bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inactivation of Cdc42 Is Necessary for Depolymerization of Phagosomal F-Actin and Subsequent Phagosomal Maturation
Authors: Lerm Maria , Brodin Veronika Patcha , Ruishalme Iida , Stendahl Olle , Särndahl Eva 
Published: April 2014

Abstract
Phagocytosis is a complex process involving the activation of various signaling pathways, such as the Rho GTPases, and the subsequent reorganization of the actin cytoskeleton. In neutrophils, Rac and Cdc42 are activated during phagocytosis but less is known about the involvement of these GTPases during the different stages of the phagocytic process. The aim of this study was to elucidate the role of Cdc42 in phagocytosis and the subsequent phagosomal maturation. Using a TAT-based protein transduction technique, we introduced dominant negative and constitutively active forms of Cdc42 into neutrophil-like HL60 (human leukemia) cells that were allowed to phagocytose IgG-opsonized yeast particles. Staining of cellular F-actin in cells transduced with constitutively active Cdc42 revealed that the activation of Cdc42 induced sustained accumulation of periphagosomal actin. Moreover, the fusion of azurophilic granules with the phagosomal membrane was prevented by the accumulated F-actin. In contrast, introducing dominant negative Cdc42 impaired the translocation per se of azurophilic granules to the periphagosomal area. These results show that efficient phagosomal maturation and the subsequent eradication of ingested microbes in human neutrophils is dependent on a strictly regulated Cdc42. To induce granule translocation, Cdc42 must be in its active state but has to be inactivated to allow depolymerization of the F-actin cage around the phagosome, a process essential for phagolysosome formation.
Corticosteroid Inhibition of Growth-Related Oncogene Protein-α via Mitogen-Activated Kinase Phosphatase-1 in Airway Smooth Muscle Cells
Authors: Issa Razao , Xie Shaoping , Khorasani Nadia , Sukkar Maria , Adcock Ian M. , Lee Kang-Yun , Chung Kian Fan 
Published: April 2014

AbstractExpression of the inflammatory chemokine, growth-related oncogene protein-α (GRO-α), from airway smooth muscle cells (ASMC) is regulated by pathways involving NF-κB and MAPK activation. We determined the effects of dexamethasone on GRO-α induced by IL-1β or TNF-α with respect to the role of MAPK pathways and of MAPK phosphatase-1 (MKP-1). Human ASMC were studied in primary culture at confluence. Dexamethasone (10−8–10−5 M) partially inhibited GRO-α expression and release induced by IL-1β and TNF-α; this was associated with an inhibition of JNK, but not of p38 or ERK phosphorylation. Together with IL-1β or TNF-α, dexamethasone rapidly induced mRNA and protein expression of MKP-1, which dephosphorylates MAPKs. Using MKP-1 small interfering RNA (siRNA) to block the expression of IL-1β- and dexamethasone-induced MKP-1 by 50%, JNK phosphorylation was doubled. The inhibitory effect of dexamethasone on GRO-α release was partially reversed in ASMC treated with MKP-1 siRNA compared with those treated with scrambled siRNA. In contrast, overexpression of MKP-1 led to a reduction in IL-1β-induced release of GRO-α, but the inhibitory effects of dexamethasone were preserved. Nuclear translocation of the glucocorticoid receptor was increased in ASMC exposed to dexamethasone and IL-1β. Using chromatin immunoprecipitation assay, glucocorticoid receptor binding to the MKP-1 promoter was increased by IL-1β and dexamethasone compared with either alone. Glucocorticoids and IL-1β or TNF-α modulate GRO-α release partly through the inhibition of JNK pathway, resulting from an up-regulation of MKP-1 expression.
Nuclear Heat Shock Protein 72 as a Negative Regulator of Oxidative Stress (Hydrogen Peroxide)-Induced HMGB1 Cytoplasmic Translocation and Release
Authors: Tang Daolin , Kang Rui , Xiao Weimin , Jiang Lei , Liu Meidong , Shi Yongzhong , Wang Kangkai , Wang Haichao , Xiao Xianzhong 
Published: April 2014

Abstract
In response to inflammatory stimuli (e.g., endotoxin, proinflammatory cytokines) or oxidative stress, macrophages actively release a ubiquitous nuclear protein, high-mobility group box 1 (HMGB1), to sustain an inflammatory response to infection or injury. In this study, we demonstrated mild heat shock (e.g., 42.5°C, 1 h), or enhanced expression of heat shock protein (Hsp) 72 (by gene transfection) similarly rendered macrophages resistant to oxidative stress-induced HMGB1 cytoplasmic translocation and release. In response to oxidative stress, cytoplasmic Hsp72 translocated to the nucleus, where it interacted with nuclear proteins including HMGB1. Genetic deletion of the nuclear localization sequence (NLS) or the peptide binding domain (PBD) from Hsp72 abolished oxidative stress-induced nuclear translocation of Hsp72-ΔNLS (but not Hsp72-ΔPBD), and prevented oxidative stress-induced Hsp72-ΔPBD-HMGB1 interaction in the nucleus. Furthermore, impairment of Hsp72-ΔNLS nuclear translocation, or Hsp72-ΔPBD-HMGB1 interaction in the nucleus, abrogated Hsp72-mediated suppression of HMGB1 cytoplasmic translocation and release. Taken together, these experimental data support a novel role for nuclear Hsp72 as a negative regulator of oxidative stress-induced HMGB1 cytoplasmic translocation and release.
IFN-γ Protects Cerulein-Induced Acute Pancreatitis by Repressing NF-κB Activation
Authors: Hayashi Takahito , Ishida Yuko , Kimura Akihiko , Iwakura Yoichiro , Mukaida Naofumi , Kondo Toshikazu 
Published: April 2014

AbstractWe explored the pathophysiological roles of IFN-γ in cerulein-induced acute pancreatitis. In wild-type (WT) mice, cerulein injection caused acute pancreatitis as evidenced by increased serum amylase levels and pathological changes such as interstitial edema, vacuolization, acinar cell necrosis, and neutrophil infiltration in pancreas. Concomitantly, cerulein treatment augmented intrapancreatic gene expression of TNF-α, KC/CXCL1, MIP-2/CXCL2, cyclooxygenase-2 (COX-2), and IFN-γ in WT mice. In situ hybridization combined with immunofluorescence analyses demonstrated that infiltrating neutrophils expressed IFN-γ mRNA. Unexpectedly, IFN-γ−/− mice exhibited exacerbated cerulein-induced pancreatic injury, with enhanced neutrophil recruitment. Moreover, intrapancreatic gene expression of TNF-α, KC/CXCL1, MIP-2/CXCL2, and COX-2 were significantly exaggerated in IFN-γ−/− mice, compared with WT mice. Cerulein activated NF-κB, an indispensable transcription factor for gene transcription of TNF-α, KC/CXCL1, MIP-2/CXCL2, and COX-2, in pancreas of cerulein-treated WT mice as evidenced by the increases in nuclear amount and DNA-binding activity of NF-κB p65. In comparison with WT mice, IFN-γ−/− mice exhibited exaggerated and prolonged NF-κB activation, probably due to reduced acetylation of Stat1, a main signal transducer of IFN-γ, because acetylated Stat1 can inhibit NF-κB activation. Indeed, IFN-γ acetylated Stat1 and reciprocally reduced NF-κB activation and COX-2 expression in neutrophils. Finally, even when administered 4 h after the first cerulein injection, IFN-γ remarkably attenuated acute pancreatitis in both WT and IFN-γ−/− mice, with reduced NF-κB activation and COX-2 expression. Thus, IFN-γ can have anti-inflammatory effects on acute pancreatitis by depressing the proinflammatory consequences of NF-κB activation.
Expression of Tie-2 by Human Monocytes and Their Responses to Angiopoietin-2
Authors: Murdoch Craig , Tazzyman Simon , Webster Steve , Lewis Claire E. 
Published: April 2014

AbstractAngiopoietins 1 and 2 bind to Tie-2 expressed on endothelial cells and regulate vessel stabilization and angiogenesis. Tie-2+ monocytes have been shown to be recruited to experimental tumors where they promote tumor angiogenesis. In this study, we show that 20% of CD14+ human blood monocytes express Tie-2, and that these cells coexpress CD16 (FcγRIII) and are predominantly CD34 negative. Ang-2 is up-regulated by endothelial cells in malignant tumors and inflamed tissues, so our finding that Ang-2 is a chemoattractant for human Tie-2+ monocytes and macrophages, suggests that it may help to recruit and regulate their distribution in such tissues. Ang-2 was also found to markedly inhibit release of the important proinflammatory cytokine, TNF-α, by monocytes in vitro. Following extravasation of monocytes, and their differentiation into macrophages, many accumulate in the hypoxic areas of inflamed and malignant tissues. Ang-2 is known to be up-regulated by hypoxia and we show that monocytes and macrophages up-regulate Tie-2 when exposed to hypoxia. Furthermore, hypoxia augmented the inhibitory effect of Ang-2 on the release of the anti-angiogenic cytokine, IL-12 by monocytes. In sum, our data indicate that Ang-2 may recruit Tie-2+ monocytes to tumors and sites of inflammation, modulate their release of important cytokines and stimulate them to express a proangiogenic phenotype.
Soluble Ig-Like Transcript 3 Inhibits Tumor Allograft Rejection in Humanized SCID Mice and T Cell Responses in Cancer Patients
Authors: Suciu-Foca Nicole , Feirt Nikki , Zhang Qing-Yin , Vlad George , Liu Zhuoru , Lin Hana , Chang Chih-Chao , Ho Eric K. , Colovai Adriana I. , Kaufman Howard , D’Agati Vivette D. , Thaker Harshwardhan M. , Remotti Helen , Galluzzo Sara , Cinti Paola , Rabitti Carla , Allendorf John , Chabot John , Caricato Marco , Coppola Roberto , Berloco Pasquale , Cortesini Raffaello 
Published: April 2014

Abstract
Attempts to enhance patients’ immune responses to malignancies have been largely unsuccessful. We now describe an immune-escape mechanism mediated by the inhibitory receptor Ig-like transcript 3 (ILT3) that may be responsible for such failures. Using a humanized SCID mouse model, we demonstrate that soluble and membrane ILT3 induce CD8+ T suppressor cells and prevent rejection of allogeneic tumor transplants. Furthermore, we found that patients with melanoma, and carcinomas of the colon, rectum, and pancreas produce the soluble ILT3 protein, which induces the differentiation of CD8+ T suppressor cells and impairs T cell responses in MLC. These responses are restored by anti-ILT3 mAb or by depletion of soluble ILT3 from the serum. Immunohistochemical staining of biopsies from the tumors and metastatic lymph nodes suggests that CD68+ tumor-associated macrophages represent the major source of soluble ILT3. Alternative splicing, resulting in the loss of the ILT3 transmembrane domain, may contribute to the release of ILT3 in the circulation. These data suggest that ILT3 depletion or blockade is crucial to the success of immunotherapy in cancer. In contrast, the inhibitory activity of soluble ILT3 on T cell alloreactivity in vitro and in vivo suggests the potential usefulness of rILT3 for immunosuppressive treatment of allograft recipients or patients with autoimmune diseases.
Novel Insight into the Agonistic Mechanism of Alefacept In Vivo: Differentially Expressed Genes May Serve as Biomarkers of Response in Psoriasis Patients
Authors: Haider Asifa S. , Lowes Michelle A. , Gardner Humphrey , Bandaru Raj , Darabi Kamruz , Chamian Francesca , Kikuchi Toyoko , Gilleaudeau Patricia , Whalen Mary S. , Cardinale Irma , Novitskaya Inna , Krueger James G. 
Published: April 2014

AbstractAlefacept is an LFA3-Ig fusion protein that binds to CD2 and is thought to inhibit T cell activation by antagonism of CD2 signaling or by lysis of CD2+ cells. Alefacept is potential future therapeutic for organ transplant recipients or graft-vs-host disease and is an approved therapeutic for psoriasis vulgaris, which is a T cell-mediated inflammatory disease. However, alefacept improves psoriasis in only ∼50% of patients treated for 12 wk. We studied the immunologic effects of alefacept in a group of psoriasis patients during treatment. We found that T cells, especially CD8+ T cells, were rapidly decreased in the peripheral circulation. Decreases in circulating T cells were not associated with induced apoptosis. Unexpectedly, in addition to suppression of inflammatory genes, we found a marked induction of mRNAs for STAT1, IL-8, and monokine induced by IFN-γ during the first day of treatment in PBMC. We confirmed the agonistic effects of alefacept in PBMC in vitro, which were similar to CD3/CD28 ligation on T cells. These data establish that alefacept activates gene expression programs in leukocytes and suggest that its therapeutic action may be as a mixed agonist/antagonist. Furthermore, responding patients to alefacept treatment show unique patterns of gene modulation. Whereas alefacept down-regulated TCRs CD3D and CD2 in responders, nonresponders reveal a higher expression of T cell activation genes such as CD69 in pretreatment PBMC. These finding suggest a potential basis for categorizing responders vs nonresponders at an early time point in treatment or before treatment of a broad range of proinflammatory diseases. This study 1) establishes alefacept as a novel CD2 agonist molecule for induction of leukocyte activation genes (prior work proposed its mechanism as a CD2 antagonist) and 2) that differential activation of genes may categorize clinical responders to this agent, critical for cost-effective use of this drug.
A Virus-Like Particle-Based Vaccine Selectively Targeting Soluble TNF-α Protects from Arthritis without Inducing Reactivation of Latent Tuberculosis
Authors: Spohn Gunther , Guler Reto , Johansen Pål , Keller Iris , Jacobs Muazzam , Beck Markus , Rohner Franziska , Bauer Monika , Dietmeier Klaus , Kündig Thomas M. , Jennings Gary T. , Brombacher Frank , Bachmann Martin F. 
Published: April 2014

Abstract
Neutralization of the proinflammatory cytokine TNF-α by mAbs or soluble receptors represents an effective treatment for chronic inflammatory disorders such as rheumatoid arthritis, psoriasis, or Crohn’s disease. In this study, we describe a novel active immunization approach against TNF-α, which results in the induction of high titers of therapeutically active autoantibodies. Immunization of mice with virus-like particles of the bacteriophage Qβ covalently linked to either the entire soluble TNF-α protein (Qβ-C-TNF1–156) or a 20-aa peptide derived from its N terminus (Qβ-C-TNF4–23) yielded specific Abs, which protected from clinical signs of inflammation in a murine model of rheumatoid arthritis. Whereas mice immunized with Qβ-C-TNF1–156 showed increased susceptibility to Listeria monocytogenes infection and enhanced reactivation of latent Mycobacterium tuberculosis, mice immunized with Qβ-C-TNF4–23 were not immunocompromised with respect to infection with these pathogens. This difference was attributed to recognition of both transmembrane and soluble TNF-α by Abs elicited by Qβ-C-TNF1–156, and a selective recognition of only soluble TNF-α by Abs raised by Qβ-C-TNF4–23. Thus, by specifically targeting soluble TNF-α, Qβ-C-TNF4–23 immunization has the potential to become an effective and safe therapy against inflammatory disorders, which might overcome the risk of opportunistic infections associated with the currently available TNF-α antagonists.
TLR Stimulation Modifies BLyS Receptor Expression in Follicular and Marginal Zone B Cells
Authors: Treml Laura S. , Carlesso Gianluca , Hoek Kristen L. , Stadanlick Jason E. , Kambayashi Taku , Bram Richard J. , Cancro Michael P. , Khan Wasif N. 
Published: April 2014

Abstract
Through their differential interactions with B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL), the three BLyS family receptors play central roles in B cell survival and differentiation. Recent evidence indicates BLyS receptor levels shift following BCR ligation, suggesting that activation cues can alter overall BLyS receptor profiles and thus ligand sensitivity. In this study, we show that TLR stimuli also alter BLyS receptor expression, but in contrast to BCR ligation, TLR9 and TLR4 signals, preferentially increase transmembrane activator calcium modulator and cyclophilin ligand interactor (TACI) expression. Although both of these TLRs act through MyD88-dependent mechanisms to increase TACI expression, they differ in terms of their downstream mediators and the B cell subset affected. Surprisingly, only TLR4 relies on c-Rel and p50 to augment TACI expression, whereas TLR9 does not. Furthermore, although all follicular and marginal zone B cells up-regulate TACI in response to TLR9 stimulation, only marginal zone B cells and a subset of follicular B cells respond to TLR4. Finally, we find that both BLyS and APRIL enhance viability among quiescent and BCR-stimulated B cells. However, although BLyS enhances viability among TLR stimulated B cells, APRIL does not, suggesting that TACI but not BLyS receptor 3 may share survival promoting pathways with TLRs.
Persistent Depots of Influenza Antigen Fail To Induce a Cytotoxic CD8 T Cell Response
Authors: Jelley-Gibbs Dawn M. , Dibble John P. , Brown Deborah M. , Strutt Tara M. , McKinstry K. Kai , Swain Susan L. 
Published: April 2014

Abstract
Encounter with Ag during chronic infections results in the generation of phenotypically and functionally heterogeneous subsets of Ag-specific CD8 T cells. Influenza, an acute infection, results in the generation of similar CD8 T cell heterogeneity, which may be attributed to long-lived depots of flu Ags that stimulate T cell proliferation well after virus clearance. We hypothesized that the heterogeneity of flu-specific CD8 T cells and maintenance of T cell memory required the recruitment of new CD8 T cells to persistent depots of flu Ag, as was the case for flu-specific CD4 T cell responses. However, robust expansion and generation of highly differentiated cytolytic effectors and memory T cells only occurred when naive CD8 T cells were primed during the first week of flu infection. Priming of new naive CD8 T cells after the first week of infection resulted in low numbers of poorly functional effectors, with little to no cytolytic activity, and a negligible contribution to the memory pool. Therefore, although the presentation of flu Ag during the late stages of infection may provide a mechanism for maintaining an activated population of CD8 T cells in the lung, few latecomer CD8 T cells are recruited into the functional memory T cell pool.
Systemic Administration of IL-23 Induces Potent Antitumor Immunity Primarily Mediated through Th1-Type Response in Association with the Endogenously Expressed IL-12
Authors: Kaiga Teruo , Sato Marimo , Kaneda Hide , Iwakura Yoichiro , Takayama Tadatoshi , Tahara Hideaki 
Published: April 2014

Abstract
IL-23, a cytokine, which is composed of the p40 subunit shared with IL-12 and the IL-23-specific p19 subunit, has been shown to preferentially act on Th1 effector/memory CD4+ T cells and to induce their proliferation and IFN-γ production. The IL-23 is also reported to act on Th17-CD4+ T cells, which are involved in inducing tissue injury. In this study, we examined the antitumor effects associated with systemic administration of IL-23 and their mechanisms in mouse tumor system. Systemic administration of high-dose IL-23 was achieved using in vivo electroporation of IL-23 plasmid DNA into the pretibial muscles of C57BL/6 mice. The IL-23 treatment was associated with significant suppression of the growth of pre-existing MCA205 fibrosarcoma and prolongation of the survival of treated mice without significant toxicity when compared with those of the mice treated with EGFP. Although the therapeutic outcomes were similar to those with the IL-12 treatment, the IL-23 treatment induced characteristic immune responses distinctive to those of IL-12 treatment. The IL-23 administration even at the therapeutic levels did not induce detectable IFN-γ concentration in the serum. In vivo depletion of CD4+ T cells, CD8+ T cells, or NK cells significantly inhibited the antitumor effects of IL-23. Furthermore, the CD4+ T cells in the lymph nodes in the IL-23-treated mice showed significant IFN-γ and IL-17 response upon anti-CD3 mAb stimulation in vitro. These results and the ones in the IFN-γ or IL-12 gene knockout mice suggest that potent antitumor effects of IL-23 treatment could be achieved when the Th1-type response is fully promoted in the presence of endogenously expressed IL-12.
CD8+ T Cell-Mediated Suppression of Autoimmunity in a Murine Lupus Model of Peptide-Induced Immune Tolerance Depends on Foxp3 Expression
Authors: Singh Ram Pyare , La Cava Antonio , Wong Maida , Ebling Fanny , Hahn Bevra H. 
Published: April 2014

Abstract
Systemic lupus erythematosus is an autoimmune disease caused by autoantibodies, including IgG anti-DNA. New Zealand Black/New Zealand White F1 female mice, a model of spontaneous polygenic systemic lupus erythematosus, tolerized with an artificial peptide (pConsensus) based on anti-DNA IgG sequences containing MHC class I and class II T cell determinants, develop regulatory CD4+CD25+ T cells and CD8+ inhibitory T cells (CD8+ Ti), both of which suppress autoantibody production. CD8+ Ti inhibit primarily via secretion of TGF-β. In the present study, we show that the inhibitory function of CD8+ T cells from tolerized mice is sustained for up to 8 wk and at all times depends on expression of Foxp3. Both CD28-positive and CD28-negative CD8+ T cells contain inhibitory cells, but the expression of mRNA for Foxp3 and for TGF-β is higher and lasts longer in the CD28− subset. In vitro addition of TGF-β (in the presence of IL-2) induces Foxp3 expression in a dose-response manner. Gene inhibition or blockade with small interfering RNA of Foxp3 abrogates the ability of the CD8+ Ti to inhibit anti-DNA production and the proliferation of CD4+ Th cells. Moreover, a significant correlation between expression of Foxp3 and ability of CD8+ Ti to secrete TGF-β is observed. Therefore, CD8+ Ti in this system of tolerance are similar to CD4+CD25+ regulatory T cells in their dependence on expression of Foxp3, and there may be a bidirectional Foxp3/TGF-β autocrine loop that determines the ability of the CD8+ T cells to control autoimmunity.
A Kinetic and Dynamic Analysis of Foxp3 Induced in T Cells by TGF-β
Authors: Selvaraj Ramesh K. , Geiger Terrence L. 
Published: April 2014

Abstract
TGF-β induces Foxp3 expression in stimulated T cells. These Foxp3+ cells (induced regulatory T cells (iTreg)) share functional and therapeutic properties with thymic-derived Foxp3+ regulatory T cells (natural regulatory T cells (nTreg)). We performed a single-cell analysis to better characterize the regulation of Foxp3 in iTreg in vitro and assess their dynamics after transfer in vivo. TGF-β up-regulated Foxp3 in CD4+Foxp3− T cells only when added within a 2- to 3-day window of CD3/CD28 stimulation. Up to 90% conversion occurred, beginning after 1–2 days of treatment. Foxp3 expression strictly required TCR stimulation but not costimulation and was independent of cell cycling. Removal of TGF-β led to a loss of Foxp3 expression after an ∼4-day lag. Most iTreg transferred into wild-type mice down-regulated Foxp3 within 2 days, and these Foxp3− cells were concentrated in the blood, spleen, lung, and liver. Few of the Foxp3− cells were detected by 28 days after transfer. However, some Foxp3+ cells persisted even to this late time point, and these preferentially localized to the lymph nodes and bone marrow. CXCR4 was preferentially expressed on Foxp3+ iTreg within the bone marrow, and CD62L was preferentially expressed on those in the lymph nodes. Like transferred nTreg and in contrast with revertant Foxp3− cells, Foxp3+ iTreg retained CD25 and glucocorticoid-induced TNFR family-related gene. Thus, Foxp3 expression in naïve-stimulated T cells is transient in vitro, dependent on TGF-β activity within a highly restricted window after activation and continuous TGF-β presence. In vivo, a subset of transferred iTreg persist long term, potentially providing a lasting source for regulatory activity after therapeutic administration.