bluuebunny/crossref_metadata_2025 huggingface dataset:
Hematopoietic lineage- and stage-restricted expression of the ETS oncogene family member PU.1
Authors: Hromas R , Orazi A , Neiman RS , Maki R , Van Beveran C , Moore J , Klemsz M
Published: October 2019

The ETS oncogene family member PU.1 is a transcriptional activator that is dysregulated by Friend erythroleukemia virus insertion. Northern analysis found that PU.1 is highly expressed in cells of myeloid and B- lymphoid origin, but not expressed at all in a number of nonhematopoietic tissues. Interferon-gamma and retinoic acid downregulated PU.1 expression in marrow macrophages. In situ immunohistochemistry found that PU.1 is expressed only in early granulocytic and erythroid cells and megakaryocytes, but not in mature erythroid cells, mature granulocytes, endothelial cells, or osteocytes. Thus, its expression pattern makes PU.1 a candidate for a genetic determinant of lineage commitment and stage progression in blood cell development. It also lends insight into how PU.1 might play a role in Friend virus erythroleukemia.
Combination protocols of cytokine therapy with interleukin-3 and granulocyte-macrophage colony-stimulating factor in a primate model of radiation-induced marrow aplasia
Authors: Farese AM , Williams DE , Seiler FR , MacVittie TJ
Published: October 2019

Single cytokine therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3) has been shown to be effective in decreasing the respective periods of neutropenia and thrombocytopenia following radiation- or drug-induced marrow aplasia. The combined administration of IL-3 and GM-CSF in normal primates suggested that a sequential protocol of IL-3 followed by GM-CSF would be more effective than that of GM-CSF alone in producing neutrophils (PMN). We investigated the therapeutic efficacy of two combination protocols, the sequential and coadministration of recombinant human IL- 3 and GM-CSF relative to respective single cytokine therapy, and delayed GM-CSF administration in sublethally irradiated rhesus monkeys. Monkeys irradiated with 450 cGy (mixed fission neutron:gamma radiation) received either IL-3, GM-CSF, human serum albumin (HSA), or IL-3 coadministered with GM-CSF for days 1 through 21 consecutively postexposure, or IL-3 or HSA for days 1 through 7 followed by GM-CSF for days 7 through 21. All cytokines and HSA were injected subcutaneously at a total dose of 25 micrograms/kg/d, divided twice daily. Complete blood counts (CBC) and platelet (PLT) counts were monitored over 60 days postirradiation. The respiratory burst activity of the PMN was assessed flow cytometrically, by measuring hydrogen peroxide (H2O2) production. Coadministration of IL-3 and GM-CSF reduced the average 16-day period of neutropenia and antibiotic support in the control animals to 6 days (P = .006). Similarly, the average 10-day period of severe thrombocytopenia, which necessitated PLT transfusion in the control animals, was reduced to 3 days when IL-3 and GM-CSF were coadministered (P = .004). The sequential administration of IL-3 followed by GM-CSF had no greater effect on PMN production than GM-CSF alone and was less effective than IL-3 alone in reducing thrombocytopenia. PMN function was enhanced in all cytokine-treated animals.
Southern blot patterns, frequencies, and junctional diversity of T-cell receptor-delta gene rearrangements in acute lymphoblastic leukemia
Authors: Breit TM , Wolvers-Tettero IL , Beishuizen A , Verhoeven MA , van Wering ER , van Dongen JJ
Published: October 2019

Southern blot analysis of T-cell receptor (TCR)-delta gene rearrangements is useful for diagnostic studies on the clonality of lymphoproliferative diseases. We have developed 18 new TCR-delta gene probes by use of the polymerase chain reaction (PCR) techniques. Application of these probes for detailed analysis of the TCR-delta genes in normal control samples, 138 T-cell acute lymphoblastic leukemias (T-ALL), and 91 precursor B-ALL allowed us to determine the TCR-delta gene restriction map for five restriction enzymes, as well as the Southern blot restriction enzyme patterns of all theoretically possible TCR-delta gene rearrangements. Based on this information, it appeared that 97% of all 213 detected TCR-delta gene rearrangements in our series of ALL could be detected by use of the TCRDJ1 probe and that the majority (76%) of the 213 rearrangements could be identified precisely. In T-ALL, we found a strong preference for the complete rearrangements V delta 1-J delta 1 (33%), V delta 2-J delta 1 (10%), and V delta 3-J delta 1 (7%) and the incomplete rearrangement D delta 2- J delta 1 (11%). In precursor B-ALL, the majority of rearrangements consisted of V delta 2-D delta 3 (72%) and D delta 2-D delta 3 (10%). The junctional diversity of these 6 preferential TCR-delta rearrangements was analyzed and showed an extensive junctional insertion (approximately 30 nucleotides) for complete V delta-J delta rearrangements, whereas incomplete rearrangements had correspondingly smaller junctional regions. The detailed TCR-delta gene restriction map and probes presented here, in combination with the Southern blot patterns of TCR-delta gene rearrangements, are important for TCR-delta gene studies in ALL; all TCR-delta gene rearrangements can be detected and the majority can be identified precisely. Identification of rearrangements is a prerequisite for subsequent PCR analysis of TCR- delta gene junctional regions, eg, for detection of minimal residual disease during follow-up of ALL patients.
V gene usage by seven hybrids derived from CD5+ B-cell chronic lymphocytic leukemia and displaying autoantibody activity
Authors: Pritsch O , Magnac C , Dumas G , Egile C , Dighiero G
Published: October 2019

We report here the complete heavy and light chain variable region sequences of seven heterohybridomas derived from CD5+ chronic lymphocytic leukemia (CLL) B lymphocytes and displaying natural autoantibody activity. The three hybrids displaying a polyreactive pattern of binding used VH4 family members, ie, the VH4–18 gene in germinal configuration in two cases and a VH4 gene with 90% homology with VH4–21 for the third one. A hybrid expressing anti-Sm activity used a VH3 family member with 95.26% homology with the 30P1 gene. The three hybrids exclusively displaying rheumatoid factor activity expressed VH1 family genes: 51P1 gene for two (in germinal configuration in one, and with 93.2% homology in the other), whereas the third one used the V1–3b gene (98.8% homology). Definitive homology with known germline D segments was found for four of the seven hybrids (DN2 in 3 and DLR4 in 1) and JH use appeared to be random. The three hybrids displaying polyreactive activity expressed V kappa I, V lambda III, and V lambda II genes, all in germinal configuration. Among the three hybrids with rheumatoid factor activity, two used the same V kappa II gene with, respectively, 98% and 96% homology with a gene previously described; the third used a V lambda I gene in germinal configuration. Finally, the clone with anti-Sm activity used a V lambda III gene having 97% homology with a germinal gene. Overall, these results attempt to establish the relationship between frequent self- reactivity observed in CD5+ B-CLL and V gene usage. For VH genes, they confirm overexpression of the 51P1 gene in B-CLL and suggest nonstochastic use of two VH4 genes (4–21 and 4–18). For VL genes, available information is too scarce to lead to firm conclusions.
Incidence of Waldenstrom's macroglobulinemia
Authors: Herrinton LJ , Weiss NS
Published: October 2019

This study sought to determine the incidence and pattern of occurrence of Waldenstrom's macroglobulinemia, a plasmacytoid lymphocyte malignancy that involves monoclonal production of the IgM M-component type. Cases with Waldenstrom's macroglobulinemia have been reported since 1978 to the population-based cancer registry that serves western Washington state, and since 1988 to the eight other cancer registries that participate in the National Cancer Institute's Surveillance, Epidemiology, and End-Results program. Persons less than 85 years old newly diagnosed with Waldenstrom's macroglobulinemia were identified through 1989. The age-standardized annual incidence rate was 6.1 per million in white men and 2.5 per million in white women (1980 US standard). Only five cases were reported in black women, among whom the age-standardized annual incidence rate was 3.6 per million. No cases were reported among black men (5.8 cases expected, based on the rates in white men); this finding may be due to chance, underdiagnosis of Waldenstrom's macroglobulinemia in this group, or may reflect a truly low rate. Further investigation of a large, racially diverse population is required to better characterize the epidemiology of this rare disease.
Serum concentrations of granulocyte colony-stimulating factor in healthy term and preterm neonates and in those with various diseases including bacterial infections
Authors: Gessler P , Kirchmann N , Kientsch-Engel R , Haas N , Lasch P , Kachel W
Published: October 2019

The neonate is uniquely susceptible to severe and overwhelming bacterial infections. One of the most important deficits in the neonatal host defense system seems to be a quantitative and qualitative deficiency of the myeloid and the phagocytic system. Future optimal therapy of neonatal sepsis may include the use of adjuvant immunologic therapy. Granulocyte colony-stimulating factor (G-CSF) has been shown to induce neutrophilia and to enhance mature effector neutrophil function. To evaluate the role of G-CSF with respect to infection, we examined serum levels of G-CSF in term and preterm neonates, using an enzyme-linked immunosorbent assay method. G-CSF levels in healthy neonates showed peak levels up to 7 hours after birth, followed by an increase in total neutrophil cell (TNC) counts. Both G-CSF levels determined between 4 and 7 hours after birth and peak TNC counts correlated with the gestational age of the neonates. The state of nutrition, maternal treatment with glucocorticoids, maternal infection and hypertension, and the mode of delivery influenced peak G-CSF levels. Neonates with signs of infection between 4 and 7 hours after birth had higher levels of G-CSF than did healthy neonates (1,312 +/- 396 pg/mL v 176 +/- 19 pg/mL). In conclusion, the presented results of serum concentrations of G-CSF in relation to TNC counts and various diseases suggests an important role of G-CSF in the regulation of granulopoiesis during the neonatal period.
Structural and functional heterogeneity among peroxidase-negative granules in human neutrophils: identification of a distinct gelatinase- containing granule subset by combined immunocytochemistry and subcellular fractionation
Authors: Kjeldsen L , Bainton DF , Sengelov H , Borregaard N
Published: October 2019

The existence of separate gelatinase granules in human neutrophils has been a matter of debate in recent years. We have demonstrated that the 135-kD form of neutrophil gelatinase is a complex of 92-kD gelatinase and a novel 25-kD protein termed neutrophil gelatinase-associated lipocalin (NGAL) that, in addition to being complexed with part of the gelatinase, is localized in free form in peroxidase-negative specific granules. Because this association was not appreciated in earlier studies, we decided to reassess the ultrastructural localization of gelatinase using specific antibodies without immunoreactivity towards NGAL. Double-labeling immunogold electron microscopy was performed on frozen thin sections of human neutrophils. Twenty-four percent of all peroxidase-negative granules were labeled with antigelatinase antibody, but not with antilactoferrin antibody. These granules are defined as gelatinase granules. Sixteen percent reacted with antilactoferrin antibody but not with antigelatinase antibody. The rest (60%) reacted with both antibodies. All granules labeling for lactoferrin are defined as specific granules. Gelatinase granules were observed as round and oval forms of considerably smaller size than specific granules, and were less electron dense. Isolated granules obtained by subcellular fractionation were also examined by immunoelectron microscopy. This demonstrated that peroxidase-negative granules comprise a continuum from the most dense granules that contain lactoferrin but no gelatinase to the lightest that contain gelatinase but no lactoferrin. Thus, gelatinase granules do exist as a subpopulation of peroxidase-negative granules and may allow for exocytosis of gelatinase during neutrophil diapedesis without substantial mobilization of other peroxidase- negative granules, ie, specific granules.
Cloning and expression of the cDNA encoding mouse neutrophil gelatinase: demonstration of coordinate secondary granule protein gene expression during terminal neutrophil maturation
Authors: Graubert T , Johnston J , Berliner N
Published: October 2019

The 92-kD form of human type IV collagenase (gelatinase) is a member of the matrix metalloproteinase family. It is restricted in its expression to the granulocytic lineage of white blood cells. Within neutrophils it resides in secondary granules, which are markers of terminal myeloid differentiation. We have isolated and sequenced the cDNA encoding the murine counterpart to the human 92-kD metalloproteinase from a macrophage cDNA library. The human and murine genes are highly homologous and exist in an identical form in neutrophils and monocyte- macrophages in both species. Two polyadenylation signals are present in the murine 3′ untranslated sequence, accounting for equal expression of two messenger RNAs. We have shown that expression of gelatinase mRNA is controlled in a coordinate fashion together with lactoferrin, also a component of neutrophil secondary granules, and that this control occurs at the level of transcription. This is the first definitive demonstration of coordinate transcriptional regulation of secondary granule protein gene expression, a feature of normal myelopoiesis that is deranged in leukemogenesis.
Phase I trial with recombinant human interleukin-3 in patients with lymphoma undergoing autologous bone marrow transplantation
Authors: Nemunaitis J , Appelbaum FR , Singer JW , Lilleby K , Wolff S , Greer JP , Bierman P , Resta D , Campion M , Levitt D
Published: October 2019

Recombinant human interleukin-3 (rhIL-3) was administered to 30 patients undergoing autologous bone marrow transplant (ABMT) for treatment of lymphoma. In this phase I dose escalation study, rhIL-3 was administered from day 0 to 20 after ABMT by 2-hour intravenous infusion at dose levels of 1, 2, 5, and 10 micrograms/kg/d. Seventeen patients did not complete therapy with rhIL-3. Eleven requested early discontinuation for malaise, confusion, transplant complications, or rapid engraftment and were removed from the study, whereas six patients developed grade III toxicity, including fever (three patients), or headache (three patients) possibly attributable to rhIL3. Other common toxicities included diarrhea, rigors, mucositis, and rash. The maximum tolerated dose of rhIL-3 was 2 micrograms/kg/d. No evidence of earlier hematopoietic cell recovery was observed compared with similar historical patients treated with recombinant human granulocyte- macrophage colony-stimulating factor. Future trials will be needed to determine alternate schedules of administration of rhIL-3 or the use of rhIL-3 in combination or in sequence with other growth factors.
Human granulocyte-macrophage colony-stimulating factor receptor signal transduction requires the proximal cytoplasmic domains of the alpha and beta subunits
Authors: Weiss M , Yokoyama C , Shikama Y , Naugle C , Druker B , Sieff CA
Published: October 2019

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) controls the production, maturation, and function of cells in multiple hematopoietic lineages. These effects are mediated by a cell-surface receptor (GM-R) composed of alpha and beta subunits, each containing 378 and 881 amino acids, respectively. Whereas the alpha subunit exists as several isoforms that bind GM-CSF with low affinity, the beta common subunit (beta c) does not bind GM-CSF itself, but acts as a high- affinity converter for GM-CSF, interleukin-3 (IL-3), and IL-5 receptor alpha subunits. The cytoplasmic region of GM-R alpha consists of a membrane-proximal conserved region shared by the alpha 1 and alpha 2 isoforms and a C-terminal variable region that is divergent between alpha 1 and alpha 2. The cytoplasmic region of beta c contains membrane proximal serine and acidic domains. To investigate the amino acid sequences that influence signal transduction by this receptor complex, we constructed a series of cytoplasmic truncation mutants of the alpha 2 and beta subunits. To study these truncations, we stably transfected the IL-3-dependent murine cell line Ba/F3 with wild-type or mutant cDNAs. We found that the wild-type and mutant alpha subunits conferred similar low-affinity binding sites for human GM-CSF to Ba/F3, and the wild-type or mutant beta subunit converted some of these sites to high- affinity; the cytoplasmic domain of beta was unnecessary for this high- affinity conversion. Proliferation assays showed that the membrane- proximal conserved region of GM-R alpha and the serine-acidic domain of beta c are required for both cell proliferation and ligand-dependent phosphorylation of a 93-kD cytoplasmic protein. We suggest that these regions may represent an important signal transduction motif present in several cytokine receptors.
Glycoprotein IIb and IIIa retention on fibrinogen-coated surfaces after lysis of adherent platelets
Authors: Peerschke EI
Published: October 2019

The platelet-membrane glycoprotein IIb-IIIa (GPIIb-IIIa) complex is essential for platelet aggregation and is involved in the attachment of platelets to thrombogenic surfaces. This study shows the retention of GPIIb and GPIIIa on immobilized fibrinogen after Triton X-100 (Sigma Chemical Co, St Louis, MO) lysis of adherent platelets. Glycoproteins were detected using subunit specific monoclonal antibodies in a modified enzyme-linked immunosorbent assay procedure. GPIIb-IIIa retention was judged to be specific relative to GPIb recovery, and was modulated by platelet activation. Platelet exposure to adenosine diphosphate or thrombin, but not A23187 or chymotrypsin, markedly enhanced GPIIb and GPIIIa recovery relative to that observed with unstimulated platelets, or prostaglandin E1-treated platelets. Moreover, lysis of adherent platelets in the presence of 10 mmol/L EDTA, under conditions promoting GPIIb-IIIa complex dissociation (pH 8.1, 60 minutes, 37 degrees C), had no effect on GPIIb or GPIIIa subunit recovery. Platelet activation with Zn+2 also enhanced GPIIb and GPIIIa recovery on fibrinogen-coated surfaces over that observed with unstimulated platelets, but GPIIb and IIIa retention was EDTA sensitive. This correlated with the EDTA-reversible nature of Zn+2- activated platelet adhesion to fibrinogen-coated surfaces. The data (1) show that platelet adhesion to fibrinogen is accompanied by the induction of high-affinity interactions between GPIIb-IIIa and immobilized fibrinogen that are EDTA-resistant and enhanced by platelet activation with some but not all agonists, and (2) implicate these interactions in stabilizing platelet contacts with fibrinogen-coated surfaces.
Expression of MDR1 gene in acute leukemia cells: association with CD7+ acute myeloblastic leukemia/acute lymphoblastic leukemia
Authors: Miwa H , Kita K , Nishii K , Morita N , Takakura N , Ohishi K , Mahmud N , Kageyama S , Fukumoto M , Shirakawa S
Published: October 2019

MDR1 gene expression was examined in acute leukemia cells from 75 Japanese patients at diagnosis (50 with acute myeloblastic leukemia [AML]: 10 M1, 18 M2, 5 M3, 8 M4, 9 M5; 25 with acute lymphoblastic leukemia [ALL]: 13 B-precursor, 12 T-lineage). The results of MDR1 mRNA expression by reverse transcriptase polymerase chain reaction were confirmed by immunostaining using the anti-P-glycoprotein monoclonal antibody UIC2 and by a functional study using the rhodamine efflux test. Morphologically, AML M1 cases had the highest incidence of MDR1 gene expression (6 of 10 patients). Phenotypically, CD7 and CD34 were the only surface markers that were significantly associated with MDR1 gene expression (P < .01). In CD7+CD4-CD8- ALL, which is thought to originate from the lymphohematopoietic stem cell, expressed the MDR1 gene with a high incidence (six of eight patients), whereas three surface CD3+ and one CD4+CD8+ T-cell ALL (T-ALL) did not have detectable MDR1 transcripts. Only two cases of 13 B-precursor ALL had MDR1 mRNA, one of which had the Philadelphia (Ph1) chromosome. No association was observed between MDR1 gene expression and CD34 positivity in ALL. Our results that MDR1 mRNA was frequently expressed in CD7+ AML and CD7+CD4-CD8- ALL, together with the previous reports indicating clinical similarities between these leukemias, provides a clue to clarify a relationship between CD7+ AML and CD7+CD4-CD8- ALL. In addition, MDR1 expression in CD7+ AML/ALL might be responsible for the poor response to conventional chemotherapies of these types of leukemia.
Regulation of human neutrophil aggregation: comparable latent times, activator sensitivities, and exponential decay in aggregability for FMLP, platelet-activating factor, and leukotriene B4
Authors: Rochon YP , Frojmovic MM
Published: October 2019

We have recently described a flow cytometry technique, whose sensitivity allows direct measurements of latent times before the onset of aggregation, and of rates, maximal extents, and reversibility of aggregation (J Leuk Biol 50:434, 1991). We report here that activators which stimulate sustained cellular signaling associated with increases in intracellular calcium (ionomycin) or protein kinase C activation (phorbol myristate acetate, PMA) cause complete (> or = 98%) and irreversible neutrophil aggregation, with latent times for the onset of aggregation inversely proportional to the activator concentration. In contrast, the receptor-specific activators leukotriene B4 (LTB4), formyl peptide FMLP, and platelet-activating factor (PAF) gave only partial and reversible aggregatory responses, limited by the following similar properties: latent times of 4.5 seconds +/- 1.5 seconds, independent of activator concentration; similar concentrations for onset of aggregation (approximately 1 nmol/L) that increased over a similar broad range of activator concentration, with one-half maximal rates of aggregation at 10 nmol/L to 30 nmol/L, corresponding to reported dissociation constant values; comparable limited recruitment and spontaneous reversibility of aggregation; absence of interactivator synergism; and similar exponential decays in activated cell stickiness (refractoriness), with t1/2 = 15 to 30 seconds. Variable cross- desensitization was seen between LTB4 and FMLP depending on donor and activator concentrations. In vivo, these properties are expected to provide localization of the aggregatory response, minimizing the otherwise detrimental effects of circulating activated neutrophils.
Membrane attachment sites for the membrane cytoskeletal protein 4.1 of the red blood cell [see comments]
Authors: Pinder JC , Chung A , Reid ME , Gratzer WB
Published: October 2019

The identity of the membrane binding sites for the membrane cytoskeletal protein 4.1 of the human red blood cell has been investigated. Exhaustive proteolysis of the membrane with a range of proteases led to the elimination of only some 60% of all binding sites. The predominant integral membrane protein, band 3, as well as glycophorin A, was totally digested at levels of proteolysis that were essentially without effect on the number of 4.1 binding sites. Proteolysis caused scission of the polypeptide chain of glycophorin C (together with the minor product, glycophorin D, of the same gene), but left a fragment from the region of the C-terminus still attached to the membrane. We have found a low-molecular weight protein, possessing an epitope (recognized by an antibody directed against the cytoplasmic domain of glycophorin C) in common with this proteolytic fragment, in cells of a Leach phenotype, which are characterized by lack of extracellular epitopes of glycophorin C. When these membranes were extracted at low ionic strength to dissociate the membrane cytoskeleton, approximately half the content of 4.1 was liberated, compared with only some 25% from normal membranes. Cells of a different variant of the Leach phenotype, which are totally devoid of glycophorin C, lost close to 70% of their 4.1 under these circumstances. The Rh(D) transmembrane protein, which interacts with the membrane cytoskeleton, is also resistant to proteolysis of the cytoplasmic membrane surface, but Rhnull cells, devoid of this protein, showed no decreased retention of 4.1. The results suggest that glycophorin C (with D) may contain two types of binding site for 4.1, which would be sufficient in number to account for all the strong binding of 4.1 on normal membranes; modulation of binding at one of the sites by another protein or by lipid is not excluded. A possible site for reinitiation of translation overlapping the premature stop codon in the mutant expressing the truncated glycophorin C can be discerned.
Assessment of the hemostatic effectiveness of human platelets treated with aminomethyltrimethyl psoralen and UV A light using a rabbit ear bleeding time technique
Authors: Wagner SJ , Bardossy L , Moroff G , Dodd RY , Blajchman MA
Published: October 2019

The photochemical aminomethyltrimethyl psoralen (AMT), in conjunction with UV A light (UVA), has been shown to inactivate human immunodeficiency virus-1 and model viruses in platelet suspensions under conditions that have only a minimal effect on in vitro platelet properties. A rabbit ear bleeding time technique was used to assess the hemostatic effectiveness of human platelet suspensions treated with AMT/UVA. New Zealand White rabbits were made thrombocytopenic by a combination of irradiation and heterologous antirabbit platelet antiserum. Reticuloendothelial function in these rabbits was suppressed by the intravenous administration of ethyl palmitate. The hemostatic function of 1- and 5-day-old human platelet suspensions (14.5% plasma) that had been treated on day 1 with 40 micrograms/mL AMT and 24 kJ/m2 UVA (1 x UVA) was evaluated by measuring microvascular bleeding times after a standard incision. Comparable bleeding times were observed after infusion with both control and AMT/UVA-treated platelets stored for either 1 or 5 days. With the transfusion of AMT/1 x UVA-treated platelets stored for 5 days, the mean (+/- SD) bleeding time was 156.3 +/- 39.2 seconds (n = 10). With untreated platelets (no AMT/no UVA), stored for 5 days, the mean bleeding time was 189.2 +/- 36.4 seconds (n = 10). Neither AMT nor 1 x UVA treatment alone influenced the observed bleeding times. In contrast, the hemostatic effectiveness of human platelet suspensions was diminished if they were exposed to three times the standard UVA dose (72 kJ/m2) on day 1 and stored for 4 more days, regardless of whether AMT was present, with the mean bleeding time increasing to 442.2 +/- 122.6 seconds (n = 15, AMT present) or 396.0 +/- 45.9 seconds (n = 10, AMT absent). These results are consistent with data obtained from in vitro studies and indicate that virucidal AMT/1 x UVA treatment does not influence platelet hemostatic function. However, the final conditions to achieve these results must be carefully controlled.
Association of the p85 regulatory subunit of phosphatidylinositol 3- kinase with an essential erythropoietin receptor subdomain
Authors: He TC , Zhuang H , Jiang N , Waterfield MD , Wojchowski DM
Published: October 2019

Using an active, HAI epitope-tagged form of the murine erythropoietin (EPO) receptor and via direct coimmunoprecipitation, the p85 regulatory subunit of phosphatidyl inositol-3 kinase (p85/PI3-K) is shown to associate with the EPO receptor in transfected FDC-P1 cell lines. Coimmunoprecipitation of p85 with epitope-tagged EPO receptors was observed initially in FDC-HER cells labeled metabolically with [32P]orthophosphate, and association of these factors was confirmed by Western analyses of receptor immunoprecipitates using p85 antiserum. Interestingly, this association occurred in the absence of ligand, and exposure of FDC-HER cells to EPO did not detectably affect levels of receptor-associated p85 or overall levels of p85 phosphorylation. However, EPO was observed to stimulated the rapid formation of phosphatidylinositol 32P-phosphate in FDC-HER and FDC-ER cells. Through baculovirus-mediated expression of epitope-tagged EPO receptor forms in SF9 cells, domains for p85 association were mapped. Analyses of receptor forms with cytosolic truncations and deletions delineated a candidate subdomain for p85 binding to an essential extended box-2 region (P329-E374; including a putative motif for SH2 binding, Y343LVL). These findings extend a mechanistic alignment between the EPO receptor and protein tyrosine kinase-encoding receptors that likewise activate PI3-K, and expand the importance of further defining pathways to PI3-K activation.
Absence of reverse transcription-polymerase chain reaction detectable residual disease in patients with acute promyelocytic leukemia in long- term remission
Authors: Diverio D , Pandolfi PP , Biondi A , Avvisati G , Petti MC , Mandelli F , Pelicci G , Lo Coco F
Published: October 2019

Hybrid fusion genes are specific tumor markers of several leukemic subtypes. The use of reverse transcription-polymerase chain reaction (RT-PCR) to amplify chimeric cDNAs allows sensitive detection of the neoplastic clone for diagnostic and monitoring studies in these leukemias. Nonetheless, the clinical relevance of minimal residual disease (MRD) evaluation by PCR remains controversial. In this study, 9 patients (pts) with acute promyelocytic leukemia (APL) in long-term remission for 4 to 12 years were analyzed for the presence of MRD by RT- PCR amplification of the specific PML/RAR-alpha fusion gene. Seven pts had been treated with conventional chemotherapy (CHT) alone, 1 had undergone allogeneic bone marrow transplantation (BMT), and 1 autologous BMT as consolidation therapy after CHT. In 8 cases, the presence of the t(15;17) rearrangement could be documented in diagnostic BM specimens by cytogenetic and/or molecular analysis. A two- rounds “nested” RT-PCR assay with sensitivity levels of 1 in 10(5) was used to analyze BM samples collected at 32 to 141 months from the achievement of complete remission (CR). In no cases were residual PML/RAR-alpha transcripts detectable in these remission controls. All patients are in unmaintained CR at 48 to 154 months from CR and at 6 to 17 months from PCR evaluation. These results suggest that long-term survival of APL is associated with eradication of cells carrying the specific PML/RAR-alpha rearrangement, indicating that PCR negativity should be considered the therapeutic goal in these patients. Our findings further strengthen the clinical relevance of PCR monitoring studies in APL, as opposite to other leukemic subtypes (chronic myeloid leukemia and acute myeloid leukemia-M2) in which the prognostic significance of PCR evaluation is unclear.
Effects of novel retinoic acid compound, 9-cis-retinoic acid, on proliferation, differentiation, and expression of retinoic acid receptor-alpha and retinoid X receptor-alpha RNA by HL-60 cells
Authors: Kizaki M , Ikeda Y , Tanosaki R , Nakajima H , Morikawa M , Sakashita A , Koeffler HP
Published: October 2019

Retinoic acid modulates proliferation and differentiation of a wide variety of normal and leukemic cells through two distinct families of transcriptional factors: the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). A stereoisomer of retinoic acid, 9-cis- retinoic acid, is a high-affinity ligand for RXR and binds efficiently to RAR. In contrast, all-trans-retinoic acid interacts 40-fold less efficiently with RXR as compared with RAR. To clarify the biologic role of retinoic acid compounds (all-trans,- 9-cis-, and 13-cis-retinoic acid) in hematopoietic cells, we studied their effects on clonal growth, differentiation, and expression of RAR-alpha and RXR-alpha genes in HL-60 cells. At very low concentrations (10(-15) to 10(-12) mmol/L), each retinoid enhanced clonal growth of HL-60 cells. These concentrations of the retinoids had no capacity to induce differentiation of leukemic cells as measured by ability either to reduce nitroblue tetrazolium and to express CD11b antigens, suggesting that retinoids at very low concentrations may stimulate proliferation of leukemic cells rather than induce their differentiation. These findings may help explain why patients with acute promyelocytic leukemia may relapse while receiving retinoic acids. With continuous therapy, retinoids are metabolized rapidly with increased urinary excretion, lowering their plasma levels to a range that may stimulate proliferation without inducing differentiation of leukemic cells. In contrast, we found that at higher concentrations (> or = 10(-11) mmol/L) each retinoid inhibited clonal growth, reduced c-myc RNA levels, and induced differentiation of HL-60 cells. 9-cis-retinoic acid was a slightly more potent inducer of differentiation than all-trans- retinoic acid; the mechanism for this increased potency and its clinical potential requires additional studies. Steady-state levels of RAR-alpha mRNA in HL-60 cells were not affected by either 9-cis- and all-trans-retinoic acid. In contrast, 9-cis-retinoic acid, but not all- trans-retinoic acid, reduced RXR-alpha mRNA accumulation in a dose- dependent manner.
Macrophage colony-stimulating factor and granulocyte-macrophage colony- stimulating factor stimulate the synthesis of plasminogen-activator inhibitors by human monocytes
Authors: Hamilton JA , Whitty GA , Stanton H , Wojta J , Gallichio M , McGrath K , Ianches G
Published: October 2019

Macrophage colony-stimulating factor (M-CSF or CSF-1) and granulocyte- macrophage CSF (GM-CSF) have been shown to increase human monocyte urokinase-type plasminogen-activator (u-PA) activity with possible consequences for cell migration and tissue remodeling; because monocyte u-PA activity is likely to be controlled in part also by the PA inhibitors (PAIs) made by the cell, the effect of M-CSF and GM-CSF on human monocyte PAI-2 and PAI-1 synthesis was investigated. To this end, elutriation-purified human monocytes were treated in vitro with purified recombinant human M-CSF and GM-CSF, and PAI-2 and PAI-1 antigen and mRNA levels measured by specific enzyme-linked immunosorbent assays and Northern blot, respectively. Each CSF could enhance the protein and mRNA levels of PAI-2 and PAI-1 at similar concentrations for each product. This similar regulation of monocyte PAI expression in response to the CSFs contrasted with that found for the effects of lipopolysaccharide, transforming growth factor-beta and a glucocorticoid. Therefore, PAIs may be modulating the effects of the CSFs on monocyte u-PA activity at sites of inflammation and tissue remodeling.
Platelet activation and inhibition of malarial cytoadherence by the anti-CD36 IgM monoclonal antibody NL07
Authors: Alessio M , Greco NJ , Primo L , Ghigo D , Bosia A , Tandon NN , Ockenhouse CF , Jamieson GA , Malavasi F
Published: October 2019

The surface glycoprotein CD36 (GPIV) is known to mediate the adhesion of Plasmodium falciparum malaria-infected red blood cells and to be a receptor for extracellular matrix proteins such as collagen and thrombospondin. The murine monoclonal IgM antibody NL07, which is specific for CD36, has now been shown to also be a potent inhibitor of the adhesion of P falciparum malaria-infected red blood cells to C32 melanoma cells. Treatment of platelets with NL07 monoclonal antibody resulted in rapid degranulation, release of ATP and serotonin, increase in [Ca2+]i, and tyrosine phosphorylation of a substrate protein of 130 kD. In about one-half of the experiments, activation with NL07 resulted in the formation of small aggregates of 10 to 30 platelets, whereas in the other half of the experiments, large aggregates were seen similar to those induced by adenosine diphosphate (ADP) and these large aggregates could be converted to the small aggregates by ATP alpha S or by AP-2 or other antibodies against GPIIb and/or IIIa. Microaggregates of 2 to 5 platelets were seen with Glanzmann's platelets that constitutively lack GPIIb/IIIa. Aggregate formation was not seen with heat-treated serum, in the presence of anti C1q antibodies, or when using C5-, C8-, or C9-deficient human sera. Although activation of platelets with purified complement components results in a slow morphologic change without aggregation, involvement of CD36 results in rapid complement-mediated activation leading to formation of small aggregates that is largely independent of GPIIb/IIIa and that, under certain circumstances, proceeds to the formation of large ADP-dependent aggregates.
Transcriptional and posttranscriptional regulation of the expression of the erythropoietin receptor gene in human erythropoietin-responsive cell lines
Authors: Migliaccio AR , Jiang Y , Migliaccio G , Nicolis S , Crotta S , Ronchi A , Ottolenghi S , Adamson JW
Published: October 2019

With erythroid differentiation, committed progenitor cells acquire the ability to respond to erythropoietin (Epo). Epo interacts with target cells through the Epo receptor (Epo-R), whose expression is tightly regulated in a lineage-specific fashion. Epo-R expression is presumed to be progressively activated or repressed as cells progress along the erythroid or the myeloid pathway, respectively. Little is known of the mechanisms that underlie the erythroid-specific expression of the Epo-R gene. GATA-1, the major known transcription factor involved in Epo-R gene regulation, is not erythroid-specific. We have studied the regulation of the expression of the Epo-R gene in two related human Epo- responsive cell lines, UT-7 and UT-7 Epo. These lines express Epo-R at high levels because of amplification of the endogenous gene, which is apparently not rearranged. Treatment for 6 to 24 hours with the tumor promoter, phorbol myristate acetate (PMA), or 24 hours of growth factor starvation (Epo or granulocyte/macrophage colony-stimulating factor [GM- CSF]) decreased or increased the levels of Epo-R mRNA, respectively. In the case of growth factor starvation, the increase (approximately equal to threefold) in the level of Epo-R mRNA correlated directly with an increase in the rate of Epo-R gene transcription as measured by run-off assay. Both increases were observed as early as 3 hours after the growth factor was withdrawn and were reversible; levels of mRNA and transcription rates returned to baseline 3 hours after the cells were reexposed to growth factors. The changes in Epo-R expression after growth factor starvation were coordinated with changes in the level of expression of GATA-1 that were detected both at the mRNA and at the gene transcription level under these conditions (suggesting that GATA-1 was responsible for this upregulation). During PMA treatment, after a transient increase in Epo-R mRNA at 1 hour, a progressive decline in the level of Epo-R mRNA was observed; the level of Epo-R mRNA decreased by 50%, and fell below the level of detection by 6 and 24 hours, respectively. This decrement was explained in part by a fourfold reduction in the rate of gene transcription as well as a reduction (measured as levels of Epo-R mRNA in the presence of actinomycin D) in mRNA stability. The changes in transcription rate occurred in the absence of changes in the level of GATA-1 binding activity.(ABSTRACT TRUNCATED AT 400 WORDS)
Large-scale expansion of human stem and progenitor cells from bone marrow mononuclear cells in continuous perfusion cultures
Authors: Koller MR , Emerson SG , Palsson BO
Published: October 2019

There is a growing consensus that clinical practice in the areas of bone marrow (BM) transplantation and gene therapy will rely on the ex vivo expansion of hematopoietic cells. We report here on the development of continuously perfused culture systems (bioreactor systems) that expand human stem and progenitor cells from BM mononuclear cell (MNC) populations obtained without cell enrichment. In three separate experiments, 10 bioreactors were each inoculated with 3 x 10(7) BM MNC from patients undergoing marrow harvest for autologous transplantation. At various times thereafter (between days 6 and 16), duplicate bioreactors were harvested and cells were analyzed. The bioreactors contained three cell populations that were analyzed separately: nonadherent cells; cells that were loosely adherent to the endogenously formed stromal layer; and an adherent cell layer that required trypsinization for removal. Total cell numbers increased continuously to give an overall 10-fold (range, 8- to 11-fold) expansion by day 14. The adherent stromal layer significantly expanded to more than 2 x 10(7) cells, but remained less than 6% of the total cell population. Colony-forming unit-granulocyte-macrophage (CFU-GM) numbers expanded 21-fold (range, 12- to 34-fold) by day 14 and, because this expansion was greater than that for total cells, CFU-GM were enriched by as much as fourfold by day 14. Burst-forming unit-erythroid (BFU-E) numbers peaked earlier than did CFU-GM numbers, with a 12-fold (range, 6- to 18-fold) expansion obtained on day 8. In contrast to CFU- GM, which were predominantly nonadherent, BFU-E were more evenly distributed between the three cell populations. Stem cell activity was measured by the long-term culture-initiating cell (LTC-IC) limiting dilution assay. The number of LTC-IC per reactor consistently increased with time in all cultures, resulting in a 7.5-fold (range, 3.4- to 9.8- fold) expansion. In summary, more than 3 billion cells, containing 12 million CFU-GM, were reproducibly generated from the equivalent of a 10 to 15 ml BM aspirate. These data indicate that small numbers of BM MNC can be readily expanded ex vivo in continuous perfusion cultures, and that such ex vivo expansion may have direct applications in clinical and experimental BM transplantation.
Congenital plasminogen deficiency caused by a Ser572 to Pro mutation
Authors: Azuma H , Uno Y , Shigekiyo T , Saito S
Published: October 2019

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members. She presented with cerebral infarction. Sequence analysis following amplification of each exon and its flanking regions showed a single T to C transition in exon 14, which changed a Ser572 codon (TCC) to Pro572 codon (CCC). Since this mutation generates a new Fok I site, the Fok I digestion pattern of the PCR-amplified exon 14 fragments from each family member was analyzed. In all cases, the patterns were consistent with the activities and antigen levels of plasma PLG in those members. Furthermore, all PCR- amplified exon 14 fragments from 15 normal individuals were not restricted with Fok I endonuclease. We conclude that a T to C transition in exon 14 identified in the propositus is responsible for PLG deficiency inherited in this Japanese family with thrombotic episodes.
Aspirin does not inhibit adenosine diphosphate-induced platelet alpha- granule release
Authors: Rinder CS , Student LA , Bonan JL , Rinder HM , Smith BR
Published: October 2019

The involvement of metabolites of arachidonic acid in platelet-dense granule secretion and secondary platelet-platelet interactions is well characterized. However, their role in heterotypic interactions dependent on alpha-granule secretion is less well understood. Using platelet-surface expression of P-selectin as a marker of alpha-granule secretion, we have shown that: (1) aspirin treatment of platelets at doses that block dense granule secretion does not inhibit alpha-granule secretion to adenosine diphosphate (ADP); (2) synergism between epinephrine and ADP in the induction of P-selectin expression is similarly unaffected by aspirin; and (3) the ability of P-selectin to mediate adhesion of activated platelets to monocytes and polymorphonuclear lymphocytes in whole blood is also unchanged by aspirin treatment. To further explore the mechanisms responsible for platelet alpha-granule secretion, we have shown that inhibition of Na+/H+ exchange by either acidification of the extracellular medium or amiloride treatment blocked ADP-induced P-selectin expression. In contrast, incubation with the platelet lipoxygenase inhibitor 5,8,11- eicosatrynoic acid, by itself and with aspirin, did not decrease ADP- induced P-selectin expression. We conclude that platelet alpha-granule secretion in response to ADP is dependent on intact Na+/H+ exchange but is independent of the lipoxygenase- and cyclooxygenase-dependent metabolites of arachidonic acid.
Polyclonal hematopoietic reconstitution in leukemia patients at remission after suppression of specific gene rearrangements [see comments]
Authors: Lo Coco F , Pelicci PG , D'Adamo F , Diverio D , Alimena G , Montefusco E , Arcese W , Avvisati G , De Felice L , Meloni G
Published: October 2019

Clonality studies of hematopoietic reconstitution after remission were performed in 24 female patients (pts) with leukemias characterized by specific molecular markers. At diagnosis, 13 pts had promyelocytic leukemia (PML) retinoic acid receptor-alpha (RAR-alpha)-rearranged acute promyelocytic leukemia (APL), 8 Philadelphia positive (Ph′+) break-point cluster region (BCR+) chronic myeloid leukemia (CML), and 3 Ph′+ (BCR+) acute lymphoblastic leukemia (ALL). All pts were analyzed at presentation and after Southern blot suppression of specific rearrangements after various treatments, including conventional chemotherapy, autologous or allogeneic bone marrow transplant (BMT), all-trans retinoic acid, and alpha-2b interferon. DNA from BM samples collected at diagnosis and, during remission phases, were subjected to Southern blot analysis with the M27 beta probe to detect X chromosome methylation differences, and with BCR, in CML and ALL cases, or PML/RAR- a probes for gene rearrangements, in APL cases. Twenty-one of the 24 pts had polyclonal methylation patterns at remission, together with disappearance of the specific rearrangement, whereas 3 pts retained the same single unmethylated DXS255 allele detected at diagnosis despite no evidence of gene rearrangement. Concerning these 3 pts, such an apparently clonal pattern was also observed in one case in T lymphocytes and skin-derived DNA; in a second case in BM fibroblasts and T lymphocytes; and, in the third case, in blood mononuclear cells obtained from her healthy female BM donor. All these 3 pts are in unmaintained clinical and cytogenetic remission after more than 20 months off therapy. These data suggest that (1) polyclonal and presumably normal hematopoiesis occurs in APL, CML, and Ph′+ ALL pts once the major burden of leukemic cells carrying a specific rearrangement is suppressed by treatment; and (2) unbalanced X chromosome methylation patterns, or aberrant methylation of X chromosome regions may be observed in some cases, most likely reflecting constitutional features simulating a clonal picture.
Relapsed myelodysplastic clone differs from acute onset clone as shown by X-linked DNA polymorphism patterns in a patient with acute myeloid leukemia [see comments]
Authors: Jowitt SN , Yin JA , Saunders MJ
Published: October 2019

We have used a recombinant strategy based on X-chromosome-linked restriction fragment length polymorphisms to analyze clonality in a female patient with acute myeloid leukemia (AML). She presented with features compatible with a diagnosis of refractory anemia with excess of blasts in transformation, but soon progressed into overt AML. Intensive chemotherapy successfully induced a complete remission, but she later relapsed into a second myelodysplastic phase. Although analysis at presentation and relapse showed that hematopoiesis was clonal at both phases of the patient's disease, the genotype of the two clones was different. We believe the unexpected finding of a switch in clonality shows new insights into the biology and origin of AML.