bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endogenous Production of TGF-β Is Essential for Osteoclastogenesis Induced by a Combination of Receptor Activator of NF-κB Ligand and Macrophage-Colony- Stimulating Factor
Authors: Kaneda Toshio , Nojima Takaki , Nakagawa Mari , Ogasawara Aichi , Kaneko Hironori , Sato Takuya , Mano Hiroshi , Kumegawa Masayoshi , Hakeda Yoshiyuki 
Published: April 2014

AbstractDifferentiation of osteoclasts, the cells primarily responsible for bone resorption, is controlled by a variety of osteotropic hormones and cytokines. Of these factors, receptor activator of NF-κB (RANK) ligand (RANKL) has been recently cloned as an essential inducer of osteoclastogenesis in the presence of M-CSF. Here, we isolated a stroma-free population of monocyte/macrophage (M/Mφ)-like hemopoietic cells from mouse unfractionated bone cells that were capable of differentiating into mature osteoclasts by treatment with soluble RANKL (sRANKL) and M-CSF. However, the efficiency of osteoclast formation was low, suggesting the requirement for additional factors. The isolated M/Mφ-like hemopoietic cells expressed TGF-β and type I and II receptors of TGF-β. Therefore, we examined the effect of TGF-β on osteoclastogenesis. TGF-β with a combination of sRANKL and M-CSF promoted the differentiation of nearly all M/Mφ-like hemopoietic cells into cells of the osteoclast lineage. Neutralizing anti-TGF-β Ab abrogated the osteoclast generation. These TGF-β effects were also observed in cultures of unfractionated bone cells, and anti-TGF-β blocked the stimulatory effect of 1,25-dihydroxyvitamin D3. Translocation of NF-κB into nuclei induced by sRANKL in TGF-β-pretreated M/Mφ-like hemopoietic cells was greater than that in untreated cells, whereas TGF-β did not up-regulate the expression of RANK, the receptor of RANKL. Our findings suggest that TGF-β is an essential autocrine factor for osteoclastogenesis.
IL-2Rβ Agonist P1–30 Acts in Synergy with IL-2, IL-4, IL-9, and IL-15: Biological and Molecular Effects
Authors: Eckenberg Ralph , Moreau Jean-Louis , Melnyk Oleg , Thèze Jacques 
Published: April 2014

AbstractFrom the sequence of human IL-2 we have recently characterized a peptide (p1–30), which is the first IL-2 mimetic described. P1–30 covers the entire α helix A of IL-2 and spontaneously folds into a α helical homotetramer mimicking the quaternary structure of a hemopoietin. This neocytokine interacts with a previously undescribed dimeric form of the human IL-2 receptor β-chain likely to form the p1–30 receptor (p1–30R). P1–30 acts as a specific IL-2Rβ agonist, selectively inducing activation of CD8 and NK lymphocytes. From human PBMC we have also shown that p1–30 induces the activation of lymphokine-activated killer cells and the production of IFN-γ. Here we demonstrate the ability of p1–30 to act in synergy with IL-2, -4, -9, and -15. These synergistic effects were analyzed at the functional level by using TS1β, a murine T cell line endogenously expressing the common cytokine γ gene and transfected with the human IL-2Rβ gene. At the receptor level, we show that expression of human IL-2Rβ is absolutely required to obtain synergistic effects, whereas IL-2Rα specifically impedes the synergistic effects obtained with IL-2. The results suggest that overexpression of IL-2Rα inhibits p1–30R formation in the presence of IL-2. Finally, concerning the molecular effects, although p1–30 alone induces the antiapoptotic molecule bcl-2, we show that it does not influence mRNA expression of c-myc, c-jun, and c-fos oncogenes. In contrast, p1–30 enhances IL-2-driven expression of these oncogenes. Our data suggest that p1–30R (IL-2Rβ)2 and intermediate affinity IL-2R (IL-2Rβγ), when simultaneously expressed at the cell surface, may induce complementary signal transduction pathways and act in synergy.
Maturation-Dependent Expression and Function of the CD49d Integrin on Monocyte-Derived Human Dendritic Cells
Authors: Puig-Kröger Amaya , Sanz-Rodríguez Francisco , Longo Natividad , Sánchez-Mateos Paloma , Botella Luisa , Teixidó Joaquín , Bernabéu Carmelo , Corbí Angel L. 
Published: April 2014

AbstractDendritic cells (DC) are highly specialized APC that are critical for the initiation of T cell-dependent immune responses. DC exert a sentinel function while immature and, after activation by inflammatory stimuli or infectious agents, mature and migrate into lymphoid organs to prime T cells. We have analyzed integrin expression on monocyte-derived DC (MDDC) and found that expression of CD49d integrins (CD49d/CD29 and CD49d/β7) was induced/up-regulated during TNF-α- or LPS-initiated MDDC maturation, reflecting the induction/up-regulation of CD49d and β7 mRNA. CD49d mRNA steady-state level increased more than 10 times during maturation, with the highest levels observed 24 h after TNF-α treatment. CD49d integrin expression conferred mature MDDC with an elevated capacity to adhere to the CS-1 fragment of fibronectin, and also mediated transendothelial migration of mature MDDC. Up-regulation of CD49d integrin expression closely paralleled that of the mature DC marker CD83. CD49d integrin expression was dependent on cell maturation, as its induction was abrogated by N-acetylcysteine, which inhibits NF-κB activation and the functional and phenotypic maturation of MDDC. Moreover, CD49d integrin up-regulation and MDDC maturation were prevented by SB203580, a specific inhibitor of p38 mitogen-activated protein kinase, but were almost unaffected by the mitogen-activated protein/extracellular signal-related kinase kinase 1/2 inhibitor PD98059. Our results support the existence of a link between functional and phenotypic maturation of MDDC and CD49d integrin expression, thus establishing CD49d as a maturation marker for MDDC. The differential expression of CD49d on immature and mature MDDC might contribute to their distinct motility capabilities and mediate mature DC migration into lymphoid organs.
Fas/Fas Ligand Interactions Promote Activation-Induced Cell Death of NK T Lymphocytes
Authors: Leite-de-Moraes Maria C. , Herbelin André , Gouarin Christine , Koezuka Yasuhiko , Schneider Elke , Dy Michel 
Published: April 2014

AbstractNKT cells are a versatile population whose immunoregulatory functions are modulated by their microenvironment. We demonstrate herein that in addition to their IFN-γ production, NKT lymphocytes stimulated with IL-12 plus IL-18 in vitro underwent activation in terms of CD69 expression, blast transformation, and proliferation. Yet they were unable to survive in culture because, once activated, they were rapidly eliminated by apoptosis, even in the presence of their survival factor IL-7. This process was preceded by up-regulation of Fas (CD95) and Fas ligand expression in response to IL-12 plus IL-18 and was blocked by zVAD, a large spectrum caspase inhibitor, as well as by anti-Fas ligand mAb, suggesting the involvement of the Fas pathway. In accordance with this idea, NKT cells from Fas-deficient C57BL/6-lpr/lpr mice did not die in these conditions, although they shared the same features of cell activation as their wild-type counterpart. Activation-induced cell death occurred also after TCR engagement in vivo, since NKT cells became apoptotic after injection of their cognate ligand, α-galactosylceramide, in wild-type, but not in Fas-deficient, mice. Taken together, our data provide the first evidence for a new Fas-dependent mechanism allowing the elimination of TCR-dependent or -independent activated NKT cells, which are potentially dangerous to the organism.
CXCR4 Receptor Expression on Human Retinal Pigment Epithelial Cells from the Blood-Retina Barrier Leads to Chemokine Secretion and Migration in Response to Stromal Cell-Derived Factor 1α
Authors: Crane Isabel J. , Wallace Carol A. , McKillop-Smith Susan , Forrester John V. 
Published: April 2014

AbstractRetinal pigment epithelial (RPE) cells form part of the blood-retina barrier and have recently been shown to produce various chemokines in response to proinflammatory cytokines. As the scope of chemokine action has been shown to extend beyond the regulation of leukocyte migration, we have investigated the expression of chemokine receptors on RPE cells to determine whether they could be a target for chemokine signaling. RT-PCR analysis indicated that the predominant receptor expressed on RPE cells was CXCR4. The level of CXCR4 mRNA expression, but not cell surface expression, increased on stimulation with IL-1β or TNF-α. CXCR4 protein could be detected on the surface of 16% of the RPE cells using flow cytometry. Calcium mobilization in response to the CXCR4 ligand stromal cell-derived factor 1α (SDF-1α) indicated that the CXCR4 receptors were functional. Incubation with SDF-1α resulted in secretion of monocyte chemoattractant protein-1, IL-8, and growth-related oncogene α. RPE cells also migrated in response to SDF-1α. As SDF-1α expression by RPE cells was detected constitutively, we postulate that SDF-1–CXCR4 interactions may modulate the affects of chronic inflammation and subretinal neovascularization at the RPE site of the blood-retina barrier.
Identification of a Complex that Binds to the CD154 3′ Untranslated Region: Implications for a Role in Message Stability During T Cell Activation
Authors: Barnhart Bryan , Kosinski Penelope A. , Wang Zuoren , Ford Gregory S. , Kiledjian Megerditch , Covey Lori R. 
Published: April 2014

AbstractCD154 expression is regulated throughout a time course of CD3-dependent T cell activation by differential mRNA decay. To understand the molecular basis of the “stability” phase of this pathway, experiments were conducted to identify sequences and specific complexes important in this regulation. Gel retardation assays using extracts from both Jurkat T cells and CD3-activated CD4+ T cells revealed a major complex (complex I) that bound a 65-bp highly CU-rich region of the CD154 3′ untranslated region. The specificity of the CU-rich element for complex-I formation was confirmed by disruption of this complex by oligo(dCT) competition. Formation of complex I strongly correlated with CD154 mRNA stability across a time course of T cell activation. UV cross-linking identified a major oligo(dCT)-sensitive species at ∼90 kDa that showed induced and increased expression in extracts from 24- and 48-hr anti-CD3-activated T cells, respectively. This protein was absent in equivalent extracts from resting or 2-h-activated T cells. Using an in vitro decay assay, we found that a CD154-specific transcript was more rapidly degraded in 2-h-activated extract and stabilized in the 24- and 48-h extracts compared to extracts from resting T cells. Disruption of complex I resulted in the rapid decay of a CD154-specific transcript demonstrating a functional role for complex I in mRNA stabilization in vitro. These studies support a model of posttranscriptional regulation of CD154 expression being controlled in part by the interaction of a poly(CU)-binding complex with a specific sequence in the 3′ untranslated region.
Molecular Recognition of Human CD1b Antigen Complexes: Evidence for a Common Pattern of Interaction with αβ TCRs
Authors: Melián Agustín , Watts Gerald F. M. , Shamshiev Abdijapar , De Libero Gennaro , Clatworthy Anne , Vincent Michael , Brenner Michael B. , Behar Samuel , Niazi Kayvan , Modlin Robert L. , Almo Steven , Ostrov David , Nathenson Stanley G. , Porcelli Steven A. 
Published: April 2014

AbstractAg-specific T cell recognition is mediated through direct interaction of clonotypic TCRs with complexes formed between Ag-presenting molecules and their bound ligands. Although characterized in substantial detail for class I and class II MHC encoded molecules, the molecular interactions responsible for TCR recognition of the CD1 lipid and glycolipid Ag-presenting molecules are not yet well understood. Using a panel of epitope-specific Abs and site-specific mutants of the CD1b molecule, we showed that TCR interactions occur on the membrane distal aspects of the CD1b molecule over the α1 and α2 domain helices. The location of residues on CD1b important for this interaction suggested that TCRs bind in a diagonal orientation relative to the longitudinal axes of the α helices. The data point to a model in which TCR interaction extends over the opening of the putative Ag-binding groove, making multiple direct contacts with both α helices and bound Ag. Although reminiscent of TCR interaction with MHC class I, our data also pointed to significant differences between the TCR interactions with CD1 and MHC encoded Ag-presenting molecules, indicating that Ag receptor binding must be modified to accommodate the unique molecular structure of the CD1b molecule and the unusual Ags it presents.
Adenovirus E1A Oncogene Expression in Tumor Cells Enhances Killing by TNF-Related Apoptosis-Inducing Ligand (TRAIL)
Authors: Routes John M. , Ryan Sharon , Clase Amanda , Miura Tanya , Kuhl Alicia , Potter Terry A. , Cook James L. 
Published: April 2014

AbstractExpression of the adenovirus serotype 5 (Ad5) E1A oncogene sensitizes cells to apoptosis by TNF-α and Fas-ligand. Because TNF-related apoptosis-inducing ligand (TRAIL) kills cells in a similar manner as TNF-α and Fas ligand, we asked whether E1A expression might sensitize cells to lysis by TRAIL. To test this hypothesis, we examined TRAIL-induced killing of human melanoma (A2058) or fibrosarcoma (H4) cells that expressed E1A following either infection with Ad5 or stable transfection with Ad5-E1A. E1A-transfected A2058 (A2058-E1A) or H4 (H4-E1A) cells were highly sensitive to TRAIL-induced killing, but Ad5-infected cells expressing equally high levels of E1A protein remained resistant to TRAIL. Infection of A2058-E1A cells with Ad5 reduced their sensitivity to TRAIL-dependent killing. Therefore, viral gene products expressed following infection with Ad5 inhibited the sensitivity to TRAIL-induced killing conferred by transfection with E1A. E1B and E3 gene products have been shown to inhibit TNF-α- and Fas-dependent killing. The effect of these gene products on TRAIL-dependent killing was examined by using Ad5-mutants that did not express either the E3 (H5dl327) or E1B-19K (H5dl250) coding regions. A2058 cells infected with H5dl327 were susceptible to TRAIL-dependent killing. Furthermore, TRAIL-dependent killing of A2058-E1A cells was not inhibited by infection with H5dl327. Infection with H5dl250 sensitized A2058 cells to TRAIL-induced killing, but considerably less than H5dl327-infection. In summary, expression of Ad5-E1A gene products sensitizes cells to TRAIL-dependent killing, whereas E3 gene products, and to a lesser extent E1B-19K, inhibit this effect.
Role of IL-5 in Innate and Adaptive Immunity to LarvalStrongyloides stercoralisin Mice
Authors: Herbert De’Broski R. , Lee James J. , Lee Nancy A. , Nolan Thomas J. , Schad Gerhard A. , Abraham David 
Published: April 2014

AbstractProtective immunity to Strongyloides stercoralis infective larvae in mice has been shown to be dependent on IL-5 based on mAb depletion studies. The goal of this study was to determine the functional role of IL-5 during the innate and adaptive immune response to larval S. stercoralis in mice. In these studies, three strains of mice were used: wild-type C57BL/6J (WT), IL-5 knockout (KO), and IL-5 transgenic (TG). Innate responses to the larvae indicated that there was enhanced survival in the KO animals and decreased survival in the TG animals compared with WT. Furthermore, killing of larvae in TG mice was associated with eosinophil infiltration and degranulation. In studying the adaptive immune response, it was observed that immunization of KO mice did not lead to the development of protective immunity. Experiments were then performed to determine whether KO mice reconstituted with Abs or cells could then develop protective immunity. KO mice displayed protective immunity via a granulocyte-dependent mechanism following injection of purified IgM from immune wild-type animals. Immunity in KO mice could also be reconstituted by the injection of eosinophils at the time of immunization. These eosinophils did not participate in actively killing the challenge infection, but rather were responsible for the induction of a protective Ab response. We conclude that IL-5 is required in the protective immune response for the production of eosinophils, and that eosinophils were involved in larval killing during innate immunity and in the induction of protective Abs in the adaptive immune response.
CD47 Ligation Selectively Inhibits the Development of Human Naive T Cells into Th1 Effectors
Authors: Avice Marie-Noëlle , Rubio Manuel , Sergerie Martin , Delespesse Guy , Sarfati Marika 
Published: April 2014

AbstractThe CD47 Ag, also named integrin-associated protein, was recently reported to regulate the production of IL-12 by human monocytes and dendritic cells. The present study shows that CD47 ligation by CD47 mAb in primary cultures of cord blood mononuclear cells inhibits IL-12-driven Th1 cell development, as revealed by the cytokine secretion profile at restimulation and IFN-γ production at the single-cell level. F(ab′)2 fragments of CD47 mAb or the synthetic peptide 4N1K, corresponding to the CD47 binding site of thrombospondin, display the same activity. CD47 engagement does not change the phenotype of IL-12-primed cells from Th1 to Th2 or affect IL-4-induced Th2 cell development. Moreover, CD47 mAb inhibits IL-12- but not IL-4-induced IL-2 production as well as IFN-γ in primary cultures, which was correlated with a decrease of the IL-12Rβ2 chain expression. Inclusion of exogenous IL-2 at priming corrects IL-12R expression as well as the inhibition of Th1 cell development. The data thus underline the role of IL-2 in Th1 cell development and further suggest that targeting IL-2 and IL-12 simultaneously may have some therapeutic advantage in Th1 autoimmune diseases.
Human Monoclonal Antibodies Isolated from Type I Diabetes Patients Define Multiple Epitopes in the Protein Tyrosine Phosphatase-Like IA-2 Antigen
Authors: Kolm-Litty Verena , Berlo Suzanne , Bonifacio Ezio , Bearzatto Massimo , Engel Alfred M. , Christie Michael , Ziegler Anette-G. , Wild Thomas , Endl Josef 
Published: April 2014

AbstractProtein tyrosine phosphatase-like IA-2 autoantigen is one of the major targets of humoral autoimmunity in patients with insulin-dependant diabetes mellitus (IDDM). In an effort to define the epitopes recognized by autoantibodies against IA-2, we generated five human mAbs (hAbs) from peripheral B lymphocytes isolated from patients most of whom had been recently diagnosed for IDDM. Determination and fine mapping of the critical regions for autoantibody binding was performed by RIA using mutant and chimeric constructs of IA-2- and IA-2β-regions. Four of the five IgG autoantibodies recognized distinct epitopes within the protein tyrosine phosphatase (PTP)-like domain of IA-2. The minimal region required for binding by three of the PTP-like domain-specific hAbs could be located to aa 777–979. Two of these hAbs cross-reacted with the related IA-2β PTP-like domain (IA-2β aa 741-1033). A further PTP-like domain specific hAb required the entire PTP-like domain (aa 687–979) for binding, but critical amino acids clustered in the N-terminal region 687–777. An additional epitope could be localized within the juxtamembrane domain (aa 603–779). In competition experiments, the epitope recognized by one of the hAbs was shown to be targeted by 10 of 14 anti-IA-2-positive sera. Nucleotide sequence analysis of this hAb revealed that it used a VH germline gene (DP-71) preferably expressed in autoantibodies associated with IDDM. The presence of somatic mutations in both heavy and light chain genes and the high affinity or this Ab suggest that the immune response to IA-2 is Ag driven.
Impaired CD4 T Cell Activation Due to Reliance Upon B Cell-Mediated Costimulation in Nonobese Diabetic (NOD) Mice
Authors: Noorchashm Hooman , Moore Daniel J. , Noto Lauren E. , Noorchashm Negin , Reed Amy J. , Reed Alison L. , Song Howard K. , Mozaffari Reza , Jevnikar Anthony M. , Barker Clyde F. , Naji Ali 
Published: April 2014

AbstractDiabetes in nonobese diabetic (NOD) mice results from the activation of I-Ag7-restricted, islet-reactive T cells. This study delineates several characteristics of NOD CD4 T cell activation, which, independent of I-Ag7, are likely to promote a dysregulated state of peripheral T cell tolerance. NOD CD4 T cell activation was found to be resistant to antigenic stimulation via the TCR complex, using the progression of cell division as a measure. The extent of NOD CD4 T cell division was highly sensitive to changes in Ag ligand density. Moreover, even upon maximal TCR complex-mediated stimulation, NOD CD4 T cell division prematurely terminated. Maximally stimulated NOD CD4 T cells failed to achieve the threshold number of division cycles required for optimal susceptibility to activation-induced death, a critical mechanism for the regulation of peripheral T cell tolerance. Importantly, these aberrant activation characteristics were not T cell-intrinsic but resulted from reliance on B cell costimulatory function in NOD mice. Costimulation delivered by nonautoimmune strain APCs normalized NOD CD4 T cell division and the extent of activation-induced death. Thus, by disrupting the progression of CD4 T cell division, polarization of APC costimulatory function to the B cell compartment could allow the persistence and activation of diabetogenic cells in NOD mice.
HIV Gag mRNA Transfection of Dendritic Cells (DC) Delivers Encoded Antigen to MHC Class I and II Molecules, Causes DC Maturation, and Induces a Potent Human In Vitro Primary Immune Response
Authors: Weissman Drew , Ni Houping , Scales David , Dude Annie , Capodici John , McGibney Karen , Abdool Asha , Isaacs Stuart N. , Cannon Georgetta , Karikó Katalin 
Published: April 2014

AbstractDendritic cells (DC) are the major APCs involved in naive T cell activation making them prime targets of vaccine research. We observed that mRNA was efficiently transfected, resulting in superior translation in DC compared with other professional APCs. A single stimulation of T cells by HIV gag-encoded mRNA-transfected DC in vitro resulted in primary CD4+ and CD8+ T cell immune responses at frequencies of Ag-specific cells (5–12.5%) similar to primary immune responses observed in vivo in murine models. Additionally, mRNA transfection also delivered a maturation signal to DC. Our results demonstrated that mRNA-mediated delivery of encoded Ag to DC induced potent primary T cell responses in vitro. mRNA transfection of DC, which mediated efficient delivery of antigenic peptides to MHC class I and II molecules, as well as delivering a maturation signal to DC, has the potential to be a potent and effective anti-HIV T cell-activating vaccine.
Cutting Edge: The Mucosal Adjuvant Cholera Toxin Redirects Vaccine Proteins into Olfactory Tissues
Authors: van Ginkel Frederik W. , Jackson Raymond J. , Yuki Yoshikazu , McGhee Jerry R. 
Published: April 2014

AbstractWe tested the notion that the mucosal adjuvant cholera toxin (CT) could target, in addition to nasal-associated lymphoreticular tissues, the olfactory nerves/epithelium (ON/E) and olfactory bulbs (OBs) when given intranasally. Radiolabeled CT (125I-CT) or CT-B subunit (125I-CT-B), when given intranasally to mice, entered the ON/E and OB and persisted for 6 days; however, neither molecule was present in nasal-associated lymphoreticular tissues beyond 24 h. This uptake into olfactory regions was monosialoganglioside (GM1) dependent. Intranasal vaccination with 125I-tetanus toxoid together with unlabeled CT as adjuvant resulted in uptake into the ON/E but not the OB, whereas 125I-tetanus toxoid alone did not penetrate into the CNS. We conclude that GM1-binding molecules like CT target the ON/E and are retrograde transported to the OB and may promote uptake of vaccine proteins into olfactory neurons. This raises concerns about the role of GM1-binding molecules that target neuronal tissues in mucosal immunity.