bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein Kinase R Regulates Double-Stranded RNA Induction of TNF-α But Not IL-1β mRNA in Human Epithelial Cells
Authors: Meusel Tiffany R. , Kehoe Kelly E. , Imani Farhad 
Published: April 2014

AbstractEpithelial cells represent the initial site of respiratory viral entry and the first line of defense against such infections. This early antiviral response is characterized by an increase in the production of proinflammatory cytokines such as TNF-α and IL-1β. dsRNA, which is a common factor present during the life cycle of both DNA and RNA viruses, is known to induce TNF-α and IL-1β in a variety of cells. In this work we provide data showing that dsRNA treatment induces TNF-α and IL-1β in human lung epithelial cells via two different mechanisms. Our data show that dsRNA activation of dsRNA-activated protein kinase (PKR) is associated with induction of TNF-α but not IL-1β expression. An inhibitor of PKR activation blocked the dsRNA-induced elevations in TNF-α but not IL-1β mRNA in epithelial cells. Data obtained from infection of epithelial cells with a vaccinia virus lacking the PKR inhibitory polypeptide, E3L, revealed that PKR activation was essential for TNF-α but not for IL-1β expression. In this report, we provide experimental support for the differential regulation of proinflammatory cytokine expression by dsRNA and viral infections in human airway epithelial cells.
Fgr Deficiency Results in Defective Eosinophil Recruitment to the Lung During Allergic Airway Inflammation
Authors: Vicentini Lucia , Mazzi Paola , Caveggion Elena , Continolo Silvia , Fumagalli Laura , Lapinet-Vera José A. , Lowell Clifford A. , Berton Giorgio 
Published: April 2014

Abstract
Using a mouse model of allergic lung inflammation, we found that mice deficient of Fgr, a Src family tyrosine kinase highly expressed in myelomonocytic cells, fail to develop lung eosinophilia in response to repeated challenge with aerosolized OVA. Both tissue and airway eosinophilia were markedly reduced in fgr−/− mice, whereas mice with the sole deficiency of Hck, another Src family member, responded normally. Release of allergic mediators, such as histamine, IL-4, RANTES/CCL5, and eotaxin/CCL11, in the airways of OVA-treated animals was equal in wild-type and fgr−/− mice. However, lung eosinophilia in Fgr-deficient mice correlated with a defective accumulation of GM-CSF and IL-5 in the airways, whereas secretion of these cytokines by spleen cells in response to OVA was normal. Examination of mRNA expression in whole lung tissue allowed us to detect comparable expression of transcripts for eotaxin/CCL11, macrophage-inflammatory protein-1α/CCL3, macrophage-inflammatory protein-1β/CCL4, monocyte chemoattractant protein-1/CCL2, TCA-3/CCL1, IL-4, IL-10, IL-2, IL-3, IL-9, IL-15, and IFN-γ in OVA-sensitized wild-type and fgr−/− mice. In contrast, the increase in IL-5 and IL-13 mRNA expression was lower in fgr−/− compared with wild-type mice. These findings suggest that deficiency of Fgr results in a marked reduction of lung eosinophilia and the establishment of a positive feedback loop based on autocrine secretion of eosinophil-active cytokines. These results identify Fgr as a novel pharmacological target to control allergic inflammation.
Absence of Platelet Endothelial Cell Adhesion Molecule-1 (CD31) Leads to Increased Severity of Local and Systemic IgE-Mediated Anaphylaxis and Modulation of Mast Cell Activation
Authors: Wong Mae-Xhum , Roberts Donna , Bartley Paul A. , Jackson Denise E. 
Published: April 2014

AbstractPlatelet endothelial cell adhesion molecule-1 (PECAM-1) is a newly assigned member of the Ig-immunoreceptor tyrosine-based inhibitory motif superfamily, and its functional role is suggested to be an inhibitory receptor that modulates immunoreceptor tyrosine-based activation motif-dependent signaling cascades. In this study, we hypothesized that PECAM-1 plays an essential in vivo role as a counterregulator of immediate hypersensitivity reactions. We found that PECAM-1 was highly expressed on the surface of immature bone marrow mast cells and at a lower density on mature peritoneal mast cells. Examination of skin biopsies from PECAM-1+/+ and PECAM-1−/− mice revealed that absence of PECAM-1 did not affect mast cell development or the capacity of mast cells to populate tissues. To examine whether the absence of PECAM-1 would influence immediate hypersensitivity reactions, PECAM-1+/+ and PECAM-1−/− mice were presensitized with anti-DNP mouse IgE and then challenged 20 h later with DNP-BSA or PBS. PECAM-1−/− mice exhibited elevated serum histamine concentrations after Ag stimulation compared with PECAM-1+/+ mice, indicating an increased severity of systemic IgE-mediated anaphylaxis. PECAM-1−/− mice have increased sensitivity to local cutaneous IgE-dependent anaphylaxis compared with PECAM-1+/+ mice, as assessed by greater tissue swelling of their ears and mast cell degranulation in situ. PECAM-1−/− bone marrow mast cells showed enhanced dense granule serotonin release after FcεRI cross-linking in vitro. These results suggest that PECAM-1 acts as a counterregulator in allergic disease susceptibility and severity and negatively modulates mast cell activation.
TGF-β1 as an Enhancer of Fas-Mediated Apoptosis of Lung Epithelial Cells
Authors: Hagimoto Naoki , Kuwano Kazuyoshi , Inoshima Ichiro , Yoshimi Michihiro , Nakamura Norio , Fujita Masaki , Maeyama Takashige , Hara Nobuyuki 
Published: April 2014

AbstractTransforming growth factor-β1 (TGF-β1) has important roles in lung fibrosis and the potential to induce apoptosis in several types of cells. We previously demonstrated that apoptosis of lung epithelial cells induced by Fas ligation may be involved in the development of pulmonary fibrosis. In this study, we show that TGF-β1 induces apoptosis of primary cultured bronchiolar epithelial cells via caspase-3 activation and down-regulation of cyclin-dependent kinase inhibitor p21. Concentrations of TGF-β1 that were not sufficient to induce apoptosis alone could enhance agonistic anti-Fas Ab or rFas ligand-mediated apoptosis of cultured bronchiolar epithelial cells. Soluble Fas ligand in the bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF) also induced apoptosis of cultured bronchiolar epithelial cells that was significantly attenuated by anti-TGF-β Ab. Otherwise, BALF from patients with hypersensitivity pneumonitis (HP) could not induce apoptosis on bronchiolar epithelial cells, despite its comparable amounts of soluble Fas ligand. The concentrations of TGF-β1 in BALF from patients with IPF were significantly higher compared with those in BALF from patients with HP or controls. Furthermore, coincubation with the low concentration of TGF-β1 and HP BALF created proapoptotic effects comparable with the IPF BALF. In vivo, the administration of TGF-β1 could enhance Fas-mediated epithelial cell apoptosis and lung injury via caspase-3 activation in mice. Our results demonstrate a novel role of TGF-β1 in the pathophysiology of pulmonary fibrosis as an enhancer of Fas-mediated apoptosis of lung epithelial cells.
Developmental and Functional Defects of Thymic and Epidermal Vγ3 Cells in IL-15-Deficient and IFN Regulatory Factor-1-Deficient Mice
Authors: De Creus An , Van Beneden Katrien , Stevenaert Frederik , Debacker Veronique , Plum Jean , Leclercq Georges 
Published: April 2014

AbstractIn this study, the role of IL-15 and its regulation by the transcription factor IFN regulatory factor-1 (IRF-1) in murine Vγ3 T cell development and activity is assessed. Compared with wild-type (WT) mice, reduced numbers of mature Vγ3 cells were found in the fetal thymus of IL-15−/− mice, while IRF-1−/− mice displayed normal frequencies. Vγ3+ dendritic epidermal T cells (DETCs) were absent in IL-15−/− mice but present in IRF-1−/− mice. DETCs from IRF-1−/− mice displayed morphologically a less mature phenotype and showed different emergence kinetics during ontogeny. This corresponded with lower IL-15 mRNA levels in the skin epidermis. Comparable levels of IL-7 were found in the skin of WT and IL-15−/− mice. Adoptive transfer experiments of WT fetal thymocytes into IL-15−/− mice did not result in the development of Vγ3+ DETCs, confirming the nonredundant role of IL-15 in the skin during DETC development. In vitro, cytolytic activity of IL-15−/− Vγ3 cells was normal after stimulation with IL-15 and was further enhanced by addition of IL-12. In contrast, cytolytic activity of IRF-1−/− Vγ3 cells remained defective after stimulation with IL-15 in combination with IL-12. These data suggest that IL-15 is redundant for the development and/or survival of mature Vγ3 cells in the fetal thymus, whereas it is essential for the localization of Vγ3 cells in the skin. Furthermore, a possible role for IRF-1 in inducing morphological maturation of DETCs and cytolytic capacity of Vγ3 cells is suggested.
Impaired Proliferative Response of Vα24 NKT Cells from Cancer Patients Against α-Galactosylceramide
Authors: Yanagisawa Kazuhiko , Seino Ken-ichiro , Ishikawa Yuriko , Nozue Mutsumi , Todoroki Takeshi , Fukao Katashi 
Published: April 2014

AbstractHuman invariant Vα24+ NKT cells are a relatively new subpopulation of lymphocytes. It has been reported that Vα24 NKT cells are significantly involved in some human diseases. We have evaluated the number and function of Vα24 NKT cells in both healthy volunteers and cancer patients. In this study we found that Vα24 NKT cells in unfractionated PBMCs obtained from cancer patients did not respond efficiently to α-galactosylceramide (α-GalCer) in vitro. Thus, their proportion after stimulation with α-GalCer was smaller than that found in healthy volunteers. However, the cancer patients’ Vα24 NKT cells retained cytotoxic activity against malignant target cells, and they could efficiently proliferate to α-GalCer when fractionated by sorting. Furthermore, we found that addition of G-CSF to the culture could restore the low proliferative response of Vα24 NKT cells from cancer patients. These results suggest that some functions of NKT cells in cancer patients are impaired, and this observation carries significant implications for immunotherapy-based cancer treatments.
Cutting Edge: In Vitro-Generated Tolerogenic APC Induce CD8+ T Regulatory Cells That Can Suppress Ongoing Experimental Autoimmune Encephalomyelitis
Authors: Faunce Douglas E. , Terajewicz Ania , Stein-Streilein Joan 
Published: April 2014

Abstract
APC exposed to TGFβ2 and Ag (tolerogenic APC) promote peripheral Ag-specific tolerance via the induction of CD8+ T regulatory cells capable of suppressing Th1 and Th2 immunity. We postulated that tolerogenic APC might reinstate tolerance toward self-neuronal Ags and ameliorate ongoing experimental autoimmune encephalomyelitis (EAE). Seven days after immunization with myelin basic protein (MBP), mice received MBP-specific tolerogenic APC, and EAE was evaluated clinically. To test for the presence and the phenotype of T regulatory cells, CD4 and/or CD8 T cells from tolerogenic APC-treated mice were transferred to naive mice before their immunization with MBP. The MBP-specific tolerogenic APC decreased both the severity and incidence of ongoing EAE. Tolerance to self-neuronal Ags was induced in naive recipient mice via adoptive transfer of CD8+, but not CD4+ T cells. Rational use of in vitro-generated tolerogenic APC may lead to novel therapy for autoimmune disease.
Cutting Edge: IL-26 Signals through a Novel Receptor Complex Composed of IL-20 Receptor 1 and IL-10 Receptor 2
Authors: Sheikh Faruk , Baurin Vitaliy V. , Lewis-Antes Anita , Shah Nital K. , Smirnov Sergey V. , Anantha Shubha , Dickensheets Harold , Dumoutier Laure , Renauld Jean-Christophe , Zdanov Alexander , Donnelly Raymond P. , Kotenko Sergei V. 
Published: April 2014

Abstract
The receptor for IL-26 (AK155), a cytokine of the IL-10 family, has not previously been defined. We demonstrate that the active receptor complex for IL-26 is a heterodimer composed of two receptor proteins: IL-20R1 and IL-10R2. Signaling through the IL-26R results in activation of STAT1 and STAT3 which can be blocked by neutralizing Abs against IL-20R1 or IL-10R2. IL-10R2 is broadly expressed on a wide variety of tissues, whereas only a limited number of tissues express IL-20R1. Therefore, the ability to respond to IL-26 is restricted by the expression of IL-20R1. IL-10, IL-19, IL-20, IL-22, and IL-24 fail to signal through the combination of IL-10R2 and IL-20R1 proteins, demonstrating that this receptor combination is unique and specific for IL-26.
Cutting Edge: T Cells Trigger CD40-Dependent Platelet Activation and Granular RANTES Release: A Novel Pathway for Immune Response Amplification
Authors: Danese Silvio , de la Motte Carol , Reyes Brenda M. Rivera , Sans Miquel , Levine Alan D. , Fiocchi Claudio 
Published: April 2014

Abstract
Platelets, in addition to exerting hemostatic activity, contribute to immunity and inflammation. The recent report that platelets express CD40 led us to hypothesize that CD40 ligand (CD40L)-positive T cells could bind to platelets, cause their activation, and trigger granular RANTES release, creating a T cell recruitment feedback loop. Platelets were cocultured with resting or activated autologous T cells and their activation was assessed by P-selectin expression. RANTES binding to endothelial cells was assessed by confocal microscopy, and its biological activity was demonstrated by a T cell adhesion assay. CD40L-positive T cells induced platelet activation through a contact-mediated, CD40-dependent pathway resulting in RANTES release, which bound to endothelial cells and mediated T cell recruitment. Soluble CD40L induced the same events via p38, but not extracellular signal-regulated kinase, phosphorylation. These results show the existence of a novel platelet-dependent pathway of immune response amplification which brings these nonimmune cells close to the level of pathogenic relevance traditionally attributed to classical immune cells.
Visualizing the Site and Dynamics of IgG Salvage by the MHC Class I-Related Receptor, FcRn
Authors: Ober Raimund J. , Martinez Cruz , Vaccaro Carlos , Zhou Jinchun , Ward E. Sally 
Published: April 2014

Abstract
The MHC class I-related receptor, FcRn, plays a central role in regulating the serum levels of IgG. FcRn is expressed in endothelial cells, suggesting that these cells may be involved in maintaining IgG levels. We have used live cell imaging of FcRn-green fluorescent protein transfected human endothelial cells to analyze the intracellular events that control IgG homeostasis. We show that segregation of FcRn-IgG complexes from unbound IgG occurs in the sorting endosome. FcRn or FcRn-IgG complexes are gradually depleted from sorting endosomes to ultimately generate multivesicular bodies whose contents are destined for lysosomal degradation. In addition, the pathways taken by FcRn and the transferrin receptor overlap, despite distinct mechanisms of ligand uptake. The studies provide a dynamic view of the trafficking of FcRn and its ligand and have relevance to understanding how FcRn functions to maintain IgG homeostasis.
Visualization of Antigen Presentation by Actin-Mediated Targeting of Glycolipid-Enriched Membrane Domains to the Immune Synapse of B Cell APCs
Authors: Gordy Claire , Mishra Sudha , Rodgers William 
Published: April 2014

Abstract
Glycolipid-enriched membrane (GEM) domains, or lipid rafts, function in signaling in immune cells, but their properties during Ag presentation are less clear. To address this question, GEM domains were studied using fluorescence cell imaging of mouse CH27 B cells presenting Ag to D10 T cells. Our experiments showed that APCs were enriched with GEM domains in the immune synapse, and this occurred in an actin-dependent manner. This enrichment was specific to GEM domains, because a marker for non-GEM regions of the membrane was excluded from the immune synapse. Furthermore, fluorescence photobleaching experiments showed that protein in the immune synapse was dynamic and rapidly exchanged with that in other compartments of CH27 cells. To identify the signals for targeting GEM domains to the immune synapse in APCs, capping of the domains was measured in cells after cross-linking surface molecules. This showed that co-cross-linking CD48 with MHC class II was required for efficient capping and intracellular signaling. Capping of GEM domains by co-cross-linking CD48 and MHC class II occurred with co-capping of filamentous actin, and both domain capping and T cell-CH27 cell conjugation were inhibited by pretreating CH27 cells with latrunculin B. Furthermore, disruption of the actin cytoskeleton of the CH27 cells also inhibited formation of a mature immune synapse in those T cells that did conjugate to APCs. Thus, Ag presentation and efficient T cell stimulation occur by an actin-dependent targeting of GEM domains in the APC to the site of T cell engagement.
Inhibitory Effect of Toll-Like Receptor 4 on Fusion between Phagosomes and Endosomes/Lysosomes in Macrophages
Authors: Shiratsuchi Akiko , Watanabe Ikuko , Takeuchi Osamu , Akira Shizuo , Nakanishi Yoshinobu 
Published: April 2014

Abstract
Toll-like receptor 4 (TLR4) of macrophages recognizes LPS of Gram-negative bacteria in cooperation with CD14, which is also involved in the recognition of apoptotic cells. In this study we asked whether TLR4 plays a role in the phagocytic clearance of apoptotic cells by macrophages. Macrophages were prepared from peritoneal fluid of thioglycolate-treated mice carrying either a wild-type or a disrupted TLR4-encoding gene and were examined for their ability to phagocytose apoptotic mouse thymocytes, apoptotic Jurkat T cells, Ig-opsonized mouse thymocytes, Ig-opsonized zymosan particles, and latex beads. Both populations of macrophages equally expressed CD14 on their surfaces and showed almost equal activities of binding to and engulfing all these targets. However, apoptotic thymocytes, apoptotic Jurkat cells, and opsonized thymocytes disappeared more rapidly in TLR4-deficient macrophages than in wild-type macrophages, and the fusion between endosomes/lysosomes and phagosomes containing any target cells or particles was accelerated in mutant macrophages. Activation of the transcription factor NF-κB appeared not to occur in wild-type macrophages after engulfment, and the rate of apoptotic cell degradation in wild-type macrophages remained the same regardless of the activation of NF-κB. Finally, immunohistochemical analyses showed that ectopically expressed TLR4 was associated with phagosomes in a macrophage-derived cell line. All these results collectively indicate that TLR4 negatively regulates the degradation of engulfed cells in macrophages via a pathway independent of NF-κB.
IL-21 Induces the Functional Maturation of Murine NK Cells
Authors: Brady Jason , Hayakawa Yoshihiro , Smyth Mark J. , Nutt Stephen L. 
Published: April 2014

Abstract
IL-21 is a recently identified cytokine that stimulates mouse NK cell effector functions in vitro. In this study we demonstrate that IL-21 achieves its stimulatory effect by inducing the development of mature NK cells into a large granular lymphocyte phenotype with heightened effector function. IL-21 treatment results in increased cell size and granularity and a corresponding decrease in cell viability and proliferative potential. These cells up-regulate the expression of the inhibitory CD94-NKG2A receptor complex and the activation markers CD154 and killer cell, lectin-like-receptor G1. Surprisingly, IL-21 treatment also results in down-regulation of the pan-NK marker, NK1.1. Coinciding with these cellular changes IL-21 enhances cytolytic capacity across a spectrum of target sensitivities and induces IL-10 and IFN-γ production. In vivo treatment with IL-21 results in a very similar activation and phenotypic maturation of NK cells as well as a potent increase in NK cell-mediated anti-tumor immunity that is perforin dependent. These developmental changes suggested that IL-21 functions to induce the terminal differentiation of mouse NK cells, resulting in heightened NK cell-mediated cytotoxicity and immune surveillance.
NF-κB-Inducing Kinase Establishes Self-Tolerance in a Thymic Stroma-Dependent Manner
Authors: Kajiura Fumiko , Sun Shijie , Nomura Takashi , Izumi Keisuke , Ueno Tomoo , Bando Yoshimi , Kuroda Noriyuki , Han Hongwei , Li Yi , Matsushima Akemi , Takahama Yousuke , Sakaguchi Shimon , Mitani Tasuku , Matsumoto Mitsuru 
Published: April 2014

Abstract
Physical contact between thymocytes and the thymic stroma is essential for T cell maturation and shapes the T cell repertoire in the periphery. Stromal elements that control these processes still remain elusive. We used a mouse strain with mutant NF-κB-inducing kinase (NIK) to examine the mechanisms underlying the breakdown of self-tolerance. This NIK-mutant strain manifests autoimmunity and disorganized thymic structure with abnormal expression of Rel proteins in the stroma. Production of immunoregulatory T cells that control autoreactive T cells was impaired in NIK-mutant mice. The autoimmune disease seen in NIK-mutant mice was reproduced in athymic nude mice by grafting embryonic thymus from NIK-mutant mice, and this was rescued by supply of exogenous immunoregulatory T cells. Impaired production of immunoregulatory T cells by thymic stroma without normal NIK was associated with altered expression of peripheral tissue-restricted Ags, suggesting an essential role of NIK in the thymic microenvironment in the establishment of central tolerance.
Mechanisms Governing B Cell Developmental Defects in Invariant Chain-Deficient Mice
Authors: Benlagha Kamel , Park Se-Ho , Guinamard Rodolphe , Forestier Claire , Karlsson Lars , Chang Cheong-Hee , Bendelac Albert 
Published: April 2014

Abstract
Invariant chain (Ii)-deficient mice exhibit profound B cell defects that have remained poorly understood, because they could not be simply explained by impaired Ag presentation. We found that Ii deficiency induced cell autonomous defects of two distinct B cell lineages. The life span of mature follicular (FO) B cells was reduced, accounting for their markedly decreased frequency, whereas, in contrast, marginal zone (MZ) B cells accumulated. Other Ii-expressing lineages such as B1 B cells and dendritic cells were unaffected. Surprisingly, the life span of FO B cells was fully corrected in Ii/I-Aβ doubly deficient mice, revealing that Ii-free I-Aβ chains alter FO B cell survival. In contrast, the accumulation of MZ B cells was controlled by a separate mechanism independent of I-Aβ. Interestingly, in Ii-deficient mice lacking FO B cells, the MZ B cells invaded the FO zone, suggesting that intact follicules contribute to the retention of B cells in the MZ. These findings reveal unexpected consequences of Ii deficiency on the development and organization of B cell follicles.
Complete Loss of Fas Ligand Gene Causes Massive Lymphoproliferation and Early Death, Indicating a Residual Activity of gld Allele
Authors: Karray Saoussen , Kress Chantal , Cuvellier Sylvain , Hue-Beauvais Catherine , Damotte Diane , Babinet Charles , Lévi-Strauss Matthieu 
Published: April 2014

Abstract
To investigate the in vivo function of Fas ligand (FasL), we produced a mouse strain with a FasL gene flanked by loxP sequences. Mice with homozygous floxed FasL gene showed no obvious abnormalities. However, germline deletion of the FasL gene, obtained after mating with mice expressing ubiquitous Cre recombinase, resulted in an unexpectedly severe phenotype. FasL−/− mice exhibited an extreme splenomegaly and lymphadenopathy associated with lymphocytic infiltration into multiple organs and autoimmune disease. This severe phenotype led to the premature death at 4 mo of age of &gt;50% of the homozygous mice. It stands in sharp contrast with the milder disease observed in gld (generalized lymphoproliferative disease) mice, indicating that the FasL allele of these mice encodes a protein still able to bind, albeit at a very low level, the Fas receptor.