bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aberrant Toll Receptor Expression and Endotoxin Hypersensitivity in Mice Lacking a Functional TGF-β1 Signaling Pathway
Authors: McCartney-Francis Nancy , Jin Wenwen , Wahl Sharon M. 
Published: April 2014

Abstract
TGF-β1 plays a central role in maintaining normal immune function and deficiency of this potent immunosuppressive molecule is linked to uncontrolled inflammation, cachexia, and multiorgan failure as seen in the TGF-β1 null mouse. Infiltration of inflammatory cells into vital organs of the null mouse is accompanied by increased gene expression of inflammatory cytokines, including TNF-α and IL-1β, as well as inducible NO synthase, each regulated by NF-κB. Treatment with the proteasome inhibitor MG132 to prevent NF-κB activation dramatically reduced NO production and expression of inflammatory cytokines. This inflammatory phenotype with NF-κB activation in the TGF-β1 null mouse, in the absence of any identifiable pathogen, suggested activation of innate immune responses. Because Toll-like receptors (TLR) are essential in the activation of innate immunity, we examined inflamed tissue from TGF-β1 null and wild-type mice for expression of TLR4, the receptor that interacts with bacterial cell wall LPS to initiate an NF-κB-dependent signaling pathway, leading to gene transcription of inflammatory mediators. Increased TLR4 mRNA expression observed in TGF-β1 null mice as well as in mice lacking the TGF-β transcription factor Smad3 was associated with LPS hyperresponsiveness leading to increased expression of inflammatory cytokines and NO and endotoxemia. Furthermore, mice lacking both TGF-β1 and a functional TLR4 were resistant to endotoxin shock. Constitutive and/or environmental activation of TLR4 and downstream elements, in the absence of TGF-β suppression, may impact on innate and adaptive immunity and contribute to massive uncontrolled inflammation.
Cell Surface Localization of Heparanase on Macrophages Regulates Degradation of Extracellular Matrix Heparan Sulfate
Authors: Sasaki Norihiko , Higashi Nobuaki , Taka Tomohiro , Nakajima Motowo , Irimura Tatsuro 
Published: April 2014

Abstract
Extravasation of peripheral blood monocytes through vascular basement membranes requires degradation of extracellular matrix components including heparan sulfate proteoglycans (HSPGs). Heparanase, the heparan sulfate-specific endo-β-glucuronidase, has previously been shown to be a key enzyme in melanoma invasion, yet its involvement in monocyte extravasation has not been elucidated. We examined a potential regulatory mechanism of heparanase in HSPG degradation and transmigration through basement membranes in leukocyte trafficking using human promonocytic leukemia U937 and THP-1 cells. PMA-treated cells were shown to degrade 35S-sulfated HSPG in endothelial extracellular matrix into fragments of an approximate molecular mass of 5 kDa. This was not found with untreated cells. The gene expression levels of heparanase or the enzyme activity of the amount of cell lysates were no different between untreated and treated cells. Immunocytochemical staining with anti-heparanase mAb revealed pericellular distribution of heparanase in PMA-treated cells but not in untreated cells. Cell surface heparanase capped into a restricted area on PMA-treated cells when they were allowed to adhere. Addition of a chemoattractant fMLP induced polarization of the PMA-treated cells and heparanase redistribution at the leading edge of migration. Therefore a major regulatory process of heparanase activity in the cells seems to be surface expression and capping of the enzyme. Addition of the anti-heparanase Ab significantly inhibited enzymatic activity and transmigration of the PMA-treated cells, suggesting that the cell surface redistribution of heparanase is involved in monocyte extravasation through basement membranes.
Expression of Developmental Endothelial Locus-1 in a Subset of Macrophages for Engulfment of Apoptotic Cells
Authors: Hanayama Rikinari , Tanaka Masato , Miwa Keiko , Nagata Shigekazu 
Published: April 2014

AbstractA major function of macrophages is to engulf apoptotic cells to prevent them from releasing noxious materials as they die. Milk fat globule-EGF-factor 8 (MFG-E8) is a glycoprotein secreted by activated macrophages that works as a bridge between apoptotic cells and phagocytes by specifically recognizing phosphatidylserine exposed on apoptotic cells. In this study, we found that developmental endothelial locus-1 (Del-1), originally identified as an embryonic endothelial cell protein that binds αvβ3 integrin, is structurally and functionally homologous to MFG-E8. That is, both consist of a signal sequence, two epidermal growth factor domains and two factor VIII-homologous domains (C1 and C2). Del-1 bound to the apoptotic cells by recognizing phosphatidylserine via the factor VIII-homologous domains with an affinity similar to that of MFG-E8. The phagocytic activity of NIH 3T3 cells against apoptotic cells was enhanced by Del-1 through an interaction between the epidermal growth factor domain in Del-1 and αvβ3 integrin expressed in the NIH 3T3 cells. Screening of primary macrophages and macrophage cell lines for the expression of MFG-E8 and Del-1 indicated that MFG-E8 and Del-1 are expressed in different sets of macrophages. These results suggest the existence of macrophage subsets that use MFG-E8 or Del-1 differently to engulf apoptotic cells.
Impairment of IL-12-Dependent STAT4 Nuclear Translocation in a Patient with Recurrent Mycobacterium avium Infection
Authors: Toyoda Hidemi , Ido Masaru , Hayashi Tatsuya , Gabazza Esteban C. , Suzuki Koji , Bu Jun , Tanaka Shigeki , Nakano Takashi , Kamiya Hitoshi , Chipeta James , Kisenge Rodrick R. , Kang Jian , Hori Hiroki , Komada Yoshihiro 
Published: April 2014

Abstract
We examined the immunological abnormality in a patient with recurrent Mycobacterium avium infection. T cells from the patient showed decreased ability both to produce IFN-γ and to proliferate in response to IL-12. Despite decreased expression of IL-12R β1 and β2 chains in the patient’s PHA-activated T cells, there was no difference in IL-12-induced tyrosine and serine phosphorylation of STAT4 in PHA-activated T cells between the patient and healthy subjects, suggesting that IL-12R signals are transmitted to STAT4 in the patient’s PHA-activated T cells. Using EMSA, confocal laser microscopy, and Western blotting, we demonstrated that the nuclear translocation of STAT4 in response to IL-12 is reduced in PHA-activated T cells from the patient when compared with those from healthy subjects. Leptomycin B was used to examine whether nuclear export of STAT4 is increased in the patient’s T cells. However, leptomycin B treatment did not reverse impaired IL-12-induced nuclear accumulation of STAT4. Although the exact mechanism responsible for the impaired STAT4 nuclear translocation in this patient remains unclear, the absence of mutation in the IL-12Rβ1, IL-12Rβ2, STAT4, and STAT4-binding sequence of the IFN-γ gene and preservation of STAT4 tyrosine and serine phosphorylation suggest the existence of a defective STAT4 nuclear translocation. This defect is likely responsible for the impaired STAT4 nuclear translocation in IL-12-stimulated T cells, leading to impairment of both IFN-γ production and cell proliferation. To the best of our knowledge, this is the first report of a patient with atypical mycobacterial infection associated with impairment of STAT4 nuclear translocation.
Survivin Enhances Fas Ligand Expression via Up-Regulation of Specificity Protein 1-Mediated Gene Transcription in Colon Cancer Cells
Authors: Asanuma Koichi , Tsuji Naoki , Endoh Teruo , Yagihashi Atsuhito , Watanabe Naoki 
Published: April 2014

Abstract
Cancer cells are thought to possess mechanisms for evading the host’s immune surveillance system. Survivin, a member of the inhibitor-of-apoptosis family overexpressed by cancer cells, inhibits Fas-mediated apoptosis induced by immune cells. In addition, cancer cells express Fas ligand (FasL) on their surfaces as a counterattack against immune cells. Mechanisms by which cancer cells express FasL, including involvement of survivin, are unclear. In the present study, we demonstrated that survivin up-regulated FasL expression and investigated how this might occur. Quantitative immunostaining showed correlation between survivin and FasL protein expression in colon cancer tissues (r = 0.79). FasL expression was up-regulated in LS180 colon cancer cells transfected with the survivin gene. Transfectants showed increased cytotoxicity against a Fas-sensitive human T leukemia cell line, Jurkat. In contrast, FasL expression was down-regulated in SW480 cells transfected with a small inhibitory RNA to prevent survivin expression. Survivin gene transfectants showed increased DNA binding of transcription factor specificity protein 1 (Sp1) to the FasL promoter, and up-regulation of Sp1 phosphorylation at serine and threonine residues; the total amount of Sp1 was unchanged. Thus, survivin enables cancer cells not only to suppress immune cell attack by inhibiting Fas-mediated apoptotic signaling, but to attack immune cells by induction of FasL.
Cutting Edge: CD96 (Tactile) Promotes NK Cell-Target Cell Adhesion by Interacting with the Poliovirus Receptor (CD155)
Authors: Fuchs Anja , Cella Marina , Giurisato Emanuele , Shaw Andrey S. , Colonna Marco 
Published: April 2014

Abstract
The poliovirus receptor (PVR) belongs to a large family of Ig molecules called nectins and nectin-like proteins, which mediate cell-cell adhesion, cell migration, and serve as entry receptors for viruses. It has been recently shown that human NK cells recognize PVR through the receptor DNAM-1, which triggers NK cell stimulation in association with β2 integrin. In this study, we show that NK cells recognize PVR through an additional receptor, CD96, or T cell-activated increased late expression (Tactile). CD96 promotes NK cell adhesion to target cells expressing PVR, stimulates cytotoxicity of activated NK cells, and mediates acquisition of PVR from target cells. Thus, NK cells have evolved a dual receptor system that recognizes nectins and nectin-like molecules on target cells and mediates NK cell adhesion and triggering of effector functions. As PVR is highly expressed in certain tumors, this receptor system may be critical for NK cell recognition of tumors.
Monomeric IgE Stimulates NFAT Translocation Into the Nucleus, a Rise in Cytosol Ca2+, Degranulation, and Membrane Ruffling in the Cultured Rat Basophilic Leukemia-2H3 Mast Cell Line
Authors: Pandey Vinita , Mihara Shoji , Fensome-Green Amanda , Bolsover Stephen , Cockcroft Shamshad 
Published: April 2014

Abstract
Mast cells are key regulators in allergy and inflammation, and release histamine, cytokines, and other proinflammatory mediators. In the classical view, IgE acts merely to prime mast cells, attaching to FcεRs but not evoking any cell signaling response until cross-linked by the presence of a multivalent allergen. However, several recent studies have reported that IgE alone can promote cell survival and cytokine production in the absence of cross-linking by allergen. In this study we demonstrate that acute addition of monomeric IgE elicits a wide spectrum of responses in the rat basophilic leukemia-2H3 mast cell line, including activation of phospholipases Cγ and D, a rise in cytosol Ca2+, NFAT translocation, degranulation, and membrane ruffling within minutes. Calcium transients persist for hours as long as IgE is present resulting in the maintained translocation of the transcription factor NFAT to the nucleus. Removal of IgE reverses the signaling processes. Our results indicate that, far from simply preparing the cells for a response to allergen, monomeric IgE can stimulate signaling pathways that lead to degranulation, membrane ruffling, and NFAT translocation. The mechanism of activation is likely to be via aggregation of the FcεR1 because activation by IgE can be inhibited with monovalent hapten.
Flt3 Ligand Preferentially Increases the Number of Functionally Active Myeloid Dendritic Cells in the Lungs of Mice
Authors: Masten Barbara J. , Olson Gwyneth K. , Kusewitt Donna F. , Lipscomb Mary F. 
Published: April 2014

AbstractIn the present study, we investigated the effects of in vivo Flt3L administration on the generation, phenotype, and function of lung dendritic cells (DCs) to evaluate whether Flt3L favors the expansion and maturation of a particular DC subset. Injection of Flt3L into mice resulted in an increased number of CD11c-expressing lung DCs, preferentially in the alveolar septa. FACS analysis allowed us to quantify a 19-fold increase in the absolute numbers of CD11c-positive, CD45R/B220 negative DCs in the lungs of Flt3L-treated mice over vehicle-treated mice. Further analysis revealed a 90-fold increase in the absolute number of myeloid DCs (CD11c positive, CD45R/B220 negative, and CD11b positive) and only a 3-fold increase of lymphoid DCs (CD11c positive, CD45R/B220 negative, and CD11b negative) from the lungs of Flt3L-treated mice over vehicle-treated mice. Flt3L-treated lung DCs were more mature than vehicle-treated lung DCs as demonstrated by a significantly higher percentage of cells expressing MHC class II, CD86, and CD40. Freshly isolated Flt3L lung DCs were not fully mature, because after an overnight culture they continued to increase accessory molecule expression. Functionally, Flt3L-treated lung DCs were more efficient than vehicle-treated DCs at stimulating naive T cell proliferation. Our data show that administration of Flt3L favors the expansion of myeloid lung DCs over lymphoid DCs and enhanced their ability to stimulate naive lymphocytes.
CD4+CD25+ Regulatory T Cells Control the Severity of Viral Immunoinflammatory Lesions
Authors: Suvas Susmit , Azkur Ahmet Kursat , Kim Bum Seok , Kumaraguru Uday , Rouse Barry T. 
Published: April 2014

AbstractCD4+CD25+ regulatory T cells (Treg) can inhibit a variety of autoimmune and inflammatory diseases, but their involvement in regulating virus-induced immunopathology is not known. We have evaluated the role of Treg in viral immunopathological lesion stromal keratitis. This frequent cause of human blindness results from a T cell-mediated immunoinflammatory response to HSV in the corneal stroma. The results show that lesions were significantly more severe if mice were depleted of Treg before infection. The Treg was also shown to modulate lesion expression induced by adoptive transfer of pathogenic CD4+ T cells in infected SCID recipients. The mechanism of Treg control of stromal keratitis involved suppressed antiviral immunity and impaired expression of the molecule required for T cell migration to lesion sites. Interestingly, Treg isolated from ocular lesions in nondepleted mice showed in vitro inhibitory effects involving IL-10, but were not very effective in established lesions. Our results decipher the in vivo role of Treg in a virus-induced immunopathology and imply that manipulation of regulatory cell function represents a useful approach to control viral-induced immunoinflammatory disease.
The Ly-6Chigh Monocyte Subpopulation Transports Listeria monocytogenes into the Brain during Systemic Infection of Mice
Authors: Drevets Douglas A. , Dillon Marilyn J. , Schawang Jennifer S. , van Rooijen Nico , Ehrchen Jan , Sunderkötter Cord , Leenen Pieter J. M. 
Published: April 2014

Abstract
Mononuclear phagocytes can be used by intracellular pathogens to disseminate throughout the host. In the bloodstream these cells are generically referred to as monocytes. However, blood monocytes are a heterogeneous population, and the exact identity of the leukocyte(s) relevant for microbial spreading is not known. Experiments reported in this study used Listeria monocytogenes-infected mice to establish the phenotype of parasitized blood leukocytes and to test their role in systemic dissemination of intracellular bacteria. More than 90% of the blood leukocytes that were associated with bacteria were CD11b+ mononuclear cells. Analysis of newly described monocyte subsets showed that most infected cells belonged to the Ly-6Chigh monocyte subset and that Ly-6Chigh and Ly-6Cneg-low monocytes harbored similar numbers of bacteria per cell. Interestingly, systemic infection with wild-type or ΔactA mutants of L. monocytogenes, both of which escape from phagosomes and replicate intracellularly, caused expansion of the Ly-6Chigh subset. In contrast, this was not evident after infection with Δhly mutants, which neither escape phagosomes nor replicate intracellularly. Importantly, when CD11b+ leukocytes were isolated from the brains of lethally infected mice, 88% of these cells were identified as Ly-6Chigh monocytes. Kinetic analysis showed a significant influx of Ly-6Chigh monocytes into the brain 2 days after systemic infection. This coincided with both bacterial invasion and up-regulation of brain macrophage chemoattractant protein-1 gene expression. These data indicate that the Ly-6Chigh monocyte subset transports L. monocytogenes into the brain and establish their role as Trojan horses in vivo.
Preferential HLA Usage in the Influenza Virus-Specific CTL Response
Authors: Boon Adrianus C. M. , de Mutsert Gerrie , Fouchier Ron A. M. , Sintnicolaas Kees , Osterhaus Albert D. M. E. , Rimmelzwaan Guus F. 
Published: April 2014

Abstract
To study whether individual HLA class I alleles are used preferentially or equally in human virus-specific CTL responses, the contribution of individual HLA-A and -B alleles to the human influenza virus-specific CTL response was investigated. To this end, PBMC were obtained from three groups of HLA-A and -B identical blood donors and stimulated with influenza virus. In the virus-specific CD8+ T cell population, the proportion of IFN-γ- and TNF-α-producing cells, restricted by individual HLA-A and -B alleles, was determined using virus-infected C1R cells expressing a single HLA-A or -B allele for restimulation of these cells. In HLA-B*2705- and HLA-B*3501-positive individuals, these alleles were preferentially used in the influenza A virus-specific CTL response, while the contribution of HLA-B*0801 and HLA-A*0101 was minor in these donors. The magnitude of the HLA-B*0801-restricted response was even lower in the presence of HLA-B*2705. C1R cells expressing HLA-B*2705, HLA-A*0101, or HLA-A*0201 were preferentially lysed by virus-specific CD8+ T cells. In contrast, the CTL response to influenza B virus was mainly directed toward HLA-B*0801-restricted epitopes. Thus, the preferential use of HLA alleles depended on the virus studied.
CD14 Is an Acute-Phase Protein
Authors: Bas Sylvette , Gauthier Benoit R. , Spenato Ursula , Stingelin Sybille , Gabay Cem 
Published: April 2014

Abstract
The origin of soluble CD14 (sCD14) in the circulation is uncertain. To examine whether CD14 could be an acute-phase protein (APP), the levels of sCD14, IL-6, and C-reactive protein were determined by ELISA in serum and synovial fluid (SF) of patients with various arthropathies, and the regulation of CD14 synthesis was examined in liver cells. In patients with crystal-mediated or immunologically mediated arthritis (rheumatoid arthritis), serum levels of sCD14 were higher than or similar to those found in infection-mediated arthritis (reactive arthritis), precluding a relation with bacteria exposure. Levels of sCD14 were similar in SF and serum, and did not correlate with the number of SF leukocytes, excluding an important source from leukocyte membrane-bound CD14, by protease-mediated shedding. In contrast, serum levels of sCD14 in patients correlated with those of C-reactive protein, a classical APP, and IL-6, a cytokine known to regulate the synthesis of APP in the liver. Serum levels of sCD14 also correlated with disease activity in rheumatoid arthritis and reactive arthritis patients. IL-6 stimulated the production of CD14 by HepG2 hepatoma cells. By real-time PCR, the inducibility of CD14 by IL-6 was also observed at the mRNA level both in HepG2 cells and human primary hepatocytes. These in vitro results were confirmed by in vivo studies in IL-6−/− mice injected with turpentine, an experimental model of acute-phase response. Liver levels of CD14 mRNA increased in IL-6+/+, but not in IL-6−/− mice. These results indicate that sCD14 can be considered as a type 2 APP.
Lysophosphatidic Acid Induces Chemotaxis, Oxygen Radical Production, CD11b Up-Regulation, Ca2+ Mobilization, and Actin Reorganization in Human Eosinophils via Pertussis Toxin-Sensitive G Proteins
Authors: Idzko Marco , Laut Martin , Panther Elisabeth , Sorichter Stephan , Dürk Thorsten , Fluhr Joachim W. , Herouy Yared , Mockenhaupt Maja , Myrtek Daniel , Elsner Peter , Norgauer Johannes 
Published: April 2014

Abstract
Lysophosphatidic acid (LPA) is a bioactive lipid mediator, which is generated by secretory type II phospholipase A2 and is thought to play a major role in the pathogenesis of atopic diseases. In this study, the biological activity of LPA on human eosinophils was characterized. We showed by reverse transcription and PCR that human eosinophils express the mRNA of the LPA receptors endothelial differentiation gene (EDG)-2 and EDG-7. Experiments revealed that LPA has chemotactic activity toward eosinophils, stimulates the production of reactive oxygen metabolites, and induces up-regulation of the integrin CD11b. Signal pathway measurements indicated Ca2+-mobilization from intracellular stores and transient actin polymerization upon stimulation with LPA. Cell responses elicited by LPA were inhibited by pertussis toxin indicating that in eosinophils the LPA receptor(s), presumably EDG-2 and/or EDG-7, are coupled to Gi/o proteins. Moreover, LPA-induced activation of eosinophils could be completely blocked by the EDG-2/EDG-7 antagonist diacylglycerol pyrophosphate. In addition, at optimal doses the changes induced by LPA were comparable to those obtained by the other well-characterized chemotaxins. These results indicate that LPA is a strong chemotaxin and activator of eosinophils. These findings point to a novel role of LPA in the pathogenesis of diseases with eosinophilic inflammation such as atopic diseases as chemotaxin as well as activator of proinflammatory effector functions.
Neutrophil Elastase (NE)-Deficient Mice Demonstrate a Nonredundant Role for NE in Neutrophil Migration, Generation of Proinflammatory Mediators, and Phagocytosis in Response to Zymosan Particles In Vivo
Authors: Young Rebecca E. , Thompson Richard D. , Larbi Karen Y. , La Mylinh , Roberts Clare E. , Shapiro Steven D. , Perretti Mauro , Nourshargh Sussan 
Published: April 2014

Abstract
Neutrophil elastase (NE) remains a controversial player in the process of leukocyte transmigration and much of this controversy stems from conflicting reports on the effects of NE inhibitors. The availability of NE-deficient mice (NE−/−) provides a clean and elegant tool for the study of leukocyte migration in vivo. In this study, NE−/− mice were used to investigate the role of NE in leukocyte migration through cremasteric venules, as observed by intravital microscopy, induced by locally administered cytokines IL-1β and TNF-α and the particulate stimulus, zymosan. Although no defects in leukocyte responses induced by the cytokines were observed, zymosan-induced leukocyte firm adhesion and transmigration was suppressed in NE−/− mice. These responses were also inhibited in wild-type mice when zymosan was coinjected with a specific NE inhibitor. Quantification of inflammatory mediator levels in homogenates of zymosan-stimulated tissues indicated reductions in levels of IL-1β, KC, and macrophage inflammatory protein-1α in NE−/− mice. Furthermore, phagocytosis of fluorescent zymosan particles, as observed by intravital microscopy, was diminished in NE-deficient animals. Collectively, the findings of this study indicate a nonredundant role for NE in zymosan-induced leukocyte firm adhesion and transmigration, and that this defect is associated with impaired generation of proinflammatory mediators as well as phagocytosis of zymosan particles in vivo.