123 research outputs found
Eosinophils Are Important for Protection, Immunoregulation and Pathology during Infection with Nematode Microfilariae
Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO) and major basic protein-1 (MBP-1), during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL), we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity
Reconfiguration of Cliques in a Graph
We study reconfiguration problems for cliques in a graph, which determine
whether there exists a sequence of cliques that transforms a given clique into
another one in a step-by-step fashion. As one step of a transformation, we
consider three different types of rules, which are defined and studied in
reconfiguration problems for independent sets. We first prove that all the
three rules are equivalent in cliques. We then show that the problems are
PSPACE-complete for perfect graphs, while we give polynomial-time algorithms
for several classes of graphs, such as even-hole-free graphs and cographs. In
particular, the shortest variant, which computes the shortest length of a
desired sequence, can be solved in polynomial time for chordal graphs,
bipartite graphs, planar graphs, and bounded treewidth graphs
IFN-γ-inducible protein of 10 kDa upregulates the effector functions of eosinophils through β2 integrin and CXCR3
<p>Abstract</p> <p>Background</p> <p>Eosinophils play an important role in the pathogenesis of bronchial asthma and its exacerbation. Recent reports suggest the involvement of IFN-γ-inducible protein of 10 kDa (IP-10) in virus-induced asthma exacerbation. The objective of this study was to examine whether CXCR3 ligands including IP-10 modify the effector functions of eosinophils.</p> <p>Methods</p> <p>Eosinophils isolated from the blood of healthy donors were stimulated with CXCR3 ligands and their adhesion to rh-ICAM-1 was then measured using eosinophil peroxidase assays. The generation of eosinophil superoxide anion (O<sub>2</sub><sup>-</sup>) was examined based on the superoxide dismutase-inhibitable reduction of cytochrome C. Eosinophil-derived neurotoxin (EDN) release was evaluated to determine whether CXCR3 ligands induced eosinophil degranulation. Cytokine and chemokine production by eosinophils was examined using a Bio-plex assay.</p> <p>Results</p> <p>Eosinophil adhesion to ICAM-1 was significantly enhanced by IP-10, which also significantly induced eosinophil O<sub>2</sub><sup>- </sup>generation in the presence of ICAM-1. Both the enhanced adhesion and O<sub>2</sub><sup>- </sup>generation were inhibited by an anti-β<sub>2 </sub>integrin mAb or an anti-CXCR3 mAb. Other CXCR3 ligands, such as monokine induced by IFN-γ (Mig) and IFN-inducible T cell α chemoattractant (I-TAC), also induced eosinophil adhesion and O<sub>2</sub><sup>- </sup>generation in the presence of ICAM-1. IP-10, but not Mig or I-TAC, increased the release of EDN. IP-10 increased the production of a number of cytokines and chemokines by eosinophils.</p> <p>Conclusions</p> <p>These findings suggest that CXCR3 ligands such as IP-10 can directly upregulate the effector functions of eosinophils. These effects might be involved in the activation and infiltration of eosinophils in the airway of asthma, especially in virus-induced asthma exacerbation.</p
Genomic analysis of human lung fibroblasts exposed to vanadium pentoxide to identify candidate genes for occupational bronchitis
BACKGROUND: Exposure to vanadium pentoxide (V(2)O(5)) is a cause of occupational bronchitis. We evaluated gene expression profiles in cultured human lung fibroblasts exposed to V(2)O(5 )in vitro in order to identify candidate genes that could play a role in inflammation, fibrosis, and repair during the pathogenesis of V(2)O(5)-induced bronchitis. METHODS: Normal human lung fibroblasts were exposed to V(2)O(5 )in a time course experiment. Gene expression was measured at various time points over a 24 hr period using the Affymetrix Human Genome U133A 2.0 Array. Selected genes that were significantly changed in the microarray experiment were validated by RT-PCR. RESULTS: V(2)O(5 )altered more than 1,400 genes, of which ~300 were induced while >1,100 genes were suppressed. Gene ontology categories (GO) categories unique to induced genes included inflammatory response and immune response, while GO catogories unique to suppressed genes included ubiquitin cycle and cell cycle. A dozen genes were validated by RT-PCR, including growth factors (HBEGF, VEGF, CTGF), chemokines (IL8, CXCL9, CXCL10), oxidative stress response genes (SOD2, PIPOX, OXR1), and DNA-binding proteins (GAS1, STAT1). CONCLUSION: Our study identified a variety of genes that could play pivotal roles in inflammation, fibrosis and repair during V(2)O(5)-induced bronchitis. The induction of genes that mediate inflammation and immune responses, as well as suppression of genes involved in growth arrest appear to be important to the lung fibrotic reaction to V(2)O(5)
FcγRIIb Inhibits Allergic Lung Inflammation in a Murine Model of Allergic Asthma
Allergic asthma is characterized by airway eosinophilia, increased mucin production and allergen-specific IgE. Fc gamma receptor IIb (FcγRIIb), an inhibitory IgG receptor, has recently emerged as a negative regulator of allergic diseases like anaphylaxis and allergic rhinitis. However, no studies to date have evaluated its role in allergic asthma. Our main objective was to study the role of FcγRIIb in allergic lung inflammation. We used a murine model of allergic airway inflammation. Inflammation was quantified by BAL inflammatory cells and airway mucin production. FcγRIIb expression was measured by qPCR and flow cytometry and the cytokines were quantified by ELISA. Compared to wild type animals, FcγRIIb deficient mice mount a vigorous allergic lung inflammation characterized by increased bronchoalveolar lavage fluid cellularity, eosinophilia and mucin content upon ragweed extract (RWE) challenge. RWE challenge in sensitized mice upregulated FcγRIIb in the lungs. Disruption of IFN-γ gene abrogated this upregulation. Treatment of naïve mice with the Th1-inducing agent CpG DNA increased FcγRIIb expression in the lungs. Furthermore, treatment of sensitized mice with CpG DNA prior to RWE challenge induced greater upregulation of FcγRIIb than RWE challenge alone. These observations indicated that RWE challenge upregulated FcγRIIb in the lungs by IFN-γ- and Th1-dependent mechanisms. RWE challenge upregulated FcγRIIb on pulmonary CD14+/MHC II+ mononuclear cells and CD11c+ cells. FcγRIIb deficient mice also exhibited an exaggerated RWE-specific IgE response upon sensitization when compared to wild type mice. We propose that FcγRIIb physiologically regulates allergic airway inflammation by two mechanisms: 1) allergen challenge mediates upregulation of FcγRIIb on pulmonary CD14+/MHC II+ mononuclear cells and CD11c+ cells by an IFN-γ dependent mechanism; and 2) by attenuating the allergen specific IgE response during sensitization. Thus, stimulating FcγRIIb may be a therapeutic strategy in allergic airway disorders
CCR2 and CXCR3 agonistic chemokines are differently expressed and regulated in human alveolar epithelial cells type II
The attraction of leukocytes from circulation to inflamed lungs depends on the activation of both the leukocytes and the resident cells within the lung. In this study we determined gene expression and secretion patterns for monocyte chemoattractant protein-1 (MCP-1/CCL2) and T-cell specific CXCR3 agonistic chemokines (Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11) in TNF-α-, IFN-γ-, and IL-1β-stimulated human alveolar epithelial cells type II (AEC-II). AEC-II constitutively expressed high level of CCL2 mRNA in vitro and in situ , and released CCL2 protein in vitro . Treatment of AEC-II with proinflammatory cytokines up-regulated both CCL2 mRNA expression and release of immunoreactive CCL2, whereas IFN-γ had no effect on CCL2 release. In contrast, CXCR3 agonistic chemokines were not detected in freshly isolated AEC-II or in non-stimulated epithelial like cell line A549. IFN-γ, alone or in combination with IL-1β and TNF-α resulted in an increase in CXCL10, CXCL11, and CXCL9 mRNA expression and generation of CXCL10 protein by AEC-II or A549 cells. CXCL10 gene expression and secretion were induced in dose-dependent manner after cytokine-stimulation of AEC-II with an order of potency IFN-γ>>IL-1β ≥ TNF-α. Additionally, we localized the CCL2 and CXCL10 mRNAs in human lung tissue explants by in situ hybridization, and demonstrated the selective effects of cytokines and dexamethasone on CCL2 and CXCL10 expression. These data suggest that the regulation of the CCL2 and CXCL10 expression exhibit significant differences in their mechanisms, and also demonstrate that the alveolar epithelium contributes to the cytokine milieu of the lung, with the ability to respond to locally generated cytokines and to produce potent mediators of the local inflammatory response
The Sylvester Resultant Matrix and Image Deblurring
This paper describes the application of the Sylvester resultant matrix to image deblurring. In particular, an image is represented as a bivariate polynomial and it is shown that operations on polynomials, specifically greatest common divisor (GCD) computations and polynomial divisions, enable the point spread function to be calculated and an image to be deblurred. The GCD computations are performed using the Sylvester resultant matrix, which is a structured matrix, and thus a structure-preserving matrix method is used to obtain a deblurred image. Examples of blurred and deblurred images are presented, and the results are compared with the deblurred images obtained from other methods
Pentraxin 3 (PTX3) Expression in Allergic Asthmatic Airways: Role in Airway Smooth Muscle Migration and Chemokine Production
Pentraxin 3 (PTX3) is a soluble pattern recognition receptor with non-redundant functions in inflammation and innate immunity. PTX3 is produced by immune and structural cells. However, very little is known about the expression of PTX3 and its role in allergic asthma.We sought to determine the PTX3 expression in asthmatic airways and its function in human airway smooth muscle cells (HASMC). In vivo PTX3 expression in bronchial biopsies of mild, moderate and severe asthmatics was analyzed by immunohistochemistry. PTX3 mRNA and protein were measured by real-time RT-PCR and ELISA, respectively. Proliferation and migration were examined using (3)H-thymidine incorporation, cell count and Boyden chamber assays.PTX3 immunoreactivity was increased in bronchial tissues of allergic asthmatics compared to healthy controls, and mainly localized in the smooth muscle bundle. PTX3 protein was expressed constitutively by HASMC and was significantly up-regulated by TNF, and IL-1β but not by Th2 (IL-4, IL-9, IL-13), Th1 (IFN-γ), or Th-17 (IL-17) cytokines. In vitro, HASMC released significantly higher levels of PTX3 at the baseline and upon TNF stimulation compared to airway epithelial cells (EC). Moreover, PTX3 induced CCL11/eotaxin-1 release whilst inhibited the fibroblast growth factor-2 (FGF-2)-driven HASMC chemotactic activity.Our data provide the first evidence that PTX3 expression is increased in asthmatic airways. HASMC can both produce and respond to PTX3. PTX3 is a potent inhibitor of HASMC migration induced by FGF-2 and can upregulate CCL11/eotaxin-1 release. These results raise the possibility that PTX3 may play a dual role in allergic asthma
Induction of eosinophil apoptosis by hydrogen peroxide promotes the resolution of allergic inflammation
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Previous issue date: 2015Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Resolução da Resposta Inflamatória. Laboratório de Imunofarmacologia. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil.University of Edinburgh. The Queen’s Medical Research Institute. Medical Research Council Centre for Inflammation Research. Edinburgh, Scotland, UK.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Resolução da Resposta Inflamatória. Laboratório de Imunofarmacologia. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Resolução da Resposta Inflamatória. Laboratório de Imunofarmacologia. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Análises Clínicas e Toxicológicas. Laboratório de Sinalização na Inflamação. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Microbiologia. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Laboratório de Patologia Geral. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Análises Clínicas e Toxicológicas. Laboratório de Sinalização na Inflamação. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Resolução da Resposta Inflamatória. Belo Horizonte, MG, Brasil.University of Edinburgh. The Queen’s Medical Research Institute. Medical Research Council Centre for Inflammation Research. Edinburgh, Scotland, UK.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Resolução da Resposta Inflamatória. Laboratório de Imunofarmacologia. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil.Eosinophils are effector cells that have an important role in the pathogenesis of allergic disease. Defective removal of these cells
likely leads to chronic inflammatory diseases such as asthma. Thus, there is great interest in understanding the mechanisms
responsible for the elimination of eosinophils from inflammatory sites. Previous studies have demonstrated a role for certain
mediators and molecular pathways responsible for the survival and death of leukocytes at sites of inflammation. Reactive oxygen
species have been described as proinflammatory mediators but their role in the resolution phase of inflammation is poorly
understood. The aim of this study was to investigate the effect of reactive oxygen species in the resolution of allergic inflammatory
responses. An eosinophilic cell line (Eol-1) was treated with hydrogen peroxide and apoptosis was measured. Allergic
inflammation was induced in ovalbumin sensitized and challenged mouse models and reactive oxygen species were administered
at the peak of inflammatory cell infiltrate. Inflammatory cell numbers, cytokine and chemokine levels, mucus production,
inflammatory cell apoptosis and peribronchiolar matrix deposition was quantified in the lungs. Resistance and elastance were
measured at baseline and after aerosolized methacholine. Hydrogen peroxide accelerates resolution of airway inflammation by
induction of caspase-dependent apoptosis of eosinophils and decrease remodeling, mucus deposition, inflammatory cytokine
production and airway hyperreactivity. Moreover, the inhibition of reactive oxygen species production by apocynin or in
gp91phox −/− mice prolonged the inflammatory response. Hydrogen peroxide induces Eol-1 apoptosis in vitro and enhances the
resolution of inflammation and improves lung function in vivo by inducing caspase-dependent apoptosis of eosinophils
Altered Activation of Innate Immunity Associates with White Matter Volume and Diffusion in First-Episode Psychosis
First-episode psychosis (FEP) is associated with inflammatory and brain structural changes, but few studies have investigated whether systemic inflammation associates with brain structural changes in FEP. Thirty-seven FEP patients (median 27 days on antipsychotic medication), and 19 matched controls were recruited. Serum levels of 38 chemokines and cytokines, and cardiovascular risk markers were measured at baseline and 2 months later. We collected T1-and diffusion-weighted MRIs with a 3 T scanner from the patients at baseline. We analyzed the association of psychosis-related inflammatory markers with gray and white matter (WM) volume using voxel-based morphometry and WM diffusion using tract-based spatial statistics with whole-brain and region-of-interest (ROI) analyses. FEP patients had higher CCL22 and lower TGFa, CXCL1, CCL7, IFN-alpha 2 and ApoA-I than controls. CCL22 decreased significantly between baseline and 2 months in patients but was still higher than in controls. The association between inflammatory markers and FEP remained significant after adjusting for age, sex, smoking and BMI. We did not observe a correlation of inflammatory markers with any symptoms or duration of antipsychotic treatment. Baseline CCL22 levels correlated negatively with WM volume and positively with mean diffusivity and radial diffusivity bilaterally in the frontal lobes in ROI analyses. Decreased serum lan association between circulating chemokine levels and WM in FEP patients. Interestingly, CCL22 has been previously implicated in autoimmune diseases associated with WM pathology. The results suggest that an altered activation of innate immunity may contribute to WM damage in psychotic disorders.evel of ApoA-I was associated with smaller volume of the medial temporal WM. In whole-brain analyses, CCL22 correlated positively with mean diffusivity and radial diffusivity, and CXCL1 associated negatively with fractional anisotropy and positively with mean diffusivity and radial diffusivity in several brain regions. This is the first report to demonstratePeer reviewe
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