda Ryuzo , Kuwano Michihiko 
Published: October 2019

AbstractSelection of human cells for resistance to vincristine or doxorubicin often induces overexpression of the multidrug resistance 1 gene (MDR1), which encodes the cell surface P-glycoprotein, as a result of gene amplification or transcriptional activation. Moreover, overexpression of the MDR1 gene has been shown to be associated closely with clinical outcome in various hematological malignancies, including acute myeloid leukemia (AML). However, the precise mechanism underlying overexpression of the MDR1 gene during acquisition of drug resistance remains unclear. We recently described an inverse correlation between the methylation status of CpG sites at the promoter region and expression of the MDR1 gene in malignant cell lines. In this study, we expanded this analysis to 42 clinical AML samples. We adapted a quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay for gene expression and a quantitative PCR after digestion by Hpa II for methylation status of the MDR1gene. We observed a statistically significant inverse correlation between methylation and MDR1 expression in clinical samples. The hypomethylation status of the MDR1 promoter region might be a necessary condition for MDR1 gene overexpression and establishment of P-glycoprotein–mediated multidrug resistance in AML patients.
2′,5′-Oligoadenylate-Antisense Chimeras Cause RNase L to Selectively Degrade bcr/abl mRNA in Chronic Myelogenous Leukemia Cells
Authors: Maran Avudaiappan , Waller Cornelius F. , Paranjape Jayashree M. , Li Guiying , Xiao Wei , Zhang Kerry , Kalaycio Matt E. , Maitra Ratan K. , Lichtin Alan E. , Brugger Wolfram , Torrence Paul F. , Silverman Robert H. 
Published: October 2019

AbstractWe report an RNA targeting strategy, which selectively degrades bcr/abl mRNA in chronic myelogenous leukemia (CML) cells. A 2′,5′-tetraadenylate activator (2-5A) of RNase L was chemically linked to oligonucleotide antisense directed against either the fusion site or against the translation start sequence in bcr/abl mRNA. Selective degradation of the targeted RNA sequences was demonstrated in assays with purified RNase L and decreases of p210bcr/abl kinase activity levels were obtained in the CML cell line, K562. Furthermore, the 2-5A-antisense chimeras suppressed growth of K562, while having substantially reduced effects on the promyelocytic leukemia cell line, HL60. Findings were extended to primary CML cells isolated from bone marrow of patients. The 2-5A-antisense treatments both suppressed proliferation of the leukemia cells and selectively depleted levels of bcr/abl mRNA without affecting levels of β-actin mRNA, determined by reverse transcriptase-polymerase chain reaction (RT-PCR). The specificity of this approach was further shown with control oligonucleotides, such as chimeras containing an inactive dimeric form of 2-5A, antisense lacking 2-5A, or chimeras with altered sequences including several mismatched nucleotides. The control oligonucleotides had either reduced or no effect on CML cell growth and bcr/abl mRNA levels. These findings show that CML cell growth can be selectively suppressed by targeting bcr/abl mRNA with 2-5A-antisense for decay by RNase L and suggest that these compounds should be further explored for their potential as ex vivo purging agents of autologous hematopoietic stem cell transplants from CML patients.
Autocrine Signals Control CCAAT/Enhancer Binding Protein β Expression, Localization, and Activity in Macrophages
Authors: Baer Mark , Williams Simon C. , Dillner Allan , Schwartz Richard C. , Johnson Peter F. 
Published: October 2019

AbstractThe transcription factor CCAAT/enhancer binding protein β (C/EBPβ, or NF-IL6) is expressed in macrophages, where it participates in lipopolysaccharide (LPS)-mediated induction of proinflammatory cytokine genes such as interleukin-6 (IL-6) and IL-1β. We have identified activities in conditioned medium from a macrophage tumor cell line that regulates the expression, localization, and transcriptional activity of C/EBPβ. One factor was shown to be tumor necrosis factor- (TNF-), which increased C/EBPβ expression by a posttranscriptional mechanism. A second activity, designated autocrine macrophage factor (AMF), elicited a change in C/EBPβ localization from a punctate nuclear staining pattern to diffuse nuclear distribution. The punctate form of C/EBPβ correlated with increased susceptibility of this protein to cleavage by an endogenous protease during nuclear extract preparation. Conditioned medium stimulated the ability of C/EBPβ to transactivate a reporter gene and activated the expression of two cytokine genes that are putative targets of C/EBPβ. These observations suggest that diffuse distribution of C/EBPβ in the nucleus corresponds to an activated form of this protein. AMF activity could not be mimicked by an extensive set of recombinant cytokines and growth factors and therefore may represent a novel extracellular factor.
Description and Targeted Deletion of 5′ Hypersensitive Site 5 and 6 of the Mouse β-Globin Locus Control Region
Authors: Bender M.A. , Reik Andreas , Close Jennie , Telling Agnes , Epner Elliot , Fiering Steven , Hardison Ross , Groudine Mark 
Published: October 2019

AbstractThe most upstream hypersensitive site (HS) of the β-globin locus control region (LCR) in humans (5′ HS 5) and chickens (5′ HS 4) can act as an insulating element in some gain of function assays and may demarcate a β-globin domain. We have mapped the most upstream HSs of the mouse β-globin LCR and sequenced this region. We find that mice have a region homologous to human 5′ HS 5 that is associated with a minor HS. In addition we map a unique HS upstream of 5′ HS 5 and refer to this novel site as mouse 5′ HS 6. We have also generated mice containing a targeted deletion of the region containing 5′ HS 5 and 6. We find that after excision of the selectable marker in vivo, deletion of 5′ HS 5 and 6 has a minimal effect on transcription and does not prevent formation of the remaining LCR HSs. Taken together these findings suggest that the most upstream HSs of the mouse β-globin LCR are not necessary for maintaining the β-globin locus in an active configuration or to protect it from a surrounding repressive chromatin environment.