bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Interactions Between the Thrombin Receptor and the T-Cell Antigen Receptor in Human T-Cell Lines
Authors: Joyce David E. , Chen Yan , Erger Rochelle A. , Koretzky Gary A. , Lentz Steven R. 
Published: October 2019

AbstractThe proteolytically activated thrombin receptor (TR) is expressed by T lymphocytes, which suggests that thrombin may modulate T-cell activation at sites of hemostatic stress. We examined the relationship between TR function and T-cell activation in the Jurkat human T-cell line and in T-cell lines with defined defects in T-cell antigen receptor (TCR) function. Stimulation with thrombin or the synthetic TR peptide SFLLRN produced intracellular Ca2+ transients in Jurkat cells. As the concentration of TR agonist was increased, peak Ca2+ mobilization increased, but influx of extracellular Ca2+ decreased. TR signaling was enhanced in a TCR-negative Jurkat line and in T-cell lines deficient in the tyrosine kinase lck or the tyrosine phosphatase CD45, both of which are essential for normal TCR function. TCR cross-linking with anti-CD3 IgM desensitized TR signaling in Jurkat cells, but not in CD45-deficient cells. A proteinase-activated receptor (PAR-2)–specific agonist peptide, SLIGKV, produced small Ca2+ transients in both MEG-01 human megakaryocytic cells and Jurkat cells, but was less potent than the TR-specific agonist TFRIFD in both cell types. Like TR signaling, PAR-2 signaling was enhanced in TCR-negative or lck-deficient Jurkat clones. These findings provide evidence for functional cross-talk between proteolytically activated receptors and the TCR.
Seroreactivity to an Envelope Protein of Human T-Cell Leukemia/Lymphoma Virus in Patients With CD3− (Natural Killer) Lymphoproliferative Disease of Granular Lymphocytes
Authors: Loughran Thomas P. , Hadlock Kenneth G. , Yang Qing , Perzova Raisa , Zambello Renato , Semenzato Gianpietro , Foung Steven K.H. , Poiesz Bernard J. 
Published: October 2019

AbstractNatural killer (NK) cells are CD3− large granular lymphocytes (LGL) responsible for immunity against viral infections. A chronic lymphoproliferative disorder of NK cells has been described in which the expanded NK cells display a restricted phenotype and cytotoxic activity. These data raise the hypothesis that proliferating LGL in these patients result from discrete expansions of NK cells responding to an unknown, perhaps viral, antigen. Recently, it was found that mice transgenic for the tax gene of human T-cell leukemia/lymphoma virus (HTLV) develop NK leukemia. Therefore, we studied 15 patients with chronic NK lymphoproliferative disorder for evidence of HTLV infection. Sera were tested using an HTLV-I/II-enzyme linked immunosorbent assay and a modified Western blot assay containing recombinant env proteins. None of the sera met conventional criteria for HTLV seroreactivity. However, sera from 11 patients (73%) reacted with the recombinant HTLV env protein p21E. The anti-p21E reactivity of these sera was then mapped employing the recombinant proteins GD21 and BA21. No reactivity to the immunodominant HTLV epitope GD21 was observed, suggesting that prototypical HTLV infection is unlikely in these patients. This was confirmed by finding no evidence for HTLV nucleic acids by PCR analyses employing primers specific for conserved regions in the env, pol, and pX genes. In contrast, 10 of the 15 sera reacted with the epitope BA21, documenting for the first time an association between a unique seroreactivity and disease. The high incidence of BA21 seroreactivity in these patients suggests that exposure to a protein containing homology to BA21 may be important in the pathogenesis of this lymphoproliferative disorder.
In Vivo Removal of Malaria Parasites From Red Blood Cells Without Their Destruction in Acute Falciparum Malaria
Authors: Angus Brian J. , Chotivanich Kesinee , Udomsangpetch Rachanee , White Nicholas J. 
Published: October 2019

Abstract
During acute falciparum malaria infection, red blood cells (RBC) containing abundant ring-infected erythrocyte surface antigen (Pf 155 or RESA), but no intracellular parasites, are present in the circulation. These RESA-positive parasite negative RBC are not seen in parasite cultures in vitro. This indicates that in acute falciparum malaria there is active removal of intraerythrocytic parasites by a host mechanism in vivo (probably the spleen) without destruction of the parasitized RBC. This may explain the observed disparity between the drop in hematocrit and decrease in parasite count in some hyperparasitemic patients. The fate of these “once-parasitized” RBC in vivo is not known.
Presence in Human Erythrocyte Membranes of a Novel Form of Sialidase Acting Optimally at Neutral pH
Authors: Venerando Bruno , Fiorilli Amelia , Croci Gian Luigi , Tettamanti Guido 
Published: October 2019

AbstractThe feature of intact human erythrocytes and erythrocyte white ghosts is a unique sialidase activity with acidic optimal pH (acidic sialidase). The treatment of white ghosts with mildly alkaline isotonic solutions at 37°C, like that used to produce resealed ghosts, is accompanied by the expression, together with the acidic sialidase, of a novel sialidase with a pH optimum of 7.2 (neutral sialidase) that remained masked in the inside-out vesicles prepared from white ghosts. Exhaustive treatment of resealed ghosts with Bacillus Thuringiensis phosphatidylinositol-specific phospholipase C causes an almost complete release of the acidic sialidase, with the neutral enzyme remaining totally unaffected. The treatment of resealed ghosts with 1.2% Triton X-100 resulted in the solubilization of only the neutral sialidase, whereas 3.6% octylglucoside also solubilized the acidic sialidase. The neutral enzyme affected not only the artificial substrate but also any sialoderivatives of a ganglioside, glycoprotein, and oligosaccharide nature; the acidic enzyme did not affect sialoglycoproteins. Erythrocyte endogenous gangliosides were hydrolyzed by both sialidases, whereas the endogenous sialoglycoproteins responded to only the neutral enzyme. It was definitely proved that the acidic sialidase is located on the outer erythrocyte membrane surface, so presumably the neutral enzyme has the same location. It could be that the newly discovered neutral sialidase has a physiologic role in the releasing of sialic acid from erythrocytes during the erythrocyte aging process, leading to eventual phagocytosis by macrophages.
Expression of SCL Is Normal in Transfusion-Dependent Diamond-Blackfan Anemia But Other bHLH Proteins Are Deficient
Authors: Zhang Min-Ying , Clawson Gary A. , Olivieri Nancy F. , Bell Laurie L. , Begley C. Glenn , Miller Barbara A. 
Published: October 2019

AbstractBasic helix-loop-helix proteins, which are tissue specific (SCL) or broadly expressed (E proteins), interact positively to regulate erythroid specific genes. Here, expression of SCL and two broadly expressed E proteins, E47 and HEB, was high early in erythroid differentiation and declined during maturation. Stimulation of erythroid progenitors/precursors with stem cell factor (SCF ) enhanced SCL and E protein levels, one mechanism by which SCF may increase erythroid proliferation. Interactions between SCL and E proteins are competed by Id2, which binds and sequesters E proteins. Upregulation of Id2, demonstrated here late in erythroid differentiation, may downregulate genes involved in erythroid proliferation/differentiation. We examined expression of bHLH proteins in transfusion-dependent patients with Diamond-Blackfan anemia (DBA) to determine if these interactions are disrupted. In erythroblasts from patients, expression of SCL protein and mRNA was normal and SCL increased in response to SCF. However, E47 and HEB protein levels were significantly decreased. Id2 was strongly expressed in patients. Through reduction of SCL/E protein heterodimer formation, abnormal levels of bHLH transcription factors may affect expression of erythroid specific genes, such as β globin. Stimulation of Diamond-Blackfan cells with SCF partially compensated for this defect, enhancing expression of E47, HEB, and SCL. SCF may function to increase SCL/E protein heterodimer formation, which may be one of the mechanisms through which SCF stimulates erythroid proliferation/ differentiation in DBA.
Bone Marrow Contains Virus-Specific Cytotoxic T Lymphocytes
Authors: Slifka Mark K. , Whitmire Jason K. , Ahmed Rafi 
Published: October 2019

AbstractImmunizing bone marrow donors prior to bone marrow transplant (BMT) has the potential for adoptively transferring specific immunity against opportunistic pathogens. Studies have shown that long-term antibody production occurs in the bone marrow and that specific humoral immunity may be transferred from donor to recipient following BMT. However, the magnitude and duration of T-cell memory in the bone marrow compartment has not been adequately investigated. In this study, virus-specific CD8+ T-cell responses in the bone marrow were compared with those observed in the spleen of mice acutely infected with lymphocytic choriomeningitis virus (LCMV). During the acute stages of infection, most CD8+ T cells in the spleen and bone marrow showed upregulated surface expression of the activation/memory marker, LFA-1 (LFA-1hi). After clearing LCMV infection, the antiviral immune response subsided to homeostatic levels and the ratio of CD8+/LFA-1hi to CD8+/LFA-1lo T cells in the spleen and bone marrow of LCMV immune mice returned to the value observed in naive mice. Virus-specific ex vivo effector cytotoxic T-lymphocyte (CTL) responses could be identified in both spleen and bone marrow compartments at 8 days postinfection. LCMV-specific CTL precursor (CTLp) frequencies peaked in the bone marrow at 8 days postinfection and averaged one in 200 to one in 650 CD8+ T cells, a frequency similar to that observed in the spleen. After clearing the acute infection, potent LCMV-specific CTL memory responses could be demonstrated in the bone marrow for at least 325 days postinfection, indicating long-term persistence of antiviral T cells at this site. Adoptive transfer of LCMV-immune bone marrow into severe combined immunodeficiency (SCID) mice provided protection against viral challenge, whereas SCID mice that received naive bone marrow became chronically infected upon challenge with LCMV. These results indicate that after acute viral infection, virus-specific memory T cells can be found in the bone marrow compartment and are maintained for an extended period, and when adoptively transferred into an immunodeficient host, they are capable of conferring protection against chronic viral infection.
Retrovirus-Mediated Gene Transfer of NPM-ALK Causes Lymphoid Malignancy in Mice
Authors: Kuefer Martin U. , Look A. Thomas , Pulford Karen , Behm Frederick G. , Pattengale Paul K. , Mason David Y. , Morris Stephan W. 
Published: October 2019

AbstractApproximately 5% to 10% of all non-Hodgkin's lymphomas contain a t(2; 5)(p23; q35) chromosomal rearrangement, which we have previously shown results in the generation of the fusion protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK). To assess the transforming potential of NPM-ALK in an animal model, we infected 5-fluorouracil–treated murine bone marrow using retroviral stocks and transplanted this infected marrow into lethally irradiated BALB/cByJ mice. Male mice were transplanted with bone marrow from female donors at 10 weeks of age, with 7 of the animals receiving marrow infected with a retroviral construct, pSRαMSVtkneo-NPM-ALK, that contains the human NPM-ALK cDNA, and 4 serving as a control group, receiving “empty” pSRαMSVtkneo-infected marrow. Whereas all mice in the control group were alive and well up to 11 months after transplantation, 4 of the 7 mice transplanted with marrow containing the NPM-ALK construct developed lymphoma within 4 to 6 months. Tumors arose in the mesenteric lymph nodes, with metastases to the lungs, kidneys, liver, spleen, and the paraspinal area. When cells from the tumors and bone marrow were transplanted into sublethally irradiated secondary recipients, 10 of these 13 mice developed tumors within 9 months. Immunoblot analysis of cell lysates using an ALK polyclonal antibody showed NPM-ALK expression in all tumors examined. Histologically, the tumors were composed of a uniform population of large immunoblastic cells with basophilic cytoplasm, centrally placed nuclei, and distinct nucleoli. Genotypic analysis showed that the tumors were B-lineage and clonal, with rearrangements of the Ig heavy- and κ light-chain loci and no rearrangements of the T-cell receptor β locus. Immunocytochemical studies confirmed the presence of IgM heavy chains and κ light chains within the tumor cells. Thus, in this retroviral gene transfer model, NPM-ALK expression in mice causes B-lineage large-cell lymphoma, suggesting a direct causative role for this activated fusion tyrosine kinase in human lymphoma.
An In Vitro Analysis of the Combination of Hemophilia A and Factor VLEIDEN
Authors: van ‘t Veer Cornelis , Golden Neal J. , Kalafatis Michael , Simioni Paolo , Bertina Rogier M. , Mann Kenneth G. 
Published: October 2019

AbstractThe classification of factor VIII deficiency, generally used based on plasma levels of factor VIII, consists of severe (<1% normal factor VIII activity), moderate (1% to 4% factor VIII activity), or mild (5% to 25% factor VIII activity). A recent communication described four individuals bearing identical factor VIII mutations. This resulted in a severe bleeding disorder in two patients who carried a normal factor V gene, whereas the two patients who did not display severe hemophilia were heterozygous for the factor VLEIDEN mutation, which leads to the substitution of Arg506 → Gln mutation in the factor V molecule. Based on the factor VIII level measured using factor VIII–deficient plasma, these two patients were classified as mild/moderate hemophiliacs. We studied the condition of moderate to severe hemophilia A combined with the factor VLEIDEN mutation in vitro in a reconstituted model of the tissue factor pathway to thrombin. In the model, thrombin generation was initiated by relipidated tissue factor and factor VIIa in the presence of the coagulation factors X, IX, II, V, and VIII and the inhibitors tissue factor pathway inhibitor, antithrombin-III, and protein C. At 5 pmol/L initiating factor VIIa⋅tissue factor, a 10-fold higher peak level of thrombin formation (350 nmol/L), was observed in the system in the presence of plasma levels of factor VIII compared with reactions without factor VIII. Significant increase in thrombin formation was observed at factor VIII concentrations less than 42 pmol/L (∼6% of the normal factor VIII plasma concentration). In reactions without factor VIII, in which thrombin generation was downregulated by the addition of protein C and thrombomodulin, an increase of thrombin formation was observed with the factor VLEIDEN mutation. The level of increase in thrombin generation in the hemophilia A situation was found to be dependent on the factor VLEIDEN concentration. When the factor VLEIDEN concentration was varied from 50% to 150% of the normal plasma concentration, the increase in thrombin generation ranged from threefold to sevenfold. The data suggested that the analysis of the factor V genotype should be accompanied by a quantitative analysis of the plasma factor VLEIDEN level to understand the effect of factor VLEIDEN in hemophilia A patients. The presented data support the hypothesis that the factor VLEIDEN mutation can increase thrombin formation in severe hemophilia A.
Defective Actin Reorganization and Polymerization of Wiskott-Aldrich T Cells in Response to CD3-Mediated Stimulation
Authors: Gallego Marı́a Dolores , Santamarı́a Manuel , Peña José , Molina Ignacio J. 
Published: October 2019

AbstractThe Wiskott-Aldrich syndrome (WAS) is a severe immunodeficiency and platelet deficiency disease arising from mutation(s) in the WASP gene, which in normal cells encodes an intracellular protein able to interact with other proteins relevant to the control of cytoskeleton organization. Immunodeficiency is mainly due to T-cell progressive malfunction. Salient defects of WAS T cells are a CD3-restricted impairment in proliferative responses and cytoskeletal abnormalities, including the frequent appearance of T cells with atypical morphology. We have investigated the possibility that the CD3-restricted defect and some of the cytoskeletal defects of WAS T cells are linked. For this purpose, we immortalized by means of infection with Herpesvirus Saimiri a number of previously described allospecific WAS T-cell lines. The resulting cells preserve the surface, molecular, and functional phenotypes of their parental lines, including a negligible WASP mRNA expression as well as the CD3-restricted defect and cytoskeleton abnormalities. Results show that, in CD3-stimulated WAS T cells, the pattern of temporal changes in cell shape and F-actin distribution is substantially different from that of control cells. Furthermore, polymerization of actin, a critical step in the CD3-mediated cytoskeleton reorganization, does not occur in WAS T-cell lines in response to OKT3 stimulation. In conclusion, our data link both CD3 and cytoskeletal defects in WAS T cells, strongly suggesting that cytoskeleton abnormalities are an underlying cause for WAS immunodeficiency.
Natural Killer (NK) Cells Are Functionally Abnormal and NK Cell Progenitors Are Diminished in Granulocyte Colony-Stimulating Factor–Mobilized Peripheral Blood Progenitor Cell Collections
Authors: Miller Jeffrey S. , Prosper Felipe , McCullar Valarie 
Published: October 2019

AbstractGranulocyte colony-stimulating factor (G-CSF)–mobilized peripheral blood progenitor cell (PBPC) collections are increasingly emerging as the graft of choice in many centers for autologous transplantation, and with increasing frequency for allogeneic transplantation. However, the role of myeloid cytokines in lymphoid function, lymphoid progenitors, and immune-mediated antitumor responses is not known. We studied PBPC collections from normal donors mobilized with G-CSF (10 μg/kg). CD56+/CD3− natural killer (NK) cells sorted from PBPC products exhibited a diminished ability to kill tumor targets, were less responsive in acquiring increased cytolysis with interleukin-2 (IL-2), and proliferated less than NK cells from normal unprimed peripheral blood. This abnormality was not explained by a change in phenotype of NK cells normally circulating in the blood after G-CSF administration. We could not demonstrate any direct suppressive effect on normal unprimed NK cell proliferation or cytotoxicity by culture with pharmacologic concentrations of G-CSF. We next evaluated the effects of G-CSF on CD34+ NK cell progenitors. CD34+/CD2+, CD34+/CD7+, and CD34+/CD10+ progenitors were markedly diminished in G-CSF–mobilized PBPC products. CD34+ cells cultured in limiting dilution assays showed a sixfold decrease in NK cell progenitors when derived from G-CSF–mobilized CD34+ PBPCs compared with CD34+ cells derived from unprimed marrow. The finding of decreased NK cell function, inhibited proliferation, and diminished cloning frequency after treatment with G-CSF could be mimicked in vitro by culture of primitive marrow progenitors (CD34+, lineage-negative, HLA-DR−) on stromal layers in the presence of exogenous G-CSF. The findings presented here show that G-CSF administration to normal donors decreases NK cell function and the relative frequency of NK cell progenitors within the CD34+ progenitor population. Overcoming this diminished lymphoid capacity may be important to facilitate early posttransplant immunotherapy. Our in vitro model will be used in future studies to determine the mechanism of the G-CSF–induced suppression of NK cell progenitors, which may occur early in the differentiation process.
Abnormalities of Chromosome Band 8p11 in Leukemia: Two Clinical Syndromes Can Be Distinguished on the Basis of MOZ Involvement
Authors: Aguiar Ricardo C.T. , Chase Andrew , Coulthard Stephanie , Macdonald Donald H.C. , Carapeti Melina , Reiter Andreas , Sohal Jastinder , Lennard Anne , Goldman John M. , Cross Nicholas C.P. 
Published: October 2019

Abstract
Two distinct leukemia syndromes are associated with abnormalities of chromosome band 8p11. First, a myeloproliferative disorder with features characteristic of both chronic myeloid leukemia and non-Hodgkin's lymphoma and second, an acute myeloid leukemia (AML) with French-American-British (FAB) M4/5 morphology and prominent erythrophagocytosis. The two syndromes are exemplified by a t(8; 13)(p11; q12) and a t(8; 16)(p11; p13), respectively, but cytogenetic variants of both have been described. Recently, the t(8; 16) has been cloned and shown to fuse the MOZ gene at 8p11 to the CBP gene at 16p13. We have used fluorescence in situ hybridization (FISH), Southern blotting, and reverse transcriptase-polymerase chain reaction (RT-PCR) to refine the 8p11 breakpoint in three cases with t(8; 13)(p11; q12) and in a single case of AML-M5 with a clinical picture apparently identical to that found in patients with a t(8; 16), but characterized by an inv(8)(p11q13). FISH analysis was performed with several 8p11 CEPH yeast artificial chromosome (YAC) clones. YAC 782H11 was centromeric to the one case with t(8; 13) tested, but was telomeric to the inv(8). YAC 847B12 was telomeric to both the t(8; 13) and the inv(8), whereas YAC 829D12 was centromeric to the t(8; 13), but split by the inv(8). Southern blotting and PCR of YAC 829D12 showed that it contained the MOZ gene. A 900-bp MOZ fragment encompassing the published t(8; 16) breakpoint was amplified by PCR from normal peripheral blood leukocyte cDNA and used to probe Southern blots of patient DNA. A rearrangement was detected in the case with inv(8), but not in any of the three cases with t(8; 13). Southern blotting with a CBP probe and RT-PCR with MOZ and CBP primers suggested that the inv(8) does not result in a cryptic MOZ-CBP fusion. It is likely, therefore, that MOZ is fused to a novel gene at 8q13 in this case. We conclude that the t(8; 13) breakpoint is flanked by YACs 782H11 and 847B12 and is at least 1 Mb telomeric to MOZ. MOZ is involved, however, in a new variant of the t(8; 16).
Cyclin D1 Expression in Mantle Cell Lymphoma Is Accompanied by Downregulation of Cyclin D3 and Is Not Related to the Proliferative Activity
Authors: Ott M. Michaela , Bartkova Jirina , Bartek Jiri , Dürr Alexander , Fischer Lars , Ott German , Müller-Hermelink Hans Konrad , Kreipe Hans 
Published: October 2019

AbstractThe cell cycle regulatory protein cyclin D1 is essential for G1-S phase transition in several epithelial and mesenchymal tissues but is apparently not essential in normal mature B cells. An overexpression of cyclin D1 is induced by the chromosomal translocation t(11; 14)(q13; q32), which characterizes non-Hodgkin's lymphomas (NHLs) of mantle cell type. We studied 26 cases of mantle cell lymphoma (MCL) for the expression of cyclins D1 and D3. A total of 23 lymphomas showed a nuclear staining for cyclin D1, whereas reactive B cells of residual germinal centers were constantly negative. When compared with cyclin D3, an inverse staining pattern emerged. Whereas the B cells of residual germinal centers reacted strongly positive for cyclin D3, there was low or missing expression of cyclin D3 in MCL cells. In other B-cell lymphomas (n = 55), including chronic lymphocytic leukemia, low-grade lymphomas of mucosa-associated lymphatic tissue, follicular lymphomas, and diffuse large B-cell lymphomas, no cyclin D1 expression could be detected and 89% of these cases displayed cyclin D3 positivity. Lymphoma cell lines harboring the t(11; 14) showed cyclin D1 protein but no or very low levels of cyclin D3; three other B-cell lines, a T-cell line, and peripheral blood lymphocytes strongly expressed cyclin D3 and reacted negatively for cyclin D1. We conclude that the chromosomal translocation t(11; 14) leads to an abnormal protein expression of cyclin D1 in the tumor cells of MCL and induces a consecutive downregulation of cyclin D3. In contrast to other B-NHLs, cyclin D1 and D3 expression in MCL is not related to the growth fraction.