bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired Activation of NFκB in T Cells From a Subset of Renal Cell Carcinoma Patients Is Mediated by Inhibition of Phosphorylation and Degradation of the Inhibitor, IκB
Authors: Ling Weijun , Rayman Patricia , Uzzo Robert , Clark Peter , Kim Hyung Jin , Tubbs Raymond , Novick Andrew , Bukowski Ronald , Hamilton Thomas , Finke James 
Published: October 2019

Activation of the transcription factor NFκB in peripheral blood T cells from patients with renal cell carcinoma (RCC) is compromised. This impaired signaling function results from a failure of RelA and c-Rel to translocate to the nucleus though normal levels of Rel proteins are present in the cytoplasm. We demonstrate here in a subset of RCC patients that the defect in NFκB activation is attributable to the absence of phosphorylation and degradation of the inhibitor IκB. In patient T cells there was no stimulus dependent decrease in the cytoplasmic level of IκB. Coimmunoprecipitation studies showed that RelA was in complex with IκB and was not released after stimulation. Moreover, the phosphorylated form of IκB detected in normal T cells after activation is absent in patient T cells. Additional experiments showed that soluble products from RCCs (RCC-S) can reproduce the same phenotype in T cells from healthy individuals. Supernatant fluid from cultured explants of RCC, but not normal kidney, inhibited the stimulus dependent nuclear translocation of NFκB without altering the cytoplasmic levels of RelA, c-Rel, and NFκB1. Phosphorylation and degradation of IκB was also blocked by RCC-S. The mechanistic similarities between patient-derived T cells and normal T cells cultured with RCC-S suggest that the tumor-derived products may be the primary mediators of impaired T-cell function in this tumor system.© 1998 by The American Society of Hematology.
Distinct Regulation of T-Cell Death by CD28 Depending on Both Its Aggregation and T-Cell Receptor Triggering: A Role for Fas-FasL
Authors: Collette Y. , Benziane A. , Razanajaona D. , Olive D. 
Published: October 2019

CD28 is a major coreceptor that regulates cell proliferation, anergy, and viability of T cells. The negative selection by T-cell receptor (TCR)-induced cell death of immature thymocytes as well as of activated human antigen-specific T-cell clone, requires a costimulatory signal that can be provided by CD28. Conversely, CD28-mediated signals increase expression of Bcl-XL, a survival gene, and promote survival of naive T cells cultured in the absence of antigen or costimulation. Because CD28 appears to both protect from, or induce T-cell death, one important question is to define the activation and cellular parameters that dictate the differential role of CD28 in T-cell apoptosis. Here, we compared different CD28 ligands for their ability to regulate TCR-induced cell death of a murine T-cell hybridoma. In these cells, TCR triggering induced expression of Fas and FasL, and cell death was prevented by anti-Fas blocking monoclonal antibody (MoAb). When provided as a costimulus, both CD28 MoAb and the B7.1 and B7.2 counter receptors downregulated, yet did not completely abolish T-cell receptor–induced apoptosis. This CD28 cosignal resulted in both upregulation of Bcl-XL and prevention of FasL expression. In marked contrast, when given as a single signal, CD28 MoAb or B7.1 and B7.2 induced FasL expression and resulted in T-cell death by apoptosis, which was dependent on the level of CD28 ligation. Furthermore, triggering of CD28 upregulated FasL and induced a marked T-cell death of previously activated normal peripheral T cells. Our results identify Fas and FasL as crucial targets of CD28 in T-cell death regulation and show that within the same cell population, depending on its engagement as a single signal or as a costimulus together with the TCR, CD28 can either induce a dose-dependent death signal or protect from cell death, respectively. These data provide important insights into the role of CD28 in T-cell homeostasis and its possible implication in neoplastic disorders.© 1998 by The American Society of Hematology.
The Chimeric E2A-HLF Transcription Factor Abrogates p53-Induced Apoptosis in Myeloid Leukemia Cells
Authors: Altura Rachel A. , Inukai Takeshi , Ashmun Richard A. , Zambetti Gerard P. , Roussel Martine F. , Look A. Thomas 
Published: October 2019

Leukemic lymphoblasts expressing the E2A-HLF oncoprotein possess wild-type p53 genes, but do not undergo apoptosis in response to DNA damage. Experimentally, E2A-HLF prevents apoptosis due to growth factor deprivation or γ-irradiation in interleukin-3 (IL-3)–dependent murine pro-B cells. To directly test the chimeric protein’s ability to abrogate p53-mediated cell death, we used mouse myeloid leukemia cells (M1p53tsval) that constitutively express a temperature-sensitive (ts) mutant p53 gene and undergo apoptosis when p53 assumes an active wild-type configuration. This effect is blocked by treatment with IL-6, which allows the cells to survive in culture despite wild-type p53 activation. We introduced E2A-HLF into M1p53tsval cells and found that they were resistant to p53-mediated apoptosis and that E2A-HLF effectively substituted for the survival functions of IL-6. The expression of p53-responsive genes such as p21 and Bax was upregulated normally, suggesting that E2A-HLF acts downstream of p53 to block execution of the p53-induced apoptotic program. NFIL3, a growth factor-regulated bZIP protein that binds to the same DNA-consensus site as E2A-HLF, delays apoptosis in IL-3–dependent pro-B cells deprived of growth factor. By contrast, in the present study, enforced expression of NFIL3 failed to protect M1p53tsval cells from p53-dependent apoptosis and actively antagonized the ability of IL-6 to rescue cells from that fate, consistent with its role as either a transcriptional repressor or activator, depending on the cell type in which it is expressed. We conclude that the E2A-HLF chimera abrogates p53-induced apoptosis in leukemic cells, possibly through the transcriptional modulation of cell death pathways that are activated by p53 in response to DNA damage.
© 1998 by The American Society of Hematology.
Macrophage Lineage Cells in Inflammation: Characterization by Colony-Stimulating Factor-1 (CSF-1) Receptor (c-Fms), ER-MP58, and ER-MP20 (Ly-6C) Expression
Authors: Chan James , Leenen Pieter J.M. , Bertoncello Ivan , Nishikawa Shin-Ichi , Hamilton John A. 
Published: October 2019

Macrophage populations resident in tissues and at sites of inflammation are heterogeneous and with local proliferation sometimes evident. Using the convenient murine peritoneal cavity as an inflammation model, the appearance of macrophage lineage cells was followed with time in both thioglycollate- and sodium periodate-induced exudates. The cells were characterized by their proliferative response in vitro in response to colony-stimulating factor-1 (CSF-1) (or macrophage colony-stimulating factor [M-CSF]), particularly by their ability to form colonies in agar, in combination with flow cytometry (surface marker expression and forward and side scatter characteristics). We propose that c-Fms (CSF-1 receptor), unlike other markers, is a uniformly expressed and specific marker suitable for the detection of macrophage-lineage cells in tissues, both in the steady state and after the initiation of an inflammatory reaction. It was shown that the bone marrow myeloid precursor markers, ER-MP58 and ER-MP20 (Ly-6C), but not ER-MP12 (PECAM-1), are expressed by a high proportion of macrophage-lineage cells in the inflamed peritoneum. The macrophage colony-forming cells (M-CFCs) in a 16-hour thioglycollate-induced exudate were phenotyped as c-Fms+ERMP12−20+58+, properties consistent with their being more mature than bone marrow M-CFCs. It is proposed that ER-MP58, as well as ER-MP20, may be a useful marker for distinguishing inflammatory macrophage-lineage cells from the majority of those residing normally in tissues.© 1998 by The American Society of Hematology.
Expression Profile of Active Genes in Granulocytes
Authors: Itoh Koichi , Okubo Kousaku , Utiyama Hiroyasu , Hirano Tetsuo , Yoshii Junji , Matsubara Kenichi 
Published: October 2019

A number of genes active in granulocytes have been intensively studied as to the function of their products and their expression controls. However, the intensities and relative order of these gene activities have not been studied. This report describes an expression profile of 748 different species of active genes in human peripheral granulocytes obtained by analyzing a 3′-directed cDNA library that faithfully represents the mRNA population in the source cells. A significant fraction (20.3% of the total) of the expressed genes in granulocytes consisted of nuclear proteins such as DNA binding proteins, of secretory proteins such as cytokines, and of membrane proteins such as major histocompatibility complex (MHC) proteins and receptors. By comparing this expression profile with 11 profiles similarly obtained with unrelated human cells/tissues, we discovered 10 novel genes that are likely to act specifically in granulocytes. Comparison of this expression profile with that obtained with granulocytoids widely used as a granulocyte model by inducing a cultured promyelocytic leukemia cell line HL60 showed similarities and dissimilarities of gene expressions.© 1998 by The American Society of Hematology.
A Single Dose of Thrombopoietin Shortly After Myelosuppressive Total Body Irradiation Prevents Pancytopenia in Mice by Promoting Short-Term Multilineage Spleen-Repopulating Cells at the Transient Expense of Bone Marrow–Repopulating Cells
Authors: Neelis Karen J. , Visser Trudi P. , Dimjati Wati , Thomas G. Roger , Fielder Paul J. , Bloedow Duane , Eaton Dan L. , Wagemaker Gerard 
Published: October 2019

Thrombopoietin (TPO) has been used in preclinical myelosuppression models to evaluate the effect on hematopoietic reconstitution. Here we report the importance of dose and dose scheduling for multilineage reconstitution after myelosuppressive total body irradiation (TBI) in mice. After 6 Gy TBI, a dose of 0.3 μg TPO/mouse (12 μg/kg) intraperitoneally (IP), 0 to 4 hours after TBI, prevented the severe thrombopenia observed in control mice, and in addition stimulated red and white blood cell regeneration. Time course studies showed a gradual decline in efficacy after an optimum within the first hours after TBI, accompanied by a replacement of the multilineage effects by lineage dominant thrombopoietic stimulation. Pharmacokinetic data showed that IP injection resulted in maximum plasma levels 2 hours after administration. On the basis of the data, we inferred that a substantial level of TPO was required at a critical time interval after TBI to induce multilineage stimulation of residual bone marrow cells. A more precise estimate of the effect of dose and dose timing was provided by intravenous administration of TPO, which showed an optimum immediately after TBI and a sharp decline in efficacy between a dose of 0.1 μg/mouse (4 μg/kg; plasma level 60 ng/mL), which was fully effective, and a dose of 0.03 μg/mouse (1.2 μg/kg; plasma level 20 ng/mL), which was largely ineffective. This is consistent with a threshold level of TPO required to overcome initial c-mpl–mediated clearance and to reach sufficient plasma levels for a maximum hematopoietic response. In mice exposed to fractionated TBI (3 × 3 Gy, 24 hours apart), IP administration of 0.3 μg TPO 2 hours after each fraction completely prevented the severe thrombopenia and anemia that occurred in control mice. Using short-term transplantation assays, ie, colony-forming unit–spleen (CFU-S) day 13 (CFU-S-13) and the more immature cells with marrow repopulating ability (MRA), it could be shown that TPO promoted CFU-S-13 and transiently depleted MRA. The initial depletion of MRA in response to TPO was replenished during long-term reconstitution followed for a period of 3 months. Apart from demonstrating again that MRA cells and CFU-S-13 are separate functional entities, the data thus showed that TPO promotes short-term multilineage repopulating cells at the expense of more immature ancestral cells, thereby preventing pancytopenia. The short time interval available after TBI to exert these effects shows that TPO is able to intervene in mechanisms that result in functional depletion of its multilineage target cells shortly after TBI and emphasizes the requirement of dose scheduling of TPO in keeping with these mechanisms to obtain optimal clinical efficacy.© 1998 by The American Society of Hematology.
CD80-Transfected Acute Myeloid Leukemia Cells Induce Primary Allogeneic T-Cell Responses Directed at Patient Specific Minor Histocompatibility Antigens and Leukemia-Associated Antigens
Authors: Mutis Tuna , Schrama Ellen , Melief Cornelis J.M. , Goulmy Els 
Published: October 2019

Despite sufficient levels of HLA class I and class II expression, acute myeloid leukemia (AML) cells usually fail to induce a significant T-cell response in vitro. Therefore, we investigated whether in vitro modifications could enhance the T-cell stimulatory properties of AML cells. AML cells were either cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4), and tumor necrosis factor- (TNF-), or transfected with the CD80 (B7.1) gene and used as stimulator cells for primed and unprimed allogeneic T cells. Cytokine treatment increased HLA class I and II expression, but did not induce CD80 on AML cells. Cytokine-treated AML cells efficiently presented nominal and allo-antigens to primed T-cell clones, induced strong T-cell proliferation in HLA mismatched mixed lymphocyte reactions (MLR), but failed to induce primary T-cell responses from an HLA identical bone marrow donor in MLR. In contrast, CD80-transfected AML cells induced T-cell proliferation of HLA-identical bone marrow donor peripheral blood mononuclear cell (PBMC) in primary MLR, allowing the generation of leukemia reactive CD4+ T-cell lines and clones. The majority of the generated oligoclonal (25 of 35) T-cell cultures showed patient specific reactivity that did not discriminate between patient’s leukemic cells and Epstein-Barr virus (EBV)-transformed B cells (EBV-LCL). The remaining 10 oligoclonal T-cell cultures recognized only leukemic cells. One of these latter leukemia reactive oligoclonal T cells was cloned. The majority of the clones (25 of 29) reacted against both leukemic cells and patient’s EBV-LCL. A minority of the T-cell clones with the CD4 phenotype (four of 29) showed strong HLA-DP restricted reactivity against leukemic cells, but not against patient’s EBV-LCL or against HLA-matched nonleukemic cells, indicating that their target antigens are preferentially expressed by leukemic cells. In conclusion, our study shows that the in vitro allogeneic T-cell response induced by CD80-transfected AML cells is mainly directed against patient’s specific minor histocompatibility antigens, while antigens preferentially expressed by leukemic cells can also trigger T-cell responses.© 1998 by The American Society of Hematology.
Phosphorylation of BCL-2 After Exposure of Human Leukemic Cells to Retinoic Acid
Authors: Hu Z.-B. , Minden M.D. , McCulloch E.A. 
Published: October 2019

Serine phosphorylation of bcl-2 has been reported after treatment of cells with protein kinase C, okadaic acid, taxol, and other chemotherapeutic agents that attack microtubules. We report here that bcl-2 is phosphorylated on serine in acute myeloblastic leukemia (AML) blasts exposed to all trans retinoic acid (ATRA). Two-dimension gels (isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]) disclosed a novel acidic isoform of bcl-2 in ATRA-treated blast cells from a continuous line and from two AML patients; when the cell lysates were digested with λ-phosphatase, bcl-2 reverted to the control position, indicating that it was phosphorylated. Metabolic labeling experiments using32Pi showed that, while control bcl-2 was labeled, incorporation was greatly increased when cells were treated with ATRA. A comparison of bcl-2 from blasts treated with ATRA or taxol showed that bcl-2 was phosphorylated on serine in cells treated with either agent; however, both qualitative and quantitative differences were seen. Qualitatively, the phosphorylated isoform from taxol-treated cells was slightly larger than the native isoform and could be distinguished on 10% to 20% SDS-polyacrylamide gradient gels, while the phosphorylated bcl-2 after ATRA ran as a single band on gradient gels at the same position as control bcl-2. Quantitatively, all bcl-2 from ATRA-treated cells was in the phosphorylated isoform, while after taxol, both phosphorylated and native bcl-2 was present; incorporation of 32Pi into bcl-2 was stimulated to greater extent in ATRA-treated compared with taxol-treated cells. We used immunoprecipitation experiments to ask if bcl-2 phosphorylated after ATRA or taxol had altered capacity to dimerize with bax. No change in dimerization was demonstrated. We conclude that: bcl-2 is phosphorylated on serine after treatment of AML blasts with ATRA; bcl-2 phosphorylation after ATRA is different from that seen after taxol; bcl-2 phosphorylated after either agent retains capacity to dimerize with bax. The ATRA or taxol-induced phosphorylation of bcl-2 can also be seen in blast cells obtained from AML patients.
© 1998 by The American Society of Hematology.
Rh50 Glycoprotein Gene and Rhnull Disease: A Silent Splice Donor Is trans to a Gly279→Glu Missense Mutation in the Conserved Transmembrane Segment
Authors: Huang Cheng-Han , Liu Zhi , Cheng Guangjie , Chen Ying 
Published: October 2019

Rhnull disease includes the amorph and regulator types that are thought to result from homozygous mutations at theRH30 and RH50 loci, respectively. Here we report an unusual regulator Rhnull where two G→A nucleotide (nt) transitions occurred in trans, targeting different regions of the two copies of Rh50 gene. The nt 836 G→A mutation was a missense change located in exon 6; it converted Gly into Glu at position 279, a central amino acid of the transmembrane segment 9 (TM9). While cDNA analysis showed expression of the 836A(Glu279) allele only, genomic studies showed the presence of both 836A(Glu279) and 836G(Gly279) alleles. A detailed analysis of gene organization led to the identification in the Rh50(836G) allele of a defective donor splice site, caused by a G→A mutation in the invariant GT element of intron 1. This is the first known example of such mutations that has apparently abolished the functional splicing of a pre-mRNA encoding a multipass integral membrane protein. With a silent phenotypic copy intrans, the negatively charged Glu279 residue may disrupt TM9 and impair the interaction of the missense protein with Rh30 polypeptides. To evaluate the significance of the mutation, we took a comparative genomic approach and identified Rh50 homologues in different species. We found that Gly279 is a conserved residue and its adjacent amino acid sequence is identical fromCaenorhabditis elegans to human. These findings provide new insight into the diversity of Rhnull disease and suggest that the C-terminal region of Rh50 may also participate in protein-protein interactions involving Rh complex formation.© 1998 by The American Society of Hematology.
Leukemic Predisposition of Mice Transplanted With Gene-Modified Hematopoietic Precursors Expressing flt3 Ligand
Authors: Hawley Teresa S. , Fong Andrew Z.C. , Griesser Henrik , Lyman Stewart D. , Hawley Robert G. 
Published: October 2019

flt3/flk-2 ligand (FL) is a cytokine that exhibits synergistic activities in combination with other early acting factors on subpopulations of hematopoietic stem/progenitor cells. In addition to normal hematopoietic precursors, expression of the FL receptor, flt3R, has been frequently demonstrated on the blast cells from patients with acute B-lineage lymphoblastic, myeloid, and biphenotypic (also known as hybrid or mixed) leukemias. Because many of these leukemic cell types express FL, the possibility has been raised that altered regulation of FL-mediated signaling might contribute to malignant transformation or expansion of the leukemic clone. In humans, FL is predominantly synthesized as a transmembrane protein that must undergo proteolytic cleavage to generate a soluble form. To investigate the consequences of constitutively expressing the analogous murine FL isoform in murine hematopoietic stem/progenitor cells, lethally irradiated syngeneic mice (18 total) were engrafted with post–5-fluorouracil–treated bone marrow cells transduced ex vivo with a recombinant retroviral vector (MSCV-FL) encoding murine transmembrane FL. Compared with control mice (8 total), MSCV-FL mice presented with a mild macrocytic anemia but were otherwise healthy for more than 5 months posttransplant (until 22 weeks). Subsequently, all primary MSCV-FL recipients observed for up to 1 year plus 83% (20 of 24) of secondary MSCV-FL animals that had received bone marrow from asymptomatic primary hosts reconstituted for 4 to 5 months developed transplantable hematologic malignancies (with mean latency periods of 30 and 23 weeks, respectively). Phenotypic and molecular analyses indicated that the tumor cells expressed flt3R and displayed B-cell and/or myeloid markers. These data, establishing that dysregulated expression of FL in primitive hematopoietic cells predisposes flt3R+ precursors to leukemic transformation, underscore a potential role of this cytokine/receptor combination in certain human leukemias.© 1998 by The American Society of Hematology.
Treatment of B-Cell Lymphoma With Chimeric IgG and Single-Chain Fv Antibody–Interleukin-2 Fusion Proteins
Authors: Liu Shih-Jen , Sher Yuh-Pyng , Ting Chou-Chik , Liao Kuang-Wen , Yu Cheng-Ping , Tao Mi-Hua 
Published: October 2019

Anti-idiotype (Id) antibodies (Abs) have been shown to be effective in treatment of B-cell lymphoma in animal models and in clinical trials. The combination of interleukin-2 (IL-2) can augment the therapeutic effect of anti-Id Abs. To further improve the power of the combined therapy, a monoclonal anti-Id Ab, S5A8, specifically recognizing a murine B-cell lymphoma 38C13, was genetically modified to contain the IL-2 domain and thus use the unique targeting ability of Abs to direct IL-2 to the tumor site. Two forms of the anti-Id–IL-2 fusion proteins were constructed: one configuration consisting of mouse-human chimeric IgG (chS5A8–IL-2) and the other containing only the variable light (VL) and variable heavy (VH) Ab domains covalently connected by a peptide linker (scFvS5A8-IL-2). Both forms of the anti-Id–IL-2 fusion proteins retained IL-2 biological activities and were equivalent in potentiating tumor cell lysis in vitro. In contrast, the antigen-binding ability of scFvS5A8–IL-2 was 30- to 40-fold lower than that of the bivalent chS5A8–IL-2. Pharmacokinetic analysis showed that scFvS5A8–IL-2 was eliminated about 20 times faster than chS5A8–IL-2. Finally, it was shown that chS5A8–IL-2 was very proficient in inhibiting 38C13 tumor growth in vivo, more effectively than a combined therapy with anti-Id Abs and IL-2, whereas scFvS5A8–IL-2 did not show any therapeutic effect. These results demonstrate that the anti-Id–IL-2 fusion protein represents a potent reagent for treatment for B-cell lymphoma and that the intact IgG fusion protein is far more effective than its single-chain counterpart.© 1998 by The American Society of Hematology.