bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutual inhibition of murine erythropoiesis and granulopoiesis during combined erythropoietin, granulocyte colony-stimulating factor, and stem cell factor administration: in vivo interactions and dose-response surfaces
Authors: de Haan G , Engel C , Dontje B , Nijhof W , Loeffler M
Published: October 2019

We investigated the in vivo effects of erythropoietin (EPO) on granulopoiesis and, conversely, the effect of granulocyte colony- stimulating factor (G-CSF) treatment on erythropoiesis. Recombinant human EPO at four different doses in combination with recombinant human G-CSF also at four different doses was simultaneously administered for 7 days to splenectomized mice. In total, 16 different combinations of growth factors were thus tested. G-CSF administration increased granulocyte production as expected, whereas immature colony-forming unit granulocyte-macrophage numbers were decreased. EPO analogously increased late erythroid cell numbers. Both EPO and G-CSF dose- dependently inhibited late cell stages of the opposite lineage, with EPO abrogating G-CSF-stimulated granulopoiesis and, conversely, G-CSF inhibiting EPO-stimulated erythropoiesis. In a subsequent experiment, we tested whether these lineage-competitive effects could be prevented by coadministering stem cell factor (SCF). In these three factor- treated mice, all granuloid and erythroid cell stages increased, thereby reducing the effect of the mutual inhibition. We conclude that EPO-stimulated erythropoiesis and G-CSF-stimulated granulopoiesis inhibited each other at a late level. Simultaneous SCF administration increased the input into both the erythroid and granuloid compartment and thereby compensated the mutual inhibition. This study shows that intricate dose-response relationships exist between various growth factors that should be carefully analyzed before combinations of these factors are used in humans.
Prevalence and clinical significance of elevated antiphospholipid antibodies in patients with idiopathic thrombocytopenic purpura
Authors: Stasi R , Stipa E , Masi M , Oliva F , Sciarra A , Perrotti A , Olivieri M , Zaccari G , Gandolfo GM , Galli M
Published: October 2019

Antibodies against phospholipid antigens (APA) have been demonstrated in idiopathic thrombocytopenic purpura (ITP), but their clinical and pathogenetic significance has remained elusive. In this study we analyzed the prevalence and clinical features of ITP patients with elevated APA. In addition, we prospectively evaluated APA levels after treatment with corticosteroids and compared them with platelet- associated immunoglobulin (PAIgG) titers. We studied 149 patients with newly diagnosed ITP. Of these, 78 had a platelet count less than 50 x 10(9)/L and received an initial treatment with oral prednisone (PDN). In 71 asymptomatic cases with platelet counts between 50 x 10(9)/L and 120 x 10(9)/L, no therapy was scheduled. However, in five of them, the platelet count fell below 50 x 10(9)/L after more than 12 months; these patients were treated with PDN. Tests for APA included the measurement of anticardiolipin antibodies (ACA) with a solid-phase immunoassay and the detection of the lupus-like anticoagulant (LA) activity with coagulation tests that included kaolin-clotting time, dilute Russel's Viper venom time, activated partial thromboplastin time (aPTT), and dilute aPTT. Controls consisted of 174 apparently healthy subjects. Either LA or elevated ACA was seen in 69 patients (46.3%) at diagnosis. LA and ACA were both elevated in 24 cases (16.1% of the overall patient population and 34.8% of patients with high APA concentrations). No correlation was found between LA ratio values and ACA-IgG or -IgM titers, or between ACA-IgG and ACA-IgM levels. The presence of these antibodies was not associated with sex, age, platelet count, or the severity of hemorrhages. PAIgG was detected in 106 of 127 cases (83%). Again, no relationship was observed with clinical parameters or with APA levels. However, all cases with elevated APA also had increased PAIgG. With regard to the clinical course, we were not able to detect any significant difference between patients with normal and elevated APA. An initial complete response to prednisone treatment was observed in 43 of 83 cases (51.8%), with 13 (15.7%) achieving a prolonged complete remission. APA levels were not significantly modified after PDN therapy and on relapse. We conclude that APA positivity is a common finding in patients with ITP and does not select a category with different clinical features. APA levels are not influenced by immunosuppressive therapy with steroids and are not related to the activity of the disease. Therefore, we do not support a role for APA in the pathogenesis of ITP.
Clonal dysregulation of the antibody response to tetanus-toxoid after bone marrow transplantation
Authors: Gerritsen EJ , Van Tol MJ , Van 't Veer MB , Wels JM , Khouw IM , Touw CR , Jol-Van Der Zijde CM , Hermans J , Rumke HC , Radl J
Published: October 2019

After bone marrow transplantation (BMT), a prolonged dysregulation of humoral immunity can be observed. In the present study, we investigated whether this is reflected in an abnormal production of specific antibodies (Ab) to the T-cell-dependent recall antigen tetanus-toxoid (TT). The study group consisted of children receiving transplants of an unmodified allogeneic graft and of adults receiving either a T-cell- depleted allogeneic or an unmodified autologous BM graft. Findings were compared with those in healthy controls. In pediatric graft recipients, who were routinely revaccinated early after BMT, the Ab response was quantitatively superior to that in adult graft recipients who did not receive early revaccination. In the majority of graft recipients, the time period after vaccination required to reach the peak level of antibodies was prolonged and the number of responding TT-specific B- cell clones was markedly decreased in comparison with controls. In controls, a low frequency of dominant B-cell clones may produce low quantities of homogeneous Ab components (H-Ab) against a heterogeneous background. However, in BM graft recipients, “overshooting” of Ab production by separate B-cell clones was observed, resulting in the development of H-Ab at a relatively high concentration. These abnormalities were present up to 10 years after BMT, irrespective of either the age of the recipient, the modulation of the graft, or the vaccination schedule used. It is hypothesized that the dysregulated Ab production is the consequence of activation of a restricted number of resting memory B cells, present in germinal centers, repopulating gradually after BMT. Our data show that routine revaccination early after BMT improves the humoral immune response. However, because of a clonally dysregulated Ab production, long-lasting qualitative defects may be present even after normalization of Ab titers.
Glucose-6 phosphate dehydrogenase mutations and haplotypes in various ethnic groups
Authors: Xu W , Westwood B , Bartsocas CS , Malcorra-Azpiazu JJ , Indrak K , Beutler E
Published: October 2019

Mutations that produce glucose-6-phosphate dehydrogenase (G6PD) deficiency have been identified in samples from patients with hemolytic disease in the United States, and in G6PD-deficient samples from Greece, the Canary Islands, the Czech and Slovak Republics, South China, and in samples from the Coriell Cell Repository. Eight new mutations are described. Particularly unusual were a nonsense mutation (“G6PD Georgia”1284A), a deletion of six bases (“G6PD Stony Brook” 724– 729 del) coding for two amino acids, and a deletion of the invariant dinucleotide ApG at the 3′ acceptor splice site in the highly conserved sequence between intron 10 and exon 11 (“G6PD Varnsdorf”). In addition, five new missense point mutations were identified: “G6PD Cleveland”820A creates a deduced AA 274 Glu-->Lys; “G6PD West Virginia”910T AA 303 Val- ->Phe; “G6PD Fushan”1004A, AA 335 Ala-->Asp; “G6PD Olomouc”1141C AA 381 Leu-->Phe; and “G6PD Praha”1166G AA 389 Glu-->Gly. All of the new mutations except for “G6PD Fushan”1004A were found in patients with hereditary nonspherocytic hemolytic anemia. A coincidental finding in the case of G6PD “West Virginia” was a C-->T transition at nucleotide 1,191. This silent mutation, Asn-->Asn, appears to be rare. Haplotype analysis of mutations in samples from the Canary Islands and South China agreed with previous findings.
Harvesting and enrichment of hematopoietic progenitor cells mobilized into the peripheral blood of normal donors by granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF: potential role in allogeneic marrow transplantation
Authors: Lane TA , Law P , Maruyama M , Young D , Burgess J , Mullen M , Mealiffe M , Terstappen LW , Hardwick A , Moubayed M
Published: October 2019

To explore the use of stem/progenitor cells from peripheral blood (PB) for allogeneic transplantation, we have studied the mobilization of progenitor cells in normal donors by growth factors. Normal subjects were administered either granulocyte-macrophage colony-stimulating factor (GM-CSF) at 10 micrograms/kg/d, or G-CSF at 10 micrograms/kg/d, or a combination of G- and GM-CSF at 5 micrograms/kg/d each, administered subcutaneously for 4 days, followed by leukapheresis on day 5. Mononuclear cells expressing CD34 (CD34+ cells) were selectively enriched by affinity labeling using Dynal paramagnetic microspheres (Baxter Isolex; Baxter Healthcare Corp, Santa Ana, CA). The baseline CD34+ cells in peripheral blood before mobilization was 0.07% +/- 0.05% (1.6 +/- 0.7/microL; n = 18). On the fifth day after stimulation (24 hours after the fourth dose), the CD34+ cells were 0.99% +/- 0.40% (61 +/- 14/microL) for the 8 subjects treated with G-CSF, 0.25% +/- 0.25% (3 +/- 3/microL, both P < .01 v G-CSF) for the 5 subjects administered GM-CSF, and for the 5 subjects treated with G- and GM-CSF, 0.65% +/- 0.28% (41 +/- 18/microL, P < .5 v GM-CSF). Parallel to this increase in CD34+ cells, clonogenic assays showed a corresponding increase in CFU- GM and BFU-E. The total number of CD34+ cells collected from the G-CSF group during a 3-hour apheresis was 119 +/- 65 x 10(6) and was not significantly different from that collected from the group treated with G- and GM-CSF (101 +/- 35 x 10(6) cells), but both were greater than that from the group treated with GM-CSF (12.6 +/- 6.1 x 10(6); P < .01 for both comparisons). Analysis of the CD34+ subsets showed that a significantly higher percentage of cells with the CD34+/CD38- phenotype is found after mobilization with G- and GM-CSF. In the G-CSF group, immunomagnetic selection of CD34+ cells permitted the enrichment of the CD34+ cells in the apheresis product to 81% +/- 11%, with a 48% +/- 12% yield and to a purity of 77% +/- 21% with a 51% +/- 15% recovery in the G- and GM-CSF group. T cells were depleted from a mean of 4.5 +/- 2.0 x 10(9) to 4.3 +/- 5.2 x 10(6) after selection, representing 99.9% depletion. We conclude that it is feasible to collect sufficient numbers of PB progenitor cells from normal donors with one to two leukapheresis procedures for allogeneic transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)
Protein C deficiency in a controlled series of unselected outpatients: an infrequent but clear risk factor for venous thrombosis (Leiden Thrombophilia Study) [see comments]
Authors: Koster T , Rosendaal FR , Briet E , van der Meer FJ , Colly LP , Trienekens PH , Poort SR , Reitsma PH , Vandenbroucke JP
Published: October 2019

A deficiency of protein C (PC), antithrombin, or protein S is strongly associated with deep-vein thrombosis in selected patients and their families. However, the strength of the association with venous thrombosis in the general population is unknown. This study was a population-based, patient-control study of 474 consecutive outpatients, aged less than 70 years, with a first, objectively diagnosed, episode of venous thrombosis and without an underlying malignant disease, and 474 healthy controls who matched for age and sex. Relative risks were estimated as matched odds ratios. Based on a single measurement, there were 22 (4.6%) patients with a PC deficiency (PC activity, less than 0.67 U/mL or PC antigen, less than 0.33 U/mL when using coumarins). Among the controls, the frequency was 1.5% (seven subjects). Thus, there is a threefold increase in risk of thrombosis in subjects with PC levels below 0.67 or 0.33 U/mL [matched odds ratio, 3.1; 95% confidence interval (CI), 1.4 to 7.0]. When a PC deficiency was based on two repeated measurements, the relative risk for thrombosis increased to 3.8 (95% CI, 1.3 to 10); when it was based on DNA-confirmation, the relative risk increased further to 6.5 (95% CI, 1.8 to 24). In addition, there was a gradient in thrombosis risk, according to PC levels. The results for antithrombin are similar to those for PC, although less pronounced (relative risk, 2.2; 95% CI, 1.0 to 4.7). We could not find an association between reduced total protein S (relative risk, 0.7; 95% CI, 0.3 to 1.8) or free protein S levels (relative risk, 1.6; 95% CI, 0.6 to 4.0) and thrombosis risk. Although not very frequent, PC and antithrombin deficiency are clearly associated with an increase in thrombosis risk.
Overexpression of the HOX4A (HOXD3) homeobox gene in human erythroleukemia HEL cells results in altered adhesive properties
Authors: Taniguchi Y , Komatsu N , Moriuchi T
Published: October 2019

We previously isolated the human homeobox gene HOX4A (HOXD3) on chromosome 2 from a human genomic library and determined its nucleotide sequence. In the present study, expression of the HOX4A gene was investigated in human hematopoietic cell lines. Reverse transcriptase-mediated polymerase chain reaction analysis showed that the HOX4A gene was expressed in erythroleukemia HEL and K562 cells but not in promyelocytic leukemia HL-60 cells. To study the role of the HOX4A gene in erythropoiesis, expression vectors containing the HOX4A gene in the sense or antisense orientation were introduced into HEL cells. The sense transfectants overexpressing the HOX4A gene formed aggregates, which were composed of densely associated cells adhering to tissue-culture dishes, whereas the parental HEL cells and antisense transfectants adhered poorly to the dishes. Furthermore, the sense transfectants overexpressing the HOX4A gene attached more efficiently to fibronectin and collagen than did the antisense transfectants and parental HEL cells. Northern blot analysis showed that integrin beta 3 mRNA levels were significantly increased in the HEL cells overexpressing the HOX4A gene, whereas the integrin beta 1 and alpha IIb mRNA levels did not show a distinct correlation with HOX4A mRNA levels. Fluorescence-activated cell sorting analysis showed that the sense transfectants overexpressing the HOX4A gene expressed increased levels of integrin alpha IIb beta 3 (GP IIb-IIIa) complex as compared with the parental HEL cells and antisense transfectants. These results implicate the homeobox gene HOX4A in the regulation of cell adhesion processes.
In vitro and in vivo activity of topotecan against human B-lineage acute lymphoblastic leukemia cells
Authors: Uckun FM , Stewart CF , Reaman G , Chelstrom LM , Jin J , Chandan-Langlie M , Waddick KG , White J , Evans WE
Published: October 2019

Topotecan [(S)-9-dimethylaminomethyl-10-hydroxycamptothecin hydrochloride; SK&F 104864-A, NSC 609699], a water soluble semisynthetic analogue of the alkaloid camptothecin, is a potent topoisomerase I inhibitor. Here we show that topotecan stabilizes topoisomerase I/DNA cleavable complexes in radiation-resistant human B-lineage acute lymphoblastic leukemia (ALL) cells, causes rapid apoptotic cell death despite high-level expression of bcl-2 protein, and inhibits ALL cell in vitro clonogenic growth in a dose-dependent fashion. Furthermore, topotecan elicited potent antileukemic activity in three different severe combined immunodeficiency (SCID) mouse models of human poor prognosis ALL and markedly improved event-free survival of SCID mice challenged with otherwise fatal doses of human leukemia cells at systemic drug exposure levels that can be easily achieved in children with leukemia.
Overexpression of cyclin D2 in chronic B-cell malignancies
Authors: Delmer A , Ajchenbaum-Cymbalista F , Tang R , Ramond S , Faussat AM , Marie JP , Zittoun R
Published: October 2019

Tumor progression in B-cell chronic lymphocytic leukemia (B-CLL) is thought to result from the gradual accumulation of small resting G0/G1 phase lymphoid cells rather than the proliferation of actively dividing cells. The recent identification of G1 cyclins that are likely to control both the progression through G0 and G1 phase and the G1/S transition prompted us to study the mRNA expression of D-type cyclins in the peripheral blood lymphocytes from 34 patients with B-CLL, 7 patients with lymphoplasmacytic lymphoma (LPL), and 2 patients with mantle cell lymphoma (MCL). Cyclin D2 mRNA was, on average, 5- to 10-fold overexpressed in most of the samples studied (B-CLL, 29/34; LPL, 7/7; MCL, 0/2) as compared with normal resting B lymphocytes, in which cyclin D2 mRNA was barely detectable. In situ hybridization with cyclin D2 digoxigenin-labeled mRNA probe showed that all the cells from a given sample were stained with approximately the same intensity. Cyclin D3 was never detected in any of the samples tested, whereas cyclin D1 was expressed in only the 3 cases (1 LPL and 2 MCL) bearing a t(11;14) translocation. A trisomy 12 was found in 4 of 19 (21%) B-CLL or LPL cases for which cytogenetic analysis was available. Although the cyclin D2 gene has been mapped to chromosome 12p13, there was no apparent correlation between trisomy 12 and the level of cyclin D2 expression. Cell cycle analysis by flow cytometry after staining with propidium iodide consistently showed that more than 96% of the cells were in G0/G1 phase, whatever the importance of cyclin D2 overexpression was, and that cyclin D2 overexpression in B-CLL was not associated with any modifications of the cell cycle repartition. No consistent overexpression of cyclin D2 was found in acute myeloid leukemias. In conclusion, overexpression of cyclin D2 mRNA was found to be an almost constant feature in B-CLL and LPL. Therefore, it led us to hypothesize, with the support of data from some transfection experiments previously reported in murine hematopoietic cell lines, that cyclin D2 might play a role in B-CLL pathogenesis, possibly by preventing cells from programmed cell death.
C5a- and tumor necrosis factor-alpha-induced leukocytosis occurs independently of beta 2 integrins and L-selectin: differential effects on neutrophil adhesion molecule expression in vivo
Authors: Jagels MA , Chambers JD , Arfors KE , Hugli TE
Published: October 2019

We previously demonstrated in rabbits that various neutrophil chemotactic factors share an ability to induce recruitment of polymorphonuclear leukocytes (PMN) from bone marrow when administered intravenously (Jagels and Hugli, J Immunol 148:1119, 1992). In the study reported here, we investigated the effects of chemotactic factors on the expression of beta 2 integrins and L-selectin in vivo and the roles of these adhesionmolecules in the recruitment process. Leukocytosis was induced by infusion of either C5a (5 micrograms/kg), N-formyl-methionyl-leucyl-phenylalanine (f-MLP; 2.5 micrograms/kg), or tumor necrosis factor alpha (TNF-alpha; 100 ng/kg). C5a increased the expression of CD18 (the common subunit of beta 2 integrins) on PMN by nearly twofold and decreased levels of L-selectin by 50% within 15 minutes after administration. Levels of beta 2 integrins returned to baseline 2 to 3 hours after induction of leukocytosis. L-selectin remained depressed for more than 5 hours, demonstrating that shedding was induced in the recruited bone marrow leukocytes as well as in circulating PMN. In contrast to the response to C5a, TNF-alpha did not cause upregulation of CD18 or shedding of L-selectin. Levels of L-selectin were consistently increased 60 minutes after administration of TNF-alpha, coinciding with a rapid rise in the number of band-form PMN in the circulation. Intact IgG and F(ab)2 forms of the anti-CD18 monoclonal antibody IB4 or the anti-L-selectin antibody DREG-200 were administered intravenously 15 minutes before induction of leukocytosis by the chemotactic factors. Neither IB4 nor its F(ab)2 fragments blocked leukocytosis induced by C5a, f-MLP, or TNF-alpha. DREG-200 also did not block leukocytosis induced by f-MLP, C5a, or TNF-alpha. These results suggest that leukocyte emigration from the bone marrow into the circulation proceeds through interactions distinct from those involved in neutrophil chemotaxis and diapedesis. Shedding of L-selectin from C5a-recruited bone marrow leukocytes demonstrates activation of these cells in the recruitment process and may reflect a potential mechanism for their release. The dissimilar effects of C5a and TNF-alpha on expression of adhesion molecules may result from distinct stimulatory pathways and suggests differential activation states for cellular recruitment by these inflammatory factors.
CD16+ monocytes in patients with cancer: spontaneous elevation and pharmacologic induction by recombinant human macrophage colony- stimulating factor
Authors: Saleh MN , Goldman SJ , LoBuglio AF , Beall AC , Sabio H , McCord MC , Minasian L , Alpaugh RK , Weiner LM , Munn DH
Published: October 2019

The small subset of circulating monocytes that express the maturation-associated CD16 antigen has recently been reported to be elevated in patients with bacterial sepsis. We now show that this novel CD16+ monocyte population is also spontaneously expanded in patients with cancer. We studied 14 patients with metastatic gastrointestinal carcinoma enrolled ina clinical trial of recombinant human macrophage colony-stimulating factor (rhMCSF) plus monoclonal antibody D612. We found that before any cytokine treatment, 12 of 14 patients constitutively displayed significant elevations in both the percentage and the absolute number of CD16+ monocytes, as compared with both normal subjects and ill patients with elevated monocyte counts but without malignancy. CD16+ monocytes accounted for 46% +/- 22% of total monocytes in the patients with cancer versus 5% +/- 3% for controls (P < .01). The increase was not attributable to infection or intercurrent illness and appeared to be associated with the underlying malignancy itself. A similar spontaneous elevation of CD16+ monocytes was observed in 35 of 44 additional patients diagnosed with a variety of other solid tumors. When patients with gastrointestinal carcinoma were treated with rhMCSF, there was a marked further increase in the percentage of CD16+ monocytes (to 83% +/- 11%), as well as in the absolute number of CD16+ cells and the level of CD16 antigen expression. In every case, the patients with cancer showed a greater CD16+ monocyte response than the maximal response obtained in normal volunteer subjects treated witha similar regimen of rhMCSF (n = 5, P < .001), suggesting that the presence of malignancy primed patients for enhanced responsiveness to rhMCSF. We hypothesize that spontaneous expansion of the CD16+ monocyte population may represent a novel biologic marker for a widespread and previously unsuspected host immune response to malignancy.
The syndrome of hepatic veno-occlusive disease after marrow transplantation
Authors: Bearman SI
Published: October 2019

The clinical syndrome of VOD is a frequent cause of nonrelapse mortality among patients receiving high-dose cytoreductive regimens. Patients likely to develop VOD have existing liver dysfunction, evidence of infection before conditioning, tend to receive more intensive preparative regimens, and often receive marrow from alternative donors. Therapeutic drug monitoring of busulfan and pharmacokinetic dose adjustments appear to be useful in reducing the incidence of VOD in patients receiving this agent. Data are contradictory as regards whether pharmacologic prophylaxis is effective. Patients who will develop severe VOD are characterized by a rapid increase in serum bilirubin as well as weight. Supportive management of these patients should attempt to preserve respiratory as well as renal function, sometimes a very difficult task. Treatment with recombinant tissue plasminogen activator has promise. However, given its potential for toxicity, a prospective randomized trial should be performed. Hopefully, as more data regarding the molecular and cellular mechanisms of this illness are elucidated, more thoughtful prevention strategies will be developed. This will be necessary, particularly as newer, more intensive preparative regimens are being developed, as access to alternative donors increases, and as more diseases will be treated with this approach.
High-molecular-weight kininogen is exclusively membrane bound on endothelial cells to influence activation of vascular endothelium
Authors: Hasan AA , Cines DB , Ngaiza JR , Jaffe EA , Schmaier AH
Published: October 2019

An important biologic function of high-molecular-weight kininogen (HK) is to deliver bradykinin (BK) to its cellular receptors. Internalization and degradation of HK may provide a mechanism by which endothelial cells modulate the production of BK and control its activities. Therefore, we investigated the binding and subsequent distribution of biotinylated-HK (biotin-HK) associated with human umbilical vein endothelial cells (HUVEC). HUVEC bound 3 to 4 times more HK and with greater avidity at 1 to 3 hours at 37 degrees C than at 4 degrees C (Bmax = 1.0 +/- 0.02 x 10(7) molecules/cell, kd = 7 +/- 3 nmol/L v Bmax = 2.6 +/- 0.2 x 10(6) molecules/cell, kd = 46 +/- 8 nmol/L). However, there was no evidence that the difference was caused by internalization of HK at the higher temperature. First, the same amount of biotin-HK was associated with nonpermeabilized and permeabilized HUVEC using buffers containing 20 to 50 mumol/L zinc ion in the absence or presence of 2 mmol/L calcium ion. Second, binding of biotin-HK to HUVEC was approximately 92% reversible at 1 hour when the cells were maintained at both 37 degrees C and 4 degrees C. Third, neither chloroquine nor primaquine altered the amount of biotin-HK bound to HUVEC. Fourth, biotin-HK bound to HUVEC was almost completely removed by pronase. Fifth, the nonpermeable dye, crystal violet, almost completely quenched the fluorescence signal emitted by HUVEC-associated fluorescein isothiocyanate (FITC) HK. Finally, the localization of HUVEC-bound FITC-HK was restricted to the membrane as shown by laser scanning confocal microscopy. The expression of HK binding sites had an absolute requirement for metabolic energy, but was not dependent on new protein synthesis. Membrane-bound HK contributed to the anticoagulant nature of endothelial cells by blocking human alpha-thrombin binding and its resultant induction of prostacyclin formation. These studies indicate that HK is not internalized by HUVEC, but remains primarily on cell surfaces to be accessible for BK liberation and to modulate the binding and actions of alpha-thrombin.
The efficacy of CD3 x CD19 bispecific monoclonal antibody (BsAb) in a clonogenic assay: the effect of repeated addition of BsAb and interleukin-2
Authors: Haagen IA , Geerars AJ , de Lau WB , Bast BJ , de Gast BC
Published: October 2019

To evaluate the potency by which human T cells are targeted and activated by bispecific monoclonal antibodies (BsAbs) to lyse tumor cells, a clonogenic assay was developed. The efficacy of a CD3 x CD19 BsAb binding to both the CD3 T-cell antigen and the CD19 B-cell antigen was already proven in 51Cr-release assays and in 3-day activation cultures. To achieve more quantitative results, a 14-day clonogenic assay, based on limiting-dilution, was performed for the determination of the initial and residual number of clonogenic units obtained with a CD19+ pre-pre-B acute lymphoblastic leukemia (ALL-B) cell line. Elimination of up to 5 logs of ALL-B cells by freshly isolated peripheral blood mononuclear cells (PBMCs) cultured with BsAb plus interleukin-2 (IL-2) could be detected. The presence of human IgG did not abolish the effect. Repeated addition of each of the two agents was necessary, because a single treatment produced only a 1- to 2-log kill. CD3 monoclonal antibody and IL-2 stimulation (“lymphokine-activated killer cell” conditions) resulted in only a 2-log kill. The number of T cells proved critical in lysis of ALL-B cells, with a 5-log kill using a T-cell:B-cell ratio of 3:1 but with only a 1-log kill using a ratio of 1:1. PBMCs isolated from patients with non-Hodgkin's lymphoma, both in relapse or remission, proved to be as competent as those from healthy donors in removing ALL-B cells. This clonogenic assay shows the importance of repeated administration of CD3 x CD19 BsAb and IL-2 and offers the possibility to compare it with other therapies in B-cell malignancy.
Delayed infusion of immunocompetent donor cells after bone marrow transplantation breaks graft-host tolerance allows for persistent antileukemic reactivity without severe graft-versus-host disease
Authors: Johnson BD , Truitt RL
Published: October 2019

The development of graft-host tolerance after bone marrow transplantation (BMT) is crucial to avoid the problems of graft-versus-host disease (GVHD) and graft rejection. GVHD can be eliminated by depleting mature donor T cells from the BM inoculum, thereby facilitating the development of graft-host tolerance. However, T-cell depletion often results in an increased incidence of graft rejection and an increased frequency of leukemia relapse. Thus, although graft-host tolerance is a desirable outcome, it can pose a significant threat to leukemia-bearing hosts. Using a major histocompatability complex (MHC)-matched allogeneic model of BMT (B10.BR into AKR), we found that irradiated recipients given donor BM alone displayed mixed T-cell chimerism and did not develop GVHD. Graft-host tolerance developed by 8 weeks after BMT in these chimeras, and they were susceptible to low-dose leukemia challenge. When sufficient numbers of donor spleen cells, as a source of T-cells, were added to the BM graft, AKR hosts developed severe and lethal GVHD. Antihost reactive donor T cells persisted in chimeras undergoing GVHD, indicating that graft-host tolerance did not develop. When administration of the spleen cells was delayed for 7 to 21 days after BMT, there was significantly less mortality because of GVHD. Day 21 was the optimal time for infusion of cells without development of GVHD. Graft-host tolerance was broken by the delayed infusion of donor cells, as indicated by the persistence of antihost-reactive donor T cells in these chimeras in T-cell receptor cross-linking and mixed lymphocyte reaction assays. Importantly, the persistence of antihost-reactive donor T cells correlated with along-term antileukemic effect that was still present at 100 days after transplant. Multiple infusions of immunocompetent donor cells could be administered without increasing the risk for GVHD if delayed until 21 days post-BMT. Delayed infusions of donor spleen cells also resulted in a long-term antileukemic effect in the absence of GVHD in an MHC-haplotype-mismatched model of BMT (SJL into [SJL x AKR]F1). Although delayed infusion of normal donor cells did not induce GVHD, spleen cells from donors previously sensitized to host alloantigens induced GVHD when infused 21 days after BMT. Thus, the ability of previously activated cells to induce GVHD was not inhibited in the same manner as naive cells. Results from limiting dilution analysis assays indicated that alloactivated interleukin-2-secreting CD4+ T cells were preferentially inhibited over cytolytic T cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Thrombopoietin induces tyrosine phosphorylation and activation of the Janus kinase, JAK2
Authors: Tortolani PJ , Johnston JA , Bacon CM , McVicar DW , Shimosaka A , Linnekin D , Longo DL , O'Shea JJ
Published: October 2019

Thrombopoietin (TPO) is a recently characterized growth and differentiation factor for megakaryocytes and platelets that exerts its effects via the receptor, c-MpI. This receptor is a member of the hematopoietin receptor superfamily and is essential for megakaryocyte maturation; however, the molecular mechanisms of TPO and c-MpI action have not been elucidated. Recently, the Janus kinases have emerged as important elements in signaling via this family of receptors. In this report, we show that, in the M07e megakaryocytic cell line, which expresses c-MpI and proliferates in response to TPO, TPO induces phosphorylation of a number of substrates between 80 and 140 kD. Specifically, we show that stimulation with TPO induces the rapid tyrosine phosphorylation of a 130-kD protein that we identify as the Janus kinase, JAK2. However, no detectable tyrosine phosphorylation of JAK1, JAK3, or TYK2 was observed. TPO also induced activation of JAK2 phosphotransferase activity in vitro. Taken together, these data indicate that JAK2 likely plays a key role in TPO-mediated signal transduction.
Evaluation of the relationship between protein S and C4b-binding protein isoforms in hereditary protein S deficiency demonstrating type I and type III deficiencies to be phenotypic variants of the same genetic disease
Authors: Zoller B , Garcia de Frutos P , Dahlback B
Published: October 2019

Type III protein S deficiency is characterized by a low plasma level of free protein S, whereas the total concentration of protein S is normal. In contrast, both free and total protein S levels are low in type I deficiency. To elucidate the molecular mechanism behind the selective deficiency of free protein S in type III deficiency, the relationship between the plasma concentrations of beta-chain containing isoforms of C4b-binding protein (C4BP beta+) and different forms of protein S (free, bound, and total) was evaluated in 327 members of 18 protein S-deficient families. In normal relatives (n = 190), protein S correlated well with C4BP beta+, with free protein S (96 +/- 23 nmol/L) being equal to the molar excess of protein S (355 +/- 65 nmol/L) over C4BP beta+ (275 +/- 47 nmol/L). In protein S-deficient family members (n = 117), the equimolar relationship between protein S (215 +/- 50 nmol/L) and C4BP beta+ (228 +/- 51 nmol/L), together with the high affinity of the interaction, resulted in low levels of free protein S (16 +/- 10 nmol/L). Free protein S levels were distinctly low in protein S-deficient members, whereas in 47 of the protein S-deficient individuals, the concentration of total protein S was within the normal range, which fulfils the criteria for type III deficiency. The remaining 70 had low levels of both total and free protein S and, accordingly, would be type I deficient. Coexistence of type I and type III deficiency was found in 14 families, suggesting the two types of protein S deficiency to be phenotypic variants of the same genetic disease. Interestingly, not only protein S but also C4BP beta+ levels were decreased in orally anticoagulated controls and even more so in anticoagulated protein S-deficient members, suggesting that the concentration of C4BP beta+ is influenced by that of protein S. In conclusion, our results indicate that type I and type III deficiencies are phenotypic variants of the same genetic disease and that the low plasma concentrations of free protein S in both types are the result of an equimolar relationship between protein S and C4BP beta+.
Heterogeneity in CBF beta/MYH11 fusion messages encoded by the inv(16)(p13q22) and the t(16;16)(p13;q22) in acute myelogenous leukemia
Authors: Shurtleff SA , Meyers S , Hiebert SW , Raimondi SC , Head DR , Willman CL , Wolman S , Slovak ML , Carroll AJ , Behm F
Published: October 2019

Inv(16)(p13q22) is one of the most frequent chromosomal rearrangements found in acute myelogenous leukemia (AML), representing approximately 16% of documented karyotypic abnormalities. The inv(16) breakpoints have been cloned and shown to involve the non-DNA binding component of the AML-1 transcription factor complex termed core binding factor beta gene (CBF beta) on 16q and the smooth muscle myosin heavy chain gene (MYH11) on 16p. In this study, we analyzed 37 cases of inv(16)-containing AML and 4 cases with t(16;16)(p13;q22) for expression of the CBF beta/MYH11 chimeric message by reverse transcription-polymerase chain reaction (PCR) analysis. CBF beta/MYH11 chimeric messages were detected in 33 of 37 cases with the inv(16) and in the 4 t(16;16)-containing cases. Sequence analysis of PCR products showed extensive breakpoint heterogeneity in both CBF beta and MYH11. In addition to the previously described breakpoint in CBF beta at nucleotide (nt) 495 (amino acid 165), we have identified a second novel fusion point at nt 399 (amino acid 133) in 7% of the cases. Similarly, a unique breakpoint site was identified in MYH11 at nt 1098, as well as at three previously characterized sites at nts 994, 1201, and 1921. Of the 4 PCR-negative cases, 2 of 3 tested lacked CBF beta rearrangements by Southern blot analysis, suggesting the possible involvement of a different genomic locus in some cases with cytogenetic evidence of inv(16). To assess whether the portions of CBF-beta contained within the CBF beta/MYH11 chimeric products retain the ability to interact with their heterodimeric DNA-binding partner AML-1, we performed in vitro DNA- binding analysis. Recombinant CBF-beta polypeptides consisting of the N-terminal 165 amino acids retained their ability to interact with AML-1, whereas mutants containing only the N-terminal 133 amino acids interacted with AML-1 less efficiently. These data suggest that different CBF beta/MYH11 products may vary subtly in their biologic activities.
Granulocyte-macrophage colony-stimulating factor increases 5- lipoxygenase gene transcription and protein expression in human neutrophils
Authors: Stankova J , Rola-Pleszczynski M , Dubois CM
Published: October 2019

The complex process of neutrophil activation and accumulation is orchestrated by a cascade of cytokines and bioactive lipids produced at the site of inflammation. Neutrophils are a rich source of the potent inflammatory lipid leukotriene B4(LTB4). Granulocyte-macrophage colony-stimulating factor (GM-CSF) can activate neutrophils for an exponential increase in LTB4 production in response to a number of subsequent stimuli. In this report, we examined the temporal regulation, by GM-CSF, of the gene and protein expression of 5-lipoxygenase (5-LOX), a key enzyme of the LTB4 production pathway. Human neutrophils were exposed to 10 ng/mL of GM-CSF for various periods of time and 5-LOX mRNA was measured by Northern blot analysis. We observed no change in 5-LOX mRNA at early time points (0.25 to 3 hours); however, by 18 hours we observed a significant augmentation of 5-LOX-specific message (4.3 +/- 1.7-fold increase; n = 6). Nuclear transcription assays indicated that the rate of 5-LOX gene transcription was augmented threefold in neutrophils incubated with GM-CSF, whereas the half-life of the message was not markedly changed. Parallel experiments indicated that the levels of 5-LOX protein were also increased by GM-CSF. The augmentation was observed within 30 minutes after stimulation and was maximal (5.23 +/- 2.6; n = 4) at 18 hours. Incubation of GM-CSF-stimulated neutrophils with protein synthesis inhibitors resulted in a time-dependent impairment of their ability to produce LTB4, with no inhibition seen during the first hours, a 75% decrease seen by 12 hours, and greater than 95% inhibition seen at 18 hours. Collectively, our data imply that GM-CSF can regulate LTB4 production by two distinct mechanisms: a short-term increase that is not related to increased 5-LOX mRNA expression and is independent of protein synthesis, and a sustained increase in LTB4 production that is associated with the transcriptional activation of the 5-LOX gene, increase in 5-LOX mRNA levels, and dependence on protein synthesis. Such transcriptional modulation of 5-LOX enzyme expression may provide new approaches for therapeutic intervention in protracted inflammatory conditions.
Association and activation of Btk and Tec tyrosine kinases by gp130, a signal transducer of the interleukin-6 family of cytokines
Authors: Matsuda T , Takahashi-Tezuka M , Fukada T , Okuyama Y , Fujitani Y , Tsukada S , Mano H , Hirai H , Witte ON , Hirano T
Published: October 2019

Interleukin-6 (IL-6), leukemia inhibitory factor, oncostatin M, IL-11, and ciliary neurotrophic factor constitute the IL-6 family of cytokines and play important roles in hematopoiesis, immune response, and nervous system. The receptors for the IL-6 family of cytokines share gp130 through which signals are generated, although the cytoplasmic region of gp130 does not contain any catalytic domain. In this study we show that in addition to Jak family tyrosine kinase, the stimulation of gp130 by IL-6 plus soluble IL-6 receptor alpha induced the activation of Btk and Tec tyrosine kinases, whereas IL-3 and granulocyte colony-stimulating factor activated Tec but not Btk in a pro-B cell line. Furthermore, both Btk and Tec kinases were associated with gp130 without the ligand stimulation. Because Btk is a critical tyrosine kinase for B lymphopoiesis and Tec is considered to be involved in hematopoiesis, the results suggest the involvement of gp130-Btk-Tec signal pathway in early lymphohematopoiesis.
The role of the homeobox gene, HOX B7, in human myelomonocytic differentiation
Authors: Lill MC , Fuller JF , Herzig R , Crooks GM , Gasson JC
Published: October 2019

Homeobox genes encode transcription factors known to be important morphogenic regulators during embryogenesis. An increasing body of work implies a role for homeobox genes in both hematopoiesis and oncogenesis. We have analyzed the role of the homeobox gene, HOX B7, in the program of differentiation of the biphenotypic myeloid cell line, HL60. Induction of monocytic differentiation in HL-60 cells by vitamin D3 resulted in rapid expression of HOX B7 mRNA, but stimulation with phorbol ester or dimethyl sulfoxide (DMSO) did not. Constitutive overexpression of HOX B7 in the HL60 cell line inhibited the granulocytic differentiation associated with stimulation with DMSO or retinoic acid, but had no effect on the monocytic differentiation induced by vitamin D3. Normal human monocytes do not constitutively express HOX B7, nor are they able to be induced to do so by stimulation with colony-stimulating factor 1 (CSF-1) and gamma interferon (IFN gamma), or with vitamin D3 and lipopolysaccharide. Human bone marrow (BM) cells were found to express HOX B7 in response to granulocyte- macrophage CSF (GM-CSF) and antisense oligonucleotides directed against HOX B7 inhibited the formation of colonies derived from GM-CSF- stimulated BM. These data suggest a critical role for HOX B7 in myelomonocytic differentiation.
Substitution of Val for Met at residue 239 of platelet glycoprotein Ib alpha in Japanese patients with platelet-type von Willebrand disease
Authors: Takahashi H , Murata M , Moriki T , Anbo H , Furukawa T , Nikkuni K , Shibata A , Handa M , Kawai Y , Watanabe K
Published: October 2019

Genomic DNA was studied from four patients with platelet-type von Willebrand disease (vWD) from two Japanese families previously reported. The entire coding region of platelet glycoprotein (GP) Ib alpha, a component of the platelet receptor for von Willebrand factor (vWF), was examined by polymerase chain reaction (PCR) followed by direct DNA sequence analysis. A single point mutation was found in all patients resulting in substitution of Val (GTG) for Met (ATG) at residue 239 of GPIb alpha. All patients were heterozygous for the mutation, whereas none of the unaffected family members had an amino acid substitution at residue 239. Because the nucleotide substitution destroys an NIa III restriction site on GPIb alpha, PCR products were subjected to digestion with this enzyme; DNA fragments from both normal and mutant alleles were detected in all affected individuals. In allele- specific PCR, DNA was amplified from patients' genomic DNA using either adenine- or guanine-containing primers, whereas only adenine-containing primer successfully amplified DNA from normal individuals. Cloning of amplified DNA into bacteriophage M13mp19 and subsequent DNA sequence analysis confirmed the mutation in these families. The absence of the amino acid substitution at residue 239 of GPIb alpha in the normal individuals tested, together with the linkage of this substitution to the phenotypic expression of disease in these two families and in a family recently described suggest that this amino acid change is a molecular basis for platelet-type vWD, and the substitution may produce a quite similar phenotype to the one reported previously (Gly to Val at residue 233 of GPIb alpha).
Morphology, immunophenotype, and distribution of latently and/or productively Epstein-Barr virus-infected cells in acute infectious mononucleosis: implications for the interindividual infection route of Epstein-Barr virus
Authors: Anagnostopoulos I , Hummel M , Kreschel C , Stein H
Published: October 2019

The present study was undertaken to unequivocally demonstrate the morphology, immunophenotype, and localization of Epstein Barr virus (EBV)-infected cells as well as the type of infection (latent versus productive) in tonsils of acute infectious mononucleosis. Paraffin sections from nine cases with clinical, serologic, and morphologic evidence of EBV infection were analyzed for the detection of small transcripts, designated EBER1 & 2, and BHLF1 by in situ hybridization (ISH) using nonisotopically labeled probes. ISH was combined with immunohistology, employing a broad panel of antibodies against B-, T-, epithelial-, macrophage-, and follicular dendritic cell (FDC)-antigens. All EBER-positive cells could be identified as lymphocytes, as they did not exhibit any morphologic or immunologic characteristics of epithelial cells, macrophages, or FDCs. A preferential accumulation of EBER-positive cells was noted around crypts, within surface squamous epithelium, and in the surroundings of necrosis. The majority of these lymphocytes could be shown to be B cells, which morphologically included Reed-Sternberg (RS)-like cells, immunoblasts, medium-sized lymphoid cells, as well as cells with plasmacytoid differentiation. In all cases, a varying number of EBER-positive T cells could be identified. ISH for BHLF1-RNA detection showed that almost all cases contained single positive small lymphoid cells, indicating a transition from latent to productive infection cycle. Such cells could also be detected within the crypt epithelium reaching up to its surface. Additional screening of 123 oropharyngeal mucosa samples from patients without evidence of acute EBV-infection, using the polymerase chain reaction for EBV-DNA detection combined with EBER- and BHLF1-ISH showed single latently infected lymphocytes in only one case. Our data imply that infected lymphocytes and not epithelial cells are, in fact, the reservoir for EBV infection, and that these are the cells that participate in the interindividual virus transfer.