bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term injection of antiapoptotic cytokine combinations soon after lethal γ-irradiation promotes survival
Authors: Hérodin Francis , Bourin Philippe , Mayol Jean-François , Lataillade Jean-Jacques , Drouet Michel
Published: March 2003

Recovery from radiation-induced (RI) myelosuppression depends on hematopoietic stem and progenitor cell survival and the active proliferation/differentiation process, which requires early cytokine support. Single cytokine or late-acting growth factor therapy has proved to be inefficient in ensuring reconstitution after severe RI damage. This work was aimed at evaluating the in vivo survival effect of combinations of early-acting cytokines whose antiapoptotic activity has been demonstrated in vitro: stem cell factor (SCF [S]), FMS-like tyrosine kinase 3 ligand (FLT-3 ligand [F]), thrombopoietin (TPO [T]), interleukin-3 (IL-3 [3]), and stromal derived factor-1 (SDF-1). B6D2F1 mice underwent total body irradiation at 8 Gy cesium Cs 137 γ radiation (ie, lethal dose 90% at 30 days) and were treated soon after irradiation, at 2 hours and at 24 hours, with recombinant murine cytokines, each given intraperitoneally at 50 μg/kg per injection. All treatments induced 30-day survival rates significantly higher than control (survival rate, 8.3%). 4F (SFT3) and 5F (4F + SDF-1) were the most efficient combinations (81.2% and 87.5%, respectively), which was better than 3F (SFT, 50%), TPO alone (58.3%), and SDF-1 alone (29.2%) and also better than 4F given at 10 μg/kg per injection (4F10, 45.8%) or as a 50 μg/kg single injection at 2 hours (4Fs, 62.5%). Despite delayed death occurring mainly from day 150 on and possible long-term hematopoiesis impairment, half the 30-day protective effects of 4F and 5F were preserved at 300 days. Our results show that short- and long-term survival after irradiation depends on appropriate multiple cytokine combinations and at optimal concentrations. The proposal is made that an emergency cytokine regimen could be applied to nuclear accident victims as part of longer cytokine treatment, cell therapy, or both.
Circulating CD20 is detectable in the plasma of patients with chronic lymphocytic leukemia and is of prognostic significance
Authors: Manshouri Taghi , Do Kim-anh , Wang Xuemei , Giles Francis J. , O'Brien Susan M. , Saffer Helen , Thomas Deborah , Jilani Iman , Kantarjian Hagop M. , Keating Michael J. , Albitar Maher
Published: March 2003

CD20 is a 33- to 36-kDa transmembrane phosphoprotein involved in the activation, proliferation, and differentiation of B lymphocytes. The predicted amino acid sequence of the CD20 suggests 4 transmembrane-spanning regions with both N- and C-termini located in the cytoplasm. We demonstrate herein that significant levels of circulating CD20 (cCD20) can be detected in the plasma of patients with chronic lymphocytic leukemia (CLL) and that cCD20 interferes with the binding of rituximab, a humanized anti-CD20 monoclonal antibody, to CLL cells. An enzyme-linked immunosorbent assay (ELISA) was developed to measure circulating cCD20 levels in the plasma. We measured cCD20 levels in the plasma of 180 patients with CLL and correlated these levels with clinical characteristics and outcome. Circulating CD20 levels correlated positively with β2-microglobulin level (p = .006) and percentage of CD38+ cells (p = .03) and negatively with platelet count (p = .004) and hemoglobin level (p = .02). Patients with advanced Rai (III/IV) or Binet (C) stage disease had significantly higher levels of cCD20 than did patients with earlier-stage disease (P = .01 and P = .006, respectively). There was no correlation between cCD20 level and age, lymphocyte count, or white blood cell count. Using a recursive classification method, we found that patients with a cCD20 level more than 1875 nM/L had significantly shorter survival than those with cCD20 1875 nM/L or below (P = .01). The prognostic value of cCD20 was independent of Rai staging or hemoglobin level. Prospective evaluation is indicated to establish whether rituximab dosing should be adjusted according to cCD20 levels.
Role of the WT1 tumor suppressor in murine hematopoiesis
Authors: Alberta Julia A. , Springett Gregory M. , Rayburn Helen , Natoli Thomas A. , Loring Janet , Kreidberg Jordan A. , Housman David
Published: March 2003

The WT1 tumor-suppressor gene is expressed by many forms of acute myeloid leukemia. Inhibition of this expression can lead to the differentiation and reduced growth of leukemia cells and cell lines, suggesting that WT1 participates in regulating the proliferation of leukemic cells. However, the role of WT1 in normal hematopoiesis is not well understood. To investigate this question, we have used murine cells in which the WT1 gene has been inactivated by homologous recombination. We have found that cells lacking WT1 show deficits in hematopoietic stem cell function. Embryonic stem cells lacking WT1, although contributing efficiently to other organ systems, make only a minimal contribution to the hematopoietic system in chimeras, indicating that hematopoietic stem cells lacking WT1 compete poorly with healthy stem cells. In addition, fetal liver cells lacking WT1 have an approximately 75% reduction in erythroid blast-forming unit (BFU-E), erythroid colony-forming unit (CFU-E), and colony-forming unit–granulocyte macrophage–erythroid–megakaryocyte (CFU-GEMM). However, transplantation of fetal liver hematopoietic cells lackingWT1 will repopulate the hematopoietic system of an irradiated adult recipient in the absence of competition. We conclude that the absence of WT1 in hematopoietic cells leads to functional defects in growth potential that may be of consequence to leukemic cells that have alterations in the expression of WT1.
SOCS-1, a negative regulator of cytokine signaling, is frequently silenced by methylation in multiple myeloma
Authors: Galm Oliver , Yoshikawa Hirohide , Esteller Manel , Osieka Rainhardt , Herman James G.
Published: March 2003

The suppressor of cytokine signaling (SOCS) family of proteins has been implicated in the negative regulation of several cytokine pathways, particularly the receptor-associated tyrosine kinase/signal transducer and activator of transcription (Jak/STAT) pathways of transcriptional activation. SOCS-1 (also known as JAB and SSI-1) inhibits signaling by many cytokines. Because of the previously observed hypermethylation-associated inactivation of SOCS-1in hepatocellular carcinoma and the critical role of interleukin-6 (IL-6) as a survival factor in multiple myeloma (MM), we examined CpG island methylation of the SOCS-1 gene in MM cell lines and primary MM samples. Aberrant SOCS-1methylation was found in the IL-6–dependent MM cell lines U266 and XG1, which correlated with transcriptional silencing. Treatment of these cell lines with the demethylating agent 5-aza-2′-deoxycytidine (DAC) up-regulated SOCS-1 expression. Methylation-associated inactivation of SOCS-1 in hematopoietic cell lines correlated with greater sensitivity to the chemical JAK inhibitor AG490. Using methylation-specific polymerase chain reaction (MSP), we found that SOCS-1 is hypermethylated in 62.9% (23/35) of MM patient samples. In contrast, methylation analysis of malignant lymphomas of various histologies revealed SOCS-1 hypermethylation in only 3.2% (2/62), and there was no methylation of SOCS-1 in normal peripheral blood leukocytes or bone marrow cells. We conclude thatSOCS-1 is frequently inactivated by hypermethylation in MM patients. Silencing of the SOCS-1 gene may impair negative regulation of the Jak/STAT pathway and therefore result in greater responsiveness to cytokines, thus supporting survival and expansion of MM cells.
Effective contribution of transplanted vascular progenitor cells derived from embryonic stem cells to adult neovascularization in proper differentiation stage
Authors: Yurugi-Kobayashi Takami , Itoh Hiroshi , Yamashita Jun , Yamahara Kenichi , Hirai Hideyo , Kobayashi Takuya , Ogawa Minetaro , Nishikawa Satomi , Nishikawa Shin-Ichi , Nakao Kazuwa
Published: March 2003

We demonstrated that Flk-1+ cells derived from mouse embryonic stem (ES) cells can differentiate into both endothelial cells (ECs) and mural cells (MCs) to suffice as vascular progenitor cells (VPCs). In the present study, we investigated the importance of the stage of ES cell differentiation on effective participation in adult neovascularization. We obtained Flk-1+LacZ-expressing undifferentiated VPCs. Additional culture of these VPCs with vascular endothelial growth factor (VEGF) resulted in a mixture of ECs and MCs (differentiated VPCs). We injected VPCs subcutaneously into tumor-bearing mice. Five days after the injection, whereas undifferentiated VPCs were often detected as nonvascular cells, differentiated VPCs were more specifically incorporated into developing vasculature mainly as ECs. VPC-derived MCs were also detected in vascular walls. Furthermore, transplantation of differentiated VPCs augmented tumor blood flow in nude mice. These results indicate that a specific vascular contribution in adult neovascularization can be achieved by selective transplantation of ES cell–derived VPCs in appropriate differentiation stages, which should be the basis for vascular regeneration schemes.
Thromboembolic events in children with acute lymphoblastic leukemia (BFM protocols): prednisone versus dexamethasone administration
Authors: Nowak-Göttl Ulrike , Ahlke Elvira , Fleischhack Gudrun , Schwabe Dirk , Schobess Rosmarie , Schumann Christiane , Junker Ralf
Published: March 2003

Alterations in hemostasis leading to symptomatic thromboembolism have been observed in patients with acute lymphoblastic leukemia (ALL) receiving Escherichia coli asparaginase (CASP) combined with steroids. Moreover, hereditary prothrombotic risk factors are associated with an increased risk for venous thromboembolism in pediatric ALL patients treated according to the BFM 90/95 protocols (including CASP combined with prednisone during induction therapy). To assess whether the thromboembolic risk associated with established prothrombotic risk factors is modified by treatment modalities (prednisone or dexamethasone), the present analysis was performed. Three hundred thirty-six consecutively recruited leukemic children treated according to different BFM protocols (PRED group, n = 280, 60 mg/m2 prednisone; DEXA group, n = 56, 10 mg/m2 dexamethasone during induction therapy) were studied. Study end point was the onset of symptomatic vascular accidents during induction therapy. Cumulative thromboembolism-free survival was significantly reduced in children in the PRED group (thrombosis frequency, 10.4%) compared with children in the DEXA group (thrombosis frequency, 1.8%; P = .028). Although no significant difference was found in the overall prevalence of prothrombotic risk factors, 46.5% of patients in the PRED group who experienced thromboembolic events were carriers of a prothrombotic risk factor, whereas no carrier in the DEXA group had a thromboembolism. At the time of maximum CASP activity, fibrinogen and activities of antithrombin, plasminogen, and protein S were significantly reduced in the PRED group. No significant correlation could be found between CASP activity and levels of coagulation factors. In conclusion, the use of dexamethasone instead of prednisone, administered with CASP, significantly reduced the onset of venous thromboembolism.
Lactadherin inhibits enzyme complexes of blood coagulation by competing for phospholipid-binding sites
Authors: Shi Jialan , Gilbert Gary E.
Published: March 2003

Lactadherin, a glycoprotein of the milk-fat globule membrane, contains tandem C domains with homology to discoidin-type lectins and to membrane-binding domains of blood-clotting factors V and VIII. We asked whether the structural homology confers the capacity to compete for the membrane-binding sites of factor VIII and factor V and to function as an anticoagulant. Our results indicate that lactadherin competes efficiently with factor VIII and factor V for binding sites on synthetic phosphatidylserine-containing membranes with half-maximal displacement at lactadherin concentrations of 1 to 4 nM. Binding competition correlated to functional inhibition of factor VIIIa–factor IXa (factor Xase) enzyme complex. In contrast to annexin V, lactadherin was an efficient inhibitor of the prothrombinase and the factor Xase complexes regardless of the degree of membrane curvature and the phosphatidylserine content. Lactadherin also inhibited the factor VIIa–tissue factor complex efficiently whereas annexin V was less effective. Because the inhibitory concentration of lactadherin was proportional to the phospholipid concentration, and because lactadherin was not an efficient inhibitor in the absence of phospholipid, the major inhibitory effect of lactadherin relates to blocking phospholipid sites rather than forming inhibitory protein-protein complexes. Lactadherin was also an effective inhibitor of a modified whole blood prothrombin time assay in which clotting was initiated by dilute tissue factor; 60 nM lactadherin prolonged the prothrombin time 150% versus 20% for 60 nM annexin V. These results indicate that lactadherin can function as a potent phospholipid-blocking anticoagulant.
The vitamin D3 analog EB1089 induces apoptosis via a p53-independent mechanism involving p38 MAP kinase activation and suppression of ERK activity in B-cell chronic lymphocytic leukemia cells in vitro
Authors: Pepper Chris , Thomas Alun , Hoy Terry , Milligan Donald , Bentley Paul , Fegan Chris
Published: March 2003

EB1089, a novel vitamin D3 analog, has been shown to have cytotoxic and antiproliferative properties in a variety of malignant cells. However, its potential as a treatment for B-cell chronic lymphocytic leukemia (B-CLL) has not been evaluated. EB1089 induced apoptosis in all of the 102 B-CLL samples tested with a mean LD50 (the concentration of EB1089 required to kill 50% of cells) value (± SD) of 2.1 × 10−8 M (± 1.4 × 10−8 M). Furthermore, no significant difference was found in the cytotoxicity of EB1089 in B-CLL samples from previously treated and untreated patients (P = .1637). Induction of apoptosis was associated with a reduction in Bcl-2 and Mcl-1 protein expression, but this was evident only in the apoptotic cells. In contrast, the expression of Bax, p21, and p53 was not altered in the viable or apoptotic cells from either B- or T-lymphocyte lineages. EB1089-induced apoptosis was preceded by activation of p38 mitogen–activated protein (MAP) kinase and suppression of extracellular signal–regulated kinase (ERK) activity, and this was associated with downstream activation of caspase-3. The pancaspase inhibitor (Z-VAD-FMK) and the caspase-9 inhibitor (Z-LEHD-FMK) were able to partially abrogate the apoptotic effects of EB1089 but did not affect the phosphorylation of p38 MAP kinase or the suppression of ERK. The B-CLL cells in the study were shown to highly express vitamin D receptor, but an additional receptor-independent mechanism of cell killing cannot be ruled out at this stage. These findings show that EB1089 is a potent apoptosis-inducing agent in B-CLL cells and may be useful in the treatment of B-CLL patients, particularly those with p53 mutations or drug-resistant disease.
Signaling mechanisms coupled to tyrosines in the granulocyte colony-stimulating factor receptor orchestrate G-CSF–induced expansion of myeloid progenitor cells
Authors: Hermans Mirjam H. A. , van de Geijn Gert-Jan , Antonissen Claudia , Gits Judith , van Leeuwen Daphne , Ward Alister C. , Touw Ivo P.
Published: March 2003

Granulocyte colony-stimulating factor (G-CSF) is the major regulator of neutrophil production. Studies in cell lines have established that conserved tyrosines Tyr704, Tyr729, Tyr744, Tyr764 within the cytoplasmic domain of G-CSF receptor (G-CSF-R) contribute significantly to G-CSF–induced proliferation, differentiation, and cell survival. However, it is unclear whether these tyrosines are equally important under more physiologic conditions. Here, we investigated how individual G-CSF-R tyrosines affect G-CSF responses of primary myeloid progenitors. We generated G-CSF-R–deficient mice and transduced their bone marrow cells with tyrosine “null” mutant (m0), single tyrosine “add-back” mutants, or wild-type (WT) receptors. G-CSF–induced responses were determined in primary colony assays, serial replatings, and suspension cultures. We show that removal of all tyrosines had no major influence on primary colony growth. However, adding back Tyr764 strongly enhanced proliferative responses, which was reverted by inhibition of ERK activity. Tyr729, which we found to be associated with the suppressor of cytokine signaling, SOCS3, had a negative effect on colony formation. After repetitive replatings, the clonogenic capacities of cells expressing m0 gradually dropped compared with WT. The presence of Tyr729, but also Tyr704 and Tyr744, both involved in activation of signal transducer and activator of transcription 3 (STAT3), further reduced replating efficiencies. Conversely, Tyr764 greatly elevated the clonogenic abilities of myeloid progenitors, resulting in a more than 104-fold increase of colony-forming cells over m0 after the fifth replating. These findings suggest that tyrosines in the cytoplasmic domain of G-CSF-R, although dispensable for G-CSF–induced colony growth, recruit signaling mechanisms that regulate the maintenance and outgrowth of myeloid progenitor cells.
The spectrum of PIG-A gene mutations in aplastic anemia/paroxysmal nocturnal hemoglobinuria (AA/PNH): a high incidence of multiple mutations and evidence of a mutational hot spot
Authors: Mortazavi Yousef , Merk Bruno , McIntosh Jenny , Marsh Judith C. W. , Schrezenmeier Hubert , Rutherford Tim R.
Published: March 2003

Paroxysmal nocturnal hemoglobinuria (PNH) may arise during long-term follow- up of aplastic anemia (AA), and many AA patients have minor glycosylphosphatidylinositol (GPI) anchor–deficient clones, even at presentation. PIG-A gene mutations in AA/PNH and hemolytic PNH are thought to be similar, but studies on AA/PNH have been limited to individual cases and a few small series. We have studied a large series of AA patients with a GPI anchor–deficient clone (AA/PNH), including patients with minor clones, to determine whether their pattern of PIG-A mutations was identical to the reported spectrum in hemolytic PNH. AA patients with GPI anchor–deficient clones were identified by flow cytometry and minor clones were enriched by immunomagnetic selection. A variety of methods was used to analyzePIG-A mutations, and 57 mutations were identified in 40 patients. The majority were similar to those commonly reported, but insertions in the range of 30 to 88 bp, due to tandem duplication of PIG-A sequences, and deletions of more than 10 bp were also seen. In 3 patients we identified identical 5-bp deletions by conventional methods. This prompted the design of mutation-specific polymerase chain reaction (PCR) primers, which were used to demonstrate the presence of the same mutation in an additional 12 patients, identifying this as a mutational hot spot in thePIG-A gene. Multiple PIG-A mutations have been reported in 10% to 20% of PNH patients. Our results suggest that the large majority of AA/PNH patients have multiple mutations. These data may suggest a process of hypermutation in the PIG-A gene in AA stem cells.
Expression of CD57 defines replicative senescence and antigen-induced apoptotic death of CD8+ T cells
Authors: Brenchley Jason M. , Karandikar Nitin J. , Betts Michael R. , Ambrozak David R. , Hill Brenna J. , Crotty Laura E. , Casazza Joseph P. , Kuruppu Janaki , Migueles Stephen A. , Connors Mark , Roederer Mario , Douek Daniel C. , Koup Richard A.
Published: March 2003

Virus-specific CD8+ T-cell responses play a pivotal role in limiting viral replication. Alterations in these responses, such as decreased cytolytic function, inappropriate maturation, and limited proliferative ability could reduce their ability to control viral replication. Here, we report on the capacity of HIV-specific CD8+ T cells to secrete cytokines and proliferate in response to HIV antigen stimulation. We find that a large proportion of HIV-specific CD8+ T cells that produce cytokines in response to cognate antigen are unable to divide and die during a 48-hour in vitro culture. This lack of proliferative ability of HIV-specific CD8+ T cells is defined by surface expression of CD57 but not by absence of CD28 or CCR7. This inability to proliferate in response to antigen cannot be overcome by exogenous interleukin-2 (IL-2) or IL-15. Furthermore, CD57 expression on CD8+ T cells, CD4+ T cells, and NK cells is a general marker of proliferative inability, a history of more cell divisions, and short telomeres. We suggest, therefore, that the increase in CD57+ HIV-specific CD8+ T cells results from chronic antigen stimulation that is a hallmark of HIV infection. Thus, our studies define a phenotype associated with replicative senescence in HIV-specific CD8+ T cells, which may have broad implications to other conditions associated with chronic antigenic stimulation.
Humoral immune response in mice against a circulating antigen induced by adenoviral transfer is strictly dependent on expression in antigen-presenting cells
Authors: De Geest Bart R. , Van Linthout Sophie A. , Collen Désiré
Published: March 2003

Adenoviral transfer of human apo A-I in Balb/c mice induces a strong humoral immune response against the transgene product when expression is driven from the ubiquitously active CMVpromoter but induces no immune response when driven by the hepatocyte-specific 256–base pair apo A-I promoter. Here the hypothesis was tested, which is that the humoral immune response against the circulating transgene product correlates with its expression in antigen-presenting cells. No humoral immune response was observed after adenoviral transfer of vectors with human apo A-I expression driven by the hepatocyte-specific apo C-II or 1.5-kilobase (kb) humanα1-antitrypsin promoter, but antibodies were induced after transfer with vectors driven by the ubiquitously activeU1b promoter and the murine MHCII Eβpromoter. A strict correlation was observed between antigen expression in the spleen and the occurrence of an immune response. Coinjection of the 1.5-kb human α1-antitrypsin and the murine MHCII Eβ promoter–driven vectors resulted in a very short-lived humoral immune response against human apo A-I, suggesting that the time course of human apo A-I expression is a critical determinant of the development of tolerance for human apo A-I. High titers of antibodies against human apo A-I after subcutaneous gene transfer with the MHCII Eβ promoter–driven vector underscore the potential of this promoter for vaccination purposes. In conclusion, humoral immune response in mice against a circulating antigen induced by adenoviral transfer is strictly dependent on expression in antigen-presenting cells.
A single viral protein HCMV US2 affects antigen presentation and intracellular iron homeostasis by degradation of classical HLA class I and HFE molecules
Authors: Arieh Sayeh Vahdati-Ben , Laham Nihay , Schechter Chana , Yewdell Jon W. , Coligan John E. , Ehrlich Rachel
Published: March 2003

HFE is a nonclassical class I molecule that associates with β2-microglobulin (β2m) and with the transferrin receptor. HFE accumulates in transferrin-containing endosomes, and its overexpression in human cell lines correlates with decreased transferrin receptor (TFR)–mediated iron uptake and decreased intracellular iron pools. A mutation that interferes with proper folding and assembly of HFE complexes results in a severe iron-overload disease hereditary hemochromatosis. We previously suggested that viruses could also interfere with iron metabolism through the production of proteins that inactivate HFE, similarly to classical class I proteins. In particular, we demonstrated in a transient expression system that human cytomegalovirus (HCMV) US2 targeted HFE for proteasomal degradation. Here we demonstrate that the stable expression of HCMV US2 in HEK 293 cells constitutively expressing HFE leads to loss of HFE expression both intracellularly and on the cell surface, and the significant reduction of classical class I expression. Both HFE and classical class I molecules are targeted to degradation via a similar pathway. This HCMV US2-mediated degradation of HFE leads to increased intracellular iron pools as indicated by reduced synthesis of TfR and increased ferritin synthesis. Whether this interference with regulation of iron metabolism potentiates viral replication and/or promotes damage of HCMV-infected tissues remains to be determined. Nevertheless, the deleterious effect of US2 on the expression of HFE and classical class I major histo-compatibility complexes (MHC) provides HCMV with an efficient tool for altering cellular metabolic functions, as well as supporting the escape of virus-infected cells from cytotoxic T lymphocyte (CTL)–mediated immune responses.
Oncolytic measles viruses displaying a single-chain antibody against CD38, a myeloma cell marker
Authors: Peng Kah-Whye , Donovan Kathleen A. , Schneider Urs , Cattaneo Roberto , Lust John A. , Russell Stephen J.
Published: March 2003

Live attenuated measles virus (MV-Edm) has potent oncolytic activity against myeloma xenografts in mice. Therapy of multiple myeloma, a disseminated plasma cell malignancy, would require systemic administration of the virus. Thus, the virus should ideally be targeted to infect only myeloma cells to minimize collateral damage to normal tissues: viral binding to its natural receptors must be ablated and a new specificity domain that targets entry into myeloma cells be added. This study covers 2 critical steps toward generating such a retargeted virus: (1) a new specificity domain against the plasma cell marker CD38 was constructed in the form of a single-chain antibody (scFv) and (2) display of that scFv on the measles viral envelope glycoprotein successfully redirected virus entry through CD38 expressed on target cells devoid of the natural MV receptors. The anti-CD38 scFv was tethered to the C-terminus of the hemagglutinin (H) glycoprotein of MV-Edm through a Factor Xa protease cleavable linker. Immunoblot analysis demonstrated that the scFv was efficiently incorporated into recombinant viral particles. Replication of MV-αCD38 was not hindered by the scFv, reaching titers comparable to MV-Edm. Chinese hamster ovary (CHO) cells were resistant to infection by MV-Edm and MV-αCD38. In contrast, CHO cells expressing CD38 became susceptible to infection by MV-αCD38 but not MV-Edm. Removal of the displayed scFv rendered MV-αCD38 noninfectious on CHO-CD38 cells. Tumorigenicity of CHO-CD38 cells in immunocompromised mice was significantly attenuated by MV-αCD38, resulting in enhanced survival of these mice compared with the control group.
Platelet P-selectin facilitates atherosclerotic lesion development
Authors: Burger Peter C. , Wagner Denisa D.
Published: March 2003

P-selectin is an adhesion molecule expressed on activated platelets and endothelium. It is known to play an important role in atherosclerosis. P-selectin also circulates in plasma in a soluble form (sP-selectin), which induces procoagulant microparticle formation. We investigated the role of platelet versus endothelial P-selectin in generating sP-selectin and in the formation of atherosclerotic lesions in the apolipoprotein E (apoE)–deficient mouse model. For this we transplanted apoE−/−P-selectin−/− and apoE−/−P-selectin+/+ lethally irradiated mice with bone marrow of either genotype. Seven months after transplantation, we determined from the chimeric animals that the majority of circulating sP-selectin was of endothelial origin. Thus, in atherosclerosis, the procoagulant sP-selectin reflects endothelial rather than platelet activation. We found that endothelial P-selectin was crucial for the promotion of atherosclerotic lesion growth because in its absence only relatively small lesions developed. However, platelet P-selectin also contributed to the lesion development because lesions in wild-type recipients receiving transplants with wild-type platelets were 30% larger than those receiving P-selectin-deficient platelets (P < .008) and were more frequently calcified (80% versus 44%). In comparison with P-selectin wild-type animals, absence of either endothelial or platelet P-selectin inhibited migration of smooth muscle cells into the lesion. Thus, in addition to endothelium, platelets and their P-selectin also actively promote advanced atherosclerotic lesion development.
Interleukin 4–induced gene 1 is activated in primary mediastinal large B-cell lymphoma
Authors: Copie-Bergman Christiane , Boulland Marie-Laure , Dehoulle Catherine , Möller Peter , Farcet Jean-Pierre , Dyer Martin J. S. , Haioun Corinne , Roméo Paul-Henri , Gaulard Philippe , Leroy Karen
Published: March 2003

The molecular markers that distinguish primary mediastinal large B-cell lymphoma (PMBL) from nonmediastinal diffuse large B-cell lymphomas (NM-DLBLs) remain to be identified. Using cDNA representational difference analysis to compare PMBL and NM-DLBL transcripts, we isolated a cDNA fragment homologous to the mouse B-cell interleukin 4 (IL-4)–inducible gene FIG1(interleukin 4–induced gene 1) transcript. The human FIG1mRNA encodes a 567 amino acid protein that comprises a signal peptide and a large flavin-binding amino oxidase domain, and shares significant homology with secreted apoptosis-inducing L-amino acid oxidases. Northern blot studies showed that FIG1 mRNA expression is mainly restricted to lymphoid tissues. It is expressed at low levels in thymus, spleen, tonsils, and reactive lymph nodes, and is highly up-regulated in IL-4+CD40–activated tonsillar B cells. Interestingly, in human B-cell lines, FIG1 mRNA expression appeared restricted to the PMBL-derived MedB-1 and Karpas 1106 cell lines. Using real-time reverse transcriptase–polymerase chain reaction (RT-PCR), we demonstrated that all but one PMBL (16/17) displayed high FIG1 mRNA levels, whereas most NM-DLBLs (12/18) and all low-grade B-cell lymphomas tested (8/8) exhibited low FIG1 mRNA levels. The difference between PMBLs and NM-DLBLs was statistically significant (Fisher test;P = .0003). Southern blot studies did not show rearrangement of the FIG1 gene. FIG1 gene expression might be due to a constitutive activation of a cytokine signaling pathway in PMBL.
Splenic marginal zone lymphoma
Authors: Franco Vito , Florena Ada Maria , Iannitto Emilio
Published: March 2003

Splenic marginal zone lymphoma (SMZL) is a specific low-grade small B-cell lymphoma that is incorporated in the World Health Organization classification. Characteristic features are splenomegaly, moderate lymphocytosis with villous morphology, intrasinusoidal pattern of involvement of various organs, especially bone marrow, and relative indolent course. Tumor progression with increase of blastic forms and aggressive behavior are observed in a minority of patients. Molecular and cytogenetic studies have shown heterogeneous results probably because of the lack of standardized diagnostic criteria. To date, no definitive therapy has been established. Therapeutic options include treatment abstention, splenectomy, splenic irradiation, and chemotherapy.
The heat shock protein Gp96 binds to human neutrophils and monocytes and stimulates effector functions
Authors: Radsak Markus P. , Hilf Norbert , Singh-Jasuja Harpreet , Braedel Sibylla , Brossart Peter , Rammensee Hans-Georg , Schild Hansjoerg
Published: March 2003

The endoplasmic reticulum (ER)–resident heat shock protein Gp96 is involved in protein folding and is released into the extracellular space after necrotic cell death. In this context, Gp96 has immunostimulatory properties: it activates dendritic cells or macrophages and delivers associated peptides into the antigen presentation pathway, resulting in the induction of specific T-cell responses. The inflammatory response after necrotic tissue damage leads to the recruitment of polymorphonuclear neutrophils (PMNs) and monocytes, allowing them to make their first encounter with Gp96. We therefore investigated whether PMNs and monocytes interact with Gp96. We were able to show that PMNs and monocytes specifically bind fluorescein isothiocyanate (FITC)–conjugated Gp96. The binding of Gp96-FITC was competed by lipopolysaccharide (LPS) or fucoidan, a known inhibitor of scavenger receptors. Interestingly, the binding of LPS-FITC was also competed not only by fucoidan, but by Gp96, suggesting that LPS and Gp96 share a common receptor on PMNs. One important effector function of PMNs is the clearance of an inflammatory site by phagocytosis. We therefore assessed the influence of Gp96 on phagocytic activity using fluorochrome-labeled polystyrene beads. We found a marked enhancement of phagocytosis in the presence of Gp96 and concluded that PMNs not only bind Gp96, but are also activated by it. Additionally, Gp96-stimulated PMNs and especially monocytes release large amounts of interleukin-8, a potent neutrophil-attracting chemokine. In conclusion, we demonstrate that Gp96 specifically binds to and activates PMNs and monocytes, extending the function of Gp96 as a danger signal to additional members of the innate immune system.
SgIGSF: a new mast-cell adhesion molecule used for attachment to fibroblasts and transcriptionally regulated by MITF
Authors: Ito Akihiko , Jippo Tomoko , Wakayama Tomohiko , Morii Eiichi , Koma Yu-ichiro , Onda Hiroaki , Nojima Hiroshi , Iseki Shoichi , Kitamura Yukihiko
Published: March 2003

Microphthalmia transcription factor (MITF) is a basic-helix-loop-helix-leucine zipper-type transcription factor. The mutant mi and Miwh alleles encode MITFs with deletion and alteration of a single amino acid, respectively, whereas the tg is a null mutation. In coculture with NIH/3T3 fibroblasts, the numbers of cultured mast cells (CMCs) derived from C57BL/6 (B6)mi/mi, B6Miwh/Miwh, and B6tg/tg mice that adhered to NIH/3T3 fibroblasts were one third as large as the number of B6+/+CMCs that adhered to NIH/3T3 fibroblasts. From a cDNA library of B6+/+ CMCs, we subtracted messenger RNAs expressed by B6mi/mi CMCs and found a clone encoding SgIGSF, a recently identified member of the immunoglobulin superfamily. Northern and Western blot analyses revealed that SgIGSF was expressed in B6+/+ CMCs but not in CMCs derived from MITF mutants. Immunocytochemical analysis showed that SgIGSF localized to the cell-to-cell contact areas between B6+/+ CMCs and NIH/3T3 fibroblasts. Transfection of B6mi/mi and B6tg/tg CMCs with SgIGSF cDNA normalized their adhesion to NIH/3T3 fibroblasts. NIH/3T3 fibroblasts did not express SgIGSF, indicating that SgIGSF acts as a heterophilic adhesion molecule. Transfection of B6tg/tg CMCs with normal MITF cDNA elevated their SgIGSF expression to normal levels. These results indicated that SgIGSF mediated the adhesion of CMCs to fibroblasts and that the transcription of SgIGSF was critically regulated by MITF.
POEMS syndrome: definitions and long-term outcome
Authors: Dispenzieri Angela , Kyle Robert A. , Lacy Martha Q. , Rajkumar S. Vincent , Therneau Terry M. , Larson Dirk R. , Greipp Philip R. , Witzig Thomas E. , Basu Rita , Suarez Guillermo A. , Fonseca Rafael , Lust John A. , Gertz Morie A.
Published: March 2003

The POEMS syndrome (coined to refer to polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) remains poorly understood. Ambiguity exists over the features necessary to establish the diagnosis, treatment efficacy, and prognosis. We identified 99 patients with POEMS syndrome. Minimal criteria were a sensorimotor peripheral neuropathy and evidence of a monoclonal plasmaproliferative disorder. To distinguish POEMS from neuropathy associated with monoclonal gammopathy of undetermined significance, additional criteria were included: a bone lesion, Castleman disease, organomegaly (or lymphadenopathy), endocrinopathy, edema (peripheral edema, ascites, or effusions), and skin changes. The median age at presentation was 51 years; 63% were men. Median survival was 165 months. With the exception of fingernail clubbing (P = .03) and extravascular volume overload (P = .04), no presenting feature, including the number of presenting features, was predictive of survival. Response to therapy (P < .001) was predictive of survival. Pulmonary hypertension, renal failure, thrombotic events, and congestive heart failure were observed and appear to be part of the syndrome. In 18 patients (18%), new disease manifestations developed over time. More than 50% of patients had a response to radiation, and 22% to 50% had responses to prednisone and a combination of melphalan and prednisone, respectively. We conclude that the median survival of patients with POEMS syndrome is 165 months, independent of the number of syndrome features, bone lesions, or plasma cells at diagnosis. Additional features of the syndrome often develop, but the complications of classic multiple myeloma rarely develop.
PECAM-1–dependent neutrophil transmigration is independent of monolayer PECAM-1 signaling or localization
Authors: O'Brien Christopher D. , Lim Poay , Sun Jing , Albelda Steven M.
Published: March 2003

Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31), a tyrosine phosphoprotein highly expressed on endothelial cells and leukocytes, is an important component in the regulation of neutrophil transendothelial migration. Engagement of endothelial PECAM-1 activates tyrosine phosphorylation events and evokes prolonged calcium transients, while homophilic engagement of neutrophil PECAM-1 activates leukocyte β-integrins. Although PECAM-1 modulates polymorphoneutrophil transmigration via homophilic PECAM-1–PECAM-1 interaction, the mechanisms underlying endothelial PECAM-1 function are unknown. Proposed mechanisms include (1) formation of a haptotactic gradient that “guides” neutrophils to the cell-cell border, (2) service as a “passive ligand” for neutrophil PECAM-1, ultimately mediating activation of neutrophil β integrins, (3) regulation of endothelial calcium influx, and (4) mediation of SH2 protein association, and/or (5) catenin and non-SH2 protein interaction. Utilizing PECAM-1–null “model” endothelial cells (REN cells), we developed a neutrophil transmigration system to study PECAM-1 mutations that specifically disrupt PECAM-1–dependent signaling and/or PECAM-1 cell localization. We report that interleukin-1β (IL-1β) elicits PECAM-1–dependent transmigration that requires homophilic PECAM–PECAM-1 engagement, but not heterophilic neutrophil PECAM-1 interactions, and is intercellular adhesion molecule-1 dependent. Conversely, whereas IL-8 and leukotriene-B4–mediated transmigration is PECAM-1–independent, PECAM-1 and IL-8–dependent transmigration represent separable and additive components of cytokine-induced transmigration. Surprisingly, neither monolayer PECAM-1–regulated calcium signaling, cell border localization, nor the PECAM-1 cytoplasmic domain was required for monolayer PECAM-1 regulation of neutrophil transmigration. We conclude that monolayer (endothelial cell) PECAM-1 functions as a passive homophilic ligand for neutrophil PECAM-1, which after engagement leads to neutrophil signal transduction, integrin activation, and ultimately transmigration in a stimulus-specific manner.
Analysis of TCR, pTα, and RAG-1 in T-acute lymphoblastic leukemias improves understanding of early human T-lymphoid lineage commitment
Authors: Asnafi Vahid , Beldjord Kheira , Boulanger Emmanuelle , Comba Béatrice , Le Tutour Patricia , Estienne Marie-Hélène , Davi Frédéric , Landman-Parker Judith , Quartier Pierre , Buzyn Agnès , Delabesse Eric , Valensi Françoise , Macintyre Elizabeth
Published: March 2003

T-acute lymphoblastic leukemias (T-ALLs) derive from human T-lymphoid precursors arrested at various early stages of development. Correlation of phenotype and T-cell receptor (TCR) status with RAG-1 and pTα transcription in 114 T-ALLs demonstrated that they largely reflect physiologic T-lymphoid development. Half the TCRαβ lineage T-ALLs expressed a pre-TCR, as evidenced by RAG-1, pTα, and cTCRβ expression, absence of TCRδ deletion, and a sCD3−, CD1a+, CD4/8 double-positive (DP) phenotype, in keeping with a population undergoing β selection. Most TCRγδ T-ALLs were pTα, terminal deoxynucleotidyl transferase (TdT), and RAG-1lo/neg, double-negative/single-positive (DN/SP), and demonstrated only TCRβ DJ rearrangement, whereas 40% were pTα, TdT, and RAG-1 positive, DP, and demonstrated TCRβ V(D)J rearrangement, with cTCRβ expression in proportion. As such they may correspond to TCRαβ lineage precursors selected by TCRγδ expression, to early γδ cells recently derived from a pTα+ common αβ/γδ precursor, or to a lineage-deregulated αβ/γδ intermediate. Approximately 30% of T-ALLs were sCD3/cTCRβ− and corresponded to nonrestricted thymic precursors because they expressed non–T-restricted markers such as CD34, CD13, CD33, and CD56 and were predominantly DN, CD1a, pTα, and RAG-1 low/negative, despite immature TCRδ and TCRγ rearrangements. TCR gene configuration identified progressive T-lymphoid restriction. T-ALLs, therefore, provide homogeneous expansions of minor human lymphoid precursor populations that can aid in the understanding of healthy human T-cell development.
High-level expression of BCL3 differentiates t(2;5)(p23;q35)-positive anaplastic large cell lymphoma from Hodgkin disease
Authors: Nishikori Momoko , Maesako Yoshitomo , Ueda Chiyoko , Kurata Masayuki , Uchiyama Takashi , Ohno Hitoshi
Published: March 2003

Anaplastic large cell lymphoma (ALCL) with t(2;5)(p23;q35) and Hodgkin disease (HD) share many cellular features, including expression of CD30. We compared gene expression profiles of 4 ALCL (Karpas 299, SU-DHL-1, DEL, SR-786) and 3 HD cell lines and found thatBCL3, which encodes a nuclear protein belonging to the IκB family of inhibitors of nuclear factor–κB (NF-κB) transcriptional factors, was expressed at higher levels in ALCL than HD. Northern and Western blotting analyses confirmed the high-level expression of BCL3 in ALCL at both mRNA and protein levels. We established a real-time reverse transcriptase–mediated polymerase chain reaction assay to measure the BCL3 mRNA level and found a predominant level of BCL3 expression in t(2;5)+ ALCL; the levels of cell lines and clinical materials were comparable to or higher than that of a B-cell chronic lymphocytic leukemia carrying t(14;19)(q32;q13). Southern blotting and fluorescence in situ hybridization disclosed that the BCL3gene copies were amplified in SU-DHL-1, whereas Karpas 299 carried 4 BCL3 gene loci. The BCL3 gene contains 2 cytosine-guanine dinucleotide (CpG) islands, and the intragenic 3′ CpG was entirely demethylated in SU-DHL-1 and DEL. In contrast to HD, in which NF-κB was constitutively activated, ALCL cells consistently showed (p50)2 homodimer binding activity on electrophoretic mobility shift assay. It is suggested that the high-level nuclear Bcl-3 sequestrates the (p50)2 homodimer to the nucleus, which may account for the contradictory effect of CD30 stimulation on ALCL and HD. We propose that BCL3 is overexpressed by genetic and epigenetic modifications, potentially contributing to the development of t(2;5)+ ALCL.
Primary immune responses to human CMV: a critical role for IFN-γ–producing CD4+ T cells in protection against CMV disease
Authors: Gamadia Laila E. , Remmerswaal Ester B. M. , Weel Jan F. , Bemelman Frederieke , van Lier René A. W. , Ten Berge Ineke J. M.
Published: March 2003

The correlates of protective immunity to disease-inducing viruses in humans remain to be elucidated. We determined the kinetics and characteristics of cytomegalovirus (CMV)–specific CD4+ and CD8+ T cells in the course of primary CMV infection in asymptomatic and symptomatic recipients of renal transplants. Specific CD8+ cytotoxic T lymphocyte (CTL) and antibody responses developed regardless of clinical signs. CD45RA−CD27+CCR7− CTLs, although classified as immature effector cells in HIV infection, were the predominant CD8 effector population in the acute phase of protective immune reactions to CMV and were functionally competent. Whereas in asymptomatic individuals the CMV-specific CD4+ T-cell response preceded CMV-specific CD8+T-cell responses, in symptomatic individuals the CMV-specific effector-memory CD4+ T-cell response was delayed and only detectable after antiviral therapy. The appearance of disease symptoms in these patients suggests that functional CD8+ T-cell and antibody responses are insufficient to control viral replication and that formation of effector-memory CD4+ T cells is necessary for recovery of infection.
Shear stress inhibits adhesion molecule expression in vascular endothelial cells induced by coculture with smooth muscle cells
Authors: Chiu Jeng-Jiann , Chen Li-Jing , Lee Pei-Ling , Lee Chih-I , Lo Leu-Wei , Usami Shunichi , Chien Shu
Published: March 2003

Vascular endothelial cells (ECs), which exist in close proximity to vascular smooth muscle cells (SMCs), are constantly subjected to blood flow–induced shear stress. Although the effect of shear stress on endothelial biology has been extensively studied, the influence of SMCs on endothelial response to shear stress remains largely unexplored. We examined the potential role of SMCs in regulating the shear stress–induced gene expression in ECs, using a parallel-plate coculture flow system in which these 2 types of cells were separated by a porous membrane. In this coculture system, SMCs tended to orient perpendicularly to the flow direction, whereas the ECs were elongated and aligned with the flow direction. Under static conditions, coculture with SMCs induced EC gene expression of intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin, while attenuating EC gene expression of endothelial nitric oxide synthase (eNOS). Shear stress significantly inhibited SMC-induced adhesion molecule gene expression. These EC responses under static and shear conditions were not observed in the absence of close communication between ECs and SMCs, and they were also not observed when ECs were cocultured with fibroblasts instead of SMCs. Our findings indicate that under static conditions, coculture with SMCs induces ICAM-1, VCAM-1, and E-selectin gene expression in ECs. These coculture effects are inhibited by shear stress and require specific interaction between ECs and SMCs in close contact.
Pretreatment of donors with interleukin-18 attenuates acute graft-versus-host disease via STAT6 and preserves graft-versus-leukemia effects
Authors: Reddy Pavan , Teshima Takanori , Hildebrandt Gerhard , Williams Debra L. , Liu Chen , Cooke Kenneth R. , Ferrara James L.M.
Published: March 2003

Interleukin-18 (IL-18) is a unique cytokine that modulates both TH1/TH2 responses, but its ability to modulate diseases through induction of TH2 cytokines is unclear. It has been shown to play an important role in allogeneic bone marrow transplantation (BMT). Because immune responses of allogeneic BM donors may affect acute graft-versus-host disease (GVHD), we investigated the effect of pretreating BM transplant donors with IL-18 on the severity of acute GVHD using a well-characterized experimental BMT model (BALB/c→B6). Pretreatment of allogeneic BM transplant donors with IL-18 significantly improved survival (80% vs 0%; P < .001), and reduced clinical, biochemical, and pathologic indices of acute GVHD in BM transplant recipients. IL-18 pretreatment was associated with reduced interferon γ (IFN-γ) and greater IL-4 secretion by donor T cells after BMT. Acute GVHD mortality was reduced when IL-18 was administered to donors deficient in IFN-γ and signal transducer and activator of transcription 4 (STAT4) but not STAT6 signaling molecules, suggesting a critical role for STAT6 signaling in IL-18's protective effect. IL-18 treatment did not alter donor CD8+ cytotoxic T-lymphocyte (CTL) activity and preserved graft-versus-leukemia (GVL) effects after allogeneic BMT (70% vs 10%; P < .01). Together these data illustrate that pretreatment of donors with IL-18 prior to allogeneic BMT attenuates acute GVHD in a STAT6-dependent mechanism while preserving GVL effects.