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Results 451 - 500 of 1084
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Erwig Lars-Peter - - 2007
Cells undergo apoptosis in development, tissue homeostasis, and disease and are subsequently cleared by professional and nonprofessional phagocytes. There is now overwhelming evidence that phagocyte function is profoundly altered following apoptotic cell uptake, with consequences for the ensuing innate and adaptive immune response. Pathogens and tumors exploit the changes in ...
Kinchen Jason M - - 2007
Programmed cell death is critical both for organ formation during development and during adult life, when billions of cells must be removed every day. The culmination of the apoptotic process is the specific recognition and engulfment of the apoptotic cell by a phagocyte. A number of recent studies have revealed ...
Gokoh Maiko - - 2007
2-Arachidonoylglycerol is an endogenous ligand for the cannabinoid receptors (CB1 and CB2). While evidence is accumulating that the CB1 receptor plays important regulatory roles in various nervous tissues and cells, the physiological roles of the CB2 receptor, which is abundantly expressed in the immune system, are yet to be determined. ...
Li Bing - - 2007
The therapeutic benefits of fungal beta-glucans have been demonstrated as immuno-stimulating agents. In this study, we aimed to explore the mechanisms used by yeast beta-glucan-rich particles to activate murine resident macrophages for cytokine secretion. We demonstrated that resident macrophages were effectively activated by whole yeast beta-glucan particles (WGPs), such as ...
van Zandbergen G - - 2007
Professional phagocytes like polymorphonuclear neutrophil granulocytes (PMN) and macrophages (MF) kill pathogens as the first line of defense. These cells possess numerous effector mechanisms to eliminate a threat at first contact. However, several microorganisms still manage to evade phagocytic killing, survive and retain infectivity. Some pathogens have developed strategies to ...
Michlewska Sylwia S The Queen's Medical Research Institute, MRC Centre for Inflammation Research, University of Edinburgh Medical School, Edinburgh, Scotland, UK. - - 2007
Phagocytic clearance of apoptotic cells is an important physiologic homeostatic mechanism that is associated with non-inflammatory or anti-inflammatory sequalae. Disruption of the process of apoptotic cell clearance may contribute to development of a number of inflammatory and autoimmune diseases. In this review, we summarize the molecular pathways that have been ...
Mueller Ruediger B - - 2007
Apoptotic cells promote the phagocytosis of themselves via the exposure of "eat me" signals. Furthermore, a second, "find me" signal is required to attract phagocytes. In this review the double function of lysophosphatidylcholine for the clearance of apoptotic material as factor leading to attraction of phagocytes as a soluble "find ...
Bartz, Jason C.
The long-term objective of this proposal is to identify mechanisms of prion transport to secondary lymphoreticular system (LRS) tissues. The hypothesis to be tested is that following peripheral exposure to prions; host proteins (e.g. complement) bind prions allowing for trapping by cells in the spleen and enhancing uptake by macrophages, ...
Khandani Arian - - 2007
Phagocytosis is a complex sequence of events involving coordinated remodeling of the plasma membrane with the underlying cytoskeleton. Although the role of the actin cytoskeleton is becoming increasingly elucidated, the role of microtubules (MTs) remains poorly understood. Here, we examine the role of MTs during FcgammaR-mediated phagocytosis in RAW264.7 mouse ...
Chou C-L - - 2007
OBJECTIVE: The phagocytic recognition and clearance of the recruited inflammatory cells with prolonged survival play a pivotal role in relieving tissue inflammation and maintaining tissue homeostasis. Transgenic mice expressing Bcl-2 in mature neutrophils demonstrated that Bcl-2 attenuated neutrophil apoptosis, while the homeostasis of the neutrophil population was essentially unaffected. This ...
Scannell Michael - - 2007
The resolution of inflammation is a dynamically regulated process that may be subverted in many pathological conditions. Macrophage (Mphi) phagocytic clearance of apoptotic leukocytes plays an important role in the resolution of inflammation as this process prevents the exposure of tissues at the inflammatory site to the noxious contents of ...
Haberzettl Petra - - 2007
The uptake of respirable quartz particles by alveolar macrophages (AM) is believed to cause an inflammatory response, which is discussed as a crucial step in quartz pathogenicity. However, little is known about the mechanism and the relevance of particle uptake. Therefore, the aim of this study was to analyze the ...
Lee Jimmy S - - 2007
Mononuclear phagocytes are critical modulators and effectors of innate and adaptive immune responses, and PI-3Ks have been shown to be multifunctional monocyte regulators. The PI-3K family includes eight catalytic isoforms, and only limited information is available about how these contribute to fine specificity in monocyte cell regulation. We examined the ...
Atabai Kamran K Lung Biology Center, Cardiovascular Research Institute, Department of Medicine, University of California, San Francisco, CA 94143-2922, USA. - - 2007
Mammary gland involution is a period of intensive tissue remodeling. Over the course of a relatively brief period, a large proportion of the mammary gland epithelium undergoes programmed cell death and is removed by phagocytes. In addition, the gland is cleared of residual milk fat globules as well as milk ...
Jalava Pasi I - - 2007
We investigated the cytotoxic and inflammatory activities of size-segregated particulate samples (particulate matter, PM) from contrasting air pollution situations in Europe. Coarse (PM10-2.5), fine (PM2.5-0.2), and ultrafine (PM0.2) particulate samples were collected with a modified Harvard high-volume cascade impactor (HVCI). Mouse RAW 264.7 macrophages were exposed to the samples for ...
Cerone S I - - 2007
The in vitro effect of different concentrations of beta-hydroxybutyric acid (betaHBA) on bovine milk leukocytes was examined. betaHBA level similar to those found in cows with clinical ketosis induced a significant inhibitory effect on the nitroblue tetrazolium reduction as a mean of assaying the metabolic integrity of macrophages after the ...
Behnsen Judith - - 2007
The fungal pathogens Aspergillus fumigatus and Candida albicans are major health threats for immune-compromised patients. Normally, macrophages and neutrophil granulocytes phagocytose inhaled Aspergillus conidia in the two-dimensional (2-D) environment of the alveolar lumen or Candida growing in tissue microabscesses, which are composed of a three-dimensional (3-D) extracellular matrix. However, neither ...
Kwinn Laura A - - 2007
Group A Streptococcus (GAS) is a Gram-positive bacterium associated with a variety of mucosal and invasive human infections. GAS systemic disease reflects the diverse abilities of this pathogen to avoid eradication by phagocytic defenses of the innate immune system. Here we review how GAS can avoid phagocyte engagement, inhibit complement ...
Aronoff David M - - 2007
PGI(2) (prostacyclin) is a lipid mediator with vasodilatory and antithrombotic effects used in the treatment of vasoconstrictive/ischemic diseases including pulmonary artery hypertension. However, emerging research supports a role for PGs, including PGI(2), in the regulation of both innate and acquired immunity. As PGI(2) is unstable, we sought to define the ...
Takemura Yukihiro Y Molecular Cardiology Unit, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118, - - 2007
Obesity and type 2 diabetes are associated with chronic inflammation. Adiponectin is an adipocyte-derived hormone with antidiabetic and antiinflammatory actions. Here, we demonstrate what we believe to be a previously undocumented activity of adiponectin, facilitating the uptake of early apoptotic cells by macrophages, an essential feature of immune system function. ...
Morrow Dympna M P - - 2007
Pseudomonas. aeruginosa (PA) is a leading cause of nosocomial pneumonia in patients receiving mechanical ventilation with hyperoxia. Exposure to supraphysiological concentrations of reactive oxygen species during hyperoxia may result in macrophage damage that reduces their ability to phagocytose PA. We tested this hypothesis in cultured macrophage-like RAW 264.7 cells and ...
Brennan Catherine A CA Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA. - - 2007
Phagocytic blood cells are critical to innate immune defense: They internalize and destroy microbial invaders and produce signals that trigger other immune responses. Despite this central role, the in vivo contributions of phagocytosis to systemic immune activation are not well understood. Drosophila has proven a fruitful model for the investigation ...
Passantino L - - 2007
Fish erythrocytes are endowed with the ability to produce cytokine like factors when stimulated with Candida albicans (Ca). To evaluate whether similar activities are still conserved in bird erythrocytes (BE), a morphological, cytochemical and immunological evaluation was conducted on peripheral cells in chickens (Gallus gallus). BE form rosettes with monocytes ...
Ashwood Paul P Department of Medical Microbiology and Immunology and MIND Institute, University of California at Davis, Wet Lab Building, Sacramento, CA 95817, USA. - - 2007
Fine particles (10(2)- to 10(3)-nm diameter) are potentially potent adjuvants in acquired immune responses but little is known about their interaction with pathogen-associated molecular patterns (PAMPs) and impact upon innate immunity. Here we show that 200-nm-sized, food-grade titanium dioxide avidly binds lipopolysaccharide (LPS) with bridging calcium cations, and the complex ...
Stoilova Yordanka D - - 2007
Susceptibility of patients with burn injuries to infections is associated with disturbances of the humoral and cell-mediated immunity. The aim of the present study was to investigate the dynamics of phagocytic indices and serum immunoglobulin levels in patients with burn injuries as there is a high risk of colonization and ...
Vollmers H Peter - - 2007
Immunity, based on a natural and an educated system, is responsible for recognition and elimination of infectious particles, cellular waste, modified self and transformed cells. This dual system guarantees that dangerous particles are removed immediately after appearance and that a memory with maturated weapons exists, if the organism is re-infected ...
Veranth John M - - 2007
BACKGROUND: The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of ...
Premanandan, Christopher
Bacillus anthracis is a gram-positive, spore forming facultative anaerobic bacteria and is the etiologic agent for anthrax. Pulmonary anthrax is the form associated with the highest mortality in humans and is considered a significant threat due to its potential as a bioterrorist weapon. We examined the functionality and the expression ...
Kay, Jason
Macrophages are a central player in the immune system. They are sentinels that&#13;phagocytose and degrade senescent cells and foreign invading microorganisms such as&#13;bacteria and yeast, and then present antigens derived from the foreign invaders to&#13;activate the adaptive immune system. Macrophages also regulate immunity through the&#13;release of cytokines that control the ...
Müller Karin - - 2007
Ferumoxtran-10, a dextran-coated ultrasmall superparamagnetic iron oxide particle, has the potential to reveal macrophages in vivo using magnetic resonance imaging potentially acting as a marker of inflammatory status. Pending clinical trials, we examined the interactions of Ferumoxtran-10 with human monocyte-macrophages (HMMs) in vitro to assess its safety and lack of ...
Kiss Robert S - - 2006
Engulfment of apoptotic cells by phagocytes is important throughout development and adult life. When phagocytes engulf apoptotic cells, they increase their cellular contents including cholesterol and phospholipids, but how the phagocytes respond to this increased load is poorly understood. Here, we identify one type of a phagocyte response, wherein the ...
Greenberg Michael E - - 2006
The phagocytosis of apoptotic cells within an organism is a critical terminal physiological process in programmed cell death. Evidence suggests that apoptotic cell engulfment and removal by macrophages is facilitated by phosphatidylserine (PS) displayed at the exofacial surface of the plasma membrane; however, neither the macrophage receptors responsible for PS ...
Chan Andrew - - 2006
Apoptosis of autoaggressive T cells in the central nervous system (CNS) and subsequent phagocytosis by microglia is probably crucial in the rapid resolution of the inflammatory infiltrate in T cell mediated neuroinflammatory diseases. In addition to mere clearance, phagocytosis of apoptotic leukocytes results in the downregulation of different microglial immune ...
Zhou Hongwei - - 2007
Particulate air pollution is linked to increased pneumonia epidemiologically and diminished lung bacterial clearance experimentally. We investigated the effect of concentrated ambient particles (CAPs, </= PM(2.5)) on the interaction of murine primary alveolar macrophages (AMs) and the murine macrophage cell line, J774 A.1, with Streptococcus pneumoniae. We found that CAPs ...
Hayakawa M - - 2006
Chromoblastomycosis is characterized by the slow development of polymorphic skin lesions (nodules, verrucas, tumores, plaques and scar tissue). Inside the host, infectious propagules adhere to epithelial cells and differentiate into sclerotic forms, which effectively resist destruction by host effector cells and allow onset of chronic disease. A cellular immune response ...
Wang Ruibo - - 2006
BACKGROUND: Exogenous Heat Shock Protein-70 (HSP70), a product of necrotic cell death, binds the lipid raft microdomains of macrophages and, within minutes, stimulates the phagocytosis and presentation of internalized antigens. The aim of this study was to identify (a) the receptor on the lipid raft microdomain that interacts with HSP70 ...
Li Jun - - 2006
The present paradigm dictates that phagocytosis is accomplished mainly by 'professional' phagocytes (such as macrophages and monocytes), whereas B cells lack phagocytic capabilities. Here we demonstrate that B cells from teleost fish have potent in vitro and in vivo phagocytic activities. Particle uptake by B cells induced activation of 'downstream' ...
Potter Paul K - - 2007
It is now accepted that the recognition and uptake of apoptotic cells by phagocytes is a complex process involving a large number of opsonins, receptors and ligands, however the relative contribution of all these molecules are still debated. Here we examined the role of CD31 (PECAM-1) in the recognition/uptake of ...
Frahm Jana - - 2006
The aim of the present study is to investigate whether extremely low frequency electromagnetic fields (ELF-EMF) affect certain cellular functions and immunologic parameters of mouse macrophages. In this study, the influence of 50 Hz magnetic fields (MF) at 1.0 mT was investigated on the phagocytic activity and on the interleukin-1beta ...
Millet Sam - - 2007
Studies that blend a comparative approach to immunology with an appreciation for physiological ecology are defining an important new field in biology--ecological immunology. However, a panel of assays that permits a comparative approach to immunology is not yet available. In this paper, we describe several assays of innate immunity that ...
Orlando Kelly A - - 2006
Apoptotic cells undergo a number of changes to prepare for phagocytosis; most occur during the execution phase of apoptosis, when dying cells undergo shrinkage and/or fragmentation into apoptotic bodies and express phagocytic markers on their surface. Although events during the execution phase are important to prepare corpses for phagocytosis, the ...
Liu G - - 2006
The termination of the apoptotic programme occurs in most cases via recognition and clearance by phagocytes, especially the professional phagocytes, such as macrophages and immature dendritic cells. Engulfed cells do not simply disappear from the midst of living tissues. The fine-defined presentation of yielded self-antigens to T cells is a ...
Gilmour James S - - 2006
Glucocorticoids promote macrophage phagocytosis of leukocytes undergoing apoptosis. Prereceptor metabolism of glucocorticoids by 11beta-hydroxysteroid dehydrogenases (11beta-HSDs) modulates cellular steroid action. 11beta-HSD type 1 amplifies intracellular levels of active glucocorticoids in mice by reactivating corticosterone from inert 11-dehydrocorticosterone in cells expressing the enzyme. In this study we describe the rapid (within ...
Sydlik Ulrich - - 2006
Apoptosis and proliferation are important causes of adverse health effects induced by inhaled ultrafine particles. The molecular mechanisms of particle cell interactions mediating these end points are therefore a major topic of current particle toxicology and molecular preventive medicine. Initial studies revealed that ultrafine particles induce apoptosis and proliferation in ...
Hodge S - - 2006
Chronic obstructive pulmonary disease (COPD) is associated with increased apoptosis and defective phagocytosis in the airway. As uncleared cells can undergo secondary necrosis and perpetuate inflammation, strategies to improve clearance would have therapeutic significance. There is evidence that the 15-member macrolide antibiotic azithromycin has anti-inflammatory properties. Its effects may be ...
Cuesta Alberto - - 2007
The early cellular innate immune responses of the teleost gilthead seabream (Sparus aurata L.) against whole yeast cells were studied. Fish received a single intraperitoneal (i.p.) injection of Saccharomyces cerevisiae and leukocyte mobilization, degranulation, peroxidase content, respiratory burst, phagocytic and cytotoxic activities were assayed in both head-kidney leukocytes (HKLs) and ...
Weigert Andreas - - 2006
Programmed cell death is vital for a number of pathophysiologic settings. Apoptotic cells are rapidly engulfed by phagocytes (ie, macrophages), which in turn acquire an anti-inflammatory phenotype known as alternative activation or the M2-type. Here we show that interaction of apoptotic cells with macrophages attenuates cell death pathways in the ...
Ghosn Eliver Eid Bou - - 2006
The role of B lymphocytes in protecting the host against pulmonary Cryptococcus neoformans infection is until now, uncertain. A recent study using B lymphocyte-deficient mice suggests that B lymphocytes play a protective role in cryptococcal infection. It has been well established that at least three B cell subsets, B-1a, B-1b, ...
Dorhoi A - - 2006
Standardized ethanol extracts of Allium sativum (garlic), Glycyrrhiza glabra (licorice), Plantago major (plantain) and Hippophae rhamnoides (sea buckthorn) were assessed for their effects on cellular immunity in laying hens. Birds (n = 25) had blood samples taken and both specific and non-specific immune cell responsiveness were evaluated by a leukocyte ...
Lindbom John - - 2006
Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. Lately, wear particles generated from traffic have been recognized to be a major contributing source to the overall particle load, especially in the Nordic countries ...
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