Search results for "Tumor necrosis factor."
showing 10 items of 848 documents
Inhibition of the NF-κB Signaling Pathway Mediates the Anti-inflammatory Effects of Petrosaspongiolide M
2003
Petrosaspongiolide M (PT) is a potent secretory phospholipase A(2) inhibitor and anti-inflammatory agent. This marine metabolite reduced the production of nitrite, prostaglandin E(2), and tumor necrosis factor-alpha in the mouse air pouch injected with zymosan. These effects were also observed in mouse peritoneal macrophages stimulated with zymosan. Inhibition of these inflammatory mediators was related to reductions in inducible nitric oxide synthase, cyclo-oxygenase-2, and tumor necrosis factor-alpha expression. Since nuclear factor-kappaB (NF-kappaB) appears to play a central role in the transcriptional regulation of these proteins by macrophages, we investigated the effects of PT on thi…
Cytokine expression and antigen-presenting capacity of 4F7 + dendritic cells derived from dermis, spleen, and lymph nodes
1997
We took advantage of the recently generated 4F7 mAb, which recognizes an epitope expressed on dendritic cells (DC) from different tissues, to freshly isolate and positively sort for these cells and to characterize their cytokine pattern and antigen-presenting capacity in comparison with epidermal Langerhans cells (LC). RT-PCR and Northern blot analyses demonstrated constitutive mRNA expression of MIP-1 gamma, MIP-1 alpha, C10, and IL-1 beta in both 4F7+ DC and LC. Lipopolysaccharide (LPS) treatment resulted in the upregulation of mRNA expression of all four cytokines and in a newly detected signal for TNF alpha. Immunoblot analysis showed constitutive secretion of MIP-1 gamma, with LPS trea…
Lovastatin stimulates p75 TNF receptor (TNFR2) expression in primary human endothelial cells
2005
HMG-CoA reductase inhibitors (statins) exert pleiotropic physiological effects. Among others they attenuate cellular responses to genotoxic and inflammatory stress. We investigated the effect of lovastatin on the expression level of TNF receptors (TNFR) in primary human endothelial cells (HUVEC). ELISA, FACS and immunocytochemical analyses show that lovastatin selectively increases the cell surface expression of TNFR2 without affecting the expression level of TNFR1. This effect of lovastatin is independent from inhibition of cell-cycle progression since cells both in G1- and G2-phase showed elevated levels of TNFR2 after lovastatin treatment. To analyze the physiological relevance of lovast…
Influence of extracellular matrix proteins on the development of cultured human dendritic cells.
1998
The development of dendritic cells (DC) is still only partly understood. Recently established culture systems using CD34+ cells or monocytes as precursor cells for the generation of DC indicate the necessity of pro-inflammatory cytokines for their development. In vivo the contact to other cells or to the proteins of the extracellular matrix might also be essential for their development. In our experiments we used granulocyte-macrophage colony-stimulating factor- and IL-4-treated human monocytes as precursor cells to investigate the interaction of DC at different maturation stages with the matrix proteins fibronectin, collagen type I and collagen type IV. We demonstrate a strong beta1-integr…
Interleukin 12 enhances deficient HCV-antigen-induced Th1-type immune response of peripheral blood mononuclear cells
1998
The aim of this study was to examine the possible immunomodulating effects of rhIL-12 on the immune response induced by different hepatitis C virus (HCV) antigens. Freshly isolated peripheral blood mononuclear cells (PBMC) of 33 patients with chronic HCV infection were stimulated with optimal concentrations of antigens from the NS3, NS4, NS5, and core region of HCV in the absence or presence of interleukin12 (IL-12). Stimulation by α-CD3 + α-CD28, lipopolysaccharide (LPS), and pokeweed mitogen (PWM) were used as controls. Proliferation and cytokine production were determined by 3H-thymidine uptake and enzyme-linked immunosorbent assay (ELISA) after 72 hr. After stimulation with antigen or a…
Pro-inflammatory cytokines and prostaglandins induce maturation of potent immunostimulatory dendritic cells under fetal calf serum-free conditions.
1998
Culture conditions for human dendritic cells (DC) have been developed by several laboratories. Most of these culture methods, however, have used conditions involving fetal calf serum (FCS) to generate DC in the presence of granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4. Recently, alternative culture conditions have been described using an additional stimulation with monocyte-conditioned medium (MCM) and FCS-free media to generate DC. As MCM is a rather undefined cocktail, the yield and quality of DC generated by these cultures varies substantially. We report that a defined cocktail of tumor necrosis factor (TNF)-alpha, IL-1beta and IL-6 equals MCM in its potency to …
Effects of Th1 and Th2 cytokines on cytokine production and ICAM-1 expression on synovial fibroblasts
1995
OBJECTIVES--To investigate the influence of the Th1 and Th2 lymphokines interleukins (IL)-4 and IL-13, interferon gamma (IFN gamma), and several monokines on the adhesion of mononuclear cells to synovial fibroblasts and intercellular adhesion molecule-1 (ICAM-1) expression and cytokine production of synovial fibroblasts in patients with osteoarthritis. METHODS--Synovial fibroblasts were isolated from patients with osteoarthritis and stimulated with IL-1 beta, IL-4, IL-6, IL-10, IL-12, IL-13, tumour necrosis factor alpha (TNF alpha), and IFN gamma. Subsequently, we determined the production of IL-1 alpha, IL-1 beta, IL-6, IL-10, IL-12, IFN alpha and TNF alpha, and the expression of ICAM-1 ly…
Major histocompatibility complex regulation of cytokine production.
1996
This review describes the phenomenon of the major histocompatibility complex (MHC) control of cytokine production both in experimental animals and in humans. H-2 (mouse MHC) regulates which type of cytokine is selectively produced in response to the hapten trinitrophenyl (TNP). T cells from TNP-immune H-2k mice produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-3, IL-5, tumor necrosis factor-alpha (TNF-alpha), IL-10, and very low levels of IL-4 on reexposure to the specific antigen in vitro. By contrast, T cells from H-2d mice produce IL-3, TNF-alpha, IL-10, and IL-4 but very low levels of IL-2, IL-5 and IFN-gamma. As MHC-congenic matched strains (BALB/k and BALB/c) are used, th…
INFLAMMATORY CYTOKINES IN ACUTE ISCHEMIC STROKE.
2008
Three major cytokines, namely, tumor necrosis factor (TNF-alpha), interleukin (IL)-1, and IL-6 are produced by cultured brain cells after various stimuli such as ischemia. Neurones, astrocytes, microglia and oligodendrocytes can produce inflammatory mediators, and cytokine receptors are expressed constitutionally throughout the Central Nervous System (CNS), albeit at low levels. Cytokines are involved in virtually every facet of stroke and they have numerous pro-inflammatory and pro-coagulant effects on endothelium. TNF-alpha expression after stroke stimulates expression of tissue factor and adhesion molecules for leukocytes, release of interleukin-1 (IL-1), nitric oxide, factor VIII/von Wi…
Interaction Between Cytokines and Oxidative Stress in Acute Pancreatitis
2006
Acute pancreatitis is an inflammation initially localized in the pancreatic gland which may lead to local and systemic complications. The development of severe acute pancreatitis is mediated by pathophysiological mechanisms involved in the systemic inflammatory response, cytokines and oxidative stress being their components of major importance. Nevertheless, it is still unknown why an episode of acute pancreatitis remains mild or progresses to a severe form. Activated leukocytes are the main source of cytokines. Interleukin 1beta and tumor necrosis factor alpha (TNF-alpha) initiate and propagate almost all the consequences of the systemic inflammatory response syndrome, leading to amplifica…