bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leishmania donovani Affects Antigen Presentation of Macrophage by Disrupting Lipid Rafts
Authors: Chakraborty Debabani , Banerjee Subha , Sen Abhik , Banerjee Kalyan K. , Das Pradip , Roy Syamal 
Published: April 2014

Abstract
Leishmania donovani-infected splenic macrophages and P388D1 (P388D1(I)) failed to activate T cells in response to low dose of exogenous peptide. The membrane fluidity of P388D1(I) was greater than that of the normal counterpart P388D1(N), but could be reduced either by exposing the cell below phase transition point or by loading cholesterol into membrane (L-P388D1(I)), and this was associated with enhanced Ag-presenting ability of P388D1(I). Presentation of endogenous leishmanial Ag, kinetoplastid membrane protein-11, was also defective, but could be corrected by loading cholesterol into membrane. Because membrane rafts are important for Ag presentation at a low peptide dose, raft architecture of P388D1(I) was studied using raft (CD48 and cholera toxin-B) and non-raft (CD71) markers in terms of their colocalization with I-Ad. Binding of anti-CD48 mAb and cholera toxin B subunit decreased significantly in P388D1(I), and consequently, colocalization with I-Ad was not seen, but this could be restored in L-P388D1(I). Conversely, colocalization between I-Ad and CD71 remained unaffected regardless of the presence or the absence of intracellular parasites. P388D1(N) and L-P388D1(I), but not P388D1(I), formed peptide-dependent synapse with T cells quite efficiently and this was found to be corroborated with both intracellular Ca2+ mobilization in T cells and IL-2 production. This indicated that intracellular parasites disrupt the membrane rafts, possibly by increasing the membrane fluidity, which could be corrected by making the membrane rigid. This may be a strategy that intracellular L. donovani adopts to evade host immune system.
TNF-α-Dependent and -Independent Maturation of Dendritic Cells and Recruited CD11cintCD11b+ Cells during Oral Salmonella Infection
Authors: Sundquist Malin , Wick Mary Jo 
Published: April 2014

Abstract
Maturation of dendritic cells (DC) is crucial for their ability to induce adaptive immunity. Although several mediators of DC maturation have been found, their contributions to DC maturation during infection are poorly understood. In this study we show that murine conventional (CD11chigh) DC up-regulate costimulatory molecules in a subset-specific manner after oral Salmonella infection. Although both CD8α+ and CD8α− subsets increase CD86 expression, CD40 was preferentially up-regulated on CD8α+ DC, and CD80 was preferentially increased on CD8α− DC. In addition, high levels of CD80 and CD86 were found on CD11cintCD11b+ cells that accumulated in infected organs. Costimulatory molecules were simultaneously induced on CD11chigh and CD11cintCD11b+ cells in Peyer’s patches, mesenteric lymph nodes and spleen 5 days after infection despite different kinetics of peak bacterial burden in these organs. Up-regulation of costimulatory molecules occurred on all DC within the respective subset. Moreover, &lt;1% of CD11c-expressing cells associated with Salmonella expressing enhanced GFP in vivo. Thus, DC maturation did not depend on bacterial uptake. Rather, infection-induced up-regulation of CD80, CD86, and CD40 on CD11c-expressing cells of mesenteric lymph nodes was dependent on TNFR type I (TNFRI) signaling. Although indirect up-regulation of costimulatory molecules on DC and CD11cintCD11b+ cells was TNFRI dependent, cells directly associated with Salmonella were able to mature independently of TNFRI signaling. Thus, Salmonella-induced TNF-α is an important mediator of indirect DC maturation during infection, whereas a TNF-α-independent maturation pathway contributes to direct maturation of bacteria-associated DC.
α-Galactosylceramide Can Act As a Nasal Vaccine Adjuvant Inducing Protective Immune Responses against Viral Infection and Tumor
Authors: Ko Sung-Youl , Ko Hyun-Jeong , Chang Woo-Sung , Park Se-Ho , Kweon Mi-Na , Kang Chang-Yuil 
Published: April 2014

Abstract
α-Galactosylceramide (α-GalCer) is a ligand of invariant Vα14+ NKT cells and is presented by CD1d molecule on APC. NKT cells produce a large amount of Th1 and Th2 cytokines in response to α-GalCer-presented APC. In this study, we assessed whether α-GalCer could act as an effective nasal vaccine adjuvant for mucosal vaccine that would be capable of inducing systemic as well as mucosal immune responses. When α-GalCer was administered with OVA via the intranasal route to C57BL/6 and BALB/c mice, significant OVA-specific mucosal secretory IgA, systemic IgG, and CTL responses were induced with mixed Th1 and Th2 cytokine profiles seen in both strains of mice. Interestingly, as BALB/c mice were intranasally immunized with PR8 hemagglutinin Ag isolated from influenza virus A/PR/8/34 together with α-GalCer, significant protection was afforded against influenza viral infection. When α-GalCer was coimmunized with a replication-deficient live adenovirus to BALB/c mice, it significantly induced both humoral and cellular immune responses. In addition, intranasal administration of OVA with α-GalCer showed complete protection against EG7 tumor challenge in C57BL/6. The adjuvant effects induced by intranasal coadministration with α-GalCer were blocked in CD1d−/− mice, indicating that the immune responses were exclusively mediated by CD1d molecule on APC. Most interestingly, intranasally coadministered α-GalCer activated naive T cells and triggered them to differentiate into functional effector T cells when CFSE-labeled OT-1 cells were adoptively transferred into syngeneic mice. Overall, our results are the first to show that α-GalCer can act as a nasal vaccine adjuvant inducing protective immune responses against viral infections and tumors.
Expression of Many Immunologically Important Genes in Mycobacterium tuberculosis-Infected Macrophages Is Independent of Both TLR2 and TLR4 but Dependent on IFN-αβ Receptor and STAT1
Authors: Shi Shuangping , Blumenthal Antje , Hickey Christopher M. , Gandotra Sheetal , Levy David , Ehrt Sabine 
Published: April 2014

Abstract
Macrophages respond to several subcellular products of Mycobacterium tuberculosis (Mtb) through TLR2 or TLR4. However, primary mouse macrophages respond to viable, virulent Mtb by pathways largely independent of MyD88, the common adaptor molecule for TLRs. Using microarrays, quantitative PCR, and ELISA with gene-disrupted macrophages and mice, we now show that viable Mtb elicits the expression of inducible NO synthase, RANTES, IFN-inducible protein 10, immune-responsive gene 1, and many other key genes in macrophages substantially independently of TLR2, TLR4, their combination, or the TLR adaptors Toll-IL-1R domain-containing adapter protein and Toll-IL-1R domain-containing adapter inducing IFN-β. Mice deficient in both TLR2 and TLR4 handle aerosol infection with viable Mtb as well as congenic controls. Viable Mtb also up-regulates inducible NO synthase, RANTES, IFN-inducible protein 10, and IRG1 in macrophages that lack mannose receptor, complement receptors 3 and 4, type A scavenger receptor, or CD40. These MyD88, TLR2/4-independent transcriptional responses require IFN-αβR and STAT1, but not IFN-γ. Conversely, those genes whose expression is MyD88 dependent do not depend on IFN-αβR or STAT1. Transcriptional induction of TNF is TLR2/4, MyD88, STAT1, and IFN-αβR independent, but TNF protein release requires the TLR2/4-MyD88 pathway. Thus, macrophages respond transcriptionally to viable Mtb through at least three pathways. TLR2 mediates the responses of a numerically minor set of genes that collectively do not appear to affect the course of infection in mice; regulation of TNF requires TLR2/4 for post-transcriptional control, but not for transcriptional induction; and many responding genes are regulated through an unknown, TLR2/4-independent pathway that may involve IFN-αβR and STAT1.
Inhibition of Neutrophil Elastase by α1-Protease Inhibitor at the Surface of Human Polymorphonuclear Neutrophils
Authors: Korkmaz Brice , Attucci Sylvie , Jourdan Marie-Lise , Juliano Luiz , Gauthier Francis 
Published: April 2014

Abstract
The uncontrolled proteolytic activity in lung secretions during lung inflammatory diseases might be due to the resistance of membrane-bound proteases to inhibition. We have used a new fluorogenic neutrophil elastase substrate to measure the activity of free and membrane-bound human neutrophil elastase (HNE) in the presence of α1-protease inhibitor (α1-Pi), the main physiological inhibitor of neutrophil serine proteases in lung secretions. Fixed and unfixed neutrophils bore the same amounts of active HNE at their surface. However, the HNE bound to the surface of unfixed neutrophils was fully inhibited by stoichiometric amounts of α1-Pi, unlike that of fixed neutrophils. The rate of inhibition of HNE bound to the surface of unfixed neutrophils was the same as that of free HNE. In the presence of α1-Pi, membrane-bound elastase is almost entirely removed from the unfixed neutrophil membrane to form soluble irreversible complexes. This was confirmed by flow cytometry using an anti-HNE mAb. HNE activity rapidly reappeared at the surface of HNE-depleted cells when they were triggered with the calcium ionophore A23187, and this activity was fully inhibited by stoichiometric amounts of α1-Pi. HNE was not released from the cell surface by oxidized, inactive α1-Pi, showing that active inhibitor is required to interact with active protease from the cell surface. We conclude that HNE activity at the surface of human neutrophils is fully controlled by α1-Pi when the cells are in suspension. Pericellular proteolysis could be limited to zones of contact between neutrophils and subjacent protease substrates where natural inhibitors cannot penetrate.
Specific Inhibition of MyD88-Independent Signaling Pathways of TLR3 and TLR4 by Resveratrol: Molecular Targets Are TBK1 and RIP1 in TRIF Complex
Authors: Youn Hyung S. , Lee Joo Y. , Fitzgerald Katherine A. , Young Howard A. , Akira Shizuo , Hwang Daniel H. 
Published: April 2014

Abstract
TLRs can activate two distinct branches of downstream signaling pathways. MyD88 and Toll/IL-1R domain-containing adaptor inducing IFN-β (TRIF) pathways lead to the expression of proinflammatory cytokines and type I IFN genes, respectively. Numerous reports have demonstrated that resveratrol, a phytoalexin with anti-inflammatory effects, inhibits NF-κB activation and other downstream signaling pathways leading to the suppression of target gene expression. However, the direct targets of resveratrol have not been identified. In this study, we attempted to identify the molecular target for resveratrol in TLR-mediated signaling pathways. Resveratrol suppressed NF-κB activation and cyclooxygenase-2 expression in RAW264.7 cells following TLR3 and TLR4 stimulation, but not TLR2 or TLR9. Further, resveratrol inhibited NF-κB activation induced by TRIF, but not by MyD88. The activation of IFN regulatory factor 3 and the expression of IFN-β induced by LPS, poly(I:C), or TRIF were also suppressed by resveratrol. The suppressive effect of resveratrol on LPS-induced NF-κB activation was abolished in TRIF-deficient mouse embryonic fibroblasts, whereas LPS-induced degradation of IκBα and expression of cyclooxygenase-2 and inducible NO synthase were still inhibited in MyD88-deficient macrophages. Furthermore, resveratrol inhibited the kinase activity of TANK-binding kinase 1 and the NF-κB activation induced by RIP1 in RAW264.7 cells. Together, these results demonstrate that resveratrol specifically inhibits TRIF signaling in the TLR3 and TLR4 pathway by targeting TANK-binding kinase 1 and RIP1 in TRIF complex. The results raise the possibility that certain dietary phytochemicals can modulate TLR-derived signaling and inflammatory target gene expression and can alter susceptibility to microbial infection and chronic inflammatory diseases.
Stat3 in Resident Macrophages as a Repressor Protein of Inflammatory Response
Authors: Matsukawa Akihiro , Kudo Shinji , Maeda Takako , Numata Kousuke , Watanabe Hiroyuki , Takeda Kiyoshi , Akira Shizuo , Ito Takaaki 
Published: April 2014

Abstract
Inflammation is counterbalanced by anti-inflammatory cytokines such as IL-10, in which Stat3 mediates the signaling pathway. In this study, we demonstrate that resident macrophages, but not other cell types, are important targets of IL-10 in a murine model of acute peritonitis. Injection of thioglycollate i.p. induced a considerable number of neutrophils and macrophages in the peritoneum, which was significantly augmented in mice with a cell-type specific disruption of the Stat3 gene in macrophages and neutrophils (LysMcre/Stat3flox/− mice). The augmented leukocyte infiltration was accompanied by increased peritoneal levels of TNF-α, MIP-2, KC chemokine (KC), and MCP-1/CCL2. Stat3 was tyrosine phosphorylated in peritoneal resident macrophages as well as infiltrating leukocytes in the littermate controls, suggesting that Stat3 in either or both of these cells might play a regulatory role in inflammation. The peritoneal levels of TNF-α, MIP-2, KC, and MCP-1 were similarly elevated in LysMcre/Stat3flox/− mice rendered leukopenic by cyclophosphamide treatment as compared with the controls. Adoptive transfer of resident macrophages from LysMcre/Stat3flox/− mice into the control littermates resulted in increases in the peritoneal level of TNF-α, MIP-2, KC, and MCP-1 after i.p. injection of thioglycollate. Under these conditions, control littermates harboring LysMcre/Stat3flox/− macrophages exhibited an augmented leukocyte infiltration relative to those received control macrophages. Taken together, these data provide evidence that resident macrophages, but not other cell types, play a regulatory role in inflammation through a Stat3 signaling pathway. Stat3 in resident macrophages appears to function as a repressor protein in this model of acute inflammation.
Modulation of Lipopolysaccharide-Induced Gene Transcription and Promotion of Lung Injury by Mechanical Ventilation
Authors: Altemeier William A. , Matute-Bello Gustavo , Gharib Sina A. , Glenny Robb W. , Martin Thomas R. , Liles W. Conrad 
Published: April 2014

Abstract
Mechanical ventilation (MV) with tidal volumes of 10–12 ml/kg is considered safe in the absence of acute lung injury (ALI). However, recent studies show that, when lung injury is already present, tidal volumes of this magnitude increase inflammation and injury in the lungs. We hypothesized that MV with tidal volumes of 10-ml/kg can also function as a cofactor in the initiation of ALI by modulating the transcriptional response to bacterial products. To test this hypothesis, we developed a mouse model in which MV did not independently cause inflammation or injury but augmented the inflammatory response to low-dose aspirated LPS and promoted development of ALI. We analyzed gene expression in lungs from 24 mice assigned to four different groups: control, MV only, intratracheal LPS only, and MV + LPS. There were twice as many differentially regulated genes in the MV + LPS group compared with the LPS-only group and 10 times as many differentially regulated genes compared with the MV-only group. For genes up-regulated by LPS treatment alone, the addition of MV further augmented expression. Cytokine concentrations in bronchoalveolar lavage fluid and tissue distribution of an intracellular protein, GADD45-γ, correlated with mRNA levels. We conclude that MV with conventional tidal volumes enhanced the transcriptional response to LPS and promoted development of ALI.
Local Bradykinin Formation Is Controlled by Glycosaminoglycans
Authors: Renné Thomas , Schuh Kai , Müller-Esterl Werner 
Published: April 2014

Abstract
Bradykinin is a potent inflammatory mediator that induces vasodilation, vascular leakage, and pain sensations. This short-lived peptide hormone is liberated from its large precursor protein high molecular weight kininogen (HK) through the contact system cascade involving coagulation factor XII and plasma kallikrein. Although bradykinin release is well established in vitro, the factors and mechanisms controlling bradykinin generation in vivo are still incompletely understood. In this study we demonstrate that binding of HK to glycosaminoglycans (GAGs) of the heparan and chondroitin sulfate type efficiently interferes with bradykinin release in plasma and on endothelial surfaces. Proteolytic bradykinin production on endothelial cells is restored following degradation of cell surface GAG through heparinase. Alternatively, application of HK fragments D3 or light chain, which compete with uncleaved HK for cell binding, promote kininogen proteolysis and bradykinin release. Intravital microscopy revealed that HK fragments increase bradykinin-mediated mesentery microvascular leakage. Topical application of D3 or light chain enhanced bradykinin generation and edema formation in the mouse skin. Our results demonstrate that bradykinin formation is controlled by HK binding to and detachment from GAGs. Separation of the precursor from cell surfaces is a prerequisite for its efficient proteolytic processing. By this means, fragments arising from HK processing propagate bradykinin generation, revealing a novel regulatory level for the kallikrein-kinin system.
Regulation of Basal and Induced Expression of C-Reactive Protein through an Overlapping Element for OCT-1 and NF-κB on the Proximal Promoter
Authors: Voleti Bhavya , Agrawal Alok 
Published: April 2014

Abstract
C-reactive protein (CRP) is an acute phase protein produced by hepatocytes. A minor elevation in the baseline levels of serum CRP is considered an indicator of chronic inflammation. In hepatoma Hep3B cells, IL-6 induces CRP expression by activating transcription factors STAT3 and C/EBPβ. IL-1 synergistically enhances the effects of IL-6. The first 157 bp of the CRP promoter are sufficient for IL-1 synergy. Previously, NF-κB, a transcription factor activated by IL-1β in Hep3B cells, has been shown to increase endogenous CRP expression. The purpose of this study was to investigate the possible action of NF-κB on the 157 bp of the proximal promoter. In this study we show that NF-κB requires and acts synergistically with C/EBPβ on the CRP-proximal promoter to regulate CRP expression. We located the regulatory element that consisted of overlapping binding sites for NF-κB (p50-p50 and p50-p65) and OCT-1. The κB site was responsible for the synergy between NF-κB and C/EBPβ and was also necessary for the CRP transactivation by C/EBPβ through the C/EBP site. Mutation of the κB site decreased the synergistic effect of IL-1β on IL-6-induced CRP expression. Basal CRP expression increased dramatically when binding of both OCT-1 and NF-κB was abolished. Combined data from luciferase transactivation assays and EMSA lead us to conclude that the binding of OCT-1 to the promoter, facilitated by p50-p50 in a novel way, represses, whereas replacement of OCT-1 by p50-p65 induces CRP transcription in cooperation with C/EBPβ. This model for CRP expression favors the variation seen in baseline serum CRP levels in a normal healthy population.
Dichotomal Role of TNF in Experimental Pulmonary Edema Reabsorption
Authors: Braun Clemens , Hamacher Jürg , Morel Denis R. , Wendel Albrecht , Lucas Rudolf 
Published: April 2014

Abstract
Distinct from its receptor binding sites, TNF carries a lectin-like domain, situated at the tip of the molecule, which specifically binds oligosaccharides, such as N,N′-diacetylchitobiose. In view of the apparently conflicting data concerning TNF actions in pulmonary edema, we investigated the contribution of, on the one hand, the receptor binding sites and, in contrast, the lectin-like domain of the cytokine on pulmonary fluid reabsorption in in situ and in vivo flooded rat lungs. Receptor binding sites were blocked with the human soluble TNFR type 1 construct (sTNFR1), whereas the lectin-like domain was blunted with the oligosaccharide N,N′-diacetylchitobiose. We observed that in situ, TNF failed to stimulate alveolar liquid clearance, but did so together with the sTNFR1, and this activity was neutralized by N,N′-diacetylchitobiose. In vivo TNF inhibited liquid clearance, but activated it when complexed with the sTNFR1. A TNF-derived peptide mimic of the lectin-like domain activated fluid reabsorption in flooded lungs, and this activity was blunted by cotreatment with TNF. Our results thus indicate that in these models the receptor binding sites of TNF inhibit, whereas its lectin-like domain activates, edema reabsorption.
Donor Lymphocyte Infusion Induces Long-Term Donor-Specific Cardiac Xenograft Survival through Activation of Recipient Double-Negative Regulatory T Cells
Authors: Chen Wenhao , Zhou Dejun , Torrealba Jose R. , Waddell Thomas K. , Grant David , Zhang Li 
Published: April 2014

Abstract
Previous studies have shown that pretransplant donor lymphocyte infusion (DLI) can enhance xenograft survival. However, the mechanism by which DLI induces xenograft survival remains obscure. Using T cell subset-deficient mice as recipients we show that CD4+, but not CD8+, T cells are necessary to mediate the rejection of concordant cardiac xenografts. Adoptive transfer of naive CD4+ T cells induces rejection of accepted cardiac xenografts in CD4−/− mice. This rejection can be prevented by pretransplant DLI in the absence of any other treatment. Furthermore, we demonstrate that DLI activates αβ-TCR+CD3+CD4−CD8− double-negative (DN) regulatory T (Treg) cells in xenograft recipients, and that DLI-activated DN Treg cells can inhibit the proliferation of donor-specific xenoreactive CD4+ T cells in vitro. More importantly, adoptive transfer of DLI-activated DN Treg cells from xenograft recipients can suppress the proliferation of xenoreactive CD4+ T cells and their ability to produce IL-2 and IFN-γ in vivo. Adoptive transfer of DLI-activated DN Treg cells also prevents CD4+ T cell-mediated cardiac xenograft rejection in an Ag-specific fashion. These data provide direct evidence that DLI can activate recipient DN Treg cells, which can induce donor-specific long-term cardiac xenograft survival by suppressing the proliferation and function of donor-specific CD4+ T cells in vivo.
Increased Caspase-3 Expression and Activity Contribute to Reduced CD3ζ Expression in Systemic Lupus Erythematosus T Cells
Authors: Krishnan Sandeep , Kiang Juliann G. , Fisher Carolyn U. , Nambiar Madhusoodana P. , Nguyen Hang T. , Kyttaris Vasileios C. , Chowdhury Bhabadeb , Rus Violeta , Tsokos George C. 
Published: April 2014

Abstract
T cells isolated from patients with systemic lupus erythematosus (SLE) express low levels of CD3ζ-chain, a critical molecule involved in TCR-mediated signaling, but the involved mechanisms are not fully understood. In this study we examined caspase-3 as a candidate for cleaving CD3ζ in SLE T cells. We demonstrate that SLE T cells display increased expression and activity of caspase-3. Treatment of SLE T cells with the caspase-3 inhibitor Z-Asp-Glu-Val-Asp-FMK reduced proteolysis of CD3ζ and enhanced its expression. In addition, Z-Asp-Glu-Val-Asp-FMK treatment increased the association of CD3ζ with lipid rafts and simultaneously reversed the abnormal lipid raft preclustering, heightened TCR-induced calcium responses, and reduced the expression of FcRγ-chain exclusively in SLE T cells. We conclude that caspase-3 inhibitors can normalize SLE T cell function by limiting the excessive digestion of CD3ζ-chain and suggest that such molecules can be considered in the treatment of this disease.