bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laminin isoform–specific promotion of adhesion and migration of human bone marrow progenitor cells
Authors: Gu Yu-Chen , Kortesmaa Jarkko , Tryggvason Karl , Persson Jenny , Ekblom Peter , Jacobsen Sten-Eirik , Ekblom Marja 
Published: January 2003

AbstractLaminins are αβγ heterotrimeric extracellular proteins that regulate cellular functions by adhesion to integrin and nonintegrin receptors. Laminins containing α4 and α5 chains are expressed in bone marrow, but their interactions with hematopoietic progenitors are unknown. We studied human bone marrow cell adhesion to laminin-10/11 (α5β1γ1/α5β2γ1), laminin-8 (α4β1γ1), laminin-1 (α1β1γ1), and fibronectin. About 35% to 40% of CD34+ and CD34+CD38− stem and progenitor cells adhered to laminin-10/11, and 45% to 50% adhered to fibronectin, whereas they adhered less to laminin-8 and laminin-1. Adhesion of CD34+CD38− cells to laminin-10/11 was maximal without integrin activation, whereas adhesion to other proteins was dependent on protein kinase C activation by 12-tetradecanoyl phorbol-13-acetate (TPA). Fluorescence-activated cell-sorting (FACS) analysis showed expression of integrin α6 chain on most CD34+ and CD34+CD38−cells. Integrin α6 and β1 chains were involved in binding of both cell fractions to laminin-10/11 and laminin-8. Laminin-10/11 was highly adhesive to lineage-committed myelomonocytic and erythroid progenitor cells and most lymphoid and myeloid cell lines studied, whereas laminin-8 was less adhesive. In functional assays, both laminin-8 and laminin-10/11 facilitated stromal-derived factor-1α (SDF-1α)–stimulated transmigration of CD34+ cells, by an integrin α6 receptor–mediated mechanism. In conclusion, we demonstrate laminin isoform–specific adhesive interactions with human bone marrow stem, progenitor, and more differentiated cells. The cell-adhesive laminins affected migration of hematopoietic progenitors, suggesting a physiologic role for laminins during hematopoiesis.
Changes in von Willebrand factor–cleaving protease (ADAMTS13) activity after infusion of desmopressin
Authors: Reiter Rosemarie A. , Knöbl Paul , Varadi Katalin , Turecek Peter L. 
Published: January 2003

Abstract
von Willebrand factor–cleaving protease (ADAMTS13) cleaves von Willebrand factor (VWF) and regulates its physiologic function. To investigate the relation between ADAMTS13 activity and VWF, we compared ADAMTS13 activity with the VWF-related parameters VWF antigen (VWF:Ag), VWF collagen-binding activity (VWF:CBA), VWF-propeptide, proVWF, and VWF multimeric composition in 10 healthy volunteers and 3 patients with type 1 von Willebrand disease before and after infusing 0.3 μg/kg desmopressin. The VWF-related parameters in the volunteers increased 60 minutes after start of infusion by 3.7-fold for VWF:Ag, 7.2-fold for propeptide, and 2.2-fold for VWF:CBA. Unusually large VWF multimers and traces of proVWF appeared. The ADAMTS13 activity decreased to about half the initial value. After 24 hours values returned to baseline. Patients with type 1 von Willebrand disease showed similar results. We conclude that the inverse correlation between ADAMTS13 and VWF-related parameters suggests a consumption of ADAMTS13 after the desmopressin-induced release of higher multimers of VWF.
Donor immunization with pneumococcal conjugate vaccine and early protective antibody responses following allogeneic hematopoietic cell transplantation
Authors: Molrine Deborah C. , Antin Joseph H. , Guinan Eva C. , Soiffer Robert J. , MacDonald Kristin , Malley Richard , Malinoski Frank , Trocciola Susan , Wilson Marjorie , Ambrosino Donna M. 
Published: January 2003

AbstractPatients undergoing hematopoietic cell transplantation (HCT) are at increased risk for infections with Streptococcus pneumoniaeand have long-lasting, impaired antibody responses to pneumococcal polysaccharide vaccines. We examined whether donor immunization with a heptavalent pneumococcal conjugate vaccine (PCV7) would elicit protective antibody responses to additional doses of vaccine administered early after transplantation. Ninety-six patients scheduled to receive an allogeneic hematopoietic cell transplant were randomized with their donors to receive either a dose of PCV7 vaccine or no vaccine before transplantation. All patients received PCV7 at 3 months, 6 months, and 12 months following transplantation, and serotype-specific antibody concentrations were determined after each dose. Following HCT, geometric mean antibody concentrations of patients in the immunized donor group were significantly higher for 5 of the 7 vaccine serotypes after one dose (P < .05) and for 4 of the 7 serotypes after 2 doses of vaccine (P < .03). Sixty-seven percent of patients in the immunized donor group had presumed protective IgG concentrations more than or equal to 0.50 μg/mL to all 7 serotypes following the first dose of vaccine compared to 36% in the unimmunized donor group (P = .05). After the third dose of vaccine, both groups had more than 60% of patients with concentrations at least 0.50 μg/mL to all vaccine serotypes. Donor immunization enhances early antibody responses of patients undergoing HCT to pneumococcal conjugate vaccine. A 3-dose schedule of PCV7 vaccine at 3, 6, and 12 months is immunogenic in these patients regardless of donor immunization.
An anti-C3b(i) mAb enhances complement activation, C3b(i) deposition, and killing of CD20+ cells by rituximab
Authors: Kennedy Adam D. , Solga Michael D. , Schuman Theodore A. , Chi Amos W. , Lindorfer Margaret A. , Sutherland William M. , Foley Patricia L. , Taylor Ronald P. 
Published: January 2003

AbstractWe investigated deposition of the complement protein fragment C3b and its breakdown products (collectively designated as C3b(i)) on CD20-positive cells treated with rituximab (RTX) in the presence of normal human serum (NHS). Radioimmunoassay (RIA) demonstrates that about 500 000 C3b(i) molecules deposit per cell, and fluorescence microscopy reveals that C3b(i) colocalizes with bound RTX. Use of mAb 3E7, specific for C3b(i) bound to substrates, enhances C3b(i) deposition; > 1 million C3b(i) deposit when cells are incubated with NHS, RTX and mAb 3E7. Treatment of Raji cells in NHS plus RTX leads to robust cell killing (95%) after 24 to 48 hours, and mAb 3E7 significantly enhances RTX-mediated killing of Raji and DB cells. A cynomolgus monkey model based on intravenous infusion of RTX followed by mAb 3E7 demonstrated that RTX rapidly binds to B cells and promotes complement activation and C3b(i) deposition; fluorescence microscopy analyses revealed the same pattern of colocalization of C3b(i) on cell-bound RTX in vivo as observed in vitro. Preliminary in vitro studies with blood samples from patients with chronic lymphocytic leukemia lead to similar findings. These experiments suggest that complement plays a key role in the mechanism of action of RTX; moreover, the in vivo molecular form of RTX (and possibly other antitumor mAbs) in the circulation or in tissues may include C3b(i) molecules covalently bound to the therapeutic mAb, thus allowing it to interact with cells containing both Fc and complement receptors.
Identification of immunodominant regions among promiscuous HLA-DR–restricted CD4+ T-cell epitopes on the tumor antigen MAGE-3
Authors: Consogno Giuseppe , Manici Simona , Facchinetti Valeria , Bachi Angela , Hammer Juergen , Conti-Fine Bianca M. , Rugarli Claudio , Traversari Catia , Protti Maria Pia 
Published: January 2003

AbstractThe molecular characterization of the CD4+ T-cell epitope repertoire on human tumor antigens would contribute to both clinical investigation and cancer immunotherapy. In particular, the identification of promiscuous epitopes would be beneficial to a large number of patients with neoplastic diseases regardless of their HLA-DR type. MAGE-3 is a tumor-specific antigen widely expressed in solid and hematologic malignancies; therefore, is an excellent candidate antigen. We used a major histocompatability complex (MHC) class II epitope prediction algorithm, the TEPITOPE software, to predict 11 sequence segments of MAGE-3 that could form promiscuous CD4+ T-cell epitopes. In binding assays, the synthetic peptides corresponding to the 11 predicted sequences bound at least 3 different HLA-DR alleles. Nine of the 11 peptides induced proliferation of CD4+ T cells from both healthy subjects and melanoma patients. Four immunodominant regions (residues 111-125, 146-160, 191-205, and 281-295), containing naturally processed epitopes, were recognized by most of the donors, in association with 3 to 4 different HLA-DR alleles, thus covering up to 94% of the alleles expressed in whites. On the contrary, the other promiscuous regions (residues 161-175 and 171-185) contained epitopes not naturally processed in vitro. The immunodominant epitopes identified will be useful in the design of peptide-based cancer vaccines and in the study of the functional state of tumor-specific CD4+ T cells in patients bearing tumors expressing MAGE-3.
Mural thrombus generation in type 2A and 2B von Willebrand disease under flow conditions
Authors: Sugimoto Mitsuhiko , Matsui Hideto , Mizuno Tomohiro , Tsuji Shizuko , Miyata Shigeki , Matsumoto Masanori , Matsuda Michio , Fujimura Yoshihiro , Yoshioka Akira 
Published: January 2003

AbstractTo explore the mechanisms that underlie the bleeding tendency in type 2A and 2B von Willebrand disease (VWD), we analyzed the mural thrombus generation process on a collagen surface under physiologic blood flow in a perfusion chamber using whole blood from these VWD patients. At a low shear rate (50 s−1), thrombus generation in all type 2A and 2B VWD patients was comparable to that of healthy controls. At a high shear rate (1500 s−1), thrombus generation was impaired in all type 2A patients, whereas that in type 2B VWD patients varied from normal to significantly defective, as judged by epifluorescence microscopy of thrombus surface coverage. However, in type 2B patients who showed normal thrombus generation at 1500 s−1, the height and volume of thrombi was significantly reduced, albeit with the normal surface coverage, compared with control thrombi, and von Willebrand factor (VWF) was poorly distributed within the type 2B thrombus mass when analyzed in detail by confocal laser scanning microscopy. Addition of purified VWF to patient blood completely reversed the defective spatial thrombus growth in type 2B VWD. Thus, our results confirm the impaired thrombus generation in type 2B VWD, which has never been demonstrable in previous in vitro soluble-phase platelet aggregation assays, and point to the critical function of larger VWF multimers in the proper spatial growth of mural thrombi under high shear rate conditions.
Thrombocytopenia identifies a severe familial phenotype of systemic lupus erythematosus and reveals genetic linkages at 1q22 and 11p13
Authors: Scofield R. Hal , Bruner Gail R. , Kelly Jennifer A. , Kilpatrick Jeff , Bacino Debra , Nath Swapan K. , Harley John B. 
Published: January 2003

AbstractSystemic lupus erythematosus (SLE) is a complicated autoimmune disease with a definite genetic predisposition. Thrombocytopenia predicts severe disease and death in SLE, making the identification of the related genetic risk factors especially important. We selected the 38 pedigrees that had an SLE patient with thrombocytopenia (platelets, < 10 × 109/L [< 100 000/μL]) from a collection of 184 pedigrees multiplex for SLE. Linkages were established at 1q22-23 (maximum logarithm of odds [lodmax] = 3.71) in the 38 pedigrees and at 11p13 (lodmax = 5.72) in the 13 African American pedigrees. Nephritis, serositis, neuropsychiatric involvement, autoimmune hemolytic anemia, anti–double-stranded DNA, and antiphospholipid antibody were associated with thrombocytopenia. Other results show that SLE is more severe in the families with a thrombocytopenic SLE patient, whether or not thrombocytopenia in an individual patient is considered. These results are consistent with thrombocytopenia being a component of a severe familial form of SLE and with genes at 1q22-23 and 11p13 contributing to this severe phenotype and to the subsequent high mortality associated with thrombocytopenia in SLE.
E26 leukemia virus converts primitive erythroid cells into cycling multilineage progenitors
Authors: McNagny Kelly M. , Graf Thomas 
Published: January 2003

AbstractAcute chicken leukemia retroviruses, because of their capacity to readily transform hematopoietic cells in vitro, are ideal models to study the mechanisms governing the cell-type specificity of oncoproteins. Here we analyzed the transformation specificity of 2 acute chicken leukemia retroviruses, the Myb-Ets– encoding E26 virus and the ErbA/ErbB-encoding avian erythroblastosis virus (AEV). While cells transformed by E26 are multipotent (designated “MEP” cells), those transformed by AEV resemble erythroblasts. Using antibodies to separate subpopulations of precirculation yolk sac cells, both viruses were found to induce the proliferation of primitive erythroid progenitors within 2 days of infection. However, while AEV induced a block in differentiation of the cells, E26 induced a gradual shift in their phenotype and the acquisition of the potential for multilineage differentiation. These results suggest that the Myb-Ets oncoprotein of the E26 leukemia virus converts primitive erythroid cells into proliferating definitive-type multipotent hematopoietic progenitors.
Fractional attachment of CD47 (IAP) to the erythrocyte cytoskeleton and visual colocalization with Rh protein complexes
Authors: Dahl Kris Noel , Westhoff Connie M. , Discher Dennis E. 
Published: January 2003

AbstractInteractions of CD47 and RhAG and the Rh proteins are visualized between one another and with the cytoskeleton of intact erythrocytes. In a first study, CD47 is labeled with a phycoerythrin (PhE)– tagged antibody, which generates discrete spots that reflect induced clusters of CD47. Rh and RhAG colocalize with each other and to these induced clusters, whereas Band 3 and glycophorin C remain more homogeneously dispersed on the cell periphery. In a second study, red cells are aspirated into a micropipette, and immunofluorescent maps of the surface gradients that develop for CD47 and RhAG determine cytoskeletal connectivity. CD47 and RhAG gradients on normal red cells prove to be nearly identical and also appear intermediate to those found for the fluid bilayer and network-linked glycophorin C. Similar gradients are obtained for CD47 on Rhnull cells, suggesting that linkage of CD47 to the spectrin-actin skeleton is independent of Rh or RhAG and is not affected by CD47's reduced surface expression on these cells. The results show that CD47 colocalizes with Rh and RhAG but is fractionally attached to the red cell membrane skeleton independent of these and other major integral membrane proteins involved in cytoskeletal attachment. The results imply a homogeneous base distribution of CD47, restrained by cytoskeleton linkages, plus a smaller fraction of CD47, which is able to diffuse in the membrane.
The gene encoding the transcriptional regulator Yin Yang 1 (YY1) is a myeloid transforming gene interfering with neutrophilic differentiation
Authors: Erkeland Stefan J. , Valkhof Marijke , Heijmans-Antonissen Claudia , Delwel Ruud , Valk Peter J. M. , Hermans Mirjam H. A. , Touw Ivo P. 
Published: January 2003

AbstractThe genetic defects underlying the pathogenesis of acute myeloid leukemia (AML) are still largely unknown. Retroviral insertion mutagenesis in mice has become a powerful tool to identify candidate genes involved in the development of leukemia and lymphoma. We have used this strategy with the 1.4 strain of Graffi murine leukemia virus (MuLV), which predominantly causes myeloid leukemias. Here, we report that Graffi-1.4–induced AML frequently harbors virus integrations in the gene encoding the transcription factor Yin Yang 1 (YY1). These integrations occurred in both orientations, and all were located in the 5′ promoter region of the gene, 0.5 to 1.5 kb upstream of the major transcriptional start site. Luciferase reporter assays showed that virus integration in this region increases promoter activity and renders it independent of a functional binding site for Sp1, a major transcriptional regulator of YY1. We used the murine 32D model to study the consequence of perturbed YY1 expression for myelopoiesis. YY1 protein levels were high in 32D parental cells maintained in interleukin-3–containing medium, but they dropped when the cells were induced to differentiate by granulocyte–colony-stimulating factor (G-CSF). Strikingly, G-CSF–induced neutrophilic differentiation was reduced in 32D cell transfectants ectopically expressing YY1. In similar experiments on primary bone marrow cells, enforced YY1 expression blocked the outgrowth of CFU-GM colonies. Increased YY1 expression was seen in some cases of human AML. Collectively, these data imply a possible role of perturbed expression of YY1 in the development of AML through interference with the myeloid differentiation program in the leukemic progenitor cells.
Induction of myeloma-specific cytotoxic T cells using dendritic cells transfected with tumor-derived RNA
Authors: Milazzo Caterina , Reichardt Volker L. , Müller Martin R. , Grünebach Frank , Brossart Peter 
Published: January 2003

AbstractCurrent immunotherapeutic trials for patients with multiple myeloma (MM) focus on the idiotype (Id) as a tumor-specific antigen for active immunization. To bypass the need for the identification of shared MM-associated antigens and the characterization of possible immunogenic T-cell epitopes in a human leukocyte antigen (HLA) type–restricted manner, we focused on myeloma RNA transfection of dendritic cells (DCs). Total RNA encodes the whole antigen content of tumor cells, therefore allowing the transfected DCs to process and present the most relevant peptides and to induce a possible polyclonal cytotoxic T lymphocyte (CTL) response against different immunogenic antigens. We transfected monocyte-derived DCs with total RNA from the myeloma cell lines LP-1 and U266 by electroporation and investigated the potential of these DCs to induce myeloma-specific CTLs. We show that RNA-transfected DCs induce CTLs that lyse the LP-1 and U266 myeloma cells in an antigen-specific and major histocompatibility complex (MHC) class I–restricted manner, as demonstrated by cold-target inhibition and antibody-blocking studies. Interestingly, LP-1–specific CTLs showed no specificity for the idiotype. Consistent with studies demonstrating mucin 1 (MUC1) as a myeloma-associated antigen, we found MUC1 specificity of the CTLs induced with U266-derived RNA. As corresponding epitopes, we tested the described peptides M1.1 and M1.2 and found a striking fine specificity for M1.2, assuming a possible immunodominance of this peptide. This is the first report on the induction of myeloma-specific CTLs by RNA transfection of DCs.
Curcumin (diferuloylmethane) down-regulates the constitutive activation of nuclear factor–κB and IκBα kinase in human multiple myeloma cells, leading to suppression of proliferation and induction of apoptosis
Authors: Bharti Alok C. , Donato Nicholas , Singh Sujay , Aggarwal Bharat B. 
Published: January 2003

AbstractBecause of the central role of the transcription factor nuclear factor–κB (NF-κB) in cell survival and proliferation in human multiple myeloma (MM), we explored the possibility of using it as a target for MM treatment by using curcumin (diferuloylmethane), an agent known to have very little or no toxicity in humans. We found that NF-κB was constitutively active in all human MM cell lines examined and that curcumin, a chemopreventive agent, down-regulated NF-κB in all cell lines as indicated by electrophoretic mobility gel shift assay and prevented the nuclear retention of p65 as shown by immunocytochemistry. All MM cell lines showed consitutively active IκB kinase (IKK) and IκBα phosphorylation. Curcumin suppressed the constitutive IκBα phosphorylation through the inhibition of IKK activity. Curcumin also down-regulated the expression of NF-κB–regulated gene products, including IκBα, Bcl-2, Bcl-xL, cyclin D1, and interleukin-6. This led to the suppression of proliferation and arrest of cells at the G1/S phase of the cell cycle. Suppression of NF-κB complex by IKKγ/NF-κB essential modulator-binding domain peptide also suppressed the proliferation of MM cells. Curcumin also activated caspase-7 and caspase-9 and induced polyadenosine-5′-diphosphate-ribose polymerase (PARP) cleavage. Curcumin-induced down-regulation of NF-κB, a factor that has been implicated in chemoresistance, also induced chemosensitivity to vincristine and melphalan. Overall, our results indicate that curcumin down-regulates NF-κB in human MM cells, leading to the suppression of proliferation and induction of apoptosis, thus providing the molecular basis for the treatment of MM patients with this pharmacologically safe agent.
ICSBP/IRF-8 retrovirus transduction rescues dendritic cell development in vitro
Authors: Tsujimura Hideki , Tamura Tomohiko , Gongora Celine , Aliberti Julio , Reis e Sousa Caetano , Sher Alan , Ozato Keiko 
Published: January 2003

AbstractDendritic cells (DCs) develop from bone marrow (BM) progenitor cells and mature in response to external signals to elicit functions important for innate and adaptive immunity. Interferon consensus sequence binding protein (ICSBP; also called interferon regulatory factor 8 [IRF-8]) is a hematopoietic cell–specific transcription factor expressed in BM progenitor cells that contributes to myeloid cell development. In light of our earlier observation that ICSBP−/− mice lack CD8α+DCs, we investigated the role of ICSBP in DC development in vitro in the presence of Flt3 ligand. Immature ICSBP−/− DCs developed from BM progenitor cells showed assorted defects, did not mature in response to activation signals, and failed to express CD8α and interleukin 12 (IL-12) p40, a feature consistent with ICSBP−/− DCs in vivo. We show that retroviral introduction of ICSBP restores the development of immature DCs that can fully mature on activation signals. All the defects seen with ICSBP−/− DCs were corrected after ICSBP transduction, including the expression of CD8α and IL-12 p40 as well as major histocompatability complex class II and other costimulatory molecules. ICSBP is known to regulate gene expression by interacting with partner proteins PU.1 and IRFs, thereby binding to target elements ISRE and EICE. Analysis of a series of ICSBP mutants showed that the intact DNA-binding activity as well as the ability to interact with partner proteins are required for the restoration of DC development/maturation, pointing to the transcriptional function of ICSBP as a basis of restoration. Taken together, this study identifies ICSBP as a factor critical for both early differentiation and final maturation of DCs.