bluuebunny/crossref_metadata_2025_split huggingface dataset:
Telomerase Activity in Reactive and Neoplastic Lymphoid Tissues: Infrequent Detection of Activity in Hodgkin's Disease
Authors: Brousset Pierre , Al Saati Talal , Chaouche Nadia , Zenou Reine-Claude , Schlaifer Daniel , Chittal Shashikant , Delsol Georges 
Published: October 2019

AbstractWe used the recently described sensitive and rapid detection assay called telomeric repeat amplification protocol (TRAP) to detect telomerase activity in lymphoblastoid (n = 5) and lymphoma cell lines (n = 7), hyperplastic lymph nodes (n = 6) and tonsils (n = 5), and tissues involved by non-Hodgkin's lymphoma (NHL) (n = 43) and Hodgkin's disease (HD) (n = 14). Clearly evident telomerase activity was found in all lymphoblastoid and lymphoma cell lines, and in 34 of 43 cases (80%) of NHL. These results were expected because of the proliferative and immortal nature of the cell lines and most malignant cells. However, positive results were obtained with the TRAP assay in all hyperplastic lymph nodes and tonsils, which raises the issue of derepression of telomerase activity during an immune response. Telomerase activity alone therefore does not distinguish malignant lymphoid proliferations from reactive states. Telomerase activity was detected in only 1 of 14 cases (7%) of lymphoid tissues involved by HD. Eight of the 13 negative cases were considered to be interpretable because of the lack (3 of 13 cases) or low level (5 of 13 cases) of telomerase inhibition. The five remaining cases could not be evaluated because of their telomerase inhibitor content. The findings imply either transient or very low levels of telomerase activity in HD or that HD for the greater part is a telomerase-independent neoplasm. Microdissection studies are needed to identify subsets of cells carrying telomerase activity in both reactive and neoplastic lymphoid tissues.
Interferon-β Interrupts Interleukin-6–Dependent Signaling Events in Myeloma Cells
Authors: Berger Lloyd C. , Hawley Robert G. 
Published: October 2019

AbstractType I interferons (IFNs-α and IFN-β) bind to a common receptor to exert strong antiproliferative activity on a broad range of cell types, including interleukin-6 (IL-6)–dependent myeloma cells. In this study, we investigated the effect of IFN-β pretreatment on IL-6–stimulated mitogenic signaling in the human myeloma cell line U266. IL-6 induced transient tyrosine phosphorylation of the IL-6 receptor signal-transducing subunit gp130, the gp130-associated protein tyrosine kinases Jak1, Jak2, and Tyk2, the phosphotyrosine phosphatase PTP1D/Syp, the adaptor protein Shc and the mitogen-activated protein kinase Erk2, and accumulation of GTP-bound p21ras. Prior treatment of U266 cells with IFN-β downregulated IL-6–induced tyrosine phosphorylation of gp130, Jak2, PTP1D/Syp, Shc, and Erk2, and GTP-loading of p21ras. Further analysis indicated that treatment with IFN-β disrupted IL-6–induced binding of PTP1D/Syp to gp130 and the adaptor protein Grb2; IFN-β pretreatment also interfered with IL-6–induced interaction of Shc with Grb2 and a 145-kD tyrosine-phosphorylated protein. These results suggest a novel mechanism whereby type I IFNs interrupt IL-6–promoted mitogenesis of myeloma cells in part by preventing the formation of essential signaling complexes leading to p21ras activation.
Clinical and Prognostic Significance of Femoral Marrow Magnetic Resonance Imaging in Patients With Malignant Lymphoma
Authors: Tsunoda Saburo , Takagi Shojiro , Tanaka Osamu , Miura Yasusada 
Published: October 2019

AbstractWe evaluated 56 consecutive patients with newly diagnosed lymphoma including 48 with non-Hodgkin's lymphoma (NHL) and 8 with Hodgkin's disease to determine the clinical and prognostic significance of magnetic resonance imaging (MRI) of the femoral marrow. MR images of the femoral marrow were obtained by the T1-weighted spin echo method and the short TI inversion recovery technique. Abnormal “positive” images were seen in 29 of the 56 patients (52%). All 17 patients with positive biopsy results showed abnormal images on their femoral marrow MRI. Three “positive” MRI patterns — scattered (72%), uniform (21%), and nodular (7%) — were observed. The overall survival of the patients with a positive MRI pattern was significantly poorer than that of patients with a normal pattern (P = .0129). Survival did not differ significantly according to MRI pattern. The 3-year survival rate in the patients with a normal MRI pattern was 89.9% and in the patients with a positive MRI pattern, it was 41.0%. This difference was statistically significant (P = .0279) when we evaluated only the patients with NHL. Patients with positive MRI patterns, but a normal bone marrow histology, showed a significantly shorter survival than those with a normal MRI pattern (P = .016). These results indicate that abnormal MR images of the femoral marrow are associated with a significantly poorer survival in patients with malignant lymphoma, regardless of histologic findings in the marrow.
Direct Binding of CRKL to BCR-ABL Is Not Required for BCR-ABL Transformation
Authors: Heaney Conor , Kolibaba Kathryn , Bhat Arun , Oda Tsukasa , Ohno Sayuri , Fanning Shane , Druker Brian J. 
Published: October 2019

AbstractCRKL has previously been shown to be a major tyrosine phosphorylated protein in neutrophils of patients with BCR-ABL+ chronic myelogenous leukemia and in cell lines expressing BCR-ABL. CRKL and BCR-ABL form a complex as demonstrated by coimmunoprecipitation and are capable of a direct interaction in a yeast two-hybrid assay. We have mapped the site of interaction of CRKL and BCR-ABL to the amino terminal SH3 domain of CRKL with a proline rich region in the C-terminus of ABL. The proline-rich region was mutated and the effect of this deletion on BCR-ABL transforming function was assayed. Our data show that this deletion does not impair the ability of BCR-ABL to render myeloid cells factor independent for growth. In cells expressing the proline deletion mutation of BCR-ABL, CRKL is still tyrosine phosphorylated and forms a complex with BCR-ABL as demonstrated by coimmunoprecipitation. Our data suggest that the interaction between CRKL and the proline deletion mutant of BCR-ABL is an indirect interaction as CRKL does not interact directly with the proline deletion mutant of BCR-ABL in a gel overlay assay or in a yeast two-hybrid assay. Thus, a direct interaction of CRKL and BCR-ABL is not required for CRKL to become tyrosine phosphorylated by BCR-ABL and suggests that CRKL function may still be required for BCR-ABL function through an indirect interaction.
Retroviral-Mediated Gene Transfer of gp91phox Into Bone Marrow Cells Rescues Defect in Host Defense Against Aspergillus fumigatus in Murine X-Linked Chronic Granulomatous Disease
Authors: Björgvinsdóttir Helga , Ding Chunjin , Pech Nancy , Gifford Mary A. , Li Ling Lin , Dinauer Mary C. 
Published: October 2019

AbstractThe X-linked form of chronic granulomatous disease (X-CGD), an inherited deficiency of the respiratory burst oxidase, results from mutations in the X-linked gene for gp91phox, the larger subunit of the oxidase cytochrome b. The goal of this study was to evaluate the impact of retroviral-mediated gene transfer of gp91phox on host defense against Aspergillus fumigatus in a murine model of X-CGD. Retrovirus vectors constructed using the murine stem cell virus (MSCV) backbone were used for gene transfer of the gp91phox cDNA into murine X-CGD bone marrow cells. Transduced cells were transplanted into lethally irradiated syngeneic X-CGD mice. After hematologic recovery, superoxide production, as monitored by the nitroblue tetrazolium (NBT) test, was detected in up to ≈80% of peripheral blood neutrophils for at least 28 to 35 weeks after transplantation. Neutrophil expression of recombinant gp91phox and superoxide production were significantly less than wild-type neutrophils. However, 9 of 9 mice with ≈50% to 80% NBT+ neutrophils after gene transfer did not develop lung disease after respiratory challenge with 150 to 500 A fumigatus spores, doses that produced disease in 16 of 16 control X-CGD mice. In X-CGD mice transplanted with mixtures of wild-type and X-CGD bone marrow, ≥5% wild-type neutrophils were required for protection against A fumigatus challenge. These data suggest that expression of even low levels of recombinant gp91phox can substantially improve phagocyte function in X-CGD, although correction of very small percentage of phagocytes may not be sufficient for protection against A fumigatus.
Expression of the Human Immunodeficiency Virus Type-1 Coreceptors CXCR-4 (fusin, LESTR) and CKR-5 in CD34+ Hematopoietic Progenitor Cells
Authors: Deichmann Martin , Kronenwett Ralf , Haas Rainer 
Published: October 2019

AbstractCD34+ hematopoietic progenitor cells were assessed for mRNA expression of the human immunodeficiency virus type-1 (HIV-1) coreceptors CXCR-4, also termed fusin or LESTR, and CKR-5, also called CC-CKR-5 or CCR-5. The CD34+ cells were obtained from leukapheresis products of 17 patients after granulocyte colony-stimulating factor–supported cytotoxic chemotherapy. Using a two-step enrichment procedure including immunomagnetic bead separation and fluorescence-activated cell sorting, the CD34+ cells had a median purity of 99.8%. Assessing 9 CD34+ cell samples by polymerase chain reaction after reverse transcription (RT-PCR), CXCR-4 mRNA was found in all samples, whereas CKR-5 mRNA was only present in 3 samples, even though a nested PCR was used. Eight additional CD34+ cell samples were sorted according to CD4 expression. Based on a three-color immunofluorescence analysis, the mean relative fluorescence intensity of HLA-DR was smaller on CD34+/CD4+ cells in comparison with CD34+/CD4− cells. CXCR-4 mRNA was found in 5 of 8 CD34+/CD4+ samples and in 7 of 8 CD34+/CD4− samples, whereas CKR-5 mRNA was detected in 2 CD34+/CD4+ samples and in 1 CD34+/CD4− cell sample. Looking at the total number of CD34+ cell samples examined, the proportion of specimens containing CXCR-4 mRNA was 84% in comparison with 24% of specimens positive for CKR-5 mRNA. These data suggest that CD34+/CD4+ hematopoietic progenitor cells, including true stem cell candidates, could be susceptible to HIV-1 infection. Considering the relatively low incidence of CD34+ cell samples containing CKR-5 mRNA, CD34+/CD4+ cells appear to be particularly prone for HIV-1 infection via the CXCR-4 coreceptor. Because this chemokine receptor allows T-cell–tropic HIV-1 strains to infect cells, CD34+ cells expressing CD4 and CXCR-4 might be infected by HIV-1 during later stages of the disease, following a viral phenotype switch from macrophage- to T-cell–tropic HIV-1 strains.
Thrombopoietin Does Not Induce Lineage-Restricted Commitment of Mpl-R Expressing Pluripotent Progenitors But Permits Their Complete Erythroid and Megakaryocytic Differentiation
Authors: Goncalves Frédérique , Lacout Catherine , Villeval Jean-Luc , Wendling Françoise , Vainchenker William , Duménil Dominique 
Published: October 2019

Abstract
In this study, we examined the in vitro and in vivo effects of forced expression of Mpl-R (the thrombopoietin receptor) on the progeny of murine hematopoietic stem cells. Bone marrow cells from 5-FU–treated mice were transduced with retroviral vectors containing the human Mpl-R cDNA, or the neomycine gene as a control. After 7 days cocultivation on virus-producer cells, GpE86-Mpl-R or Gp86-Neo, the types of hematopoietic progenitor cells responding to thrombopoietin (TPO) were studied by clonogenic assays. Mpl-R–infected cells gave rise to CFU-GEMM, BFU-E, CFU-MK, but not CFU-GM while Neo-infected cells produced only megakaryocytic colonies. In addition, when nonadherent cells from GpE86-Mpl-R cocultures were grown with TPO as the only stimulus for 7 days, a marked expansion of CFU-GEMM, BFU-E, and CFU-MK was observed, while no change in CFU-GM number was seen. Erythroid and megakaryocytic maturation occurred in the presence of TPO while a block in granulocytic differentiation was observed at the myeloblast stage. The direct effects of TPO on Mpl-R–transduced progenitor cells were demonstrated by single cell cloning experiments. To analyze the effects of the constitutive expression of Mpl-R on the determination of multipotent progenitors (CFU-S) and long-term repopulating stem cells, Mpl-R– or Neo-infected cells were injected into lethally irradiated recipient mice. No difference was seen in (1) the number of committed progenitor cells contained in individual CFU-S12 whether colonies arose from noninfected or Mpl-R–infected CFU-S; (2) the mean numbers of progenitor cells per leg or spleen of mice reconstituted with Mpl-R– or Neo-infected cells, 1 or 7 months after the graft; and (3) the blood parameters of the two groups of animals, with the exception of a 50% reduction in circulating platelet counts after 7 months in mice repopulated with Mpl-R–infected bone marrow cells. These results indicate that retrovirus-mediated expression of Mpl-R in murine stem cells does not modify their ability to reconstitute all myeloid lineages of differentiation and does not result in a preferential commitment toward the megakaryocytic lineage.
A Role for the Wnt Gene Family in Hematopoiesis: Expansion of Multilineage Progenitor Cells
Authors: Austin Timothy W. , Solar Gregg P. , Ziegler Francis C. , Liem Linda , Matthews William 
Published: October 2019

AbstractThe microenvironment is a key regulator of hematopoietic stem cells (HSCs) and is a likely source of extracellular factors that control stem cell fate. A better understanding of these microenvironmental factors may come from investigations of developmental cell fate determination in which the critical roles of cell-cell interactions of multipotential cells have been shown. The Wnt gene family is known to regulate the cell fate and cell-cell interactions of multipotential cells in a variety of tissues. Expression of Wnts and of their putative receptors encoded by murine homologs of the Drosophila frizzled gene in hematopoietic tissues was examined by reverse transcriptase-polymerase chain reaction. Wnt-5a and Wnt-10b were expressed in day-11 murine yolk sac, day-14 fetal liver, and fetal liver AA4+ cells. The expression profiles of four murine frizzled homologs, Mfz3-7, were nearly identical to that of Wnt-5a and Wnt-10b. Notably, Wnt-10b was expressed in the fetal liver AA4+ Sca+ c-kit+ (flASK) HSC population. A role for Wnts in HSC fate determination was studied by treatment of HSC populations in culture with soluble WNT proteins. The addition of conditioned media from cells transfected with Wnt-1, Wnt-5a, or Wnt-10b cDNAs to cultures of flASK cells stimulated a sevenfold, eightfold, and 11-fold expansion in cell number, respectively, relative to control media. Removal of WNT-5a from this media by immunodepletion depleted the stimulatory activity from the media, whereas addition of a partially purified WNT-5a stimulated a fivefold expansion relative to control cells. Transduction of flASK cells with a retrovirus bearing a Wnt-5a cDNA enhanced proliferation. We conclude that WNTs stimulate the survival/proliferation of hematopoietic progenitors, demonstrating that WNTs comprise a novel class of hematopoietic cell regulators.
Functional Characterization and Modulation of Cytokine Production by CD8+ T Cells from Human Immunodeficiency Virus-Infected Individuals
Authors: Maggi Enrico , Manetti Roberto , Annunziato Francesco , Cosmi Lorenzo , Giudizi Maria Grazia , Biagiotti Roberta , Galli Grazia , Zuccati Giuliano , Romagnani Sergio 
Published: October 2019

AbstractCD8+ T-cell clones were generated from peripheral blood mononuclear cells (PBMC) of three human immunodeficiency virus (HIV)-seronegative individuals and six HIV-seropositive individuals and assessed for their cytokine secretion profile, cytolytic potential, and chemokine production. While the great majority of CD8+ T-cell clones generated from HIV-seronegative individuals produced interferon (IFN)-γ, but not interleukin-4 (IL-4), that is a type 1 cytotoxic (Tc1) profile, high numbers of CD8+ T-cell clones generated from HIV-seropositive individuals produced IL-4 in addition to IFN-γ or IL-4 alone, thus showing a type 0 cytotoxic (Tc0)- or a type 2 cytotoxic (Tc2) profile, respectively. Tc0/Tc2 cells displayed lower cytolytic activity than Tc1 cells, including a reduced ability to lyse autologous targets pulsed with HIV or HIV peptides. By contrast, the production of chemokines RANTES and macrophage inflammatory protein-1α was comparable in Tc1, Tc0, and Tc2 clones irrespective of whether they were derived from HIV-seronegative or HIV-seropositive individuals. When CD8+ T-cell clones were generated from PBMC cultures of HIV-seronegative individuals conditioned with IL-4 plus an anti–IL-12 antibody (Ab), a shift towards the Tc0/Tc2-like profile was observed. Conversely, the addition to PBMC cultures of IL-12 plus an anti – IL-4 Ab shifted the differentiation of CD8+ T cells from HIV-infected individuals towards the Tc1-like profile, whereas IL-12 or anti–IL-4 Ab alone had a lower Tc1-promoting effect. Irradiated PBMC from HIV-infected individuals, used as feeder cells, shifted the differentiation of CD8+ T cells from a healthy HIV-seronegative individual towards the Tc0/Tc2-like profile. On the other hand, a shift towards the Tc1-like profile was noted in CD8+ T-cell clones generated from the skin specimens of two HIV-seropositive patients with Kaposi's sarcoma, successfully treated with IFN-α, in comparison to CD8+ clones generated from the same skin areas before treatment. The IFN-α–induced Tc1 shift could be prevented by the incubation of skin-infiltrating CD8+ T cells with IL-4 before cloning. Taken together, these data indicate that both defective production of IL-12 and abnormal IL-4 production in bulk PBMC populations of HIV-infected individuals may contribute to the development of high numbers of CD8+ T-cell clones showing a Tc0/Tc2-like phenotype and reduced cytolytic potential against HIV itself. They also suggest that the cytokine profile of CD8+ T-cell clones can be modulated by cytokines (or anticytokine Ab) both in vitro and in vivo.
Pentoxifylline Promotes Replication of Human Cytomegalovirus In Vivo and In Vitro
Authors: Staak Kerstin , Prösch Susanna , Stein Joachim , Priemer Christina , Ewert Ralf , Döcke Wolf-Dietrich , Krüger Detlev H. , Volk Hans Dieter , Reinke Petra 
Published: October 2019

AbstractOKT3 monoclonal antibody (MoAb) therapy is well established in the prevention and therapy of acute rejection in transplant patients. Unfortunately, this therapy is associated with several short-term (cytokine release syndrome) and long-term (infections, EBV-related lymphoma) side effects. Recently, we were able to demonstrate an association between the TNFα release following the first OKT3 MoAb infusions and the appearance of human cytomegalovirus (HCMV) reactivation several days later. In order to prevent this TNFα associated HCMV reactivation patients were additionally treated with pentoxifylline (PTX), a methylxanthine derivative that has been shown to suppress TNFα induction. Although the TNFα peak plasma level following OKT3 MoAb treatment was markedly reduced, the incidence of HCMV reactivation and HCMV disease was not influenced. In transient transfection experiments using HCMV immediate early enhancer/promoter CAT reporter gene constructs PTX enhanced the promoter activity independently from TNFα in premonocytic cells. Furthermore, PTX acted synergistically with TNFα. In virus-infected human embryonal lung fibroblasts HCMV replication was triggered in the presence of both PTX and TNFα, while either substance alone had only marginal effects. The stimulatory effect of PTX on the immediate early (IE) enhancer/promoter was mediated via CREB/ATF, a eukaryotic transcription factor that binds to the 19 bp sequence motif in the enhancer region, while TNFα stimulation was mediated by activation of the transcription factor NF-kB and its binding to the 18 bp sequence motif in the enhancer. These data suggest a potential side effect of cAMP-elevating drugs such as PTX.
Vesicular Anthracycline Accumulation in Doxorubicin-Selected U-937 Cells: Participation of Lysosomes
Authors: Hurwitz Selwyn J. , Terashima Masanori , Mizunuma Nobuyuki , Slapak Christopher A. 
Published: October 2019

AbstractThe U-A10 cell line, a doxorubicin-selected variant of human U-937 myeloid leukemia cells, exhibits a redistribution of anthracyclines into a expanded vesicular compartment. The acidic nature of this compartment was confirmed by vital staining with a pH sensitive dye, LysoSensor yellow/blue DND-160. Identification of the vesicular compartment was performed by immunofluorescence analysis. Staining for the LAMP-1 and LAMP-2 antigens showed that the vesicles are enlarged lysosomes that are eccentrically placed near the nucleus of U-A10 cells. By contrast, the expression of the multidrug resistance-associated protein and the P-glycoprotein was observed predominately on the plasma membrane of the drug-resistant cells. The accumulation of daunorubicin into cellular compartments was quantified using radiolabeled drug. Exposing cells to 3[H]-daunorubicin and then isolating intact nuclei showed that nuclei from U-A10 cells accumulated twofold to threefold less anthracycline than nuclei from U-937 cells. However, when nuclei were isolated first and then exposed to 3[H]-daunorubicin, little difference in net nuclear drug accumulation was detected. Cytoplasts prepared from U-A10 and U-937 cells were exposed to 3[H]-daunorubicin to measure cytoplasmic drug accumulation. At external daunorubicin concentrations of 100 ng/mL or higher, cytoplasts from U-A10 cells accumulated significantly more daunorubicin than cytoplasts from U-937 cells. Moreover, studies with the lysosomotropic agent chloroquine showed that U-A10 cells accumulated twofold more chloroquine and showed twofold enhanced sensitivity to this agent as compared with parental U-937 cells. Fluorescence microscopy showed that chloroquine affects vesicular anthracycline sequestration in U-A10 cells with an associated increase in daunorubicin nuclear fluorescence. Although chloroquine did not alter anthracycline cytotoxicity in parental cells, it restored daunorubicin and doxorubicin sensitivity to U-A10 cells. Taken together, these studies demonstrate that U-A10 cells exhibit a redistribution of the lysosomal compartment. The trapping of drug into an expanded acidic vesicular compartment results in decreased nuclear drug accumulation and decreased cytotoxicity. Lysosomotropic agents, such as chloroquine, warrant further study as modulators of this acquired drug-resistance phenotype.