bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of Macrophage Nitric Oxide Production by Gram-Negative Flagellin Involves Signaling Via Heteromeric Toll-Like Receptor 5/Toll-Like Receptor 4 Complexes
Authors: Mizel Steven B. , Honko Anna N. , Moors Marlena A. , Smith Pameeka S. , West A. Phillip 
Published: April 2014

AbstractThe induction of cytokine synthesis by flagellin is mediated by a Toll-like receptor 5 (TLR5) signaling pathway. Although flagellin activation of the IL-1R-associated kinase and induction of TNF-α synthesis are dependent on TLR5 and not TLR4, we have found that flagellin stimulates NO in macrophages via a pathway that requires TLR5 and TLR4. Flagellin induced NO synthesis in HeNC2 cells, a murine macrophage cell line that expresses wild-type TLR4, but not in TLR4-mutant or -deficient GG2EE and 10ScNCr/23 cells. Flagellin stimulated an increase in inducible NO synthase (iNOS) mRNA and activation of the iNOS promoter. TLR5 forms heteromeric complexes with TLR4 as well as homomeric complexes. IFN-γ permitted GG2EE and 10ScNCr/23 cells to produce NO in response to flagellin. Flagellin stimulated IFN-β synthesis and Stat1 activation. The effect of flagellin on iNOS gene expression was inhibited by a Stat1 mutant protein. Taken together, these results support the conclusions that flagellin induces distinct patterns of inflammatory mediators depending on the nature of the TLR5 signaling complex and that the induction of NO by flagellin involves signaling via TLR5/TLR4 complexes.
Activation of NF-κB in Virus-Infected Macrophages Is Dependent on Mitochondrial Oxidative Stress and Intracellular Calcium: Downstream Involvement of the Kinases TGF-β-Activated Kinase 1, Mitogen-Activated Kinase/Extracellular Signal-Regulated Kinase Kinase 1, and IκB Kinase
Authors: Mogensen Trine H. , Melchjorsen Jesper , Höllsberg Per , Paludan Søren R. 
Published: April 2014

AbstractEfficient clearance of virus infections depends on the nature of the host response raised by the infected organism. A proinflammatory cell-mediated immune response is important for elimination of many viruses, including herpesviruses. Macrophages are intimately involved in generation of a proinflammatory response, the initiation of which involves activation of the transcription factor NF-κB. However, the mechanisms of HSV-induced NF-κB activation are poorly understood. In this study we demonstrate that activation of NF-κB by HSV in macrophages is dependent on a functional viral genome and proceeds through a mechanism involving the cellular IκB kinase, as well as the upstream kinases TGF-β-activated kinase 1, mitogen-activated kinase/extracellular signal-regulated kinase kinase 1, and possibly NF-κB-inducing kinase. Furthermore, we show that HSV triggers NF-κB activation by a signaling pathway involving oxidative stress in mitochondria and intracellular calcium, because specific inhibition of mitochondria-derived reactive oxygen intermediates, as well as mitochondrial calcium channels, prevented NF-κB activation. Together, these results point to mitochondria as cellular checkpoints able to initiate NF-κB activation after virus infection and also show that the cellular NF-κB-regulating kinases IκB kinase, TGF-β-activated kinase 1, mitogen-activated kinase/extracellular signal-regulated kinase kinase 1, and possibly NF-κB-inducing kinase, are essential components in the HSV-induced signaling pathway.
Corneal IL-8 Expression Following Adenovirus Infection Is Mediated by c-Src Activation in Human Corneal Fibroblasts
Authors: Natarajan Kanchana , Rajala Maitreyi S. , Chodosh James 
Published: April 2014

Abstract
Emerging evidence indicates that intracellular signaling cascades mediate entry of pathogenic adenoviruses into target host cells as well as some of the undesirable inflammatory responses to adenoviral gene vectors. We found that Ad19 infection of cultured human corneal fibroblasts induced IL-8 gene transcription independently of IL-1β, TNF-α, and viral gene expression, suggesting that intracellular signaling events might mediate early inflammatory events in adenovirus keratitis. Heat but not UV light inactivation of the virus abrogated the effect of infection on IL-8 mRNA and protein levels, consistent with a viral binding-mediated mechanism. The tyrosine kinase inhibitor herbimycin blocked Ad19-induced IL-8 expression. Western blot analysis revealed tyrosine phosphorylation of the functionally related kinases c-Src and extracellular signal-regulated kinase (ERK) 1/2 in corneal fibroblasts within 15 min after infection. Respective inhibitors of these kinases, PP2 and PD98059, also blocked Ad19-induced IL-8 mRNA and protein expression. Application of inhibitors to Src and ERK kinase assays suggested an upstream relationship of c-Src to ERK. Finally, DNA microarray studies performed 1 h after Ad19 or mock infection of corneal fibroblasts in the presence or absence of the Src-specific inhibitor PP2 confirmed a relationship between c-Src and IL-8 expression in Ad19-infected corneal cells. c-Src may act as a global regulator of early proinflammatory host responses to Ad19 infection of the human cornea.
Differential Regulation of Lipopolysaccharide-Induced Monocyte Matrix Metalloproteinase (MMP)-1 and MMP-9 by p38 and Extracellular Signal-Regulated Kinase 1/2 Mitogen-Activated Protein Kinases
Authors: Lai Wan-Ching , Zhou Min , Shankavaram Uma , Peng Gang , Wahl Larry M. 
Published: April 2014

AbstractSignal transduction events in monocyte matrix metalloproteinase (MMP) production have been shown to include a PGE2-cAMP-dependent step. To determine earlier pathway components, we examined the role of mitogen-activated protein kinases (MAPKs) in the regulation of monocyte MMP-1 and MMP-9, two major MMPs induced by LPS. Stimulation with LPS resulted in the activation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) and mitogen-activated kinase p38. The p38-specific inhibitor SB203580 suppressed p38 activity and MMP-1 mRNA and protein, but increased ERK activity and MMP-9 mRNA and protein. In contrast, the MAPK kinase 1/2-specific inhibitor PD98059 inhibited MMP-1 and MMP-9. However, both MAPK inhibitors decreased the production of cyclooxygenase-2 and PGE2, but only the inhibition of MMP-1 by SB203580 was reversed by PGE2 or dibutyryl cAMP. Examination of the effect of these MAPK inhibitors on the promoters of MMP-1 and MMP-9 revealed that PD98059 inhibited the binding of transcription factors to all of the MMP promoter-specific complementary oligonucleotides tested. However, SB203580 only inhibited the binding of MMP-1-specific CREB and SP 1 oligonucleotides, which was reversed by PGE2. Additionally, SB203580 enhanced transcription factor binding to the oligonucleotides complementary to a NF-κB site in the promoter of MMP-9. Thus, LPS induction of MMP-1 production by monocytes is regulated by both ERK1/2 and p38, whereas MMP-9 stimulation occurred mainly through the ERK1/2 pathway. Moreover, p38 regulates MMP-1 mainly through a PGE2-dependent pathway, whereas ERK1/2-mediated MMP-1 and MMP-9 production involves the activation of additional MMP promoter sites through a PGE2-independent mechanism.
A Prominent Role for Airway Epithelial NF-κB Activation in Lipopolysaccharide-Induced Airway Inflammation
Authors: Poynter Matthew E. , Irvin Charles G. , Janssen-Heininger Yvonne M. W. 
Published: April 2014

Abstract
To reveal the causal role of airway epithelial NF-κB activation in evoking airway inflammation, a transgenic mouse was created expressing a mutant version of the inhibitory protein I-κBα. This I-κBα superrepressor (I-κBαSR) acts to repress NF-κB activation exclusively in airway epithelial cells, under the transcriptional control of the rat CC10 promoter (CC10-I-κBαSR). Compared with transgene-negative littermates, intranasal instillation of LPS did not induce nuclear translocation of NF-κB in airway epithelium of CC10-I-κBαSR transgenic mice. Consequently, the influx of neutrophils into the airways and secretion of the NF-κB-regulated neutrophilic chemokine, macrophage-inflammatory protein-2, and the inflammatory cytokine, TNF-α, were markedly reduced in CC10-I-κBαSR mice relative to the transgene-negative mice exposed to LPS. Despite an inability to activate NF-κB in airway epithelium, resident alveolar macrophages from transgene-positive mice were capable of activating NF-κB in a manner indistinguishable from transgene-negative mice. These findings demonstrate that airway epithelial cells play a prominent role in orchestrating the airway inflammatory response to LPS and suggest that NF-κB signaling in these cells is important for modulating innate immune responses to microbial products.
Differential Activation of NF-κB, AP-1, and C/EBP in Endotoxin-Tolerant Rats: Mechanisms for In Vivo Regulation of Glomerular RANTES/CCL5 Expression
Authors: Pocock Johanna , Gómez-Guerrero Carmen , Harendza Sigrid , Ayoub Murwan , Hernández-Vargas Purificación , Zahner Gunther , Stahl Rolf A. K. , Thaiss Friedrich 
Published: April 2014

AbstractChemokines play a pivotal role in the regulation of inflammatory cell infiltration in glomerular immune injury. To characterize mechanisms relevant for the regulation of chemokine expression in vivo, the LPS-mediated model of renal inflammation in rats was used in which we have previously demonstrated that the chemokine RANTES/CCL5 is expressed and secreted in glomeruli. Glomerular RANTES/CCL5 expression in this model correlated with an increased glomerular binding activity of the transcription factors AP-1, C/EBP, and NF-κB. To gain further insight into the functional roles of these transcription factors in the regulation of glomerular RANTES/CCL5 expression, we cloned the rat RANTES/CCL5 promoter and established the model of in vivo LPS tolerance. In tolerant rats, LPS-induced glomerular RANTES/CCL5 expression and activation of the transcription factors AP-1 and C/EBP were significantly reduced using both consensus and rat RANTES/CCL5-specific oligonucleotides. Reduced glomerular NF-κB binding activity after LPS injection could be demonstrated in tolerant rats only when using rat RANTES/CCL5-specific oligonucleotides. Reduced binding activity to this RANTES/CCL5-specific NF-κB binding site in the context of broad NF-κB activation might be due to changes in transcription factor interactions or chromatin remodeling processes.
Fas Is Detectable on β Cells in Accelerated, But Not Spontaneous, Diabetes in Nonobese Diabetic Mice
Authors: Darwiche Rima , Chong Mark M. W. , Santamaria Pere , Thomas Helen E. , Kay Thomas W. H. 
Published: April 2014

AbstractFas (CD95) is a potential mechanism of pancreatic β cell death in type 1 diabetes. β cells do not constitutively express Fas but it is induced by cytokines. The hypothesis of this study is that Fas expression should be measurable on β cells for them to be killed by this mechanism. We have previously reported that up to 5% of β cells isolated from nonobese diabetic (NOD) mice are positive for Fas expression by flow cytometry using autofluorescence to identify β cells. We have now found that these are not β cells but contaminating dendritic cells, macrophages, and B lymphocytes. In contrast β cells isolated from NODscid mice that are recipients of T lymphocytes from diabetic NOD mice express Fas 18–25 days after adoptive transfer but before development of diabetes. Fas expression on β cells was also observed in BDC2.5, 8.3, and 4.1 TCR-transgenic models of diabetes in which diabetes occurs more rapidly than in unmodified NOD mice. In conclusion, Fas is observed on β cells in models of diabetes in which rapid β cell destruction occurs. Its expression is likely to reflect differences in the intraislet cytokine environment compared with the spontaneous model and may indicate a role for this pathway in β cell destruction in rapidly progressive models.
Chemokines Determine Local Lymphoneogenesis and a Reduction of Circulating CXCR4+ T and CCR7 B and T Lymphocytes in Thyroid Autoimmune Diseases
Authors: Armengol Maria-Pilar , Cardoso-Schmidt Cristina B. , Fernández Marco , Ferrer Xavier , Pujol-Borrell Ricardo , Juan Manel 
Published: April 2014

AbstractChemokines and their corresponding receptors are crucial for the recruitment of lymphocytes into the lymphoid organs and for its organization acting in a multistep process. Tissues affected by autoimmune disease often contain ectopic lymphoid follicles which, in the case of autoimmune thyroid disorders, are highly active and specific for thyroid Ags although its pathogenic role remains unclear. To understand the genesis of these lymphoid follicles, the expression of relevant cytokines and chemokines was assessed by real time PCR, immunohistochemistry and by in vitro assays in autoimmune and nonautoimmune thyroid glands. Lymphotoxin α, lymphotoxin β, C-C chemokine ligand (CCL) 21, CXC chemokine ligand (CXCL) 12, CXCL13, and CCL22 were increased in thyroids from autoimmune patients, whereas CXCL12, CXCL13, and CCL22 levels were significantly higher in autoimmune glands with ectopic secondary lymphoid follicles than in those without follicles. Interestingly, thyroid epithelium produced CXCL12 in response to proinflammatory cytokines providing a possible clue for the understanding of how tissue stress may lead to ectopic follicle formation. The finding of a correlation between chemokines and thyroid autoantibodies further suggests that intrathyroidal germinal centers play a significant role in the autoimmune response. Unexpectedly, the percentage of circulating CXCR4+ T cells and CCR7+ B and T cells (but not of CXCR5) was significantly reduced in PBMCs of patients with autoimmune thyroid disease when they were compared with their intrathyroidal lymphocytes. This systemic effect of active intrathyroidal lymphoid tissue emerges as a possible new marker of thyroid autoimmune disease activity.
Irradiation of Tumor Cells Up-Regulates Fas and Enhances CTL Lytic Activity and CTL Adoptive Immunotherapy
Authors: Chakraborty Mala , Abrams Scott I. , Camphausen Kevin , Liu Kebin , Scott Tamalee , Coleman C. Norman , Hodge James W. 
Published: April 2014

Abstract
CD8+ CTL play important roles against malignancy in both active and passive immunotherapy. Nonetheless, the success of antitumor CTL responses may be improved by additional therapeutic modalities. Radiotherapy, which has a long-standing use in treating neoplastic disease, has been found to induce unique biologic alterations in cancer cells affecting Fas gene expression, which, consequently, may influence the overall lytic efficiency of CTL. Here, in a mouse adenocarcinoma cell model, we examined whether exposure of these tumor cells to sublethal doses of irradiation 1) enhances Fas expression, leading to more efficient CTL killing via Fas-dependent mechanisms in vitro; and 2) improves antitumor activity in vivo by adoptive transfer of these Ag-specific CTL. Treatment of carcinoembryonic Ag-expressing MC38 adenocarcinoma cells with irradiation (20 Gy) in vitro enhanced Fas expression at molecular, phenotypic, and functional levels. Furthermore, irradiation sensitized these targets to Ag-specific CTL killing via the Fas/Fas ligand pathway. We examined the effect of localized irradiation of s.c. growing tumors on the efficiency of CTL adoptive immunotherapy. Irradiation caused up-regulation of Fas by these tumor cells in situ, based on immunohistochemistry. Moreover, localized irradiation of the tumor significantly potentiated tumor rejection by these carcinoembryonic Ag-specific CTL. Overall, these results showed for the first time that 1) regulation of the Fas pathway in tumor cells by irradiation plays an important role in their sensitization to Ag-specific CTL; and 2) a combination regimen of tumor-targeted irradiation and CTL promotes more effective antitumor responses in vivo, which may have implications for the combination of immunotherapy and radiation therapy.
Identification of a Mutated Receptor-Like Protein Tyrosine Phosphatase κ as a Novel, Class II HLA-Restricted Melanoma Antigen
Authors: Novellino Luisa , Renkvist Nicolina , Rini Francesca , Mazzocchi Arabella , Rivoltini Licia , Greco Angela , Deho Paola , Squarcina Paola , Robbins Paul F. , Parmiani Giorgio , Castelli Chiara 
Published: April 2014

AbstractRecent studies increasingly point to a pivotal role of CD4+ T cells in human anti-tumor immune response. Here we show that lymphocytes purified from a tumor-infiltrated lymph node of a melanoma patient that had remained disease free for 10 years after surgical resection of a lymph node metastasis comprised oligoclonal class II HLA-restricted CD4+ T cells recognizing the autologous tumor cells in vitro. In fact, the CD4+ T cell clones isolated from these lymphocytes displayed a tumor-specific, cytotoxic activity in addition to a Th1-like cytokine profile. By a genetic approach, a peptide derived from a mutated receptor-like protein tyrosine phosphatase κ was identified as a novel HLA-DR10-restricted epitope for all the melanoma-specific CD4+ T cell clones. The immunogenic peptide was shown to contain the mutated residue that was crucial for T cell recognition and activation. Moreover, a systemic immunity against the mutated peptide was detectable in the patient’s peripheral blood T lymphocytes obtained during the disease-free period of follow-up. These findings further support the relevance of CD4+ T cells directed against mutated epitopes in tumor immunity and provide the rationale for a possible usage of mutated, tumor-specific Ags for immunotherapy of human cancer.
IL-10 Modulates Host Responses and Lung Damage Induced byPneumocystis cariniiInfection
Authors: Qureshi Mahboob H. , Harmsen Allen G. , Garvy Beth A. 
Published: April 2014

AbstractHost responses to Pneumocystis carinii infection mediate impairment of pulmonary function and contribute to the pathogenesis of pneumonia. IL-10 is known to inhibit inflammation and reduce the severity of pathology caused by a number of infectious organisms. In the present studies, IL-10-deficient (IL-10 knockout (KO)) mice were infected with P. carinii to determine whether the severity of pathogenesis and the efficiency of clearance of the organisms could be altered in the absence of IL-10. The clearance kinetics of P. carinii from IL-10 KO mice was significantly enhanced compared with that of wild-type (WT) mice. This corresponded to a more intense CD4+ and CD8+ T cell response as well as an earlier neutrophil response in the lungs of IL-10 KO mice. Furthermore, IL-12, IL-18, and IFN-γ were found in the bronchoalveolar lavage fluids at earlier time points in IL-10 KO mice suggesting that alveolar macrophages were activated earlier than in WT mice. However, when CD4+ cells were depleted from P. carinii-infected IL-10 KO mice, the ability to enhance clearance was lost. Furthermore, CD4-depleted IL-10 KO mice had significantly more lung injury than CD4-depleted WT mice even though the intensity of the inflammatory responses was similar. This was characterized by increased vascular leakage, decreased oxygenation, and decreased arterial pH. These data indicate that IL-10 down-regulates the immune response to P. carinii in WT mice; however, in the absence of CD4+ T cells, IL-10 plays a critical role in controlling lung damage independent of modulating the inflammatory response.
Autocrine Type I IFN and Contact with Endothelium Promote the Presentation of Influenza A Virus by Monocyte-Derived APC
Authors: Qu Chunfeng , Moran Thomas M. , Randolph Gwendalyn J. 
Published: April 2014

AbstractPurified monocytes infected with influenza A virus do not become mature dendritic cells (DCs) and they present viral peptides poorly to autologous memory T cells. In this study, we investigated whether influenza A-infected monocytes matured to DCs with a high capacity to stimulate T cells when they were infected with influenza A virus in a model tissue setting wherein they were cocultured with endothelium grown on a type I collagen matrix. Intercellular interactions with endothelium strongly promoted the Ag-presenting capacity of monocyte-derived cells infected with influenza A virus, and the heterologous coculture system also enhanced production of IFN-α by monocytes in the absence of plasmacytoid cells. Production of IFN-α in the presence of endothelium correlated with monocyte differentiation to mature DCs and their ability to stimulate proliferation and IFN-γ production by autologous T cells. Monocyte-derived cells that developed into migratory DCs promoted proliferation of influenza A virus-specific CD4+ and CD8+ cells, whereas those that developed into macrophages promoted proliferation of CD8+ T cells only. This onset of APC activity could be partially blocked with Ab to the IFN-αβ receptor when monocytes were infected with UV-treated virus, but neutralizing this pathway was inconsequential when monocytes were infected with live virus. Thus, type I IFN and direct contact with endothelium promote development of influenza A virus-presenting activity in monocyte-derived cells in a setting in which this differentiation does not depend on plasmacytoid cells. However, when infected with live influenza virus, the role of type I IFN in mediating differentiation and Ag-presenting capacity is expendable, apparently due to other mechanisms of virus-mediated activation.
Acceleration of Human Neutrophil Apoptosis by TRAIL
Authors: Renshaw Stephen A. , Parmar Jasvir S. , Singleton Vanessa , Rowe Sarah J. , Dockrell David H. , Dower Steven K. , Bingle Colin D. , Chilvers Edwin R. , Whyte Moira K. B. 
Published: April 2014

AbstractNeutrophil granulocytes have a short lifespan, with their survival limited by a constitutive program of apoptosis. Acceleration of neutrophil apoptosis following ligation of the Fas death receptor is well-documented and TNF-α also has a transient proapoptotic effect. We have studied the role of the death receptor ligand TRAIL in human neutrophils. We identified the presence of mRNAs for TRAIL, TRAIL-R2, and TRAIL-R3, and cell surface expression of TRAIL-R2 and -R3 in neutrophil populations. Neutrophil apoptosis is specifically accelerated by exposure to a leucine zipper-tagged form of TRAIL, which mimics cell surface TRAIL. Using blocking Abs to TRAIL receptors, specifically TRAIL-R2, and a TRAIL-R1:FcR fusion protein, we have excluded a role for TRAIL in regulating constitutive neutrophil apoptosis. No additional proapoptotic effect of leucine zipper TRAIL was identified following TRAIL treatment of neutrophils in the presence of gliotoxin, an inhibitor of NF-κB, suggesting TRAIL does not activate NF-κB in human neutrophils. TRAIL treatment of human neutrophils did not induce a chemotactic response. The susceptibility of neutrophils to TRAIL-mediated apoptosis suggests a role for TRAIL in the regulation of inflammation and may provide a mechanism for clearance of neutrophils from sites of inflammation.