bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heme Oxygenase-1 Mediates the Anti-Inflammatory Effects of Acute Alcohol on IL-10 Induction Involving p38 MAPK Activation in Monocytes
Authors: Drechsler Yvonne , Dolganiuc Angela , Norkina Oxana , Romics Laszlo , Li Weibo , Kodys Karen , Bach Fritz H. , Mandrekar Pranoti , Szabo Gyongyi 
Published: April 2014

Abstract
Inflammation and immunoregulatory cytokines play a central role in alcohol-induced liver damage. We previously reported that acute alcohol treatment augments IL-10 and inhibits TNF-α production in monocytes. Heme oxygenase-1 (HO-1), a stress-inducible protein, also regulates IL-10 and TNF-α production. Here, we report that augmentation of LPS-induced IL-10 production by alcohol was prevented by inhibition of HO-1 activity. Acute ethanol increased LPS-induced enzyme activity and RNA levels of HO-1, and DNA binding of AP-1, a transcription factor essential in HO-1 regulation. LPS-induced phospho-p38 MAPK levels were augmented by ethanol treatment and the p38 inhibitor, SB203580, prevented both the ethanol-induced increase in IL-10 production and the inhibitory effect of ethanol on TNF-α production. Ethanol-induced down-regulation of TNF-α production was abrogated by inhibition of HO-1. We found that LPS-induced activation of NF-κB, a regulator of TNF-α, was inhibited by both ethanol treatment and HO-1 activation, but the ethanol-induced inhibition of NF-κB was HO-1 independent. In LPS-challenged mice in vivo, both acute alcohol administration and HO-1 activation augmented IL-10 and inhibited TNF-α serum levels. These results show that 1) acute alcohol augments HO-1 activation in monocytes, 2) HO-1 activation plays a role in alcohol-induced augmentation of IL-10 production likely via increased p38 MAPK activation, and 3) HO-1 activation is involved in attenuation of TNF-α production by alcohol independent of inhibition of NF-κB activation by alcohol. Thus, HO-1 activation is a key mediator of the anti-inflammatory effects of acute alcohol on monocytes.
Combinatorial SNARE Complexes Modulate the Secretion of Cytoplasmic Granules in Human Neutrophils
Authors: Mollinedo Faustino , Calafat Jero , Janssen Hans , Martín-Martín Belén , Canchado Javier , Nabokina Svetlana M. , Gajate Consuelo 
Published: April 2014

Abstract
Mobilization of human neutrophil granules is critical for the innate immune response against infection and for the outburst of inflammation. Human neutrophil-specific and tertiary granules are readily exocytosed upon cell activation, whereas azurophilic granules are mainly mobilized to the phagosome. These cytoplasmic granules appear to be under differential secretory control. In this study, we show that combinatorial soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes with vesicle-associated membrane proteins (VAMPs), 23-kDa synaptosome-associated protein (SNAP-23), and syntaxin 4 underlie the differential mobilization of granules in human neutrophils. Specific and tertiary granules contained VAMP-1, VAMP-2, and SNAP-23, whereas the azurophilic granule membranes were enriched in VAMP-1 and VAMP-7. Ultrastructural, coimmunoprecipitation, and functional assays showed that SNARE complexes containing VAMP-1, VAMP-2, and SNAP-23 mediated the rapid exocytosis of specific/tertiary granules, whereas VAMP-1 and VAMP-7 mainly regulated the secretion of azurophilic granules. Plasma membrane syntaxin 4 acted as a general target SNARE for the secretion of the distinct granule populations. These data indicate that at least two SNARE complexes, made up of syntaxin 4/SNAP-23/VAMP-1 and syntaxin 4/SNAP-23/VAMP-2, are involved in the exocytosis of specific and tertiary granules, whereas interactions between syntaxin 4 and VAMP-1/VAMP-7 are involved in the exocytosis of azurophilic granules. Our data indicate that quantitative and qualitative differences in SNARE complex formation lead to the differential mobilization of the distinct cytoplasmic granules in human neutrophils, and a higher capability to form diverse SNARE complexes renders specific/tertiary granules prone to exocytosis.
High-Affinity Ligand Probes of CD22 Overcome the Threshold Set by cis Ligands to Allow for Binding, Endocytosis, and Killing of B Cells
Authors: Collins Brian E. , Blixt Ola , Han Shoufa , Duong Bao , Li Hongyi , Nathan Jay K. , Bovin Nicolai , Paulson James C. 
Published: April 2014

Abstract
CD22 (Siglec-2) is a key regulator of B cell signaling whose function is modulated by interaction with extracellular glycan ligands mediated through its N-terminal Ig domain. Its preferred ligand is the sequence Siaα2-6Gal that is abundantly expressed on N-linked glycans of B cell glycoproteins, and by binding to CD22 in cis causes CD22 to appear “masked” from binding to synthetic sialoside probes. Yet, despite the presence of cis ligands, CD22 redistributes to sites of cell contact by binding to trans ligands on neighboring cells. In this study, we demonstrate the dynamic equilibrium that exists between CD22 and its cis and trans ligands, using a high-affinity multivalent sialoside probe that competes with cis ligands and binds to CD22 on native human and murine B cells. Consistent with the constitutive endocytosis reported for CD22, the probes are internalized once bound, demonstrating that CD22 is an endocytic receptor that can carry ligand-decorated “cargo” to intracellular compartments. Conjugation of the sialoside probes to the toxin saporin resulted in toxin uptake and toxin-mediated killing of B lymphoma cell lines, suggesting an alternative approach for targeting CD22 for treatment of B cell lymphomas.
Simvastatin Treatment Ameliorates Autoimmune Disease Associated with Accelerated Atherosclerosis in a Murine Lupus Model
Authors: Aprahamian Tamar , Bonegio Ramon , Rizzo Jennifer , Perlman Harris , Lefer David J. , Rifkin Ian R. , Walsh Kenneth 
Published: April 2014

Abstract
Patients with systemic lupus erythematosus develop accelerated atherosclerosis independent of traditional risk factors. The 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors are widely prescribed for hyperlipidemia, but they also exhibit anti-inflammatory actions that appear to be independent of their suppressive actions on plasma cholesterol levels. In this study, we analyzed the effect of the HMG-CoA reductase inhibitor simvastatin on disease manifestations in gld.apoE−/− mice that lack functional Fas ligand and apolipoprotein E and exhibit accelerated atherosclerosis and aggravated lupus-like features. Wild-type, gld, apoE−/−, and gld.apoE−/− mice were maintained on a high cholesterol Western diet and received daily simvastatin (0.125 mg/kg) or saline for 12 wk. Serum cholesterol levels were unaffected by simvastatin treatment, but atherosclerotic lesion area was reduced in both apoE−/− and gld.apoE−/− mice treated with simvastatin. Simvastatin also reduced the lymphadenopathy, renal disease, and proinflammatory cytokine production seen in gld.apoE−/−, but not gld, mice. The immunomodulatory effects in gld.apoE−/− mice were associated with enhanced STAT6 and decreased STAT4 induction in submandibular lymph node cells. Along with reductions in serum TNF-α and IFN-γ levels, there was also an increase in IL-4 and IL-10 transcript levels in lymph nodes. These data indicate that HMG-CoA reductase inhibitors ameliorate atherosclerosis and lupus-like autoimmunity independent of their cholesterol-lowering effects via a shift from a Th1 to a Th2 phenotype in the gld.apoE−/− model. Thus, the anti-inflammatory activities of statins may have utility for the treatment of both autoimmunity and atherosclerosis in patients with systemic lupus erythematosus.
Membrane-Associated TGF-β1 Inhibits Human Memory T Cell Signaling in Malignant and Nonmalignant Inflammatory Microenvironments
Authors: Broderick Lori , Bankert Richard B. 
Published: April 2014

Abstract
TGF-β1 is present on cells derived from the microenvironment of human lung tumors and nonmalignant inflammatory tissues. We establish that this cell-associated cytokine mediates hyporesponsiveness of the memory T cells in these microenvironments in situ by blocking TCR signaling. T cells derived from these tissues failed to translocate NF-κB to the nucleus in response to CD3 + CD28 cross-linking. This nonresponsiveness was reversed by an anti-TGF-β1-neutralizing Ab. Refractoriness of the memory T cells to TCR activation was also reversed by the removal of TGF-β1 by briefly pulsing the cells in a low pH buffer. Addition of exogenous TGF-β1 to eluted T cells re-established their nonresponsive state. Neither TGF-β1, anti-TGF-β1 Ab, nor low pH affected TCR signaling potential of peripheral blood T cells. We conclude that TGF-β1 mediates a physiologically relevant regulatory mechanism, selective for memory T cells present in the tumor microenvironment and nonmalignant chronic inflammatory tissues.
Structural Basis for the Interaction of CCR5 with a Small Molecule, Functionally Selective CCR5 Agonist
Authors: Saita Yuji , Kodama Eiichi , Orita Masaya , Kondo Mitsuhiro , Miyazaki Takahiro , Sudo Kenji , Kajiwara Keiko , Matsuoka Masao , Shimizu Yasuaki 
Published: April 2014

Abstract
The chemokine receptor CCR5 is an attractive target for HIV-1 drug development, as individuals whose cells lack surface CCR5 expression are highly resistant to HIV-1 infection. CCR5 ligands, such as CCL5/RANTES, effectively inhibit HIV-1 infection by competing for binding opportunities to the CCR5 and inducing its internalization. However, the inherent proinflammatory activity of the chemotactic response of CCR5 ligands has limited their clinical use. In this study, we found that a novel small molecule, functionally selective CCR5 agonist, 2,2-dichloro-1-(triphenylphosphonio)vinyl formamide perchlorate (YM-370749), down-modulates CCR5 from the cell surface without inducing a chemotactic response and inhibits HIV-1 replication. In molecular docking studies of YM-370749 and a three-dimensional model of CCR5 based on the rhodopsin crystal structure as well as binding and functional studies using various CCR5 mutants, the amino acid residues necessary for interaction with YM-370749 were marked. These results provide a structural basis for understanding the activation mechanism of CCR5 and for designing functionally selective agonists as a novel class of anti-HIV-1 agents.
Human Cytomegalovirus-Encoded UL16 Discriminates MIC Molecules by Their α2 Domains
Authors: Spreu Jessica , Stehle Thilo , Steinle Alexander 
Published: April 2014

Abstract
Human CMV infection results in MHC class I down-regulation and induction of NKG2D ligand expression favoring NK recognition of infected cells. However, human CMV-encoded UL16 counteracts surface expression of several NKG2D ligands by intracellular retention. Interestingly, UL16 interacts with MICB, but not with the closely related MICA, and with UL16-binding proteins (ULBP) ULBP1 and ULBP2, which are only distantly related to MICB, but not with ULPB3 or ULBP4, although all constitute ligands for NKG2D. Here, we dissected the molecular basis of MICA-MICB discrimination by UL16 to elucidate its puzzling binding behavior. We report that the UL16-MICB interaction is independent of glycosylation and demonstrate that selective MICB recognition by UL16 is governed by helical structures of the MICB α2 domain. Transplantation of the MICB α2 domain confers UL16 binding capacity to MICA, and thus, diversification of the MICA α2 domain may have been driven by the selective pressure exerted by UL16.
Dengue Virus Induces Expression of CXC Chemokine Ligand 10/IFN-γ-Inducible Protein 10, Which Competitively Inhibits Viral Binding to Cell Surface Heparan Sulfate
Authors: Chen Jia-Perng , Lu Hsin-Lin , Lai Szu-Liang , Campanella Gabriele S. , Sung Jui-Ming , Lu Mei-Yi , Wu-Hsieh Betty A. , Lin Yi-Ling , Lane Thomas E. , Luster Andrew D. , Liao Fang 
Published: April 2014

AbstractDengue virus is an arthropod-borne flavivirus that causes a mild febrile illness, dengue fever, or a potentially fatal syndrome, dengue hemorrhagic fever/dengue shock syndrome. Chemokines primarily orchestrate leukocyte recruitment to the areas of viral infection, which makes them critical mediators of immune and inflammatory responses. In the present study, we investigated the induction and function of chemokines in mice early after infection with dengue virus in vivo. We found that CXCL10/IFN-γ-inducible protein 10 (IP-10) expression was rapidly and transiently induced in liver following infection. The expressed CXCL10/IP-10 likely mediates the recruitment of activated NK cells, given that anti-CXCL10/IP-10-treated mice showed diminished NK cell infiltration and reduced hepatic expression of effector molecules in activated NK cells after dengue virus infection. Of particular interest, we found that CXCL10/IP-10 also was able to inhibit viral binding to target cells in vitro. Further investigation revealed that various CXCL10/IP-10 mutants, in which the residues that mediate the interaction between the chemokine and heparan sulfate were substituted, failed to exert the inhibitory effect on dengue binding, which suggests that CXCL10/IP-10 competes with dengue virus for binding to heparan sulfate on the cell surface. Moreover, subsequent plaque assays showed that this inhibition of dengue binding blocked viral uptake and replication. The inhibitory effect of CXCL10/IP-10 on the binding of dengue virus to cells may represent a novel contribution of this chemokine to the host defense against viral infection.
Processing and Presentation of a Mycobacterial Antigen 85B Epitope by Murine Macrophages Is Dependent on the Phagosomal Acquisition of Vacuolar Proton ATPase and In Situ Activation of Cathepsin D
Authors: Singh Christopher R. , Moulton Rachel A. , Armitige Lisa Y. , Bidani Akhil , Snuggs Mark , Dhandayuthapani Subramanian , Hunter Robert L. , Jagannath Chinnaswamy 
Published: April 2014

Abstract
Mycobacterium tuberculosis (strain H37Rv) and bacillus Calmette-Guérin (BCG) vaccine inhibit phagosome maturation in macrophages and their effect on processing, and presentation of a secreted Ag85 complex B protein, Ag85B, by mouse macrophages was analyzed. Macrophages were infected with GFP-expressing mycobacterial strains and analyzed for in situ localization of vacuolar proton ATPase (v-ATPase) and cathepsin D (Cat D) using Western blot analysis and immunofluorescence. H37Rv and BCG phagosomes excluded the v-ATPase and maintained neutral pH while the attenuated H37Ra strain acquired v-ATPase and acidified. Mycobacterial phagosomes acquired Cat D, although strains BCG and H37Rv phagosomes contained the inactive 46-kDa form, whereas H37Ra phagosomes had the active 30-kDa form. Infected macrophages were overlaid with a T cell hybridoma specific for an Ag85B epitope complexed with MHC class II. Coincident with active Cat D, H37Ra-infected macrophages presented the epitope to T cells inducing IL-2, whereas H37Rv- and BCG-infected macrophages were less efficient in IL-2 induction. Bafilomycin inhibited the induction of macrophage-induced IL-2 from T cells indicating that v-ATPase was essential for macrophage processing of Ag85B. Furthermore, the small interfering RNA interference of Cat D synthesis resulted in a marked decrease in the levels of macrophage-induced IL-2. Thus, a v-ATPase-dependent phagosomal activation of Cat D was required for the generation of an Ag85B epitope by macrophages. Reduced processing of Ag85B by H37Rv- and BCG-infected macrophages suggests that phagosome maturation arrest interferes with the efficient processing of Ags in macrophages. Because Ag85B is immunodominant, this state may lead to a decreased ability of the wild-type as well as the BCG vaccine to induce protective immunity.
Bone Marrow Stromal Cell Antigen 2 Is a Specific Marker of Type I IFN-Producing Cells in the Naive Mouse, but a Promiscuous Cell Surface Antigen following IFN Stimulation
Authors: Blasius Amanda L. , Giurisato Emanuele , Cella Marina , Schreiber Robert D. , Shaw Andrey S. , Colonna Marco 
Published: April 2014

Abstract
Type I IFN-producing cells (IPC) are sentinels of viral infections. Identification and functional characterization of these cells have been difficult because of their small numbers in blood and tissues and their complex cell surface phenotype. To overcome this problem in mice, mAbs recognizing IPC-specific cell surface molecules have been generated. In this study, we report the identification of new Abs specific for mouse IPC, which recognize the bone marrow stromal cell Ag 2 (BST2). Interestingly, previously reported IPC-specific Abs 120G8 and plasmacytoid dendritic cell Ag-1 also recognize BST2. BST2 is predominantly specific for mouse IPC in naive mice, but is up-regulated on most cell types following stimulation with type I IFNs and IFN-γ. The activation-induced promiscuous expression of BST2 described in this study has important implications for the use of anti-BST2 Abs in identification and depletion of IPC. Finally, we show that BST2 resides within an intracellular compartment corresponding to the Golgi apparatus, and may be involved in trafficking secreted cytokines in IPC.
Type 1 IFN Deficiency in the Absence of Normal Splenic Architecture during Lymphocytic Choriomeningitis Virus Infection
Authors: Louten Jennifer , van Rooijen Nico , Biron Christine A. 
Published: April 2014

AbstractThe innate immune system uses different mechanisms to respond to infectious pathogens. Experiments evaluating the requirements for a type 1 IFN (IFN-αβ) response to lymphocytic choriomeningitis virus (LCMV) resulted in the surprising discovery that mice deficient in B and T cell development, i.e., RAG-deficient and SCID, had profoundly reduced levels of IFN-αβ in serum and spleen, despite high viral replication. In addition to lacking an adaptive immune system, these strains exhibit aberrant splenic architecture, and the defect in type 1 IFN production was also observed in mice lacking normal splenic marginal zone (MZ) organization due to genetic deficiencies in B cell development or in cytokine functions required for development of the MZ, i.e., μMT, lymphotoxin-α, and TNFR1. Interestingly, the IFN-αβ reduction was not observed after murine CMV infection. Depletion of phagocytic cells from normally developed spleens by treatment with clodronate-containing liposomes demonstrated that these populations were required for the type 1 IFN response to LCMV, but not to murine CMV, and for control of viral replication. Complete repopulation of the MZ was necessary to restore normal IFN-αβ production. In contrast, control of LCMV replication correlated with the return of CD11c+ cells. Taken together, these results demonstrate the complexity and sophistication of the splenic MZ in sensing and responding to particular pathogens and reveal the importance of organ architecture in the production of type 1 IFN.
Synchrony of High Endothelial Venules and Lymphatic Vessels Revealed by Immunization
Authors: Liao Shan , Ruddle Nancy H. 
Published: April 2014

Abstract
The mature phenotype of peripheral lymph node (LN) high endothelial venules (HEVs), defined as MAdCAM-1lowPNAdhighLTβRhigh HEC-6SThigh, is dependent on signaling through the lymphotoxin-β receptor (LTβR). Plasticity of PLN HEVs during immunization with oxazolone was apparent as a reversion to an immature phenotype (MAdCAM-1highPNAdlowLTβRlow HEC-6STlow) followed by recovery to the mature phenotype. The recovery was dependent on B cells and was inhibited by LTβR-Ig treatment. Concurrent with HEV reversion, at day 4 following oxazolone or OVA immunization, reduced accumulation of Evans blue dye and newly activated DCs in the draining LNs revealed a temporary afferent lymphatic vessel (LV) functional insufficiency. T cell priming to a second Ag was temporarily inhibited. At day 7, lymphangiogenesis peaked in both the skin and draining LN, and afferent LV function was restored at the same time as HEV phenotype recovery. This process was delayed in the absence of B cells. LV and HEV both express the LTβR. During lymphangiogenesis in the draining LN, HEV, and LV were directly apposed; some vessels appeared to express both PNAd and LYVE-1. Pretreatment with LTβR-Ig drastically reduced the number of PNAd+LYVE-1+ vessels, suggesting a reduction in LV and HEV cross-talk. The concordance in time and function and the close physical contact between LVs and HEVs in the remodeling process after immunization indicate that the two vascular systems are in synchrony and engage in cross-talk through B cells and LTβR.
Leukotriene B4 Receptors BLT1 and BLT2: Expression and Function in Human and Murine Mast Cells
Authors: Lundeen Katherine A. , Sun Binggang , Karlsson Lars , Fourie Anne M. 
Published: April 2014

AbstractLeukotriene B4 (LTB4) is a potent activator and chemoattractant for leukocytes and is implicated in several inflammatory diseases. The actions of LTB4 are mediated by two cell surface receptors, BLT1, which is predominantly expressed in peripheral blood leukocytes, and BLT2, which is expressed more ubiquitously. Recently, BLT1 expression and LTB4-dependent chemotaxis have been reported in immature mast cells (MCs). We now show the first evidence for BLT2 mRNA expression, in addition to BLT1, in murine bone marrow-derived MCs (mBMMCs) and in a human MC line (HMC-1). Protein expression of BLT1 was confirmed by mAb staining in HMC-1 cells and shown to be predominantly intracellular. Both HMC-1 cells and mBMMCs migrated to LTB4 in a dose-dependent manner in chemotaxis assays. Migration to LTB4 could be inhibited by either a BLT1- or BLT2-selective antagonist. Significant dose-dependent migration of mBMMCs also was observed to 12-(S)-hydroxyeicosotetraenoic acid, a BLT2-selective agonist, demonstrating functional BLT2 activity in these cells. Stimulation of mBMMCs with LTB4 induced transient, dose-dependent, ERK phosphorylation and changes in Akt phosphorylation. Dose-dependent ERK phosphorylation also was observed in response to 12-(S)-hydroxyeicosotetraenoic acid, indicating signaling downstream of BLT2. Pretreatment of mBMMCs with stem cell factor significantly down-regulated expression of BLT1 and BLT2 mRNA and inhibited their migration to LTB4. This study demonstrates expression of functional LTB4 receptors, both BLT1 and BLT2, in murine and human MCs and a regulatory role for stem cell factor in their expression. These receptors may mediate recruitment and accumulation of MCs in response to LTB4 production in areas of inflammation.