bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic heterogeneity of primitive leukemic hematopoietic cells in patients with chronic myeloid leukemia
Authors: Udomsakdi C , Eaves CJ , Lansdorp PM , Eaves AC
Published: October 2019

The peripheral blood of chronic myeloid leukemia (CML) patients with chronic-phase disease and elevated white blood cell (WBC) counts typically contains markedly increased numbers of a variety of neoplastic pluripotent and lineage-restricted hematopoietic progenitors. These include cells detected in standard colony assays as well as their more primitive precursors. The latter are referred to as long-term culture-initiating cells (LTC-IC) because of their ability to generate clonogenic cell progeny detectable after a minimum of 5 weeks incubation on competent fibroblast feeder layers. In this study, we have investigated a number of the properties of the LTC-IC and clonogenic cells present in the blood of such CML patients with high WBC counts. This included an analysis of the light scattering properties of these progenitors, as well as their expression of CD34 and HLA-DR, Rhodamine-123 staining, and in vitro sensitivity to 4- hydroperoxycyclophosphamide. In the case of LTC-IC, the production of different types of lineage-restricted and multipotent progeny was also analyzed. Most of the circulating LTC-IC and clonogenic cells in the CML patients studied (on average approximately 70% and approximately 90%, respectively) showed features of proliferating or activated cells. This is in marked contrast to the majority of progenitors in the blood of normal individuals and most of the LTC-IC in normal marrow, all of which exhibit a phenotype expected of quiescent cells. Interestingly, a significant proportion of the circulating clonogenic cells and LTC-IC in the CML samples studied (on average approximately 10% and approximately 30%, respectively) appeared to be phenotypically similar to normal circulating progenitors, although their absolute numbers were indicative of a neoplastic origin. Both phenotypes of circulating CML clonogenic cells and LTC-IC could be obtained at approximately 10% to 20% purity by differential multiparameter sorting. These findings suggest that expansion of the Philadelphia chromosome-positive clone at the level of the earliest types of hematopoietic cells results from the activation of mechanisms that enable some, but not all, signals that block the cycling of normal stem cells to be bypassed or overcome. In addition, they provide strategies for purifying these primitive leukemic cells that should facilitate further analysis of the mechanisms underlying their abnormal proliferative behavior.
Isolation of a cDNA clone encoding a zinc finger protein highly expressed in T-leukemia lines
Authors: Wu BY , Hanley EW , Turka LA , Nabel GJ
Published: October 2019

A cDNA clone encoding a novel zinc finger protein expressed in lymphoid cells has been isolated. This protein contains 5 repeats of the C2H2 motif previously described in the Drosophila gap gene, Kruppel, which is involved in embryo segmentation. Northern blot analysis showed that the messenger RNA (mRNA) encoding this protein is expressed at high levels in a variety of T-leukemia cell lines, at lower levels in some B cells, but is not observed in nonlymphoid cells. Within the T lineage, the mRNA is found at high levels in both alpha beta and gamma delta T cells. These data suggest that this cDNA, designated Hkr-T1, represents a gene that may contribute to the determination of the differentiation and the specificity within lymphoid cells.
t(9;14)(p13;q32) denotes a subset of low-grade non-Hodgkin's lymphoma with plasmacytoid differentiation
Authors: Offit K , Parsa NZ , Filippa D , Jhanwar SC , Chaganti RS
Published: October 2019

In this series of 426 consecutively ascertained, karyotypically abnormal non-Hodgkin's lymphomas (NHLs) derived from 407 patients, a t(9;14)(p13;q32) was encountered in 7 cases; an additional case demonstrated t(9;14)(p1?3;q32). At the time of detection of t(9;14), four cases were small lymphocytic lymphomas with plasmacytoid features; in three of these the t(9;14) was the sole karyotypic abnormality. In two cases of large-cell NHL demonstrating t(9;14), retrospective review of prior lymph node biopsies showed the presence of a small lymphocytic lymphoma of the plasmacytoid subtype. The remaining two cases comprised a large-cell lymphoma of the brain and a follicular NHL. Thus, six of eight cases (75%) had an initial identical low-grade histology. Immunohistochemical analysis of six cases showed no reactivity with CD1, CD2, CD4, CD5, CD8, and CD10 and high reactivity with CD19 and CD20. All four lymphocytic lymphomas and one of the two large-cell NHLs showed cytoplasmic Ig, consistent with plasmacytoid differentiation. Of the eight cases in this series, six presented with or developed stage IV disease; all were characterized by a 6-month to 5-year clinical phase of indolent disease before treatment was instituted. All five patients with low-grade NHL at the time of cytogenetic analysis were alive with recurrent disease at 3-year median follow-up. The remaining three patients with large-cell diffuse histologies relapsed after intensive therapy and expired at a median of 3 years from diagnosis; two of these showed previous or metachronous small lymphocytic tumors. These results suggest a novel biologically distinct subset of NHL; a neoplasm of mature B lymphocytes with plasmacytoid differentiation, characterized by t(9;14); and an indolent presentation followed by gradual clinical progression of disease.
Alteration of the proliferative rate of acute myelogenous leukemia cells in vivo in patients
Authors: Preisler HD , Raza A , Larson RA
Published: October 2019

Ten patients with active acute myelogenous leukemia (AML) received either 13 cis retinoic acid (RA) + alpha interferon (IFN) or recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) for 3 days. Cell cycle measurements were performed before and at the conclusion of administration of the bioactive agent(s). The proliferative rate of the leukemia cells in vivo decreased in four of five patients receiving RA+IFN whereas in one patient proliferation accelerated. The proliferative rate of AML cells accelerated in three of the five patients who received rhGM-CSF and slowed in two patients. These data show that while the proliferative rate of AML cells can be altered in vivo, the effect produced by bioactive agents may be the opposite of the desired effect. Furthermore, the studies described here demonstrate the usefulness of marrow biopsies for measuring the percent S-phase cells and the importance of measuring the duration of S phase so that the effects of bioactive agents on the cell cycle time of the leukemia cells can be determined.
Epstein-Barr virus burden in Hodgkin's disease is related to latent membrane protein gene expression but not to active viral replication
Authors: Joske DJ , Emery-Goodman A , Bachmann E , Bachmann F , Odermatt B , Knecht H
Published: October 2019

The Epstein-Barr virus (EBV) has been increasingly detected in Hodgkin's disease (HD), but its role in pathogenesis remains uncertain. We analyzed 20 specimens of HD known to contain EBV DNA by a sensitive reverse transcriptase polymerase chain reaction (RT-PCR). The cases were assessed for the presence of RNA transcripts of the BNLF1 gene (coding for the viral latent membrane protein [LMP]) and the late replicative gene BLLF1 (coding for the principle envelope glycoprotein [gp220/350]). LMP RNA transcripts were found in 9 of 20 (45%) cases, mostly those containing many copies of viral DNA and of mixed cellularity (MC) histological subtype. Only one LMP RNA-positive case was also positive for RNA transcripts of the active replication gene BLLF1. Our results show that viral burden in HD is not primarily related to active viral replication, but is associated with LMP gene expression.
Unexpected consistent involvement of V beta gene segments in inappropriate T-cell receptor beta gene rearrangements occurring in B- lineage acute lymphoblastic leukemias
Authors: Dombret H , Loiseau P , Bories JC , Sigaux F
Published: October 2019

T-cell receptor beta (TCR beta) gene rearrangements occur in a third of early B-cell acute lymphoblastic leukemias (ALLs). V, D, and J segments involved in these inappropriate rearrangements remain unknown and are of interest, both because partial D beta J beta and complete V beta D beta J beta recombinations occur at distinct stages of thymic maturation and because these rearrangements are regulated differently. We have therefore studied in detail seven cases of B-lineage ALL that show inappropriate clonal TCR beta gene rearrangements. Analysis of genomic DNA by Southern hybridization with C beta, J beta 1, V beta 8, and V beta 11 probes suggested the involvement of V beta segment in tumor cell rearrangements. A complete genomic library constructed from one case was screened with a C beta probe, and the TCR beta gene rearrangement was cloned and fully sequenced to show an out of frame V beta 2.2-J beta 2.6 recombination. TCR beta gene rearrangements occurring in other cases were further analyzed by polymerase chain reaction (PCR) using J beta and V beta primers and the resulting specific PCR products were sequenced. Evidence of clonal V beta rearrangements was obtained in all cases. These unexpected findings represent the first definitive demonstration that complete V beta(D beta)J beta rearrangements can occur in B-lineage cells and contrast with the previously reported lack of V beta(D beta)J beta rearrangement in B cells from V beta-J beta-C beta-E mu transgenic mice. In the context of increasing evidence that rearrangements are linked to transcription of unrearranged gene segments, these data prompt a search in B-lineage ALL cells for the presence of germline V beta transcripts whose deregulated expression may be linked to early transforming events.
Thrombospondin mediates adherence of CD36+ sickle reticulocytes to endothelial cells
Authors: Sugihara K , Sugihara T , Mohandas N , Hebbel RP
Published: October 2019

Initiation of vasocclusion in sickle disease pathophysiology may involve abnormal red blood cell (RBC) adhesivity to endothelium, a phenomenon influenced by both RBC and plasma factors. Using human umbilical vein endothelial cells and a gravity sedimentation adherence assay, we have examined thrombospondin (TSP) as a plasma factor in this adhesive event. The already-abnormal adherence of sickle RBCs in buffer/albumin is significantly augmented (P < .001) by the addition of TSP, with half-maximal effect at about 0.3 microgram/mL. This effect is abolished by antibodies to either TSP or glycoprotein (GP) IV (CD36), as well as peptides RGDS and CSVTCG. The even greater adherence (P < .005) of sickle RBCs in autologous platelet-rich plasma (without added TSP) is dramatically inhibited by alpha CD36 antibodies (OKM5 and alpha GPIV) and significantly diminished by alpha TSP, by peptides RGDS and CSVTCG, and by two antibodies to the vitronectin receptor (7E3 and LM609). Studies of density-separated subpopulations and of RBC adhesion to immobilized proteins, as well as analysis of sickle RBCs using fluorescence-activated cell sorting and single cell microfluorometry, show that TSP responsiveness is a feature of the immature sickle “stress” reticulocytes, which carry CD36 (and not GPIIbIIIa-like receptors) as the TSP-receptive moiety. The endothelial cell's participation in this phenomenon appears to be more complex, and the data are consistent with the notion that it involves TSP interaction with other plasma proteins and/or multiple receptor structures. Other potential adhesogenic proteins (plasma von Willebrand factor, vitronectin, fibrinogen, and fibronectin) neither exhibited an affinity for reticulocytes nor supported increased sickle RBC adherence when added to buffer/albumin in these assay systems. In aggregate, our results indicate that TSP may be the major promoter of RBC adhesivity in plasma, and they suggest that therapeutic benefit might derive from interference with sickle reticulocyte CD36, as achieved by antibodies and CSVTCG in these studies.
Impaired erythropoietin response to anemia after bone marrow transplantation
Authors: Miller CB , Jones RJ , Zahurak ML , Piantadosi S , Burns WH , Santos GW , Spivak JL
Published: October 2019

Delayed erythroid recovery is common after bone marrow transplantation (BMT), with some patients continuing to require red blood cell (RBC) transfusion support for as long as 1 year. While the etiology is multifactorial, inadequate stimulation of erythroid progenitors by the erythroid growth factor, erythropoietin, may play a role. In this study, the erythropoietin response to anemia of 70 consecutive patients undergoing BMT at the Johns Hopkins Oncology Center was compared with the erythropoietin response in uncomplicated iron deficiency anemia. Erythropoietin levels were elevated for the degree of anemia early after BMT; however, at the time of marrow recovery, erythropoietin levels were significantly suppressed in both allogeneic and autologous BMT patients compared with the iron-deficient patients. Patients with acute graft-versus-host disease (GVHD) had a more marked suppression of the erythropoietin response to anemia. In the patients who remained anemic for extended periods of time (up to 12 months after BMT), an inadequate erythropoietin response to anemia persisted. Delayed erythroid recovery after BMT is associated with inadequate erythropoietin levels. Therefore, recombinant human erythropoietin may be useful in the treatment of the anemia associated with both autologous and allogeneic BMT.
Thrombin interaction with platelet glycoprotein Ib: effect of glycocalicin on thrombin specificity
Authors: Jandrot-Perrus M , Clemetson KJ , Huisse MG , Guillin MC
Published: October 2019

We describe here the alteration of thrombin specificity induced by its interaction with glycocalicin. Glycocalicin is the external part of platelet glycoprotein Ib alpha (GPIb alpha) and contains binding sites for von Willebrand factor and thrombin. Taking advantage of its solubility, we have used glycocalicin in competition assays on various thrombin activities. Glycocalicin did not inhibit chromogenic substrate hydrolysis nor diisopropylfluorophosphate iPr2 (PF) incorporation, indicating that thrombin binding to GPIb does not alter access to or the conformation of the thrombin catalytic site. Glycocalicin competitively inhibited thrombin binding to fibrin (Ki = 0.1 mumol/L) and blocked fibrinogen clotting activity of thrombin. Glycocalicin also inhibited thrombin binding to thrombomodulin in a competitive manner (Ki = 3 to 5 mumol/L), but failed to prevent thrombin interaction with protein C in the absence of thrombomodulin. Previous results have indicated that GPIb binds to thrombin within the anion binding exosite masked by the carboxy-terminal hirudin peptide 54–65. The present results confirm the implication of the anion binding exosite in GPIb recognition, and further indicate that the thrombin binding site for GPIb overlaps with the thrombin binding sites for fibrin and thrombomodulin, whereas it is distinct from the thrombin binding site for protein C. Some of the structural requirements for thrombin binding to GPIb appear to be very similar to those reported for binding to its platelet receptor. However, thrombin-GPIb interaction does not appear to compete with receptor hydrolysis but rather increases the sensitivity and the rate of platelet responses elicited by the receptor.
Long-term engraftment of fresh human myeloma cells in SCID mice
Authors: Feo-Zuppardi FJ , Taylor CW , Iwato K , Lopez MH , Grogan TM , Odeleye A , Hersh EM , Salmon SE
Published: October 2019

Using highly purified myeloma cells from patient bone marrow, we established human-murine myeloma chimeras in severe combined immunodeficiency (SCID) mice and documented secretion of monoclonal human immunoglobulins (Hulgs) in the mice for up to 299 days. Monoclonality of circulating Hulgs was found only when highly purified myeloma cells were injected intraperitoneally. In contrast, injection of unfractionated myeloma marrow led to the development of polyclonal Hulgs in the SCID mice. The criteria for myeloma engraftment included prolonged presence of monoclonal Hulgs in the sera of SCID mice and/or detection of human myeloma cells in their tissues by immunohistochemical examination. Ninety-one percent (10/11) of the fresh purified myeloma specimens engrafted in the SCID mice. Fifty-five percent (6/11) of the patient samples resulted in human B-cell grafts, and 45% (5/11) were identifiable as human myeloma chimeras. Pathologic studies showed that most human plasmacytes were located in the peritoneal cavity but metastatic infiltrates were also found in other organs in 69% of the SCID-human myeloma chimeras. This chimeric model should provide a useful tool for characterization of growth modulation and microenvironmental interactions as well as a means of testing new therapeutic approaches to multiple myeloma.
Eosinophil peroxidase deficiency: morphological and immunocytochemical studies of the eosinophil-specific granules
Authors: Zabucchi G , Soranzo MR , Menegazzi R , Vecchio M , Knowles A , Piccinini C , Spessotto P , Patriarca P
Published: October 2019

Five eosinophil peroxidase (EPO)-deficient subjects were identified from 131,000 peripheral blood samples examined for routine automated analysis. The EPO-deficient eosinophils of these subjects met the main criteria established for EPO deficiency: absent or strongly decreased reaction for peroxidase, absent or strongly decreased staining with Sudan Black, and an increased ratio of the granule core volume to the total granule volume. In this report we show that this granule alteration is caused mainly by a decrease of its volume, particularly of the matrix, and that two other matrix proteins, eosinophil cationic protein and eosinophil derived neurotoxin, appear to be present in normal amounts in the EPO-deficient granules.
Protein phosphatase inhibitors okadaic acid and calyculin A alter cell shape and F-actin distribution and inhibit stimulus-dependent increases in cytoskeletal actin of human neutrophils
Authors: Kreienbuhl P , Keller H , Niggli V
Published: October 2019

The phosphatase inhibitors okadaic acid and calyculin A were found to elicit or to modify several neutrophil responses, suggesting that dephosphorylation plays a regulatory role. The concentrations of okadaic acid (> or = 1 mumol/L) that were effective on neutrophil functions (shape changes and marginal stimulation of pinocytosis) were shown to stimulate the incorporation of 32PO4 into many neutrophil proteins several-fold. Calyculin A was effective at 50-fold lower concentrations. In the presence of the inhibitors, the cells exhibited a nonpolar shape and the polarization response induced by chemotactic peptide was inhibited. Both phosphatase inhibitors also induced the association of F-actin with the cell membrane. A steady-state phosphatase activity is thus involved in maintaining shape and F-actin localization of resting cells. Inhibitors alone had no significant effect on the amount of cytoskeleton-associated actin. The increase in cytoskeletal actin observed at 30 minutes of stimulation with phorbol ester or 5 to 30 minutes of stimulation with chemotactic peptide, however, was abolished by okadaic acid or calyculin A, suggesting an important role of a phosphatase. In contrast, the early increase in cytoskeleton-associated actin observed at 1 minute of stimulation with peptide was not affected. This finding indicates that the increased association of actin with the cytoskeleton in the early and the later stages of neutrophil activation may be mediated by different signalling pathways.
Effects of synergistic cytokine combinations, low oxygen, and irradiated stroma on the expansion of human cord blood progenitors
Authors: Koller MR , Bender JG , Papoutsakis ET , Miller WM
Published: October 2019

Expansion of hematopoietic progenitor cells in the mononuclear cell (MNC) fraction of human cord blood was evaluated under atmospheres containing reduced (5%) and normal (20%) oxygen tensions. Cells were cultured with synergistic cytokine combinations in suspension (without stroma) and on irradiated bone marrow stroma. Addition of interleukin (IL)-3 and IL-6 (IL-3/IL-6) provided a greater expansion of both total and progenitor cells than IL-1 and IL-3 (IL-1/IL-3). IL-3/IL-6 maintained a higher level of progenitors throughout the 8-week culture period, whereas progenitors disappeared earlier from cultures with IL- 1/IL-3. This indicates that an earlier cell type was affected by IL- 3/IL-6, and/or that IL-3/IL-6 favored self-renewal while IL-1/IL-3 induced differentiation. Reduced oxygen tension enhanced the productivity of these long-term hematopoietic cultures (LTHC) under all conditions tested. In suspension cultures, reduced oxygen increased cumulative total cell production by 125% and 167%, and cumulative progenitor production by 68% and 21%, with IL-1/IL-3 and IL-3/IL-6, respectively. The presence of irradiated stroma increased cumulative progenitor cell production almost threefold in cultures without cytokines. In cultures with cytokines, the beneficial effect of stroma was less significant, but was greater under 20% O2 than 5% O2. Cultures under 5% O2 provided more progenitors and often maintained progenitors for 1 to 2 weeks longer than those under 20% O2. To quantitate more precisely the shift in cell populations induced by IL-3/IL-6 and stroma in cultures under 5% O2, flow cytometry analysis was used. By week 3, the addition of IL-3/IL-6 stimulated a 15-fold and 25-fold expansion of promyelocytes (CD15+CD11b-) in suspension and stromal cultures, respectively. Addition of IL-3/IL-6 also increased mature granulocyte (CD15hiCD11b+) and monocyte (CD15loCD11b+) numbers, while no effect was seen on T-(CD3+) or B- (CD19+) lymphocytes. Endogenous production of IL- 6 was significantly higher under 5% O2 in both suspension and stromal cultures, and IL-6 production was increased threefold by the addition of IL-1/IL-3. Very little IL-1 beta was produced in these cultures, and endogenous IL-3 and tumor necrosis factor (TNF)-alpha were undetectable by enzyme-linked immunosorbent assay (ELISA) analysis.
Hematopoietic growth factors upregulate the p65 type II interleukin-1 receptor on bone marrow progenitor cells in vitro
Authors: Dubois CM , Ruscetti FW , Jacobsen SE , Oppenheim JJ , Keller JR
Published: October 2019

Having previously shown that interleukin-1 (IL-1) induces the expression of IL-1 receptors (IL-1Rs) on bone marrow (BM) cells in vivo through an indirect mechanism, we studied whether hematopoietic growth factors (HGFs) could induce the expression of IL-1R on BM cells in vitro. In vitro treatment of light-density murine BM (LDBM) cells with either IL-3, IL-6, granulocyte--colony-stimulating factor (CSF), or granulocyte-macrophage--CSF caused a 5- to 10-fold upregulation of IL- 1R expression, whereas IL-1, IL-5, IL-7, and macrophage-CSF had no effect. Scatchard analysis showed one class of IL-1Rs on LDBM cells with an average of 66 +/- 20 sites per cells. After 24 hours of treatment with IL-3, the number of IL-1Rs increased to 413 +/- 125, without effecting the affinity. This effect required protein synthesis, but was independent of cell division. Purified lineage-negative progenitor cells (Lin-) did not express detectable levels of IL-1R, but 24 hours of treatment with IL-3, GM-CSF, and G-CSF stimulated IL-1-- specific binding. Autoradiographic analysis of Lin- cells showed that IL-1R induction by IL-3 occurs on undifferentiated blast cells. Affinity labeling of Lin- cells treated with HGFs showed an increase in a 65-Kd IL-1 binding protein that did not bind or compete with an anti- type I IL-1R antibody, suggesting that these cells expressed type II IL- 1R. These data suggest that IL-1 stimulation of myelopoiesis occurs by a mechanism involving IL-1R upregulation on hematopoietic progenitor cells by HGFs.
Interleukin-3 regulates the activity of the LYN protein-tyrosine kinase in myeloid-committed leukemic cell lines
Authors: Torigoe T , O'Connor R , Santoli D , Reed JC
Published: October 2019

The lymphokine interleukin-3 (IL-3) promotes the growth and survival of immature hematopoietic cells. Previous studies have shown that IL-3 induces rapid increases in protein-tyrosine kinase (PTK) activity in IL- 3--dependent cells. Unlike some other hematopoietic growth factor receptors (eg, c-fms and c-kit), however, the known subunits of the IL- 3 receptor (IL-3R) lack intrinsic kinase activity. Recently, it was reported that the IL-2R (whose p75 beta-subunit shares sequence homology with a known murine IL-3R subunit and a common beta-subunit of the human IL-3R and granulocyte-macrophage colony-stimulating factor [GM-CSF] receptors) can physically associate with and regulate the activity of the SRC-family PTK, p56-LCK. Because most IL-3--dependent cells contain p53/56-LYN, but not p56-LCK, we explored the effects of IL-3 on the activities of LYN and other SRC-like PTKs in two human leukemic cell lines, AML-193 and TALL-101, which are phenotypically myeloid, and whose in vitro growth is dependent on IL-3. These cells expressed four of the eight known SRC-family proto-oncogenes: lyn, fyn, yes, and hck. When these factor-dependent leukemic cell lines were deprived of lymphokine to achieve cellular quiescence and then restimulated with IL-3, rapid increases (detectable within 1 minute and maximal by 10 minutes) were observed in the activity of the p53/56-LYN kinase, as assessed by in vitro kinase assays. In contrast, no alteration in the activities of other SRC-family PTKs present in these cells was detected after restimulation with IL-3 under the same conditions. This effect of IL-3 reflected an increase in the specific activity of the LYN kinase, because levels of the 53-Kd and 56-Kd LYN proteins were unaltered by IL-3 stimulation, as assessed by immunoblotting. Furthermore, the magnitude of these inducible increases in LYN kinase activity was dependent on the concentration of IL-3, and correlated with IL-3--induced proliferation. The IL-3--induced upregulation of LYN kinase activity may be mediated by the 120-Kd common subunit of the human IL-3 and GM-CSF receptors, because GM-CSF also stimulated marked increases in the activity of the LYN kinase, whereas granulocyte-CSF (G-CSF) did not, despite inducing cellular proliferation. These observations provide the first example of an IL-3-- regulable PTK, and strongly suggest that the p53/56-LYN kinase participates in early IL-3--initiated signalling events, at least in some human leukemic cell lines.
Comparison of in vitro growth characteristics of blast cell progenitors (CFU-L) in patients with myelodysplastic syndromes and acute myeloid leukemia
Authors: Aul C , Gattermann N , Schneider W
Published: October 2019

Current knowledge is inadequate to explain the different patterns of blast cell accumulation in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). We compared the growth patterns of blast cell progenitors (CFU-L) in 23 patients with advanced MDS and 32 patients with de novo AML. Circulating blast progenitors were identified in 74% of MDS and 81% of AML samples. Primary plating efficiencies (PE1) were similar in both disorders, despite marked differences in peripheral blast cell concentrations. By cytological and cytochemical examination, colonies from MDS patients were indistinguishable from those obtained in AML. Cell cycle status was assessed by loss of colony formation following short-term exposure to cytosine arabinoside. CFU-L suicide rates (median, range) were 40% (12% to 77%) in MDS and 60.5% (27% to 98%) in AML. Actively proliferating blast cell progenitors are thus not confined to AML, but are also present in the majority of MDS patients. An important difference between MDS and AML was found when self-renewal capacity of CFU-L was examined by means of secondary plating efficiencies (PE2). Colonies could be successfully replated in 74% of AML cases. PE2 showed marked heterogeneity (2 to 730 colonies/10(5) mononuclear cells), with some values indicating excessive self-renewal capacity of CFU-L. In contrast, 62% of the MDS specimens failed to produce any secondary colony growth, and PE2 in the remaining cases was low (5 to 99/10(5) MNC). We conclude that a different balance between self-renewal and determination could be responsible for a slower pace of clonal expansion in MDS, even if the proliferative activity of clonogenic cells is similar to that in AML.
Recombinant glycosylated human interleukin-6 accelerates peripheral blood platelet count recovery in radiation-induced bone marrow depression in baboons
Authors: Herodin F , Mestries JC , Janodet D , Martin S , Mathieu J , Gascon MP , Pernin MO , Ythier A
Published: October 2019

This report was aimed at confirming the potential clinical use for a genetically engineered glycosylated human interleukin-6 (rhIL-6) in hematopoiesis. Its tolerance and efficacy were assessed on hematopoietic restoration after neutron radiation-induced bone marrow injury on baboons, which represent an adequate model of parallelism for studying hematology in the human. The particular neutron radiation absorption pattern in the body allows the preservation of underexposed bone marrow areas that mimics an autotransplantation-like situation. An initial dose finding study (1 microgram up to 20 micrograms/kg/d for 8 consecutive days) in normal baboons established a dose-dependent response regarding the peripheral platelet count (range of increase, 1.5- to 4-fold). A significant elevation in white blood cell (WBC) count, as well as a substantial reversible normochromic normocytic anemia, were observed for the highest doses only (10 and 20 micrograms/kg/d). All rhIL-6 administered doses were clinically well tolerated. In myelosuppressed baboons, a selected dose of 10 micrograms/kg/d of rhIL-6 for 13 consecutive days significantly lessened the degree of induced thrombocytopenia as compared with the control group (P = .01) and shortened the time to occurrence of the nadir, showing that the onset of recovery occurs much earlier, ie, an average of 5 days (P = .003), in the treated group. Moreover, this accelerated platelet recovery is evidenced by an 8-day shorter mean time back to baseline values (P = .03) in the rhIL-6--treated animals. At this dose no effect was observed on the WBC recovery pattern. Importantly rhIL-6 did not accentuate the radiation-induced anemia and was clinically well tolerated. All tested monkeys recovered from their induced pancytopenia and no animal loss was recorded. IL-6, tumor necrosis factor, and IL-1 blood measurements are reported. In conclusion, rhIL-6 is a potent thrombopoietic factor for the treatment of induced thrombocytopenia in nonhuman primates at a clinically well- tolerated dose.
Plasma crosslinked fibrin polymers: quantitation based on tissue plasminogen activator conversion to D-dimer and measurement in normal and patients with acute thrombotic disorders
Authors: Kornberg A , Francis CW , Marder VJ
Published: October 2019

Plasma crosslinked fibrin polymers (XLFP) are formed as a result of in vivo hemostatic activation and are elevated in thrombotic disease. We have investigated the plasmic degradation of plasma XLFP in vitro to provide information regarding the pattern of crosslinking and the composition of degradation products. Plasma XLFP were identified by sodium dodecyl sulfate (SDS)-agarose electrophoresis and Western blotting and quantitated by gel scanning. D-dimer was measured by enzyme-linked immunosorbent assay and the results were verified by SDS- polyacrylamide gel electrophoresis and Western blotting of the digests. Complete degradation of XLFP occurred only after supplementation of plasma with plasminogen (5 U/mL) and incubation with recombinant tissue plasminogen activator (rt-PA), indicating that the normal plasma plasminogen concentration limits plasmic degradation in vitro. Gel electrophoresis showed that the principal terminal degradation products of XLDP were fragments D, DD, and E, indicating that crosslinking occurred primarily through gamma chain dimers. After adding a low concentration of thrombin to plasma in vitro, XLFP increased progressively before clotting, and the concentration correlated with the increase in the D-dimer concentration after degradation (r = .98). Plasma XLFP and D-dimer concentrations in plasmic digests were significantly elevated in patients with stroke (150 +/- 83 micrograms/mL and 88 +/- 32 micrograms/mL), myocardial infarction (217 +/- 110 micrograms/mL and 84 +/- 30 micrograms/mL), and venous thrombosis (187 +/- 80 micrograms/mL and 86 +/- 19 micrograms/mL) compared with normals (28 +/- 12 micrograms/mL and 25 +/- 7 micrograms/mL). There was a strong correlation between the plasma concentration of XLFP and the D-dimer immunoreactivity of plasma after plasmic degradation (r = .87). The results indicate that XLFP in plasma are crosslinked primarily through gamma chains and degrade to fragment DD with plasminogen activation. Also, the immunoreactivity of in vitro plasmic digests of plasma reflects the concentration of XLFP and may provide a useful indirect measure of in vivo hemostatic activation in patients with thrombotic disease.
Phenotypic changes induced by interleukin-2 (IL-2) and IL-3 in an immature T-lymphocytic leukemia are associated with regulated expression of IL-2 receptor beta chain and of protein tyrosine kinases LCK and LYN
Authors: O'Connor R , Torigoe T , Reed JC , Santoli D
Published: October 2019

We have previously reported the establishment of an interleukin-3 (IL- 3)-dependent and phenotypically myeloid cell line (TALL-103/3), obtained by culturing cells from an immature T-lymphoblastic leukemia in the presence of IL-3. These cells differentiated into a T-lymphoid cell line (TALL-103/2) upon removal of IL-3 and incubation in IL-2. Despite the different phenotype, the two cell lines remained karyotypically and genotypically identical. Here, we have analyzed the phenotypic changes and the signaling events induced by these two lymphokines in TALL-103/3 cells by switching them to temporary growth in IL-2 and returning them to IL-3. All four sublines obtained (the myeloid in IL-3 and the lymphoid in IL-2) expressed RNA for CD3, IL-2 receptor (R) alpha, and T-cell receptor (TCR)-gamma and -delta chains. However, cells cultured in IL-3 failed to express detectable levels of the IL-2R beta chain at both the protein and RNA levels, whereas cells exposed to IL-2 always expressed IL-2R beta. In parallel with the changes in IL-2R beta expression, the SRC-like protein tyrosine kinase (PTK) p56 LCK could not be detected in IL-3-dependent cells, but was abundant in the IL-2-dependent cells and underwent markedly increased autophosphorylation in response to IL-2. In contrast, p53/p56 LYN was highly expressed in IL-3-dependent cells, and greatly decreased when these cells were switched to growth in IL-2. LYN kinase autophosphorylation modestly increased in response to IL-3. None of the other kinases in the SRC family that were tested underwent increased autophosphorylation after lymphokine stimulation, indicating the specificity of IL-2 for LCK and of IL-3 for LYN. The TALL-103 cell lines provide a unique system to study the interaction between lymphokines and SRC-family PTKs in signal transduction pathways leading to hematopoietic cell differentiation.
Blood platelets stimulate the expression of chondroitin sulfate proteoglycan in human monocytes
Authors: Uhlin-Hansen L , Langvoll D , Wik T , Kolset SO
Published: October 2019

Mononuclear phagocytes synthesize chondroitin sulfate proteoglycan (CSPG), which is constitutively secreted. Because mononuclear phagocytes are known to interact with blood platelets, the effect of platelets on the release of CSPG in cultured human monocytes was investigated. After 6 days in vitro, the monocytes were supplied with fresh medium with different additions and subsequently exposed to [35S]sulfate for 24 hours before the medium fractions were harvested and analyzed for content of [35S]CSPG. Indirect evidence for the release of stimulatory factors from blood platelets was found when the addition of medium containing 50% serum made from platelet-rich plasma increased the expression of [35S]CSPG almost sevenfold compared with serum-free medium, whereas medium containing 50% serum made from platelet-depleted plasma increased the expression of [35S]CSPG about fourfold. Further, direct evidence for the stimulatory effect of platelets was found as the addition of autologous platelets to serum- free medium increased the expression of [35S]CSPG about threefold, and addition of supernatant from a corresponding number of thrombin- stimulated platelets was almost as efficient. The effect of five different platelet-derived factors (which are all present in serum) was investigated. Both platelet-derived growth factor (PDGF), platelet factor 4 (PF 4), and prostaglandin E2 (PGE2) used in physiologic concentrations were found to stimulate the expression of [35S]CSPG twofold to threefold, whereas transforming growth factor-beta had a slight inhibitory effect. 12-Hydroxyeicosatetraenoic acid had no significant effect on the expression of [35S]CSPG. Further evidence for the stimulatory effect of PDGF, PF 4, and PGE2 was found as serum depleted of these factors had significantly less stimulatory effect than control serum. The increased incorporation of [35S]sulfate into [35S]CSPG in cultures stimulated with serum or platelet-derived factors was not due to differences in molecular size or extent of sulfation of the proteoglycan molecules.
Role of individual gamma-carboxyglutamic acid residues of activated human protein C in defining its in vitro anticoagulant activity
Authors: Zhang L , Jhingan A , Castellino FJ
Published: October 2019

To evaluate the contributions of individual gamma-carboxyglutamic acid (gla) residues to the overall Ca(2+)-dependent anticoagulant activity of activated human protein C (APC), we used recombinant (r) DNA technology to generate protein C (PC) variants in which each of the gla precursor glutamic acid (E) residues (positions 6, 7, 14, 16, 19, 20, 25, 26, and 29) was separately altered to aspartic acid (D). In one case, a gla26V mutation ([gla26V]r-PC) was constructed because a patient with this particular substitution in coagulation factor IX had been previously identified. Two additional r-PC mutants were generated, viz, an r-PC variant containing a substitution at arginine (R) 15 ([R15]r-PC), because this particular R residue is conserved in all gla- containing blood coagulation proteins, as well as a variant r-PC with substitution of an E at position 32 ([F31L, Q32E]r-PC), because gla residues are found in other proteins at this sequence location. This latter protein did undergo gamma-carboxylation at the newly inserted E32 position. For each of the 11 recombinant variants, a subpopulation of PC molecules that were gamma-carboxylated at all nonmutated gla- precursor E residues has been purified by anion exchange chromatography and, where necessary, affinity chromatography on an antihuman PC column. The r-PC muteins were converted to their respective r-APC forms and assayed for their amidolytic activities and Ca(2+)-dependent anticoagulant properties. While no significant differences were found between wild-type (wt) r-APC and r-APC mutants in the amidolytic assays, lack of a single gla residue at any of the following locations, viz, 7, 16, 20, or 26, led to virtual complete disappearance of the Ca(2+)-dependent anticoagulant activity of the relevant r-APC mutant, as compared with its wt counterpart. On the other hand, single eliminations of any of the gla residues located at positions 6, 14, or 19 of r-APC resulted in variant recombinant molecules with substantial anticoagulant activity (80% to 92%), relative to wtr-APC. Mutation of gla residues at positions 25 and 29 resulted in r-APC variants with significant but low (24% and 9% of wtr-APC, respectively) levels of anticoagulant activity. The variant, [R15L]r-APC, possessed only 19% of the anticoagulant activity of wrt-APC, while inclusion of gla at position 32 in the variant, [F31L, Q32gla]r-APC, resulted in a recombinant enzyme with an anticoagulant activity equivalent to that of wtr-APC.
Enhanced expression of interleukin-3 and granulocyte-macrophage colony- stimulating factor receptor subunits in murine hematopoietic cells stimulated with hematopoietic growth factors
Authors: Liboi E , Jubinsky P , Andrews NC , Nathan DG , Mathey-Prevot B
Published: October 2019

AIC2A and AIC2B are closely related genes encoding components of the receptors for murine interleukin-3 (IL-3) (AIC2A) and granulocyte- macrophage colony-stimulating factor (GM-CSF) and IL-5 (AIC2B). We have studied the parallel regulation of expression of these genes in erythroid and myeloid progenitor cell lines. AIC2A and AIC2B transcription was transiently induced in these cells in response to a variety of hematopoietic growth factors, including erythropoietin (EPO), monocyte-CSF, IL-3, GM-CSF, and stem cell factor (SCF or kit ligand). Run-on assays established that the increase occurred mainly at the transcriptional level. Immunoprecipitation experiments confirmed that the increase in messenger RNA expression resulted in augmented synthesis of both AIC2A and AIC2B proteins, and binding studies further showed these proteins to be functional. We observed a fourfold increase in low-affinity IL-3 sites in an erythroid precursor cell line stimulated with EPO, and a threefold increase in GM-CSF high-affinity sites in a myeloid cell line stimulated with IL-3. In addition, we showed that the increase in the IL-3 receptor chain AIC2A in the erythroid precursor cell line correlated with the ability of IL-3 to exert a cooperative effect with EPO in the induction of beta-globin in these cells.
Sensitivity of fresh acute myeloid leukemia cells to etoposide: relationship with cell growth characteristics and DNA single-strand breaks
Authors: Chiron M , Demur C , Pierson V , Jaffrezou JP , Muller C , Saivin S , Bordier C , Bousquet C , Dastugue N , Laurent G
Published: October 2019

In this study, we evaluated the individual in vitro sensitivity of fresh acute myeloid leukemia (AML) cells to VP-16, and attempted to correlate VP-16 cytotoxicity with AML cell growth characteristics and drug-induced DNA single-strand breaks (SSB). Primary (PE1) colony inhibition assays allowed us to characterize two distinct groups of AML: group I (patients 1 through 6), which displayed sensitivity to VP- 16 similar to that of normal CFU-GM (IC90 of 20.52 +/- 2.44 micrograms/mL v 20.48 +/- 2.23 micrograms/mL after 1 hour drug exposure, respectively); and group II (patients 7 through 11), which was more sensitive to VP-16 (IC90 of 7.26 +/- 2.93 micrograms/mL, P = .004). Subsequently, groups I and II were termed normosensitive and hypersensitive, respectively. This objective VP-16 sensitivity classification, as determined by PE1, remained unaltered when assessed by secondary (PE2) colony inhibition assay (evaluating the self-renewal fraction of AML progenitors), or by cytofluorometric viability assay (evaluating the ultimately differentiated blast cell population). These findings would suggest that individual sensitivity to VP-16 of a particular cell population is maintained throughout CFU-AML differentiation. Finally, we report that sensitivity of AML cells to VP- 16 did not correlate either with cell growth characteristics or with SSB generation. Indeed, AML cell sensitivity to VP-16 appeared more closely related to DNA repair kinetics after drug removal, ie, hypersensitivity being essentially characterized by a prolonged retention of SSB during the posttreatment period. Interestingly, the established HL-60 cell line, which presented greater sensitivity to VP- 16 cytotoxicity than KG1, HEL, and K562, was also found to exhibit delayed DNA SSB repair kinetics, as compared with the other AML cell lines. These results suggest that hypersensitivity to VP-16 of some AML cells may be related to a deficient DNA-repair mechanism.
c-kit Gene was not transcribed in cultured mast cells of mast cell- deficient Wsh/Wsh mice that have a normal number of erythrocytes and a normal c-kit coding region
Authors: Tono T , Tsujimura T , Koshimizu U , Kasugai T , Adachi S , Isozaki K , Nishikawa S , Morimoto M , Nishimune Y , Nomura S
Published: October 2019

The Wsh is a mutant allele at the W (c-kit) locus of mice. Mice of Wsh/Wsh genotype have white hairs and black eyes. Although adult C57BL/6-Wsh/Wsh mice were not anemic, they showed a remarkable depletion of mast cells. Most homozygous or double heterozygous mutant mice at the W (c-kit) locus, of which mast-cell depletion was comparable to that of Wsh/Wsh mice, are deficient in germ cells. However, male and female Wsh/Wsh mice have an appreciable number of germ cells in their gonads. We investigated the mechanism of specific depletion of mast cells in Wsh/Wsh mice. Cultured mast cells (CMC) derived from the spleen of Wsh/Wsh mice neither attached to normal (+/+) fibroblasts nor survived in the coculture with +/+ fibroblasts. The c-kit messenger RNA (mRNA) was strongly expressed in +/+ CMC, but not detectable in Wsh/Wsh CMC. Despite the lack of c-kit mRNA in Wsh/Wsh CMC, the c-kit mRNA was normally detectable in the cerebellum and weakly detectable in the testis and spleen of Wsh/Wsh mice. No significant changes were found in the nucleotide sequence of the c-kit transcripts obtained from the cerebellum of Wsh/Wsh mice. Development of mast cells, erythrocytes, and germ cells in Wsh/Wsh mice appeared to be parallel with the magnitude of the c-kit gene expression in each cell type.
Partial deletion of an antithrombin III allele in a kindred with a type 1 deficiency
Authors: Fernandez-Rachubinski F , Rachubinski RA , Blajchman MA
Published: October 2019

This report details the precise mapping of a partially deleted human antithrombin III (AT-III) allele, found in a kindred with an inherited type 1 AT-III deficiency. Using truncated AT-III probes generated by polymerase chain reaction (PCR) amplification from a full-length AT-III cDNA, as well as other genomic probes specific for the 5′ upstream region of the AT-III gene, we were able to characterize a partial deletion on an AT-III allele encompassing exons 1 and 2 of the AT-III gene, and a region 5′ to the coding sequences. The absence of the 5′ upstream region in the affected AT-III allele was confirmed directly by the PCR amplification of a 1.5-kb polymorphic fragment of genomic DNA samples from family members. The precise determination of the 5′ breakpoint of the affected allele was made possible by two different approaches: (1) subcloning plus biotin capture PCR, or (2) inverse PCR. This allowed us to confirm the mapping of the deletion obtained by Southern analysis; to show that the 3′ region of the mutant AT-III allele, including exons 3 to 7, was intact; and to sequence approximately 0.7 kb upstream to the breakpoint in the mutant allele. Furthermore, PCR amplification of the region of the breakpoint provided unique products detectable only in affected members of this kindred. The breakpoint in the partially deleted allele is 480 bp upstream from the 5′ boundary of exon 3. No significant homology was found between the 0.7-kb sequence upstream to the breakpoint of the mutant allele and known human sequences.