bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular features responsible for the absence of immunoglobulin heavy chain protein synthesis in an IgH− subgroup of multiple myeloma
Authors: Szczepański Tomasz , van 't Veer Mars B. , Wolvers-Tettero Ingrid L. M. , Langerak Anton W. , van Dongen Jacques J. M. 
Published: October 2019

AbstractThis study involved 12 patients with multiple myeloma (MM), in whom malignant plasma cells did not contain immunoglobulin heavy chain (IgH) protein chains. Southern blot analysis revealed monoallelic Jh gene rearrangements in 10 patients, biallelic rearrangement in 1 patient, and biallelic deletion of the Jh and Cμ regions in 1 patient. Heteroduplex polymerase chain reaction analysis enabled the identification and sequencing of 9 clonal Jhgene rearrangements. Only 4 of the joinings were complete Vh-(D)-Jhrearrangements, including 3 in-frame rearrangements with evidence of somatic hypermutation. Five rearrangements concerned incomplete Dh-Jh joinings, mainly associated with deletion of the other allele. Curiously, in at least 1 of these 5 cases the second allele seemed to be in germline configuration, whereas the in-frame Vκ-Jκgene rearrangements contained somatic mutations. The configuration of the IGH genes was further investigated by use of Ch probes. In 5 patients the rearrangements in the Jh and Ch regions were not concordant, probably caused by illegitimate IGH class switch recombination (chromosomal translocations to 14q32.3). These data indicate that in many IgH− MM patients illegitimateIGH class switch rearrangement or illegitimate deletion of the functional Vh-(Dh)-Jhallele are responsible for IgH negativity. For example, the exclusive presence ofDh-Jhrearrangements in combination with mutated IGK genes can only be explained in terms of normal B-cell development, if the second (functional) IGH allele is deleted, which was probably the case in most patients. Therefore, defects at the DNA level are responsible for the lack of IgH protein production in most IgH− MM patients.
LSP1 modulates the locomotion of monocyte-differentiated U937 cells
Authors: Li Yao , Zhang Qihong , Aaron Rosemary , Hilliard Lee , Howard Thomas H. 
Published: October 2019

AbstractTo examine the effect of lymphocyte specific protein 1 (LSP1) on phagocytic cell motility, stable transfection of LSP1-null U937 cell line with an episomal expression vector carrying the LSP1 complementary DNA created lines expressing varied LSP1 levels. Mock transfectants without LSP1 (U937−) and cell lines with LSP1 levels similar to those of monocytes (U937+) or 4-fold those of monocytes (U937++++) express LSP1 as indicated and express other actin-binding proteins at normal levels before or after monocytic induction (MI) with dibutyryl cyclic adenosine monophosphate. The cell lines were compared for rate of growth and cell division and, after monocytic differentiation, were video-tracked to measure locomotion as distance moved in 2 hours and examined for morphologic changes. Rates of cell division and growth were similar for different U937 cell lines at all LSP1 levels. In contrast, mean rate of locomotion (micrometers moved in 2 hours) was slower in MI–U937++++ (7.78 + 1.11μm, n = 3) and MI-U937− (23.89 + 2.78μm, n = 3) than in MI-U937+ cells (50.77 + 4.11μm, n = 3). Compared with MI-U937−, the locomotive histogram (n = 150 cells) of MI-U937+ or MI-U937++++ cells shows all cells move respectively faster or slower as an entire cell population. In LSP1+ U937 phagocytes, high LSP1 levels inhibit some (locomotion) but not all (cytokinesis) cell motile behaviors and cause the formation of surface projections. In contrast, normal LSP1 levels in U937 phagocytes enhance some (locomotion) but not all (cytokinesis) cellular motile behaviors and have no effect on cell morphology. Therefore, LSP1 level has a unique biphasic effect on cellular locomotion. The data suggest LSP1 is an important regulator of phagocyte locomotion.
The human ankyrin-1 gene is selectively transcribed in erythroid cell lines despite the presence of a housekeeping-like promoter
Authors: Gallagher Patrick G. , Romana Marc , Tse William T. , Lux Samuel E. , Forget Bernard G. 
Published: October 2019

AbstractTo begin to study the sequence variations identified in the 5′ flanking genomic DNA of the ankyrin gene in ankyrin-deficient hereditary spherocytosis patients and to provide additional insight into our understanding of the regulation of genes encoding erythrocyte membrane proteins, we have identified and characterized the erythroid promoter of the human ankyrin-1 gene. This compact promoter has characteristics of a housekeeping gene promoter, including very high G+C content and enzyme restriction sites characteristic of an HTF-island, no TATA, InR, or CCAAT consensus sequences, and multiple transcription initiation sites. In vitro DNAseI footprinting analyses revealed binding sites for GATA-1, CACCC-binding, and CGCCC-binding proteins. Transfection of ankyrin promoter/reporter plasmids into tissue culture cell lines yielded expression in erythroid, but not muscle, neural, or HeLa cells. Electrophoretic mobility shift assays, including competition and antibody supershift experiments, demonstrated binding of GATA-1, BKLF, and Sp1 to core ankyrin promoter sequences. In transfection assays, mutation of the Sp1 site had no effect on reporter gene expression, mutation of the CACCC site decreased expression by half, and mutation of the GATA-1 site completely abolished activity. The ankyrin gene erythroid promoter was transactivated in heterologous cells by forced expression of GATA-1 and to a lesser degree BKLF.
Recipient elimination of allogeneic lymphoid cells: donor CD4+ cells are effective alloantigen-presenting cells
Authors: Fast Loren D. 
Published: October 2019

AbstractThe encounter with allogeneic major histocompatibility complex (MHC) molecules expressed on donor leukocytes during transfusion of blood products has been shown to impact the recipient's immune responses in a number of settings. To better understand the responses induced by the transfer of allogeneic cells, a murine model was used to characterize the recipient responses that control the fate of the allogeneic lymphoid cells. Recipient CD8+ cells could rapidly eliminate a large number of donor cells within 3 days after injection. When elimination responses were studied in the absence of CD8+ cells, it was found that alloantibody production was the secondary elimination mechanism. Optimal recipient CD8+ and B cell responses in this model required help from CD4+ cells that could be provided by 3 different pathways. Although recipient CD4+ cells could provide help when activated by direct recognition of allogeneic MHC class II molecules expressed on donor cells or by indirect recognition of processed alloantigen presented on recipient antigen-presenting cells (APCs), the most rapid recipient responses were generated by help provided by donor CD4+ cells. Purified donor CD4+ cells were also able to induce these rapid responses, indicating that activated donor CD4+cells expressing allogeneic MHC molecules were able to effectively stimulate responses by both recipient CD8+ and B cells.
α-Fibrinogen Thr312Ala polymorphism and venous thromboembolism
Authors: Carter Angela M. , Catto Andrew J. , Kohler Hans P. , Ariëns Robert A. S. , Stickland Max H. , Grant Peter J. 
Published: October 2019

Abstract
The A-fibrinogen Thr312Ala polymorphism, which occurs in a region involved in factor XIII (FXIII)-dependent cross-linking processes, is associated with poststroke mortality in subjects with atrial fibrillation, suggesting an influence either on intraatrial clot formation or embolization. We have determined the association of Thr312Ala with deep vein thrombosis (DVT) and pulmonary embolism (PE) and have assessed the interaction of Thr312Ala with the FXIII Val34Leu polymorphism in 122 patients with DVT, 99 patients with PE, and 254 healthy control subjects. The genotype distribution of patients with PE (TT = 49%, TA = 36%, AA = 15%), but not DVT (TT = 50%, TA = 42%, AA = 8%), differed significantly from healthy control subjects (TT = 60%, TA = 34%, AA = 6%, P = .02). A significant interaction of Thr312Ala and Val34Leu was also identified (P = .01), indicating an inverse association between Leu34 and Ala312. These results support the hypothesis that Thr312Ala alters FXIII-dependent cross-linking, making formed fibrin clot more susceptible to embolization.
Ligation of the CD44 adhesion molecule inhibits drug-induced apoptosis in human myeloid leukemia cells
Authors: Allouche Michèle , Charrad Rachida Sihem , Bettaieb Ali , Greenland Catherine , Grignon Cécile , Smadja-Joffe Florence 
Published: October 2019

AbstractAdhesion molecules can improve hematopoietic cell survival; however, their role in leukemic cell resistance to drug-induced apoptosis is poorly documented. The CD44 adhesion molecule is strongly expressed on acute myeloid leukemia (AML) blasts. Using 2 myeloid cell lines, HL60 and NB4, evidence is presented that prior incubation with the CD44-specific monoclonal antibody (mAb) A3D8, reported to induce differentiation of AML blasts, significantly decreases apoptosis induced by 3 drugs used in AML chemotherapy: daunorubicin (DNR), mitoxantrone, and etoposide. In addition, in HL60 cells, CD44 ligation with A3D8 mAb fully abrogates the DNR-triggered generation of ceramide, a lipid second messenger involved in the DNR apoptotic signaling pathway. Moreover, results show that the A3D8 mAb and Bcl-2 additively inhibit DNR-induced apoptosis in HL60 cells overexpressing Bcl-2. These results suggest that, to eradicate AML blasts, the differentiation-inducing anti-CD44 mAb A3D8 should not be administered prior to apoptosis-inducing drugs.
α-Thalassemia resulting from a negative chromosomal position effect
Authors: Barbour Virginia M. , Tufarelli Cristina , Sharpe Jacqueline A. , Smith Zoe E. , Ayyub Helena , Heinlein Cynthia A. , Sloane-Stanley Jacqueline , Indrak Karel , Wood William G. , Higgs Douglas R. 
Published: October 2019

AbstractTo date, all of the chromosomal deletions that cause -thalassemia remove the structural  genes and/or their regulatory element (HS –40). A unique deletion occurs in a single family that juxtaposes a region that normally lies approximately 18-kilobase downstream of the human  cluster, next to a structurally normal -globin gene, and silences its expression. During development, the CpG island associated with the -globin promoter in the rearranged chromosome becomes densely methylated and insensitive to endonucleases, demonstrating that the normal chromatin structure around the -globin gene is perturbed by this mutation and that the gene is inactivated by a negative chromosomal position effect. These findings highlight the importance of the chromosomal environment in regulating globin gene expression.
The immunophenotype of 177 adults with acute myeloid leukemia: proposal of a prognostic score
Authors: Legrand Ollivier , Perrot Jean-Yves , Baudard Marion , Cordier Annie , Lautier Régine , Simonin Ghislaine , Zittoun Robert , Casadevall Nicole , Marie Jean-Pierre 
Published: October 2019

AbstractIn acute myeloid leukemia (AML) patients, a variety of clinical and biologic parameters, including phenotype, have been examined for potential value in predicting treatment response and survival. The European Group for the Immunological Classification of Leukaemias (EGIL) has proposed that AML be defined immunologically by the expression of 2 or more of the following myeloid markers: myeloperoxidase, CD13, CD33, CDw65, and CD117. With regard to this classification, the prognostic significance of 21 antigens taken separately and with immunophenotypic subgroups were evaluated and compared with other clinical and biological variables in 177 adult AML patients. None of the antigens tested were associated with treatment outcome. In contrast, patients with blasts disclosing a full expression of panmyeloid phenotype (defined by the expression of all 5 myeloid markers) had a higher complete remission rate (P &lt; .0001) and differed significantly in disease-free survival (P = .02) and overall survival (P = .008) than patients whose cells expressed fewer than 5 of these markers. In multivariate analysis, only age, panmyeloid phenotype, performance status, and permeability glycoprotein activity influence treatment outcome. Cytogenetics was significant in univariate analysis but not in multivariate analysis, most likely because of the redundancy with panmyeloid phenotype and a higher sensitivity of immunophenotyping. Patients whose cells exhibit the panmyeloid phenotype appear to define a relatively homogeneous biological subset of AML. The 4 independent prognostic factors were used to create a prognostic score, defined by the number of factors present. This score permitted a stratification of patients with AML, thereby allowing for the consideration of innovative therapies to improve outcome in the poorer outcome groups.
In vivo generation of human dendritic cell subsets by Flt3 ligand
Authors: Maraskovsky Eugene , Daro Elizabeth , Roux Eileen , Teepe Mark , Maliszewski Charlie R. , Hoek Jeannie , Caron Dania , Lebsack Mel E. , McKenna Hilary J. 
Published: October 2019

AbstractDendritic cells (DCs) represent a family of ontogenically distinct leukocytes involved in immune response regulation. The ability of DCs to stimulate T-cell immunity has led to their use as vectors for immunotherapy vaccines. However, it is unclear whether and to what degree in vitro–generated DCs are representative of DCs that develop in vivo. Treatment of mice with human Flt3 ligand (FL) dramatically increases the number of DCs. We report here that administration of FL to healthy human volunteers increased the number of circulating CD11c+ IL-3Rlow DC (mean 44-fold) and CD11c− IL-3Rhigh DC precursors (mean 12-fold). Moreover, the CD11c+ DCs were efficient stimulators of T cells in vitro. Thus, FL can expand the number of circulating, functionally competent human DCs in vivo.
Expression of connexin 43 (Cx43) is critical for normal hematopoiesis
Authors: Montecino-Rodriguez Encarnacion , Leathers Hyosuk , Dorshkind Kenneth 
Published: October 2019

AbstractGap junctions are intercellular channels, formed by individual structural units known as connexins (Cx), that allow the intercellular exchange of various messenger molecules. The finding that numbers of Cx43-type gap junctions in bone marrow are elevated during establishment and regeneration of the hematopoietic system has led to the hypothesis that expression of Cx43 is critical during the initiation of blood cell formation. To test this hypothesis, lymphoid and myeloid development were examined in mice with a targeted disruption of the gene encoding Cx43. Because Cx43−/− mice die perinatally, initial analyses were performed on Cx43−/−, Cx43+/−, and Cx43+/+ embryos and newborns. The data indicate that lack of Cx43 expression during embryogenesis compromises the terminal stages of primary T and B lymphopoiesis. Cx43−/− embryos and neonates had a reduced frequency of CD4+ and T-cell receptor-expressing thymocytes and surface IgM+cells compared to their Cx43+/+ littermates. Surprisingly, Cx43+/− embryos/neonates also showed defects in B- and T-cell development similar to those observed in Cx43−/− littermates, but their hematopoietic system was normal at 4 weeks of age. However, the regeneration of lymphoid and myeloid cells was severely impaired in the Cx43+/− mice after cytoablative treatment. Taken together, these data indicate that loss of a single Cx43 allele can affect blood cell formation. Finally, the results of reciprocal bone marrow transplants between Cx43+/+ and Cx43+/− mice and examination of hematopoietic progenitors and stromal cells in vitro indicates that the primary effects of Cx43 are mediated through its expression in the hematopoietic microenvironment.
JNK and p38 are activated by erythropoietin (EPO) but are not induced in apoptosis following EPO withdrawal in EPO-dependent HCD57 cells
Authors: Jacobs-Helber Sarah M. , Ryan John J. , Sawyer Stephen T. 
Published: October 2019

AbstractJun N-terminal kinase (JNK) and p38, members of the mitogen-activated protein kinase family of serine/threonine kinases, are activated as a result of cellular stress but may also play a role in growth factor-induced proliferation and/or survival or differentiation of many cells. A recent report has implicated JNK and p38 in the induction of apoptosis in the erythropoietin (EPO)-dependent erythroid cell line HCD57 following EPO withdrawal, whereas our previously reported data did not support a role for JNK in growth factor withdrawal-induced apoptosis in HCD57 cells. Therefore, further testing was done to see if JNK was activated in EPO withdrawal-induced apoptosis; the study was extended to p38 and characterized the effect of EPO on JNK and p38 activities. Treatment of HCD57 cells with EPO resulted in a gradual and sustained activation of both JNK and p38 activity; these activities decreased on EPO withdrawal. Transient activation of p42/p44 extracellular signal-related kinases (ERK) was also detected. Inhibition of ERK activity inhibited proliferation in EPO-treated cells but neither induced apoptosis nor activated JNK. Inhibition of p38 activity inhibited proliferation but did not protect HCD57 cells from apoptosis induced by EPO withdrawal. Treatment of HCD57 cells with tumor necrosis factor-alpha induced JNK activation but did not induce apoptosis. These results implicate JNK, p38, and ERK in EPO-induced proliferation and/or survival of erythroid cells but do not support a role for JNK or p38 in apoptosis induced by EPO withdrawal from erythroid cells.
Hemophilic factor VIII C1- and C2-domain missense mutations and their modeling to the 1.5-angstrom human C2-domain crystal structure
Authors: Liu Miao-Liang , Shen Betty W. , Nakaya Shelley , Pratt Kathleen P. , Fujikawa Kazuo , Davie Earl W. , Stoddard Barry L. , Thompson Arthur R. 
Published: October 2019

AbstractFactor VIII C domains contain key binding sites for von Willebrand factor (vWF) and phospholipid membranes. Hemophilic patients were screened for factor VIII C-domain mutations to provide a well-characterized series. Mutated residues were localized to the high-resolution C2 structure and to a homology model of C1. Of 30 families found with mutations in the C domains, there were 14 missense changes, and 9 of these were novel. Of the missense mutations, 10 were associated with reduced vWF binding and 8 were at residues with surface-exposed side chains. Six of the 10 mutants had nearly equivalent factor VIII clotting activity and antigen level, suggesting that reduced vWF binding could cause hemophilia by reducing factor VIII stability in circulation. When the present series was combined with previously described mutations from an online international database, 11 C1 and C2 mutations in patients with mild or moderately severe hemophilia A were associated with antibody-inhibitor development in at least one affected individual. Of these substitutions, 6 occurred at surface-exposed residues. As further details of the C1 structure and its interface with C2 become available, and as binding studies are performed on the plasma of more patients with hemophilic C-domain mutations, prediction of surface binding sites should improve, allowing confirmation by site-specific mutagenesis of surface-exposed residues.
Highly efficient gene transfer into cord blood nonobese diabetic/severe combined immunodeficiency repopulating cells by oncoretroviral vector particles pseudotyped with the feline endogenous retrovirus (RD114) envelope protein
Authors: Kelly Patrick F. , Vandergriff Jody , Nathwani Amit , Nienhuis Arthur W. , Vanin Elio F. 
Published: October 2019

Abstract
Limited expression of the amphotropic envelope receptor is a recognized barrier to efficient oncoretroviral vector–mediated gene transfer. Human hematopoietic cell lines and cord blood–derived CD34+ and CD34+, CD38− cell populations and the progenitors contained therein were transduced far more efficiently with oncoretroviral particles pseudotyped with the envelope protein of feline endogenous virus (RD114) than with conventional amphotropic vector particles. Similarly, human repopulating cells from umbilical cord blood capable of establishing hematopoiesis in immunodeficient mice were efficiently transduced with RD114-pseudotyped particles, whereas amphotropic particles were ineffective at introducing the proviral genome. After only a single exposure of CD34+ cord blood cells to RD114-pseudotyped particles, all engrafted nonobese diabetic/severe combined immunodeficiency mice (15 of 15) contained genetically modified human bone marrow cells. Human cells that were positive for enhanced green fluorescent protein represented as much as 90% of the graft. The use of RD114-pseudotyped vectors may be advantageous for therapeutic gene transfer into hematopoietic stem cells.
Distinct functional properties of highly purified hematopoietic stem cells from mouse strains differing in stem cell numbers
Authors: de Haan Gerald , Szilvassy Stephen J. , Meyerrose Todd E. , Dontje Bert , Grimes Barry , Van Zant Gary 
Published: October 2019

AbstractWe have previously demonstrated that young adult DBA/2 (DBA) mice have more stem cells than C57BL/6 (B6) mice, as measured in a cobblestone area-forming cell (CAFC) assay using unfractionated marrow. To study the nature of this difference, we have now compared the proliferative fate of single, highly enriched Sca-1+c-kit+Lin−stem cells from these strains. Although equal in frequency, functional comparison revealed that Sca-1+c-kit+Lin−cells from DBA mice contained twice as many cells with CAFC activity. DBA clones persisted much longer in vitro, and developed later in time. To assess whether these differences were of any functional relevance in vivo, we compared engraftment of lethally irradiated mice transplanted with 1000 B6 or DBA Sca-1+c-kit+Lin−cells. Recipients of enriched DBA cells recovered much faster than animals transplanted with B6 cells. We also studied endogenous hematopoietic recovery after 5-fluorouracil (5-FU) treatment in vivo. Progenitors and peripheral blood cells recovered twice as fast in DBA mice. Thus, DBA stem cells have superior proliferative potential compared with phenotypically identical stem cells obtained from B6 mice. Such genetically determined quantitative and qualitative differences in stem cell behavior likely contribute to the dramatically different hematopoietic recovery rates observed in human transplant patients.