Cryptococcal capsular glucuronoxylomannan reduces ischaemia-related neutrophil influx.
ABSTRACT The capsular polysaccharide glucuronoxylomannan (GXM) of Cryptococcus neoformans interferes with the chemotaxis and transendothelial migration of neutrophils. Intravenous administration of purified GXM has been shown to reduce the influx of inflammatory cells in an animal model of bacterial infection. Here we show that isolated GXM can also interfere with neutrophil migration in a model of inflammation not related to infection. We assessed the effects of intravenous GXM on neutrophil infiltration in a rat model of myocardial ischaemia, where neutrophil infiltration has been shown to contribute to postischaemic reperfusion injury.
Rats were subjected to coronary artery ligation followed by a 3-h reperfusion period. Myeloperoxidase-activity was measured in the ischaemic tissues as a marker of neutrophil infiltration.
Intravenous administration of GXM markedly reduced the influx of neutrophils in the ischaemic myocardium as measured by a 65% reduction of tissue MPO activity. This reduction of MPO activity was clearly correlated to the serum concentration of GXM. As complement activation by GXM was minimal at the doses applied in vivo, it is unlikely that generation of chemotactic C5a in the circulation by GXM caused the observed reduction in leucocyte migration.
Purified cryptococcal GXM has the ability to reduce neutrophil influx even outside the scope of infection.
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ABSTRACT: The surface properties of monodisperse poly (N-isopropylacrylamide-co-acrylic acid) hydrogel microspheres with different sizes were studied by measuring the electrophoretic mobility of the microspheres in the solutions at pH 7.4 with the ionic strengths between 0.005 and 0.154 M at 25, 30, 33, 35, 40, and 45 °C. Poly (N-IPAAm) microspheres show positive mobility at all ionic strengths and temperatures, while poly (N-IPAAm-co-AAc) microspheres have negative mobility. Higher absolute values of electrophoretic mobility were obtained with smaller microspheres than the larger ones at each temperature. By analyzing the data with an electrokinetic theory for “soft” surfaces, it was shown that smaller microspheres have higher surface charge density than the larger ones, although the microspheres were prepared from monomer solutions with the same monomer composition. The observed size dependence of the electrophoretic mobility suggests that charged acrylic acid monomers have a tendency to be localized in the microsphere core region, whereby the surface region of microspheres becomes poor in charges, reducing the mobility of larger microspheres. On the other hand, poly (N-IPAAm) is a thermosensitive hydrogel with a phase transition temperature around 33 °C, under which it is in a swollen state and above which in shrunken state. Therefore, the surface charge density of poly (N-IPAAm-co-AAc) microspheres increased above their phase transition temperatures. Also their surfaces became harder by the shrinkage of the polymer chains at the surfaces. It was found that the smaller microspheres show higher temperature-dependent changes in their surface charge density than the larger ones.Studies in surface science and catalysis 01/2001;
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ABSTRACT: The study was aimed to investigate the potential mechanism of inflammatory renal damage induced by shock wave. A total of 48 rats, with the right kidney cut, are randomly assigned into control group, ESWL group and ESWL + PDTC group. Rats were treated with shock wave at the left kidney. At post-shock wave 3 and 105 days, all the animals were sacrificed for detecting the expression of tumor necrosis factor (TNF)-α, intercellular adhesion molecule (ICAM)-1, and monocyte chemoattractant protein (MCP)-1. The inflammatory responses were evaluated by detecting the level of myeloperoxidase (MPO) and ED-1. The histological renal injury was also examined. Before the animals were sacrificed, the urine samples were collected for measuring the values of malondialdehyde (MDA), β2-microglobulin, interleukin (IL)-6, and IL-18. At post-shock wave 3 days, the higher expression of ICAM-1 and TNF-α were observed in shock wave-treated kidneys. The level of urine TNF-α, IL-6, and IL-18 were also increased significantly. Using PDTC obviously decreased the expression of ICAM-1 and TNF-α. It also effectively inhibited the degree of oxidative stress and neutrophil infiltration. At post-shock wave 105 days, the expression of MCP-1 and the level of urine β2-microglobulin and IL-18 were increased significantly. The histological analysis also indicated more ED-1-positive cells and serious fibrosis in shock wave-treated kidneys. PDTC significantly suppressed MCP-1 and IL-18 expression, decreased monocyte infiltration, and alleviate the degree of interstitium fibrosis. Shock wave triggered excessive inflammatory responses and aggravated renal biological damage. Several inflammatory factors including ICAM-1, MCP-1, and TNF-α were considered to play important role in this type of renal damage.Inflammation 03/2014; · 1.92 Impact Factor
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ABSTRACT: Trichoderma stromaticum, a biocontrol agent of the cacao witches' broom pathogen Moniliophthora perniciosa, has been used in Brazil as part of the integrated pest management of cacao. At the present time, little is known about the effects of T. stromaticum on the modulation of in vitro or in vivo immune responses. The present study examined the interaction of T. stromaticum spores with cellular and molecular components of the immune system following intranasal sensitization of mice. Our results showed that T. stromaticum spores prevented the expression and production of inflammatory mediators in macrophages stimulated with interferon (IFN)-γ plus lipopolysaccharide (LPS) and neutrophils stimulated with phorbol myristate 13-acetate (PMA). Quantitative polymerase chain reaction (qPCR) assays revealed that T. stromaticum spores inhibited the expression of dectin-1 and Toll-like-receptor (TLR)2/TLR4. Intranasal injection of BALB/c mice and subsequent challenge with spores of T. stromaticum induced a discrete inflammatory response in the lungs. Interestingly, the spores inhibited local and systemic production of the regulatory IL-10 and proinflammatory IFN-γ cytokines. In addition the spores presented an antiproliferative effect on spleen cells. These findings showed that the biopesticide T. stromaticum may exert immunosuppressive effects in vitro and in vivo.Journal of Toxicology and Environmental Health Part A 07/2011; 74(14):943-58. · 1.83 Impact Factor