Search results for "Chemotaxi"
showing 10 items of 146 documents
Cilomilast counteracts the effects of cigarette smoke in airway epithelial cells.
2010
Abstract Cigarette smoke extracts (CSE) alter TLR4 expression and activation in bronchial epithelial cells. Cilomilast, a phosphodiesterase-4 inhibitor, inhibits cigarette smoke-induced neutrophilia. This study was aimed to explore whether cilomilast, in a human bronchial epithelial cell line (16-HBE), counteracted CSE effects. In particular, TLR4 expression, IP-10 and IL-8 release, lymphocyte and neutrophil chemotactic activity and ERK and IkBa phosphorylation in CSE and LPS-stimulated 16-HBE were assessed. CSE increased TLR4 expression, reduced IP-10 release and lymphocyte chemotactic activity and increased IL-8 release and neutrophil chemotactic activity. Cilomilast reduced TLR4 expressi…
Cigarette smoke increases Toll-like receptor 4 and modifies lipopolysaccharide-mediated responses in airway epithelial cells.
2008
Airway epithelium is emerging as a regulator of innate immune responses to a variety of insults including cigarette smoke. The main goal of this study was to explore the effects of cigarette smoke extracts (CSE) on Toll-like receptor (TLR) expression and activation in a human bronchial epithelial cell line (16-HBE). The CSE increased the expression of TLR4 and the lipopolysaccharide (LPS) binding, the nuclear factor-kappaB (NF-kappaB) activation, the release of interleukin-8 (IL-8) and the chemotactic activity toward neutrophils. It did not induce TLR2 expression or extracellular signal-regulated signal kinase 1/2 (ERK1/2) activation. The LPS increased the expression of TLR4 and induced bot…
TLR4 upregulation underpins airway neutrophilia in smokers with chronic obstructive pulmonary disease and acute respiratory failure
2010
Activation of Toll-like receptors (TLR) seems to be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Upon TLR activation the release of defensins, including human beta defensin 2 (HBD-2), may occur. In this study, we explored the innate responses in patients with respiratory failure, with and without COPD, requiring intubation and mechanical ventilation. Mini-bronchoalveolar lavage (mini-BAL) samples were collected from nonsmoker subjects without COPD (n = 10), smokers without COPD (n = 6), and smokers with COPD (n = 15). TLR4, TLR2, and HBD-2 expression was evaluated by immunocytochemistry; interleukin (IL)-8, IP-10, and HBD-2 concentrations were evaluated by e…
Angiotensin II Induces Neutrophil Accumulation In Vivo Through Generation and Release of CXC Chemokines
2004
Background—Angiotensin II (Ang II) is implicated in the development of cardiac ischemic disorders in which prominent neutrophil accumulation occurs. Ang II can be generated intravascularly by the renin-angiotensin system or extravascularly by mast cell chymase. In this study, we characterized the ability of Ang II to induce neutrophil accumulation.Methods and Results—Intraperitoneal administration of Ang II (1 nmol/L) induced significant neutrophil recruitment within 4 hours (13.3±2.3×106neutrophils per rat versus 0.7±0.5×106in control animals), which disappeared by 24 hours. Maximal levels of CXC chemokines were detected 1 hour after Ang II injection (577±224 pmol/L cytokine-inducible neut…
Olive Oil–Based Lipid Emulsion's Neutral Effects on Neutrophil Functions and Leukocyte–Endothelial Cell Interactions
2006
Infection remains a drawback of parenteral nutrition (PN), probably related, among other factors, to immunosuppressive effects of its lipid component. Newer preparations may have lesser immunosuppressive impact. This study examines the effects of an olive oil-based lipid emulsion (long-chain triacylglycerols-monounsaturated fatty acids [LCT-MUFA]; ClinOleic) on various functions of human neutrophils in vitro and on rat leukocyte-endothelial cell interactions in vivo compared with LCT (Intralipid) and 50% LCT-50% medium-chain triacylglycerols (MCT; Lipofundin) mixture.Neutrophils isolated from healthy donors were incubated with concentrations (0.03-3 mmol/L) of lipid emulsions encompassing c…
Immune escape mechanism: defective resting and stimulated leukocyte-endothelium interaction in hepatocellular carcinoma of the rat.
2004
Hepatocellular carcinoma represents an increasing therapeutic challenge due to its high incidence and early metastasis. Numerous studies have demonstrated the influence of the vascular system on tumor growth and development. In addition, the role of leukocyte-endothelium interaction in tumor vessels is of particular significance with regard to immunological tumor therapy. In this study we used an experimental in vivo animal model that allows a quantitative analysis on vessel morphology, microcirculation, and leukocyte-endothelium interaction. The vessel architecture in tumor tissue was found to be extremely heterogeneous, with a consecutively variable blood flow velocity. Following superfus…
Biochemical, morphological and immunological findings in a patient with a cutis laxa-associated inborn disorder (De Barsy syndrome).
1986
Clinical symptoms of a male infant are described and compared with cases now classified as the De Barsy syndrome, a distinct disorder related to cutis laxa. Morphologically, clastic fibres in skin were frayed and reduced in number and density. The collagen fibril network was normal. Biochemical studies on collagen metabolism in a skin specimen and in cultured skin fibroblasts showed a normal amino acid content and a normal electrophoretic pattern of collagen constituents. The chemotactic migration of cultured fibroblasts was diminished when compared with fibroblasts from donors of different age groups. Immunological investigations revealed an impaired granulocyte function.
Chemotactic response of human alveolar macrophages and blood monocytes elicited by exposure to sulfur dioxide.
1996
An experimental study was undertaken to investigate the in vitro effect of sulfur dioxide on the chemotactic activity of alveolar macrophages (AM) and blood monocytes (BM). The cells were placed on a polycarbonate membrane and exposed to SO2 0.5, 1.5 and 2.5 ppm for 15 min. Control experiments were performed with exposure of the cells to synthetic air with 5% CO2. After gas exposure the cells were incubated with the chemotactic active agent C5a in 5% carbon dioxide (CO2) at 37 degrees C for 60 min. The numbers of AM and BM passing actively through the membrane were quantified using light microscopy. Our results show a dose-dependent reduction in the migration rate of cells under SO2 exposur…
β2Integrin deficiency yields unconventional double-negative T cells distinct from mature classical natural killer T cells in mice
2009
Expressed on leucocytes, beta(2) integrins (CD11/CD18) are specifically involved in leucocyte function. Using a CD18-deficient (CD18(-/-)) mouse model, we here report on their physiological role in lymphocyte differentiation and trafficking. CD18(-/-) mice present with a defect in the distribution of lymphocytes with highly reduced numbers of naïve B and T lymphocytes in inguinal and axillary lymph nodes. In contrast, cervical lymph nodes were fourfold enlarged harbouring unconventional T-cell receptor-alphabeta (TCR-alphabeta) and TCR-gammadelta CD3(+) CD4(-) CD8(-) (double-negative; DN) T cells that expanded in situ. Using adoptive transfer experiments, we found that these cells did not h…
C1-Esterase-Inhibitor Treatment at Early Reperfusion of Hemorrhagic Shock Reduces Mesentery Leukocyte Adhesion and Rolling
2001
Objective: Complement activation probably plays a pathogenic role in multiple organ failure in shock. This study evaluates the effects of C1-esterase-inhibitor treatment on leukocyte-endothelial interaction in the mesenteric microcirculation in hemorrhagic shock. Methods: Rats underwent median laparotomy and exteriorization of an ileal loop for intravital microscopy of the mesenteric microcirculation. Volume controlled hemorrhagic shock was provoked by arterial blood withdrawal (2.5 mL/ 100 g body wt. for 60 minutes) followed by a 4-hour reperfusion period. C1-INH (100 IU/kg body wt. i.v.) or 0.9% NaCl i.v. were administered as a bolus at the beginning of reperfusion. Reperfusion time mimic…