bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monocyte Cell Surface Glycosaminoglycans Positively Modulate IL-4-Induced Differentiation toward Dendritic Cells
Authors: den Dekker Els , Grefte Sander , Huijs Tonnie , ten Dam Gerdy B. , Versteeg Elly M. M. , van den Berk Lieke C. J. , Bladergroen Bellinda A. , van Kuppevelt Toin H. , Figdor Carl G. , Torensma Ruurd 
Published: April 2014

Abstract
IL-4 induces the differentiation of monocytes toward dendritic cells (DCs). The activity of many cytokines is modulated by glycosaminoglycans (GAGs). In this study, we explored the effect of GAGs on the IL-4-induced differentiation of monocytes toward DCs. IL-4 dose-dependently up-regulated the expression of DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), CD80, CD206, and CD1a. Monocytes stained positive with Abs against heparan sulfate (HS) and chondroitin sulfate (CS) B (CSB; dermatan sulfate), but not with Abs that recognize CSA, CSC, and CSE. Inhibition of sulfation of monocyte/DC cell surface GAGs by sodium chlorate reduced the reactivity of sulfate-recognizing single-chain Abs. This correlated with hampered IL-4-induced DC differentiation as evidenced by lower expression of DC-SIGN and CD1a and a decreased DC-induced PBL proliferation, suggesting that sulfated monocyte cell surface GAGs support IL-4 activity. Furthermore, removal of cell surface chondroitin sulfates by chondroitinase ABC strongly impaired IL-4-induced STAT6 phosphorylation, whereas removal of HS by heparinase III had only a weak inhibitory effect. IL-4 bound to heparin and CSB, but not to HS, CSA, CSC, CSD, and CSE. Binding of IL-4 required iduronic acid, an N-sulfate group (heparin) and specific O sulfates (CSB and heparin). Together, these data demonstrate that monocyte cell surface chondroitin sulfates play an important role in the IL-4-driven differentiation of monocytes into DCs.
CD27 Defines Phenotypically and Functionally Different Human NK Cell Subsets
Authors: Vossen Mireille T. M. , Matmati Mourad , Hertoghs Kirsten M. L. , Baars Paul A. , Gent Mi-Ran , Leclercq Georges , Hamann Jörg , Kuijpers Taco W. , van Lier René A. W. 
Published: April 2014

Abstract
The absence of the TNF-receptor family member CD27 marks the stable acquisition of cytolytic effector functions by both CD4+ and CD8+ T cells. We found that the majority of circulating human NK cells was CD27−. These cells were largely CD56dim, contained high levels of perforin and granzyme B, and were able to exert strong cytotoxic activity. In contrast, circulating CD27+ NK cells were mostly CD56dim/bright, had significant lower levels of perforin and granzyme B, and had a low cytolytic potential. Primary and secondary lymphoid organs were markedly enriched for CD27+ NK cells. When correlating the expression of CD27 to recently defined developmental stages of NK cells in tonsil, we observed that CD27 was exclusively found on mature CD94+, stage 4 NK cells. On these cells, regulation of CD27 expression appeared to be controlled by the common γ-chain cytokine IL-15, and down-regulation of CD27 was specifically induced by its ligand, CD70. Thus, the absence of CD27 expression allows the definition of cytotoxic effector cells within the known mature NK cell subsets in humans.
IFN-β Provides Immuno-Protection in the Retina by Inhibiting ICAM-1 and CXCL9 in Retinal Pigment Epithelial Cells
Authors: Hooks John J. , Nagineni Chandrasekharam N. , Hooper Laura C. , Hayashi Kozaburo , Detrick Barbara 
Published: April 2014

Abstract
The retinal pigment epithelial (RPE) cell is a potent regulatory cell that facilitates normal physiologic processes and plays a critical role in a variety of retinal diseases. We evaluated IFN-β production in human RPE cells through TLR signaling and investigated the effects of IFN-β on RPE cells. RPE cells treated with poly(I:C) or infected with an RNA virus produce IFN-β. Kinetic studies revealed that IFN-β levels continue to increase over a 48-h period and this was associated with the up-regulation of IRF-7 gene expression, a known positive feedback molecule for IFN-β production. Microarray analysis revealed that in IFN-β treated cells, 480 genes of 22,283 genes were up or down-regulated by &gt;2-fold. We hypothesize that IFN-β induction during TLR signaling in the retina is an immunosuppressive factor produced to limit immunopathologic damage. Cytokine activation of RPE cells results in the production of the chemokines, CXCL9 and CXCL10, and the adhesion molecule, ICAM-1. Pretreatment of RPE cells with IFN-β resulted in inhibition of ICAM-1 production and elimination of CXCL9 production. This treatment did not alter CXCL10 production. Anti-IFN-β Ab blocked the inhibitory action of IFN-β. Real time PCR analysis revealed that IFN-β treatment inhibited gene expression of sICAM-1 and CXCL9. The results indicate a critical role for RPE cell derived IFN-β in the down-regulation of CXCL9 and ICAM-1 expression in the retina and suggest that the inhibition of CXCL9 is an immuno-suppressive mechanism that protects the retina from excessive inflammation.
A Specific Anti-Aire Antibody Reveals Aire Expression Is Restricted to Medullary Thymic Epithelial Cells and Not Expressed in Periphery
Authors: Hubert François-Xavier , Kinkel Sarah A. , Webster Kylie E. , Cannon Ping , Crewther Pauline E. , Proeitto Anna I. , Wu Li , Heath William R. , Scott Hamish S. 
Published: April 2014

AbstractAutoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is an autoimmune disorder caused by mutations in the autoimmune regulator gene AIRE. We examined the expression of Aire in different organs (thymus, spleen, and lymph nodes) in C57BL/6 mice, using a novel rat mAb, specific for murine Aire. Using flow cytometry, directly fluorochrome-labeled mAb revealed Aire expression in a rare thymic cellular subset that was CD45−, expressed low levels of Ly51, and was high for MHC-II and EpCam. This subset also expressed a specific pattern of costimulatory molecules, including CD40, CD80, and PD-L1. Immunohistochemical analysis revealed that Aire+ cells were specifically localized to the thymus or, more precisely, to the cortico-medulla junction and medulla, correlating with the site of negative selection. Although in agreement with previous studies, low levels of Aire mRNA was detected in all dendritic cell subtypes however lacZ staining, immunohistochemistry and flow cytometry failed to detect Aire protein. At a cellular level, Aire was expressed in perinuclear speckles within the nucleus. This report provides the first detailed analysis of Aire protein expression, highlighting the precise location at both the tissue and cellular level.
Differential Sensitivity to Itk Kinase Signals for T Helper 2 Cytokine Production and Chemokine-Mediated Migration
Authors: Sahu Nisebita , Mueller Cynthia , Fischer Angela , August Avery 
Published: April 2014

Abstract
Allergic asthma is dependent on chemokine-mediated Th2 cell migration and Th2 cytokine secretion into the lungs. The inducible T cell tyrosine kinase Itk regulates the production of Th2 cytokines as well as migration in response to chemokine gradients. Mice lacking Itk are resistant to developing allergic asthma. However, the role of kinase activity of Itk in the development of this disease is unclear. In addition, whether distinct Itk-derived signals lead to T cell migration and secretion of Th2 cytokines is also unknown. Using transgenic mice specifically lacking Itk kinase activity, we show that active kinase signaling is required for control of Th2 responses and development of allergic asthma. Moreover, dominant suppression of kinase Itk activity led to normal Th2 responses, but significantly reduced chemokine-mediated migration, resulting in prevention of allergic asthma. These observations indicate that signals required for Th2 responses and migration are differentially sensitive to Itk activity. Manipulation of Itk’s activity can thus provide a new strategy to treat allergic asthma by differentially affecting migration of T cells into the lungs, leaving Th2 responses intact.
TLR Agonists Promote Marginal Zone B Cell Activation and Facilitate T-Dependent IgM Responses
Authors: Rubtsov Anatoly V. , Swanson Cristina L. , Troy Scott , Strauch Pamela , Pelanda Roberta , Torres Raul M. 
Published: April 2014

Abstract
Although IgM serves as a first barrier to Ag spreading, the cellular and molecular mechanisms following B lymphocyte activation that lead to IgM secretion are not fully understood. By virtue of their anatomical location, marginal zone (MZ) B cells rapidly generate Ag-specific IgM in response to blood-borne pathogens and play an important role in the protection against these potentially harmful Ags. In this study, we have explored the contribution of TLR agonists to MZ B cell activation and mobilization as well as their ability to promote primary IgM responses in a mouse model. We demonstrate that diverse TLR agonists stimulate MZ B cells to become activated and leave the MZ through pathways that are differentially dependent on MyD88 and IFN-αβ receptor signaling. Furthermore, in vivo stimulation of MZ B cells with TLR agonists led to a reduction in the expression of the sphingosine-1-phosphate (S1P) receptors expressed by MZ B cells and/or increased CD69 cell surface levels. Importantly, as adjuvants for a T cell-dependent protein Ag, TLR agonists were found to accelerate the kinetics but not magnitude of the Ag-specific IgM response. Together, these data demonstrate that in vivo TLR agonist treatment enhances the early production of Ag-specific IgM and activates MZ B cells to promote their relocation.
A Role for CD8 in the Developmental Tuning of Antigen Recognition and CD3 Conformational Change
Authors: Gil Diana , Schrum Adam G. , Daniels Mark A. , Palmer Ed 
Published: April 2014

Abstract
TCR engagement by peptide-MHC class I (pMHC) ligands induces a conformational change (Δc) in CD3 (CD3Δc) that contributes to T cell signaling. We found that when this interaction took place between primary T lineage cells and APCs, the CD8 coreceptor was required to generate CD3Δc. Interestingly, neither enhancement of Ag binding strength nor Src kinase signaling explained this coreceptor activity. Furthermore, Ag-induced CD3Δc was developmentally attenuated by the increase in sialylation that accompanies T cell maturation and limits CD8 activity. Thus, both weak and strong ligands induced CD3Δc in preselection thymocytes, but only strong ligands were effective in mature T cells. We propose that CD8 participation in the TCR/pMHC interaction can physically regulate CD3Δc induction by “translating” productive Ag encounter from the TCR to the CD3 complex. This suggests one mechanism by which the developmentally regulated variation in CD8 sialylation may contribute to the developmental tuning of T cell sensitivity.
Structural and Biological Basis of CTL Escape in Coronavirus-Infected Mice
Authors: Butler Noah S. , Theodossis Alex , Webb Andrew I. , Dunstone Michelle A. , Nastovska Roza , Ramarathinam Sri Harsha , Rossjohn Jamie , Purcell Anthony W. , Perlman Stanley 
Published: April 2014

Abstract
Cytotoxic T lymphocyte escape occurs in many human infections, as well as mice infected with the JHM strain of mouse hepatitis virus, which exhibit CTL escape variants with mutations in a single epitope from the spike glycoprotein (S510). In all CTL epitopes prone to escape, only a subset of all potential variants is generally detected, even though many of the changes that are not selected would result in evasion of the T cell response. It is postulated that these unselected mutations significantly impair virus fitness. To define more precisely the basis for this preferential selection, we combine x-ray crystallographic studies of the MHC class I (Db)/S510 complexes with viral reverse genetics to identify a prominent TCR contact residue (tryptophan at position 4) prone to escape mutations. The data show that a mutation that is commonly detected in chronically infected mice (tryptophan to arginine) potently disrupts the topology of the complex, explaining its selection. However, other mutations at this residue, which also abrogate the CTL response, are never selected in vivo even though they do not compromise virus fitness in acutely infected animals or induce a significant de novo CTL response. Thus, while structural analyses of the S510/Db complex provide a strong basis for why some CTL escape variants are selected, our results also show that factors other than effects on virus fitness limit the diversification of CD8 T cell epitopes.
Autoantibody Profiling in Multiple Sclerosis Reveals Novel Antigenic Candidates
Authors: Somers Veerle , Govarts Cindy , Somers Klaartje , Hupperts Raymond , Medaer Rob , Stinissen Piet 
Published: April 2014

Abstract
An important contribution of B cells and autoantibodies has been demonstrated in the pathogenesis of multiple sclerosis (MS), leading to interest in the use of such autoantibodies as diagnostic or prognostic biomarkers. The objective of this study was to identify novel Ab biomarkers for MS using “serological Ag selection”. Using a phage display library derived from MS brain plaques, we applied serological Ag selection to identify antigenic targets specifically interacting with Abs present in the cerebrospinal fluid (CSF) of 10 relapsing-remitting MS patients. These antigenic targets were further evaluated on a large panel of CSF from 63 other MS patients, 30 patients with other inflammatory disorders, and 64 patients with noninflammatory neurological disorders. A panel of eight antigenic targets was identified that showed a 86% specificity and 45% sensitivity in discriminating MS patients and controls. Four of the antigenic targets showed exclusive reactivity (100% specificity; 23% sensitivity) in the MS group as compared with the control group. Detailed bio-informatic analyses revealed a novel Ag, SPAG16. Among the novel phage peptides identified, novel epitopes were generated from untranslated sequences and out-of-frame sequences. Of 10 relapsing-remitting patients used for serological Ag selection, Ab reactivity toward one of the eight antigenic targets was also demonstrated in serum of 38% CSF-positive patients. Autoantibody profiles against epitopes derived from MS brain tissue could serve as diagnostic markers or form the basis for the identification of a subgroup of MS patients.
Suppression of an Already Established Tumor Growing through Activated Mucosal CTLs Induced by Oral Administration of Tumor Antigen with Cholera Toxin
Authors: Wakabayashi Ayako , Nakagawa Yohko , Shimizu Masumi , Moriya Keiichi , Nishiyama Yasuhiro , Takahashi Hidemi 
Published: April 2014

AbstractPriming of CTLs at mucosal sites, where various tumors are originated, seems critical for controlling tumors. In the present study, the effect of the oral administration of OVA plus adjuvant cholera toxin (CT) on the induction of Ag-specific mucosal CTLs as well as their effect on tumor regression was investigated. Although OVA-specific TCRs expressing lymphocytes requiring in vitro restimulation to gain specific cytotoxicity could be detected by OVA peptide-bearing tetramers in both freshly isolated intraepithelial lymphocytes and spleen cells when OVA was orally administered CT, those showing direct cytotoxic activity without requiring in vitro restimulation were dominantly observed in intraepithelial lymphocytes. The magnitude of such direct cytotoxicity at mucosal sites was drastically enhanced after the second oral administration of OVA with intact whole CT but not with its subcomponent, an A subunit (CTA) or a B subunit (CTB). When OVA plus CT were orally administrated to C57BL/6 mice bearing OVA-expressing syngeneic tumor cells, E.G7-OVA, in either gastric tissue or the dermis, tumor growth was significantly suppressed after the second oral treatment; however, s.c. or i.p. injection of OVA plus CT did not show any remarkable suppression. Those mucosal OVA-specific CTLs having direct cytotoxicity expressed CD8αβ but not CD8αα, suggesting that they originated from thymus-educated cells. Moreover, the infiltration of such OVA-specific CD8+ CTLs was observed in suppressed tumor tissues. These results indicate that the growth of ongoing tumor cells can be suppressed by activated CD8αβ CTLs with tumor-specific cytotoxicity via an orally administered tumor Ag with a suitable mucosal adjuvant.
Identification of an N-Linked Glycosylation in the C4 Region of HIV-1 Envelope gp120 That Is Critical for Recognition of Neighboring CD4 T Cell Epitopes
Authors: Li Hualin , Chien Peter C. , Tuen Michael , Visciano Maria Luisa , Cohen Sandra , Blais Steven , Xu Chong-Feng , Zhang Hui-Tang , Hioe Catarina E. 
Published: April 2014

Abstract
The heavy glycosylation of HIV-1 envelope gp120 shields this important Ag from recognition by neutralizing Abs and cytolytic CD8 T cells. However, very little work has been done to understand the influence of glycosylation on the generation of gp120 epitopes and their recognition by MHC class II-restricted CD4 T cells. In this study, three conserved glycans (linked to N406, N448, and N463) flanking the C4 region of gp120 that contains many known CD4 T cell epitopes were disrupted individually or in combination by asparagine-to-glutamine substitutions. The mutant proteins lacking the N448 glycan did not effectively stimulate CD4 T cells specific for the nearby C4 epitopes, although the same mutants were recognized well by CD4 T cells specific for epitopes located in the distant C1 and C2 regions. The loss of recognition was not due to amino acid substitutions introduced to the mutant proteins. Data from trypsin digestion and mass spectrometry analyses demonstrated that the N448 glycan removal impeded the proteolytic cleavage of the nearby C4 region, without affecting more distant sites. Importantly, this inhibitory effect was observed only in the digestion of the native nondenatured protein and not in that of the denatured protein. These data indicate that the loss of the N448 glycan induces structural changes in the C4 region of gp120 that make this specific region more resistant to proteolytic processing, thereby restricting the generation of CD4 T cell epitopes from this region. Hence, N-linked glycans are critical determinants that can profoundly influence CD4 T cell recognition of HIV-1 gp120.
Activation of Human NK Cells by the Bacterial Pathogen-Associated Molecular Pattern Muramyl Dipeptide
Authors: Athié-Morales Verónica , O’Connor Geraldine M. , Gardiner Clair M. 
Published: April 2014

Abstract
Muramyl dipeptide (MDP) is a bacterial pathogen associated molecular pattern derived from both Gram-positive and -negative bacteria. It is a specific ligand for nuclear oligomerization domain 2, a pattern recognition receptor best characterized for its role in immunosurveillance in the gut. In this study, we demonstrate that human peripheral blood NK cells express nuclear oligomerization domain 2 and respond to MDP. NK cells naturally internalize MDP leading to direct cell activation, including signaling through NFκB: characterized by p50/p65 heterodimers at early stimulations times and sustained activation of p50 homodimers. Moreover, MDP synergizes with IFN-α and IL-12 to activate NK cells and stimulate IFN-γ secretion, suggesting a role for accessory cells in induction of an optimal NK cell response. Although IL-12 costimulation leads to a greater IFN-γ response by NK cells, higher levels of CD69 in response to MDP are induced in the presence of IFN-α, suggesting that different pathogen-induced cytokine profiles will affect downstream NK cell responses. In contrast, MDP alone or in combination with either IFN-α or IL-12 only poorly increases NK cell cytotoxicity. In summary, this report identifies MDP as a bacterial pathogen associated molecular pattern that activates human NK cells.
Hsp70 Translocates into the Plasma Membrane after Stress and Is Released into the Extracellular Environment in a Membrane-Associated Form that Activates Macrophages
Authors: Vega Virginia L. , Rodríguez-Silva Monica , Frey Tiffany , Gehrmann Mathias , Diaz Juan Carlos , Steinem Claudia , Multhoff Gabriele , Arispe Nelson , De Maio Antonio 
Published: April 2014

Abstract
Heat shock proteins (hsps) are intracellular chaperones that play a key role in the recovery from stress. Hsp70, the major stress-induced hsp, has been found in the extracellular medium and is capable of activating immune cells. The mechanism involved in Hsp70 release is controversial because this protein does not present a consensual secretory signal. In this study, we have shown that Hsp70 integrates into artificial lipid bilayer openings of ion conductance pathways. In addition, this protein was found inserted into the plasma membrane of cells after stress. Hsp70 was released into the extracellular environment in a membrane-associated form, sharing the characteristics of this protein in the plasma membrane. Extracellular membranes containing Hsp70 were at least 260-fold more effective than free recombinant protein in inducing TNF-α production as an indicator of macrophage activation. These observations suggest that Hsp70 translocates into the plasma membrane after stress and is released within membranous structures from intact cells, which could act as a danger signal to activate the immune system.
Neutrophil Chemokines KC and Macrophage-Inflammatory Protein-2 Are Newly Synthesized by Tissue Macrophages Using Distinct TLR Signaling Pathways
Authors: De Filippo Katia , Henderson Robert B. , Laschinger Melanie , Hogg Nancy 
Published: April 2014

Abstract
Neutrophils are the first immune cells to migrate into infected tissue sites. Therefore an important step in the initiation of an immune response is the synthesis of the neutrophil-recruiting chemokines. In this in vivo study in mice, we show that resident tissue macrophages are the source of the major neutrophil chemoattractants, KC and MIP-2. Synthesis of these chemokines is rapidly regulated at the transcriptional level by signaling through TLR2, TLR3, and TLR4 that have diverse specificities for pathogens. The major and alternative TLR signaling pathways are characterized by the adaptor proteins MyD88 or TRIF, respectively. KC and MIP-2 are both produced by signaling through MyD88. However MIP-2, but not KC, is also synthesized through the TRIF adaptor protein, identifying it as a new product of this alternative pathway. Use of both pathways by TLR4 ensures maximal levels of KC and MIP-2 that lead to robust neutrophil recruitment. However the MIP-2 generated exclusively by the TRIF pathway is still sufficient to cause an influx of neutrophils. In summary we show that TLR signaling by tissue macrophages directly controls the synthesis of neutrophil-attracting chemokines that are essential for the earliest recruitment step in the innate immune response to microbial challenge.