bluuebunny/crossref_metadata_2025 huggingface dataset:
Upregulation of c-Fos in Activated T Lymphoid and Monocytic Cells by Human Immunodeficiency Virus-1 Tat Protein
Authors: Gibellini Davide , Caputo Antonella , Capitani Silvano , La Placa Michele , Zauli Giorgio
Published: October 2019

The regulatory Tat protein of the human immunodeficiency virus type-1 (HIV-1) is essential for viral replication and also shows pleiotropic activities on various cell functions. To get further insights into the molecular mechanisms underlying the biological activity of Tat, we investigated the effect of endogenous and exogenous Tat protein on c-fos gene expression in T lymphoblastoid (Jurkat) and monocytic (U937) cell lines, as well as in primary peripheral blood mononuclear cells (PBMC). Transient cotransfection of tat cDNA in sense orientation (tat/S), together with a plasmid containing the c-fos promoter (FC3, from −711 to +42) in front of the bacterial chloramphenicol acetyltransferase (CAT) gene significantly enhanced CAT activity in Jurkat cells activated by the addition of 15% fetal calf serum (FCS) or 5 μg/mL phytohemagglutinin plus 10−7 mol/L phorbol myristate acetate (PMA) and U937 cells activated by 15% FCS or 10−7 mol/L PMA. This effect was specifically due to Tat, since Jurkat and U937 cells cotransfected either with tat cDNA in antisense orientation (tat/AS), tat carrying a mutation in the aminoacid cys22 - gly22 (tat 22/S) or with the backbone vector alone (pRPneo-SL3) did not show any significant difference in c-fos promoter activity as compared to cells transfected with FC3 plasmid alone. By using deletion mutants of the c-fos promoter, we found that the minimal DNA sequence required for Tat activity was located between nucleotides −404/−220 and that the serum responsive element (SRE, −317/−288), present within this region, was still responsive to Tat. A single point mutation in the SRE completely abrogated the responsiveness to tat/S. Exogenous recombinant Tat protein was also able to upregulate c-fos promoter activity in serum-activated Jurkat and U937 cells, as well as endogenous c-fos mRNA expression and c-Fos protein synthesis in both serum-activated cell lines and primary PBMC. c-Fos protein was shown essential for an optimal transactivation of the HIV-1 long terminal repeat (LTR) by Tat: incubation of Jurkat cells with antisense, but not sense, c-fos oligonucleotides significantly reduced either the Tat-enhanced expression of an LTR-CAT reporter construct or the levels of gag p24 in the culture supernatants of Jurkat cells and PBMC acutely infected with HIV-1. Our data suggest that the c-fos upregulation mediated by Tat might play a significant role in the control of viral gene transactivation.
Erythropoietin-Induced Activation of STAT5 Is Impaired in the Myelodysplastic Syndrome
Authors: Hoefsloot Lies H. , van Amelsvoort Martine P. , Broeders Lianne C.A.M. , van der Plas Dorien C. , van Lom Kirsten , Hoogerbrugge Hans , Touw Ivo P. , Löwenberg Bob
Published: October 2019

Patients with myelodysplastic syndrome (MDS) have ineffective in vivo and in vitro erythropoiesis, characterized by an impaired response to erythropoietin (Epo). We examined proliferation and maturation of MDS marrow cells in response to Epo in more detail. Epo-dependent DNA synthesis as well as induction of GATA-1 binding activity in marrow cells from 15 MDS cases were severely reduced as compared with normal bone marrow (NBM). Additionally, the appearance of morphologically identifiable erythroid cells was decreased in MDS cell cultures. These data indicate that both the Epo-dependent proliferation as well as the differentiation induction by Epo is suppressed. To study more upstream events of the Epo signal transduction route we investigated activation of the signal transducer and activator of transcription (STAT) 5. In all 15 MDS samples tested, STAT5 activation was absent or greatly suppressed in response to Epo. In contrast, interleukin-3 induced a normal STAT5 response in MDS cells. Further, in MDS the subset of CD71+ BM cells that is phenotypically similar to Epo-responsive cells in normal marrow, was present. We conclude that the Epo response in MDS is disturbed at an early point in the Epo receptor (EpoR) signal transduction pathway.
A New Subtype of Pre-B Acute Lymphoblastic Leukemia With t(5; 12)(q31q33; p12), Molecularly and Cytogenetically Distinct From t(5; 12) in Chronic Myelomonocytic Leukemia
Authors: Wlodarska Iwona , Aventı́n Anna , Inglés-Esteve Júlia , Falzetti Daniela , Criel Arnold , Cassiman Jean-Jacques , Mecucci Cristina , Van den Berghe Herman , Marynen Peter
Published: October 2019

Translocation t(5; 12)(q33; p13), resulting in an ETV6/PDGFRB gene fusion, is a recurrent chromosomal abnormality associated with chronic myelomonocytic leukemia (CMML). An analogous translocation was also found in four cell lines with features of pre-B acute lymphoblastic leukemia (ALL). Using fluorescence in situ hybridization (FISH) we show here that in three of these cell lines identical complex rearrangements occurred. However, the regions involved on 5q and 12p are different from the breakpoints in CMML, and the translocation is accompanied by seemingly identical cryptic deletions of both 5q and 12p chromosome sequences in all analyzed pre-B ALL cell lines. The similar cytogenetic, FISH, and immunophenotyping findings in the three cell lines suggest that the t(5; 12)(q31q33; p12) defines a new entity of pre-B ALL.
Mutations and Loss of Expression of a Mismatch Repair Gene, hMLH1, in Leukemia and Lymphoma Cell Lines
Authors: Hangaishi Akira , Ogawa Seishi , Mitani Kinuko , Hosoya Noriko , Chiba Shigeru , Yazaki Yoshio , Hirai Hisamaru
Published: October 2019

Defects in genes involved in DNA mismatch repair have been detected in both hereditary and sporadic tumors of colon, endometrium, and ovary and suggested to be associated with tumorigenesis. To investigate disruptions of the mismatch repair system in hematological malignancies, we examined alterations of the human mutL homologue 1 (hMLH1) gene, a member of the mismatch repair gene family, in a total of 43 human leukemia and lymphoma cell lines, by polymerase chain reaction–single-strand conformation polymorphism (PCR-SSCP) and sequencing analyses. Mutations of the hMLH1 gene were detected in three cell lines established from lymphoid leukemias. Moreover, Northern and Western blot analyses showed that expression of hMLH1 transcript or protein was abrogated in these three leukemia cell lines. Further studies for microsatellite loci showed that these cell lines without hMLH1 expression showed microsatellite instability. This is the first report that describes mutations and inactivation of the hMLH1 gene in human leukemia cells, suggesting that disruption of DNA mismatch repair system may play an important role in the development of human lymphoid leukemias.
The Human SHIP Gene Is Differentially Expressed in Cell Lineages of the Bone Marrow and Blood
Authors: Geier Susan J. , Algate Paul A. , Carlberg Kristen , Flowers Dave , Friedman Cynthia , Trask Barbara , Rohrschneider Larry R.
Published: October 2019

The macrophage colony-stimulating factor receptor and several other hematopoietic growth factor receptors induce the tyrosine phosphorylation of a 145- to 150-kD protein in murine cells. We have previously cloned a cDNA for the murine 150-kD protein, SHIP, and found that it encodes a unique signaling intermediate that binds the SHC PTB domain through at least one tyrosine phosphorylated (NPXY) site in the carboxyl-terminal region. SHIP also contains several potential SH3 domain-binding sites, an SH2 domain for binding other tyrosine phosphorylated proteins, and an enzymatic activity that removes the phosphate from the 5 position of phosphatidylinositol 3,4,5-phosphate or from inositol 1,3,4,5-phosphate. SHIP has a negative effect on cell growth and therefore loss or modification may have profound effects on hematopoietic cell development. In this study, we have cloned a cDNA for human SHIP and examined mRNA and protein expression of SHIP and related species in bone marrow and blood cells. Flow cytometry indicates that at least 74% of immature CD34+ cells express SHIP cross-reacting protein species, whereas within the more mature population of CD33+ cells, only 10% of cells have similar expression. The majority of T cells react positively with the anti-SHIP antibodies, but significantly fewer B cells are positive. Immunoblotting detects up to seven different cross-reacting SHIP species, with peripheral blood mononuclear cells exhibiting primarily a 100-kD protein and a CD34+ acute myeloblastic leukemia expressing mainly 130-kD and 145-kD forms of SHIP. Overall, these results indicate that there is an enormous diversity in the size of SHIP or SHIP-related mRNA and protein species. Furthermore, the expression of these protein species changes according to both the developmental stage and differentiated lineage of the mature blood cell.
Paper Electrophoresis of Abnormal Hemoglobins and Its Clinical Applications
Authors: MOTULSKY ARNO G. , PAUL MILTON H. , DURRUM E. L.
Published: October 2019

1. Paper electrophoresis of abnormal hemoglobins is a simple and convenient technic for the study of the hereditary hemoglobinopathies.

2. A semiquantitative paper electrophoretic technic is described, which allows rather accurate quantitation of the various hemoglobin components by inspection alone.

3. For exact results, the more elaborate technics of elution or photoelectric scanning may be employed. The accuracy of these quantitative technics is illustrated by artificial mixture experiments.

4. The clinical applications of the method in the study of sickle cell disease and hemoglobin C abnormalities are discussed. Apart from the more common hemoglobin abnormalities (such as sickle cell trait, sickle cell anemia, C trait, sickle cell-hemoglobin C disease), a patient with 100 per cent hemoglobin C (homozygous hemoglobin C disease) and a Negro patient with sickle cell-thalassemia disease were discovered. Normal adult hemoglobin (hemoglobin A) was found in all other hereditary and acquired anemias studied. Slightly increased amounts of fetal hemoglobin were detected in cases of hereditary nonspherocytic hemolytic disease and aregenerative anemia.

5. This technic may be used for red cell life span determinations by serially following the disappearance of a certain hemoglobin type transfused into a patient with a different hemoglobin variety. Further applications of the technic are suggested.

6. The combination of the technics of paper electrophoresis and alkali denaturation offer an adequate, simple, and practical tool for diagnosis and investigation of hereditary hemoglobinopathies.

7. Identical apparatus and buffer may be used for serum protein electrophoresis.
Constitutive Expression of Fas (Apo-1/CD95) Ligand on Multiple Myeloma Cells: A Potential Mechanism of Tumor-Induced Suppression of Immune Surveillance
Authors: Villunger Andreas , Egle Alexander , Marschitz Ingrid , Kos Marion , Böck Günther , Ludwig Heinz , Geley Stephan , Kofler Reinhard , Greil Richard
Published: October 2019

The Fas (Apo-1/CD95) ligand (FasL) plays a central role in the elimination of target cells by effector T lymphocytes and in the suppression of cellular immune responses against nonmalignant and malignant cells. We show the expression of FasL on the surface of neoplastic plasma cells. We provide evidence that the FasL is functionally active because five of five neoplastic plasma cell lines tested killed CEM-C7H2 T-acute lymphoblastic leukemia (T-ALL) cells. The effect was mediated via the Fas (Apo-1/CD95) receptor molecule because blocking of Fas on the target cells or the FasL on the tumor cells by receptor- and ligand-specific monoclonal antibodies (MoAbs), respectively, protected T cells from being killed by myeloma cells. In addition, overexpression of the cowpox virus protein CrmA, a molecule with inhibitory potential on caspase-1 and caspase-8, specifically involved in Fas-induced signaling, protected T cells from being destroyed by the neoplastic cells or the agonistic anti-Fas MoAb. The potential of the malignant plasma cells to extinguish target T cells was independent of their own sensitivity to the agonistic anti-Fas MoAb, and FasL-positive (FasL+) CEM-C7H2 T cells were incapable of killing myeloma cells. Our results suggest that tumor cell–induced suppression of the immune system may be exerted via the FasL active on malignant plasma cells. Furthermore, loss of Fas expression or insensitivity to the agonistic anti-Fas MoAb do not seem to be prerequisites for myeloma cells to defeat T cells via Fas/FasL interaction.
Features of Macrophage Differentiation Induced by p19INK4d, a Specific Inhibitor of Cyclin D–Dependent Kinases
Authors: Adachi Masashi , Roussel Martine F. , Havenith Karin , Sherr Charles J.
Published: October 2019

The mitogen-dependent induction of cyclin D–dependent kinase activity is required for cells to enter the DNA synthetic (S) phase of their division cycle. Immature 32Dcl3 myeloid cells (32D) proliferating in the presence of interleukin-3 (IL-3) normally express cyclins D2 and D3, which assemble into binary holoenzyme complexes with their catalytic subunits, CDK4 and CDK6. When 32D cells are switched to medium containing granulocyte colony-stimulating factor (G-CSF ) instead of IL-3, D-type cyclins are degraded and, in the absence of their associated kinase activity, the cells arrest in the first gap phase (G1 ) of the cell cycle and differentiate to neutrophils. We derived 32D cells in which the expression of p19INK4d, a specific polypeptide inhibitor of CDK4 and CDK6, is regulated by the heavy metal-inducible sheep metallothionein promoter. Induction of p19INK4d in response to zinc prolonged cell survival in the absence of growth factor treatment. When maintained in medium containing both IL-3 and zinc, these cells lost cyclin D–dependent kinase activity, underwent G1 phase arrest, and acquired certain morphologic, antigenic, and functional properties of mononuclear phagocytes. Cells induced to express p19INK4d did not synthesize receptors for macrophage colony-stimulating factor (M-CSF/CSF-1) and reverted to an immature myeloid phenotype when shifted back into medium containing IL-3 alone. These cells exhibited accelerated differentiation to neutrophils in response to G-CSF but also gave rise to macrophage-like cells when maintained in medium containing both G-CSF and zinc. Therefore, the acquisition of macrophage properties in response to zinc treatment neither depended upon IL-3 nor upon G1 phase arrest per se and instead reflects some ability of p19INK4d, and presumably cyclin D–dependent kinases, to affect myeloid differentiation.
Indomethacin Is a Potent Inhibitor of Pristane and Plastic Disc Induced Plasmacytomagenesis in a Hypersusceptible BALB/c Congenic Strain
Authors: Potter Michael , Wax Judith , Jones Gary M.
Published: October 2019

Continuous indomethacin (INDO) administration in the drinking water (10 to 20 μg/mL) profoundly inhibited plasmacytoma (PCT) development initiated by three 0.2- or 0.5-mL intraperitoneal (i.p.) injections of pristane in hypersusceptible BALB/c.DBA/2-Idh1-Pep3 congenic mice. The most effective inhibitions were obtained with continuous INDO treatment. When treatment was delayed until 50 to 60 days after the first pristane injection, there was approximately a 50% reduction in PCT incidence. The primary action of pristane is the induction of a chronic inflammation in the peritoneal connective tissues and the formation of a microenvironment where PCTs develop. INDO, a powerful inhibitor of prostaglandin synthases (cyclooxygenases 1 and 2), did not inhibit the formation of mesenteric oil granuloma nor the appearance of cells in this chronic inflammatory tissue carrying c-myc illegitimately joined to an Ig heavy chain switch region, ie, the t(12; 15) chromosomal translocation. INDO inhibited PCT induction by the i.p. implantation of 21 × 2 mm polycarbonate discs. These solid objects predominantly induce the formation of a patchy fibroplastic tissue on contacting peritoneal surfaces. These and previous data indicate that indomethacin inhibits an intermediate stage in PCT development after the arrival of cells bearing the T(12; 15) translocation in the oil granuloma and before these cells acquire transplantability to a pristane-conditioned host. The biological mechanism that explains how INDO inhibits PCT development is not yet established but appears to result from decreased production of prostaglandins in chronic inflammatory tissues (oil granuloma, fibroplasia), suggesting that prostaglandins play an active role in oil and solid plastic induced PCT formation.
Molecular Profile of Epstein-Barr Virus in Human Immunodeficiency Virus Type 1–Related Lymphadenopathies and Lymphomas
Authors: Ometto Lucia , Menin Chiara , Masiero Sara , Bonaldi Laura , Del Mistro Annarosa , Cattelan Anna Maria , D'Andrea Emma , De Rossi Anita , Chieco-Bianchi Luigi
Published: October 2019

Human immunodeficiency virus type 1 (HIV-1)–infected patients develop a spectrum of lymphoproliferative disorders ranging from nonneoplastic lymphadenopathies to B-cell lymphomas. Although evidence suggests that Epstein-Barr virus (EBV) might be involved, its molecular profile and expression pattern in HIV-1–related lymphoproliferations remain to be defined. Using polymerase chain reaction–based techniques, we studied EBV types and variants in 28 lymphadenopathy lesions and in 20 lymphomas (15 large cell and 5 Burkitt-like). EBV was detected in 89% of lymphadenopathies and in 80% of lymphomas; viral DNA content was significantly higher in the latter. EBNA2 and LMP1 gene analysis indicated that half of the EBV+ lymphadenopathies were coinfected with both EBV type 1 and 2 strains and/or multiple type 1 variants. Conversely, all but one lymphoma carried a single viral variant, consistently type 1 in large cell lymphomas, and type 2 in Burkitt-like tumors. Most lymphomas, but no lymphadenopathies, showed monoclonal Ig heavy-chain rearrangement. Analysis of 5 large cell lymphomas and 9 lymphadenopathies for EBV transcripts identified LMP1 mRNA in most samples, and the EBNA2 transcript in all tumors. These findings provide evidence of a heterogeneous EBV population in lymphadenopathy lesions, strengthen the notion that lymphomas arise from clonal expansion of EBV+ cells, and suggest different roles for EBV types 1 and 2 in HIV-1–related lymphoproliferations.
Mouse Mast Cells That Possess Segmented/Multi-lobular Nuclei
Authors: Gurish Michael F. , Friend Daniel S. , Webster Matthew , Ghildyal Namit , Nicodemus Christopher F. , Stevens Richard L.
Published: October 2019

Because in humans mast cells and basophils tend to possess nonsegmented and segmented/multi-lobular nuclei, respectively, nuclear morphology has been a major criterion for assessing the lineage of metachromatic cells of hematopoietic origin. Immature metachromatic cells with mono- and multi-lobular nuclei were both obtained when bone marrow cells from BALB/c mice were cultured for 3 weeks in the presence of interleukin-3. Analogous to the indigenous mature mast cells that reside in the peritoneal cavity and skin, both populations of in vitro–derived cells expressed the surface receptor c-kit, the chymase mouse mast cell protease (mMCP) 5, the tryptase mMCP-6, and the exopeptidase carboxypeptidase A (mMC-CPA). Immunogold electron microscopy confirmed the granule location of mMC-CPA and mMCP-6 in both populations of cells, and cytochemical analysis confirmed the presence of chymotryptic enzymes in the granules. Because mature mast cells possessing multi-lobular nuclei also were occasionally found in the skeletal muscle and jejunum of the BALB/c mouse, the V3 mouse mast cell line was used to investigate the developmental relationship of mast cells that have very different nuclear structures. After the adoptive transfer of V3 mast cells into BALB/c mice, v-abl–immortalized mast cells with mono- and multi-lobular nuclei were detected in the lymph nodes and other tissues of the mastocytosis mice that expressed c-kit, mMCP-5, mMCP-6, and mMC-CPA. These studies indicate that mouse mast cells can exhibit varied nuclear profiles. Moreover, the nuclear morphology of this cell type gives no insight as to its protease phenotype or stage of development.
Restoration of the CCAAT Box or Insertion of the CACCC Motif Activate δ-Globin Gene Expression
Authors: Tang Delia C. , Ebb David , Hardison Ross C. , Rodgers Griffin P.
Published: October 2019

Hemoglobin A2 (HbA2 ), which contains δ-globin as its non–α-globin, represents a minor fraction of the Hb found in normal adults. It has been shown recently that HbA2 is as potent as HbF in inhibiting intracellular deoxy-HbS polymerization, and its expression is therefore relevant to sickle cell disease treatment strategies. To elucidate the mechanisms responsible for the low-level expression of the δ-globin gene in adult erythroid cells, we first compared promoter sequences and found that the δ-globin gene differs from the β-globin gene in the absence of an erythroid Krüppel-like factor (EKLF ) binding site, the alteration of the CCAAT box to CCAAC, and the presence of a GATA-1 binding site. Second, serial deletions of the human δ-globin promoter sequence fused to a luciferase (LUC) reporter gene were transfected into K562 cells. We identified both positive and negative regulatory regions in the 5′ flanking sequence. Furthermore, a plasmid containing a single base pair (bp) mutation in the CCAAC box of the δ promoter, restoring the CCAAT box, caused a 5.6-fold and 2.4-fold (P < .05) increase of LUC activity in transfected K562 cells and MEL cells, respectively, in comparison to the wild-type δ promoter. A set of substitutions that create an EKLF binding site centered at −85 bp increased the expression by 26.8-fold and 6.5-fold (P < .05) in K562 and MEL cells, respectively. These results clearly demonstrate that the restoration of either an EKLF binding site or the CCAAT box can increase δ-globin gene expression, with potential future clinical benefit.
Granulocyte Colony-Stimulating Factor Reduces the Capacity of Blood Mononuclear Cells to Induce Graft-Versus-Host Disease: Impact on Blood Progenitor Cell Transplantation
Authors: Zeng Defu , Dejbakhsh-Jones Sussan , Strober Samuel
Published: October 2019

The feasibility of transplanting peripheral blood mononuclear cells (PBMC) from granulocyte colony-stimulating factor (G-CSF)–treated normal human donors to myeloablated allogeneic hosts has been demonstrated recently. The current work examined the ability of recombinant G-CSF to alter peripheral blood T-cell function and graft-versus-host disease (GVHD) in a murine model of allogeneic G-CSF–mobilized PBMC transplantation. Administration of recombinant G-CSF to C57BL/Ka mice markedly increased the capacity of PBMC to reconstitute lethally irradiated syngeneic hosts. T- and B-lineage lymphocytes were depleted about 10-fold in the bone marrow of the treated mice, and the T-cell yield in the blood was increased about fourfold. The ability of PBMC or purified CD4+ and CD8+ T cells to induce acute lethal GVHD in irradiated BALB/c mice was reduced after the administration of G-CSF. This was associated with decreased secretion of interferonγ and interleukin-2 (IL-2) and an increased secretion of IL-4. The donor cell inoculum, which was most successful in the rescue of irradiated allogeneic hosts, was the low-density fraction of PBMC from G-CSF–treated mice. These low-density cells were enriched for CD4−CD8−NK1.1+ T cells and secreted about 10-fold more IL-4 than the unfractionated cells from the G-CSF–treated donors.
Selective Expression of mRNA Coding for the Truncated Form of Erythropoietin Receptor in Hematopoietic Cells and Its Decrease in Patients With Polycythemia Vera
Authors: Chiba Shigeru , Takahashi Tokiharu , Takeshita Kenichi , Minowada Jun , Yazaki Yoshio , Ruddle Frank H. , Hirai Hisamaru
Published: October 2019

The mRNA encoding full-length erythropoietin (EPO) receptor (EPOR-F ) comprises exons I through VIII. Another membrane-bound EPOR (EPOR-T) isoform has a truncated cytoplasmic region and is encoded by the mRNA containing unspliced intron VII (EPOR-T mRNA). EPOR-T is believed to have a dominantly negative function against EPOR-F. We show that EPOR-T mRNA is markedly decreased in the blood cells of patients with polycythemia vera (PV). We also show that EPOR-T mRNA is not detected in erythroid/megakaryocytic leukemia cell lines, but is expressed in nonerythroid/nonmegakaryocytic lines, suggesting the presence of a cell type–specific system by which intron VII of the EPOR transcript is spliced. Deregulation of this splicing system in early hematopoietic progenitors possibly explains the profound decrease in EPOR-T mRNA and consequent pathophysiology of PV.
In Vivo Expression of B7-1 and B7-2 By Follicular Lymphoma Cells Can Prevent Induction of T-Cell Anergy But Is Insufficient to Induce Significant T-Cell Proliferation
Authors: Dorfman David M. , Schultze Joachim L. , Shahsafaei Aliakbar , Michalak Sabine , Gribben John G. , Freeman Gordon J. , Pinkus Geraldine S. , Nadler Lee M.
Published: October 2019

Expression of B7 family costimulatory molecules on B cells defines their capacity to function as antigen presenting cells (APCs). B cells that do not express B7 costimulatory molecules induce T-cell tolerance. Therefore, the expression of B7 costimulatory molecules on malignant B cells might be critical for their recognition by anti–tumor-specific T cells. Here we show that virtually all germinal center (GC)-derived B-cell lymphomas including follicular lymphoma (FL) and diffuse large cell lymphoma, but not mantle cell lymphoma or small lymphocytic lymphomas (SLL/CLL), express B7-1 (CD80) and B7-2 (CD86) on their cell surface in situ, although at extremely low levels. Despite their expression of low levels of B7-1 and B7-2, FL cells could not induce significant allogeneic T-cell proliferation. However, B7 costimulatory molecules on FL appeared to be functional because they were capable of increasing T-cell proliferation of preactivated T cells in a secondary allogeneic mixed lymphocyte response. Moreover, low B7 expression was sufficient to prevent the induction of alloantigen-specific anergy in vitro. Therefore, we postulate that whereas low-level expression of B7 is not sufficient to initiate a productive antilymphoma T-cell response, it might be sufficient to prevent T-cell tolerance in vivo.
FcαRI (CD89) as a Novel Trigger Molecule for Bispecific Antibody Therapy
Authors: Valerius Thomas , Stockmeyer Bernhard , van Spriel Annemiek B. , Graziano Robert F. , van den Herik-Oudijk Ingrid E. , Repp Roland , Deo Yashwant M. , Lund John , Kalden Joachim R. , Gramatzki Martin , G.J. van de Winkel Jan
Published: October 2019

Promising results from clinical trials with unconjugated antibodies stimulated renewed interest in immune effector mechanisms of monoclonal antibodies (MoAbs). We investigated the potential of IgA as antibody isotype for cell- or complement-mediated tumor cell lysis and assessed the potential of its myeloid Fc receptor, FcαRI (CD89), as trigger molecule for bispecific antibody (BsAb)-mediated immunotherapy. Comparing hapten-directed antibodies of human IgA2 with IgG1 or IgG3 isotypes, we found all three to mediate effective killing of sensitized tumor target cells in whole blood assays. Analysis of effector mechanisms showed IgG-mediated lysis to be predominantly complement-dependent, whereas IgA-dependent killing was primarily effector cell-mediated. A comparison of effector cell populations in antibody-dependent cell-mediated cytotoxicity (ADCC) showed neutrophils to be most important for IgA-dependent tumor cell killing, involving FcαRI as shown with Fc receptor blocking antibodies. Reverse ADCC experiments against target cells sensitized with Fc receptor antibodies, or assays with FcαRI-directed bispecific antibodies confirmed FcαRI as effective trigger molecule in polymorphonuclear neutrophil (PMN)-mediated lysis. During granulocyte colony-stimulating factor (G-CSF ) therapy, (FcαRI × HER-2/neu) bispecific antibodies induced enhanced killing of HER-2/neu positive SK-BR–3 breast cancer cells in whole blood assays. This enhanced cytotoxicity was paralleled by increased PMN counts, which lead to higher effector to target cell ratios in G-CSF–primed blood. Furthermore, bispecific antibodies, directed to FcαRI and Candida albicans, enhanced neutrophils' phagocytosis of fungi. In summary, these results identify IgA as an effective antibody isotype for immunotherapy, working primarily via FcαRI on neutrophils. They suggest FcαRI-directed bispecific antibodies and G-CSF to be an attractive combination for malignant or infectious diseases.
Recombinant Tumor Necrosis Factor Enhances the Locomotion of Memory and Naive B Lymphocytes From Human Tonsils Through the Selective Engagement of the Type II Receptor
Authors: Corcione Anna , Ottonello Luciano , Tortolina Giuseppe , Tasso Paola , Ghiotto Fabio , Airoldi Irma , Taborelli Giuseppe , Malavasi Fabio , Dallegri Franco , Pistoia Vito
Published: October 2019

Recent studies performed in mice knocked out for the tumor necrosis factor (TNF ), the lymphotoxin-α, or the type I TNF receptor (R), genes have shown that these animals display gross defects in germinal center (GC) formation, suggesting that members of the TNF and TNFR superfamilies are involved in the control of B-cell migration. Based on these premises, we have here investigated the effects of human recombinant (r) TNF on the polarization and locomotion of tonsillar B cells. rTNF increased the spontaneous polarization and locomotion of unfractionated tonsillar B lymphocytes in a dose-dependent manner by inducing a true chemotactic response. Memory (IgD−, CD38−) and naive (IgD+, CD38−), but not GC (IgD−, CD38+) B cells purified from total tonsillar B lymphocytes, showed a significantly higher locomotion in the presence than in the absence of rTNF. Accordingly, type I and II TNF receptors (TNFRs) were detected by flow cytometry on the surface of memory and naive, but not GC, B lymphocytes. Blocking experiments with monoclonal antibodies to type I or II TNFR showed that rTNF enhanced the spontaneous chemotaxis of memory and naive B cells through the selective engagement of type II TNFR. Finally, the TNF gene was found to be expressed in memory, naive and GC B lymphocytes; the cytokine was released in culture supernatants from the three B-cell subsets after stimulation. These data may support the hypothesis that human TNF is involved in the paracrine and perhaps autocrine control of B-cell migration in secondary lymphoid tissues.
Granulocyte Colony-Stimulating Factor Upregulates the Vacuolar Proton ATPase in Human Neutrophils
Authors: Niessen Hans , Meisenholder Grant W. , Li Hai-Ling , Gluck Stephen L. , Lee Beth S. , Bowman Barry , Engler Robert L. , Babior Bernard M. , Gottlieb Roberta A.
Published: October 2019

We have previously shown that granulocyte colony-stimulating factor (G-CSF ) delays spontaneous neutrophil apoptosis through activation of the vacuolar proton ATPase (v-ATPase). We have now examined the regulation of the v-ATPase in neutrophils exposed to G-CSF in vitro. When neutrophils were cultivated in the absence of G-CSF, the 57-kD cytosolic B subunit of the v-ATPase disappeared within 1 to 2 hours, its loss preceding the nuclear changes of apoptosis and coinciding with the onset of acidification. By contrast, in neutrophils cultured for 2 hours in the presence of G-CSF, the amount of the 57-kD subunit was similar to that in freshly isolated neutrophils. However, inhibition of protein synthesis with cycloheximide and actinomycin D led to loss of the 57-kD subunit even in the presence of G-CSF. These results indicated that ongoing protein synthesis was required to maintain the v-ATPase, and further suggested that G-CSF acted, at least in part, by maintaining synthesis of the 57-kD cytosolic subunit. G-CSF also promoted the translocation of the 57-and 33-kD cytosolic v-ATPase subunits to the membrane. Our findings suggested two coordinate mechanisms by which the activity of the v-ATPase could be increased by G-CSF: the synthesis of cytosolic v-ATPase subunits and their translocation to the membrane.
The Human β Globin Locus Introduced by YAC Transfer Exhibits a Specific and Reproducible Pattern of Developmental Regulation in Transgenic Mice
Authors: Porcu Susanna , Kitamura Michael , Witkowska Ewa , Zhang Zemin , Mutero Annick , Lin Chin , Chang Judy , Gaensler Karin M.L.
Published: October 2019

The human β globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult β globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the β globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from γ to β globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human β globin mRNA levels between lines. Human β globin mRNA levels were twofold to fourfold lower than that of mouse βmaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the β globin locus.
Prevalence and Natural History of Hepatitis C Infection in Patients Cured of Childhood Leukemia
Authors: Locasciulli Anna , Testa Marina , Pontisso Patrizia , Benvegnù Luisa , Fraschini Donatella , Corbetta Adele , Noventa Franco , Masera Giuseppe , Alberti Alfredo
Published: October 2019

The aim of this study was to ascertain prevalence and natural history of hepatitis C virus (HCV) infection in a large cohort of patients cured of childhood leukemia who had been followed prospectively for liver disease for at least 10 years since chemotherapy withdrawal: 114 consecutive patients entered the study. Liver function tests and ultrasonography were used to assess presence of liver disease. Patients were tested for antibody to HCV and for serum HCV-RNA at the end of chemotherapy and at the end of follow-up. At chemotherapy withdrawal, 56 patients (49%) were HCV-RNA positive, often without detectable anti-HCV, and in these cases, transaminase levels were more elevated during (P = .08) and after (P = .04) chemotherapy compared with HCV-RNA negative cases. Patients were then followed-up 13 to 27 years (mean, 17) after chemotherapy withdrawal. During this period, 38 initially anti-HCV negative patients seroconverted to anti-HCV and 17 initially anti-HCV positive cases lost reactivity. Forty patients were persistently HCV-RNA positive in serum, while 16 initially viremic patients became HCV-RNA negative during follow-up. At the end of the observation period, a persistent transaminase elevation was detected only in four HCV-RNA positive and anti-HCV positive cases, while no patient developed signs or symptoms of decompensated liver disease. Thus, hepatitis C was a frequent finding in long-term survivors after chemotherapy. It was associated with an atypical serologic profile and did not cause severe liver impairment over a period of 13 to 27 years.
Interleukin-12 Preserves the Graft-Versus-Leukemia Effect of Allogeneic CD8 T Cells While Inhibiting CD4-Dependent Graft-Versus-Host Disease in Mice
Authors: Yang Yong-Guang , Sergio Justin J. , Pearson Denise A. , Szot Gregory L. , Shimizu Akira , Sykes Megan
Published: October 2019

We have recently demonstrated that a single injection of 4,900 IU of interleukin-12 (IL-12) on the day of bone marrow transplantation (BMT) markedly inhibits acute graft-versus-host disease (GVHD) in a fully major histocompatibility complex plus minor antigen-mismatched BMT model (A/J → B10, H-2a → H-2b), in which donor CD4+ T cells are required for the induction of acute GVHD. We show here that donor CD8-dependent graft-versus-leukemia (GVL) effects against EL4 (H-2b) leukemia/lymphoma can be preserved while GVHD is inhibited by IL-12 in this model. In mice in which IL-12 mediated a significant protective effect against GVHD, marked GVL effects of allogeneic T cells against EL4 were observed. GVL effects against EL4 depended on CD8-mediated alloreactivity, protection was not observed in recipients of either syngeneic (B10) or CD8-depleted allogeneic spleen cells. Furthermore, we analyzed IL-12–treated recipients of EL4 and A/J spleen cells which survived for more than 100 days. No EL4 cells were detected in these mice by flow cytometry, tissue culture, adoptive transfer, necropsies, or histologic examination. Both GVL effects and the inhibitory effect of IL-12 on GVHD were diminished by neutralizing anti–interferon-γ (IFN-γ) monoclonal antibody. This study demonstrates that IL-12–induced IFN-γ production plays a role in the protective effect of IL-12 against GVHD. Furthermore, IFN-γ is involved in the GVL effect against EL4 leukemia, demonstrating that protection from CD4-mediated GVHD and CD8-dependent anti-leukemic activity can be provided by a single cytokine, IFN-γ. These observations may provide the basis for a new approach to inhibiting GVHD while preserving GVL effects of alloreactivity.
Panhandle Polymerase Chain Reaction Amplifies MLL Genomic Translocation Breakpoint Involving Unknown Partner Gene
Authors: Felix Carolyn A. , Kim Caroline S. , Megonigal Maureen D. , Slater Diana J. , Jones Douglas H. , Spinner Nancy B. , Stump Tammy , Hosler Matthew R. , Nowell Peter C. , Lange Beverly J. , Rappaport Eric F.
Published: October 2019

We used a new approach called panhandle polymerase chain reaction (PCR) to clone an MLL genomic translocation breakpoint in a case of acute lymphoblastic leukemia of infancy in which karyotype analysis was technically unsuccessful and did not show the translocation partner. Panhandle PCR amplified known MLL sequence 5′ of the breakpoint and 3′ sequence from the unknown partner gene from a DNA template with an intrastrand loop schematically shaped like a pan with a handle. The 7-kb panhandle PCR product contained the translocation breakpoint in MLL intron 8. The partner DNA included unique nonrepetitive sequences, Alu and mammalian apparent LTR-retrotransposon (MaLR) repetitive sequences, and a region of homology to expressed sequence tags. MaLR sequences have not been found before near leukemia-associated translocation breakpoints. The nonrepetitive sequences were not homologous to known partner genes of MLL. Screening of somatic cell hybrid and radiation hybrid lines by PCR and fluorescence in situ hybridization analysis of normal metaphase chromosomes mapped the partner DNA to chromosome band 4q21. Reverse transcriptase-PCR identified an MLL-AF-4 chimeric mRNA, indicating that panhandle PCR identified a fusion of MLL with a previously uncharacterized AF-4 intronic sequence. Panhandle PCR facilitates cloning translocation breakpoints and identifying unknown partner genes.
Allogeneic Peripheral Blood Stem Cell Transplantation May Be Associated With a High Risk of Chronic Graft-Versus-Host Disease
Authors: Storek Jan , Gooley Ted , Siadak Muriel , Bensinger William I. , Maloney David G. , Chauncey Thomas R. , Flowers Mary , Sullivan Keith M. , Witherspoon Robert P. , Rowley Scott D. , Hansen John A. , Storb Rainer , Appelbaum Frederick R.
Published: October 2019

Chronic graft-versus-host disease (GVHD) is likely caused by donor T lymphocytes. Because unmodified blood stem cell grafts contain one log more T lymphocytes than unmodified marrow grafts, we evaluated the incidence of chronic GVHD in previously reported 37 blood stem cell recipients and 37 computer-matched historical control marrow recipients (Bensinger et al, Blood 88:2794, 1996). All patients have been followed until death, relapse, or occurrence of chronic GVHD or for a minimum of 2 years. In a univariable proportional hazards regression model, the relative risk of developing clinical chronic GVHD (includes clinical limited and clinical extensive disease) by 2 years posttransplant among the peripheral blood stem cell recipients compared with the marrow recipients was 2.22 (95% confidence interval, 1.04 to 4.74; P = .039). For clinical extensive chronic GVHD, the relative risk was 2.37 (95% confidence interval, 1.07 to 5.29; P = .035). In multivariable analyses, considering also the covariables of patient age, patient cytomegalovirus serostatus, and donor cytomegalovirus serostatus, the relative risks of clinical chronic GVHD and clinical extensive chronic GVHD were also greater than 2 (P < .05). We conclude that the transplantation of unmanipulated filgrastim-mobilized blood stem cells may result in a relatively high incidence of chronic GVHD.
A Randomized, Double-Blind, Placebo-Controlled, Phase III Study of Filgrastim in Remission Induction and Consolidation Therapy for Adults With De Novo Acute Myeloid Leukemia
Authors: Heil Gerhard , Hoelzer Dieter , Sanz Miguel A. , Lechner Klaus , Liu Yin John A. , Papa Giuseppe , Noens Luc , Szer Jeff , Ganser Arnold , O'Brien Caroline , Matcham James , Barge Alan
Published: October 2019

The safety and efficacy of filgrastim as an adjunct to acute myeloid leukemia (AML) induction and consolidation therapy was assessed in this prospective double-blind, randomized, placebo-controlled, multicenter trial. A total of 521 consecutive de novo AML patients aged 16 or more years were randomized to receive filgrastim (5 μg/kg/d subcutaneously) or placebo after standard induction as well as consolidation chemotherapy. Blinded study drug was given from 24 hours after chemotherapy until the absolute neutrophil count was ≥1.0 × 109/L for 3 consecutive days. The overall complete remission rate was 68%. After a median follow-up of 24 months (range 5 to 40) the median disease-free survival was 10 months (95% confidence interval [CI], 8.7 to 10.8) and the median overall survival was 13 months (95%CI, 12.2 to 14.6). These did not differ between treatment groups. Patients receiving filgrastim experienced neutrophil recovery 5 days earlier after induction 1 than those receiving placebo (P < .0001). This was accompanied by reductions in the duration of fever (7 v 8.5 days; P = .009), parenteral antibiotic use (15 v 18.5 days; P = .0001), and hospitalization (20 v 25 days; P = .0001). Similar reductions were seen after induction 2 and the consolidation courses. There was a significant reduction in the number of patients requiring systemic antifungal therapy in the filgrastim group during induction treatment (34% v 43%; P = .04). In conclusion, filgrastim is safe in that it had no negative impact on the prognosis of the AML patients. In addition, it effectively reduced the duration of neutropenia, leading to significant clinical benefits by reducing the duration of fever; requirement for parenteral anti-infectives, specifically amphotericin B; and the duration of hospitalization.
Transplantation of Filgrastim-Mobilized Peripheral Blood Stem Cells From HLA-Identical Sibling or Alternative Family Donors in Patients With Hematologic Malignancies: A Prospective Comparison on Clinical Outcome, Immune Reconstitution, and Hematopoietic Chimerism
Authors: Beelen Dietrich W. , Ottinger Helmut D. , Elmaagacli Ahmet , Scheulen Birgit , Basu Oliver , Kremens Bernhard , Havers Werner , Grosse-Wilde Hans , Schaefer Ulrich W.
Published: October 2019

The clinical results, cellular immune reconstitution, and hematopoietic chimerism obtained after transplantation of recombinant human granulocyte colony-stimulating factor mobilized allogeneic peripheral blood stem cells (PBSCs) from genotypically human leukocyte antigen (HLA)-identical sibling (n = 36) or alternative family donors (n = 24) were prospectively compared in patients with hematologic malignancies. Thirty-two of 34 evaluable patients with HLA-identical sibling donors and all patients with alternative family donors achieved trilineage engraftment. The median time intervals to reach peripheral neutrophil counts <500/μL (13 v 17 days) or <1,000/μL (16 v 19 days) and unsupported platelet counts <20,000/μL (11 v 15 days) or <50,000/μL (19 v 24 days) as well as red blood cell and platelet transfusion requirements were not significantly different between both patient subsets. The cumulative probability of grades II through IV acute graft-versus-host disease (GVHD) for the 60 study patients was 48% ± 10% but ranged between 86% ± 12% in patients whose donors had at least one HLA-A,B,DR,DQ,DP antigen disparity in direction to acute GVHD, and 25% ± 9% in recipients of GVHD-matched transplants (P < .003). The 2-year survival estimates were 54% ± 10% for patients with alternative family donors and 65% ± 9% for patients with HLA-identical sibling donors. Multivariate analysis identified the pretransplantation disease stage, patient age, and acute GVHD as independent predictors of overall and disease-free survival, whereas alternative family donors alone had no adverse effect on these clinical endpoints. Monthly monitoring of peripheral blood T-helper cell subsets, B cells, and monocytes during the first year posttransplantation showed a nearly identical course of immune cell reconstitution in both patient subsets. In addition, no differences in the proportions of complete chimeric patients were detectable between the two patient subsets by sex chromosome and variable number of tandem repeats analysis up to 12 months posttransplantation. In conclusion, PBSCs from alternative family donors represent an attractive source for allogeneic transplantation in patients lacking HLA-identical sibling donors and should be further evaluated in comparison with marrow transplants from alternative family donors.
Limitations of Magnetic Resonance Imaging in Measurement of Hepatic Iron
Authors: Angelucci Emanuele , Giovagnoni Andrea , Valeri Gianluca , Paci Enrico , Ripalti Marta , Muretto Pietro , McLaren Christine , Brittenham Gary M. , Lucarelli Guido
Published: October 2019

To evaluate the usefulness of magnetic resonance imaging for the quantitative determination of hepatic iron, we examined 43 patients with thalassemia major and assessed the influence of pathologic changes in the liver on the precision of estimates of the hepatic iron concentration. Tissue signal intensities were measured from magnetic resonance T1-weighted images derived from gradient-echo (GE) pulse sequences and the ratio of the signal intensity of liver to muscle calculated. By excluding patients (n = 9) having a signal intensity ratio (SIR) less than or equal to 0.2, a linear relationship with hepatic iron was found and subsequent analyses were limited to these 34 patients. In 27 patients with hepatic fibrosis, an overall correlation of −0.848 was found between hepatic iron and SIR. By contrast, in the seven patients with no fibrosis, the correlation coefficient (−0.993) was significantly greater (P < .0001). Despite the differences in correlation, the regression line between hepatic iron and SIR for the patients with no fibrosis did not differ significantly with respect to either slope or intercept from that of the patients with fibrosis. Thus, the presence of fibrosis did not seem to affect the pattern of the relationship between hepatic iron and the SIR, but rather to increase the variability of the relationship. Clinically, the presence of fibrosis makes estimates of hepatic iron derived from magnetic resonance imaging so variable as to be of little practical use in the management of transfusional iron overload.