bluuebunny/crossref_metadata_2025_split huggingface dataset:
Therapeutic Targeting of IL-6 Trans Signaling Counteracts STAT3 Control of Experimental Inflammatory Arthritis
Authors: Nowell Mari A. , Williams Anwen S. , Carty Sarah A. , Scheller Jürgen , Hayes Anthony J. , Jones Gareth W. , Richards Peter J. , Slinn Simon , Ernst Matthias , Jenkins Brendan J. , Topley Nicholas , Rose-John Stefan , Jones Simon A. 
Published: April 2014

Abstract
Cytokine control of the synovial infiltrate is a central process in the development of inflammatory arthritis. In this study, we combine genetic approaches and intervention strategies to describe a fundamental requirement for IL-6-mediated STAT3 signaling in orchestrating the inflammatory infiltrate in monoarticular and systemic models of experimental arthritis. STAT3 activation via the common gp130 signal-transducing receptor for all IL-6-related cytokines led to increased retention of neutrophils and T cells within the inflamed synovium, which included STAT3-regulated IL-17A-secreting T cells. Control of leukocyte infiltration was reliant upon IL-6 signaling via its soluble receptor (termed IL-6 trans signaling), as evidenced by selective blockade of this alternative IL-6 signaling pathway using an engineered variant of soluble gp130 (sgp130Fc). This therapeutic intervention led to substantial clinical improvement in mice with emerging or established incidence of systemic arthritis. These data illustrate that IL-6 control of STAT3 is critical for regulating the synovial infiltrate in inflammatory arthritis, and suggest that selective inhibition of IL-6 trans signaling may provide a more refined intervention strategy for blocking IL-6-driven proarthritic activities.
Reciprocal Expression and Signaling of TLR4 and TLR9 in the Pathogenesis and Treatment of Necrotizing Enterocolitis
Authors: Gribar Steven C. , Sodhi Chhinder P. , Richardson Ward M. , Anand Rahul J. , Gittes George K. , Branca Maria F. , Jakub Adam , Shi Xia-hua , Shah Sohail , Ozolek John A. , Hackam David J. 
Published: April 2014

Abstract
Necrotizing enterocolitis (NEC) is a common and often fatal inflammatory disorder affecting preterm infants that develops upon interaction of indigenous bacteria with the premature intestine. We now demonstrate that the developing mouse intestine shows reciprocal patterns of expression of TLR4 and TLR9, the receptor for bacterial DNA (CpG-DNA). Using a novel ultrasound-guided in utero injection system, we administered LPS directly into the stomachs of early and late gestation fetuses to induce TLR4 signaling and demonstrated that TLR4-mediated signaling within the developing intestine follows its expression pattern. Murine and human NEC were associated with increased intestinal TLR4 and decreased TLR9 expression, suggesting that reciprocal TLR4 and TLR9 signaling may occur in the pathogenesis of NEC. Enteral administration of adenovirus expressing mutant TLR4 to neonatal mice reduced the severity of NEC and increased TLR9 expression within the intestine. Activation of TLR9 with CpG-DNA inhibited LPS-mediated TLR4 signaling in enterocytes in a mechanism dependent upon the inhibitory molecule IRAK-M. Strikingly, TLR9 activation with CpG-DNA significantly reduced NEC severity, whereas TLR9-deficient mice exhibited increased NEC severity. Thus, the reciprocal nature of TLR4 and TLR9 signaling within the neonatal intestine plays a role in the development of NEC and provides novel therapeutic approaches to this disease.
Mast Cells Contribute to Autoimmune Inflammatory Arthritis via Their Tryptase/Heparin Complexes
Authors: Shin Kichul , Nigrovic Peter A. , Crish James , Boilard Eric , McNeil H. Patrick , Larabee Katherine S. , Adachi Roberto , Gurish Michael F. , Gobezie Reuben , Stevens Richard L. , Lee David M. 
Published: April 2014

Abstract
Although mast cells (MCs) often are abundant in the synovial tissues of patients with rheumatoid arthritis, the contribution of MCs to joint inflammation and cartilage loss remains poorly understood. MC-restricted tryptase/heparin complexes have proinflammatory activity, and significant amounts of human tryptase β (hTryptase-β) are present in rheumatoid arthritis synovial fluid. Mouse MC protease-6 (mMCP-6) is the ortholog of hTryptase-β, and this serine protease is abundant in the synovium of arthritic mice. We now report that C57BL/6 (B6) mice lacking their tryptase/heparin complexes have attenuated arthritic responses, with mMCP-6 as the dominant tryptase responsible for augmenting neutrophil infiltration in the K/BxN mouse serum-transfer arthritis model. While inflammation in this experimental arthritis model was not dependent on protease-activated receptor-2, it was dependent on the chemokine receptor CXCR2. In support of the latter data, exposure of synovial fibroblasts to hTryptase-β/heparin or mMCP-6/heparin complexes resulted in expression of the neutrophil chemotactic factors CXCL1/KC, CXCL5/LIX, and CXCL8/IL-8. Our proteomics, histochemistry, and immunohistochemistry data also revealed substantial loss of cartilage-derived aggrecan proteoglycans in the arthritic joints of wild-type B6 mice but not mMCP-6-null B6 mice. These observations demonstrate the functional contribution of MC-restricted tryptase/heparin complexes in the K/BxN mouse arthritis model and connect our mouse findings with rheumatoid arthritis pathophysiology.
Citrullination of CXCL12 Differentially Reduces CXCR4 and CXCR7 Binding with Loss of Inflammatory and Anti-HIV-1 Activity via CXCR4
Authors: Struyf Sofie , Noppen Samuel , Loos Tamara , Mortier Anneleen , Gouwy Mieke , Verbeke Hannelien , Huskens Dana , Luangsay Souphalone , Parmentier Marc , Geboes Karel , Schols Dominique , Van Damme Jo , Proost Paul 
Published: April 2014

Abstract
Posttranslational proteolytic processing of chemokines is a natural mechanism to regulate inflammation. In this study, we describe modification of the CXC chemokine stromal cell-derived factor 1α/CXCL12 by peptidylarginine deiminase (PAD) that converts arginine residues into citrulline (Cit), thereby reducing the number of positive charges. The three NH2-terminal arginines of CXCL12, Arg8, Arg12, and Arg20, were citrullinated upon incubation with PAD. The physiologic relevance of citrullination was demonstrated by showing coexpression of CXCL12 and PAD in Crohn’s disease. Three CXCL12 isoforms were synthesized for biologic characterization: CXCL12-1Cit, CXCL12-3Cit, and CXCL12-5Cit, in which Arg8, Arg8/Arg12/Arg20, or all five arginines were citrullinated, respectively. Replacement of only Arg8 caused already impaired (30-fold reduction) CXCR4 binding and signaling (calcium mobilization, phosphorylation of ERK and protein kinase B) properties. Interaction with CXCR4 was completely abolished for CXCL12-3Cit and CXCL12-5Cit. However, the CXCR7-binding capacities of CXCL12-1Cit and CXCL12-3Cit were, respectively, intact and reduced, whereas CXCL12-5Cit failed to bind CXCR7. In chemotaxis assays with lymphocytes and monocytes, CXCL12-3Cit and CXCL12-5Cit were completely devoid of activity, whereas CXCL12-1Cit, albeit at higher concentrations than CXCL12, induced migration. The antiviral potency of CXCL12-1Cit was reduced compared with CXCL12 and CXCL12-3Cit and CXCL12-5Cit (maximal dose 200 nM) could not inhibit infection of lymphocytic MT-4 cells with the HIV-1 strains NL4.3 and HE. In conclusion, modification of CXCL12 by one Cit severely impaired the CXCR4-mediated biologic effects of this chemokine and maximally citrullinated CXCL12 was inactive. Therefore, PAD is a potent physiologic down-regulator of CXCL12 function.
Heat Shock Proteins HSP27 and HSP70 Are Present in the Skin and Are Important Mediators of Allergic Contact Hypersensitivity
Authors: Yusuf Nabiha , Nasti Tahseen H. , Huang Chun-Ming , Huber Brad S. , Jaleel Tarannum , Lin Hui-Yi , Xu Hui , Elmets Craig A. 
Published: April 2014

Abstract
Proteomic analysis of murine skin has shown that a variety of heat shock proteins (HSPs) are constitutively expressed in the skin. Using murine allergic contact hypersensitivity as a model, we investigated the role of two heat shock proteins, HSP27 and HSP70, in the induction of cutaneous cell-mediated immune responses. Immunohistochemical examination of skin specimens showed that HSP27 was present in the epidermis and HSP70 was present in both the epidermis and dermis. Inhibition of HSP27 and HSP70 produced a reduction in the 1-fluoro-2,4-dinitrobenzene contact hypersensitivity response and resulted in the induction of Ag-specific unresponsiveness. Treatment of dendritic cell cultures with recombinant HSP27 caused in the up-regulation of IL-1β, TNF-α, IL-6, IL-12p70, and IL-12p40 but not IL-23p19, which was inhibited when Abs to HSP27 were added. The 1-fluoro-2,4-dinitrobemzene-conjugated dendritic cells that had been treated with HSP27 had an increased capacity to initiate contact hypersensitivity responses compared with control dendritic cells. This augmented capacity required TLR4 signaling because neither cytokine production by dendritic cells nor the increased induction of contact hypersensitivity responses occurred in TLR4-deficient C3H/HeJ mice. Our findings indicate that a cascade of events occurs following initial interaction of hapten with the skin that includes increased activity of HSPs, their interaction with TLR4, and, in turn, increased production of cytokines that are known to enhance Ag presentation by T cells. The results suggest that HSPs form a link between adaptive and innate immunity during the early stages of contact hypersensitivity.
Targeting TLR2 Attenuates Pulmonary Inflammation and Fibrosis by Reversion of Suppressive Immune Microenvironment
Authors: Yang Hong-Zhen , Cui Bing , Liu Han-Zhi , Chen Zhi-Rong , Yan Hui-Min , Hua Fang , Hu Zhuo-Wei 
Published: April 2014

Abstract
Pulmonary fibrosis is a consequence of chronic lung injury and is associated with a high mortality. Despite the pathogenesis of pulmonary fibrosis remaining as an enigma, immune responses play a critical role in the deregulation of wound healing process after lung injury, which leads to fibrosis. Accumulating evidence argues the rationales for current treatments of pulmonary fibrosis using immunosuppressive agents such as corticosteroids. In this study, we report that bleomycin (BLM), a well-known fibrogenic agent functioning as a TLR2 agonist, induced the maturation of dendritic cells and release of cytokines. The BLM activation of TLR2 mediated a time-dependent alteration of immune responses in the lung. These responses resulted in an increase in the tissue-infiltrating proinflammatory cells and cytokines in the early period initially following BLM exposure and an increase in the tissue-infiltrating suppressive immune cells and factors during the later period following BLM exposure. TLR2 deficiency, however, reduced pulmonary inflammation, injury, and subsequently attenuated pulmonary fibrosis. Targeting TLR2 by a TLR2-neutralizing Ab not only markedly decreased animal death but also protected animals from the development of pulmonary fibrosis and reversed the established pulmonary fibrosis through regulating BLM-induced immunosuppressive microenvironments. Our studies suggest that TLR2 is a promising target for the development of therapeutic agents against pulmonary fibrosis and that eliminating immunosuppressive cells and factors via immunostimulants is a novel strategy for fibro-proliferative diseases. Moreover, combining BLM with an anti-TLR2 Ab or TLR2 antagonist for cancer therapy will improve the BLM therapeutic profile by enhancing anti-cancer efficacy and reducing systemic inflammation and pulmonary fibrosis.
Anti-Moesin Antibodies in the Serum of Patients with Aplastic Anemia Stimulate Peripheral Blood Mononuclear Cells to Secrete TNF-α and IFN-γ
Authors: Takamatsu Hiroyuki , Espinoza J. Luis , Lu Xuzhang , Qi Zhirong , Okawa Katsuya , Nakao Shinji 
Published: April 2014

Abstract
Moesin is an intracellular protein that links the cell membrane and cytoskeleton, while also mediating the formation of microtubules and cell adhesion sites as well as ruffling of the cell membrane. To determine the roles of anti-moesin Abs derived from the serum of patients with aplastic anemia (AA) in the pathophysiology of bone marrow failure, we studied the expression of moesin on various blood cells and the effects of anti-moesin Abs on the moesin-expressing cells. The proteins recognized by anti-moesin mAbs were detectable on the surface of T cells, NK cells, and monocytes from healthy individuals as well as on THP-1 cells. The peptide mass fingerprinting of the THP-1 cell surface protein and the knock-down experiments using short hairpin RNA proved that the protein is moesin itself. Both the anti-moesin mAbs and the anti-moesin polyclonal Abs purified from the AA patients’ sera stimulated THP-1 cells and the PBMCs of healthy individuals and AA patients to secrete 60–80% as much TNF-α as did LPS 100 ng/ml. Although the polyclonal Abs induced IFN-γ secretion from the PBMCs of healthy individuals only when the PBMCs were prestimulated by anti-CD3 mAbs, the anti-moesin Abs were capable of inducing IFN-γ secretion from the PBMCs of AA patients by themselves. Anti-moesin Abs may therefore indirectly contribute to the suppression of hematopoiesis in AA patients by inducing myelosuppressive cytokines from immunocompetent cells.
Airway Epithelial Cells Regulate the Functional Phenotype of Locally Differentiating Dendritic Cells: Implications for the Pathogenesis of Infectious and Allergic Airway Disease
Authors: Rate Angela , Upham John W. , Bosco Anthony , McKenna Kathy L. , Holt Patrick G. 
Published: April 2014

Abstract
Atopic asthma pathogenesis is driven by the combined effects of airway inflammation generated during responses to viral infections and aeroallergens, and both these pathways are regulated by dendritic cells (DC) that differentiate locally from monocytic precursors. These DCs normally exhibit a sentinel phenotype characterized by active Ag sampling but attenuated presentation capability, which limits the intensity of local expression of adaptive immunity. How this tight control of airway DC functions is normally maintained, and why it breaks down in some atopics leading to immunopathological changes in airway tissues, is unknown. We postulated that signals from adjacent airway epithelial cells (AEC) contribute to regulation of local differentiation of DC. We tested this in a coculture model containing both cell types in a GM-CSF-IL-4-enriched cytokine milieu characteristic of the atopic asthmatic airway mucosa. We demonstrate that contact with AEC during DC differentiation up-regulates expression of the function-associated markers MHC class II, CD40, CD80, TLR3, and TLR4 on DCs with concomitant up-regulation of Ag uptake/processing. Moreover, the AEC-conditioned DCs displayed increased LPS responsiveness evidenced by higher production of IL-12, IL-6, IL-10, and TNF-α. The Th2 memory-activating properties of AEC-conditioned DCs were also selectively attenuated. Data from microarray and blocking experiments implicate AEC-derived type 1 IFNs and IL-6 in modulation of DC differentiation. Collectively, these findings suggest that resting AECs modulate local DC differentiation to optimize antimicrobial defenses in the airways and in the process down-modulate capacity for expression of potentially damaging Th2 immunity.
App1: An Antiphagocytic Protein That Binds to Complement Receptors 3 and 2
Authors: Stano Paola , Williams Virginia , Villani Maristella , Cymbalyuk Eugene S. , Qureshi Asfia , Huang Yuxiang , Morace Giulia , Luberto Chiara , Tomlinson Stephen , Del Poeta Maurizio 
Published: April 2014

Abstract
In previous studies, we showed that the pathogenic fungus Cryptococcus neoformans (Cn) produces a specific and unique protein called antiphagocytic protein 1 (App1), which inhibits phagocytosis of Cn by alveolar macrophages (AMs). Phagocytosis of Cn by AMs occurs mainly through a complement- or Ab-mediated mechanism. Among AM receptors, complement receptor 3 (CR3) and FcRγ are the most common receptors involved in the phagocytic process. Because App1 inhibits phagocytosis of complement- but not Ab-coated erythrocytes, we investigated the role of CR3 in App1-macrophage interactions. We found that App1 binds to CR3 and if CR3 is absent from the surface of AMs, its antiphagocytic action is lost. When we investigated whether App1 would also bind to other complement receptor(s), we found that App1 does bind to complement receptor 2 (CR2) in a dose-dependent manner. In certain lymphoma cell lines, cellular proliferation is stimulated by complement through CR2, providing a potential use of App1 as a proliferation inhibitor of these cells. Initially discovered as an antiphagocytic protein regulating CR3-mediated innate immunity, App1 may also play a key role in the regulation of acquired immunity, because CR2 is mainly localized on B cells.
Ezrin and Moesin Function Together to Promote T Cell Activation
Authors: Shaffer Meredith H. , Dupree Renell S. , Zhu Peimin , Saotome Ichiko , Schmidt Richard F. , McClatchey Andrea I. , Freedman Bruce D. , Burkhardt Janis K. 
Published: April 2014

Abstract
The highly homologous proteins ezrin, radixin, and moesin link proteins to the actin cytoskeleton. The two family members expressed in T cells, ezrin and moesin, are implicated in promoting T cell activation and polarity. To elucidate the contributions of ezrin and moesin, we conducted a systematic analysis of their function during T cell activation. In response to TCR engagement, ezrin and moesin were phosphorylated in parallel at the regulatory threonine, and both proteins ultimately localized to the distal pole complex (DPC). However, ezrin exhibited unique behaviors, including tyrosine phosphorylation and transient localization to the immunological synapse before movement to the DPC. To ask whether these differences reflect unique requirements for ezrin vs moesin in T cell signaling, we generated mice with conditional deletion of ezrin in mature T cells. Ezrin−/− T cells exhibited normal immunological synapse organization based upon localization of protein kinase C-θ, talin, and phospho-ZAP70. DPC localization of CD43 and RhoGDP dissociation inhibitor, as well as the novel DPC protein Src homology region 2 domain-containing phosphatase-1, was also unaffected. However, recruitment of three novel DPC proteins, ezrin binding protein of 50 kDa, Csk binding protein, and the p85 subunit of PI3K was partially perturbed. Biochemical analysis of ezrin−/− T cells or T cells suppressed for moesin using small interfering RNA showed intact early TCR signaling, but diminished levels of IL-2. The defects in IL-2 production were more pronounced in T cells deficient for both ezrin and moesin. These cells also exhibited diminished phospholipase C-γ1 phosphorylation and calcium flux. We conclude that despite their unique movement and phosphorylation patterns, ezrin and moesin function together to promote T cell activation.
14-3-3γ Is Stimulated by IL-3 and Promotes Cell Proliferation
Authors: Ajjappala Brijesh S. , Kim Yong-Soo , Kim Myung-Sun , Lee Min-Young , Lee Kwang-Youl , Ki Ho-Yun , Cha Dong-Hyun , Baek Kwang-Hyun 
Published: April 2014

Abstract
IL-3 plays important roles in the growth and survival of hematopoietic progenitor cells, processes modeled in studies of the IL-3-dependent cell line Ba/F3. To gain insights into molecular mechanisms governing cell fate, we examined the patterns of proteins up-regulated following stimulation of Ba/F3 cells with IL-3. Through two-dimensional electrophoresis and proteomics-based approaches, we identified 11 proteins. Of these, expression of 14-3-3γ was significantly increased by IL-3 stimulation at both the transcriptional and translational levels. 14-3-3γ overexpression in Ba/F3 cells abrogated dependence on IL-3 and was associated with activation of PI3K and MAPK signaling cascades, suggesting that the functions of 14-3-3γ in normal hematopoietic progenitors are to promote survival and growth through the activation of distinct signaling pathways. Additionally, the up-regulation of Bax and Bad was seen with the ablation of 14-3-3γ, resulting in cell death. These results indicate that deregulated expression of 14-3-3γ may contribute to malignant transformation, possibly providing a new target for therapeutic intervention in hematopoietic neoplasms.
Cell-Mediated Immunity toToxoplasma gondiiDevelops Primarily by Local Th1 Host Immune Responses in the Absence of Parasite Replication
Authors: Gigley Jason P. , Fox Barbara A. , Bzik David J. 
Published: April 2014

AbstractA single inoculation of mice with the live, attenuated Toxoplasma gondii uracil auxotroph strain cps1-1 induces long-lasting immunity against lethal challenge with hypervirulent strain RH. The mechanism for this robust immunity in the absence of parasite replication has not been addressed. The mechanism of long-lasting immunity, the importance of route of immunization, cellular recruitment to the site of infection, and local and systemic inflammation were evaluated. Our results show that infection with cps1-1 elicits long-lasting CD8+ T cell- mediated immunity. We show that immunization with cps1-1-infected dendritic cells elicits long-lasting immunity. Intraperitoneal infection with cps1-1 induced a rapid influx of GR1+ neutrophils and two stages of GR1+CD68+ inflammatory monocyte infiltration into the site of inoculation. CD19+ B cells and CD3+ T cells steadily increase for 8 days after infection. CD8+ T cells were rapidly recruited to the site of infection and increased faster than CD4+ T cells. Surprisingly, cps1-1 infection induced high systemic levels of bioactive IL-12p70 and a very low level and transient systemic IFN-γ. Furthermore, we show significant levels of these inflammatory cytokines were locally produced at the site of cps1-1 inoculation. These findings offer new insight into immunological mechanisms and local host responses to a non-replicating type I parasite infection associated with development of long-lasting immunity to Toxoplasma gondii.
Induction of Proinflammatory Cytokines in Primary Human Macrophages by Influenza A Virus (H5N1) Is Selectively Regulated by IFN Regulatory Factor 3 and p38 MAPK
Authors: Hui Kenrie P. Y. , Lee Suki M. Y. , Cheung Chung-yan , Ng Iris H. Y. , Poon Leo L. M. , Guan Yi , Ip Nancy Y. Y. , Lau Allan S. Y. , Peiris J. S. Malik 
Published: April 2014

Abstract
The hyperinduction of proinflammatory cytokines and chemokines such as TNF-α, IFN-β, and CCL2/MCP-1 in primary human macrophages and respiratory epithelial cells by the highly pathogenic avian influenza H5N1 is believed to contribute to the unusual severity of human H5N1 disease. Here we show that TNF-α, IFN-β, and IFN-λ1 are the key mediators directly induced by the H5N1 virus in primary human macrophages. In comparison with human influenza (H1N1), the H5N1 virus more strongly activated IFN regulatory factor 3 (IRF3). IRF3 knockdown and p38 kinase inhibition separately and in combination led to a substantial reduction of IFN-β, IFN-λ1, and MCP-1 but only to a partial reduction of TNF-α. IRF3 translocation was independent of p38 kinase activity, indicating that IRF3 and p38 kinase are distinct pathways leading to cytokine production by H5N1 virus. We conclude that IRF3 and p38 kinase separately and predominantly contribute to H5N1-mediated induction of IFN-β, IFN-λ1, and MCP-1 but only partly control TNF-α induction. A more precise identification of the differences in the regulation of TNF-α and IFN-β could provide novel targets for the design of therapeutic strategies for severe human H5N1 influenza and also for treating other causes of acute respiratory distress syndrome.