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Proinflammatory Cytokines Interleukin (proinflammatory + cytokine_interleukin)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Toll-like receptor 3 agonist poly(I:C)-induced antiviral response in human corneal epithelial cells

IMMUNOLOGY, Issue 1 2006
Ashok Kumar
Summary The objective of this study was to examine the expression of Toll-like receptor 3 (TLR3) by human corneal epithelial cells (HCECs) and to determine whether exposure to the TLR3 agonist polyinosinic-polycytidylic acid [poly(I:C)]induces an antiviral response in these cells. Fluorescence-activated cell sorter (FACS) analysis revealed TLR3 to be constitutively expressed and distributed intracellularly in HCECs. Stimulation of HCECs with the TLR3 agonist poly(I:C) induced the activation of nuclear factor (NF)-,B and production of the proinflammatory cytokine interleukin (IL)-6 and the chemokine IL-8. Upon exposure to poly(I:C), HCECs initiated a potent antiviral response resulting in an increase of interferon (IFN)-, mRNA expression (7-fold). Poly(I:C) stimulation also up-regulated mRNA expression of the antiviral chemokine IFN-, inducible protein 10 (IP10), myxovirus resistance gene A and 2,,5,-oligoadenylate synthetase (5-, 10- and 9-fold, respectively), and secretion of IP10. These responses were also induced by exogenously added type 1 IFNs, but could not be blocked by pretreatment of the cells with anti-TLR3 monoclonal antibody, suggesting that the receptor was not expressed on the cell surface. Furthermore, incubation of HCECs with an endosomal acidification inhibitor, chloroquine, markedly inhibited poly(I:C)-mediated IFN-, expression in HCECs. These results suggest that corneal epithelial cells are important sentinels of the corneal innate immune system against viral infection, and that stimulation of TLR3 can induce the expression of key proinflammatory cytokines and chemokines and antiviral genes that help in the defence of the cornea against viral infection. [source]

Regulation of epithelial cell cytokine responses by the ,3,1 integrin

IMMUNOLOGY, Issue 2 2003
Farah D. Lubin
Summary Epithelial cells (EC) from various tissues can produce important cytokines and chemokines when stimulated by proinflammatory cytokines. These EC also receive signals from cell surface integrins, like the ,3,1 integrin, which is important in cell migration and wound healing of epithelial monolayers. However, little is known of the effect of integrin signals on cytokine responses by EC. Colonic Caco-2 cells treated with an anti-,3 integrin antibody prior to stimulation with the proinflammatory cytokine interleukin (IL)-1 yielded suppressed levels of mRNA and secreted IL-6, IL-8 and monocyte chemoattractant protein-1 as compared to cells treated with normal mouse immunoglobulin G. Lung A549 cells also showed a similar suppression of cytokine secretion. Likewise, treatment of the Caco-2 cells with the same antibody suppressed tumour necrosis factor-,-stimulated IL-6 secretion. Fab fragments of the anti-,3 integrin antibody did not induce the suppressive effect but did block the suppressive effect of the whole antibody suggesting that the effect of the antibody required cross-linking of the integrins. Finally, culture of the Caco-2 cells on laminin type 5 (the major ligand for this integrin) yielded depressed levels of IL-1-induced IL-6 secretion as compared to cells on laminin type 1. These data are the first indication that the ,3,1 integrin may cause a suppression of cytokine responses by EC which may be important in regulating the capacity of EC to respond during inflammation or wound healing. [source]

The Immune,Endocrine Interaction Varies with the Duration of the Inflammatory Process in Cardiac Surgery Patients

JOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2000
A. Roth-Isigkeit
The present study investigated the perioperative course of cytokine release and hypothalamic-pituitary-adrenal (HPA) axis activation in relation to the duration of the inflammatory response in cardiac surgery patients. Twelve male patients scheduled for elective coronary artery bypass grafting surgery with cardiopulmonary bypass and general anaesthesia were divided into two study groups: group 1 (n=6) underwent surgery at 13.00 h±30 min, group 2 (n=6) at 08.30 h±50 min. Blood samples were collected preoperatively and up to the first postoperative day. Postoperatively, on the day of surgery, serum concentrations of the proinflammatory cytokines interleukin (IL)-6, IL-1, and tumour necrosis factor (TNF)- , were not significantly different between the two groups, while blood concentrations of cortisol, adrenocorticotrophic hormone (ACTH) and , -endorphin in group 2 patients were significantly higher than in group 1 patients. Postoperatively, on the day of surgery, ACTH and cortisol concentrations in group 1 patients were positively correlated to the blood concentrations of IL-1,, IL-6 and TNF- ,. By contrast, group 2 patients showed no significant relationship between cytokine release and activation of HPA axis at this time. Our results suggest that in patients undergoing cardiac surgery, the cytokine response is initiated before the HPA axis is fully activated. In the early postoperative period, cytokines appear to be involved in the activation of the HPA axis, while in the later postoperative period, high cortisol concentrations may inhibit the release of IL-6. [source]

Erythema Toxicum Neonatorum: An Immunohistochemical Analysis

PEDIATRIC DERMATOLOGY, Issue 3 2001
Giovanna Marchini M.D., Ph.D.
The recruitment of leukocytes to tissues implicates the involvement of adhesion molecules, cytokines, and chemokines. We therefore performed immunohistochemistry on punch biopsy specimens from cutaneous lesions of ten 1-day-old infants with erythema toxicum using specific monoclonal antibodies directed against a variety of adhesion molecules, cytokines, chemokines, and cell type-specific membrane markers. Biopsy specimens of noninflamed skin from four matched newborns and four adults served as controls. The immunohistologic features of erythema toxicum in all 10 infants included a strong staining of the adhesion molecule E-selectin in the vessel wall and the presence of numerous inflammatory cells that were identified as dendritic cells (CD1a, CD83, HLA-DR, CD40, and ICAM-1 positive), eosinophils (EG2 positive), neutrophils (CD15 positive), macrophages (CD14, CD68, and Mac387 positive), and E-selectin-expressing cells. Furthermore, the lesions showed a high incidence of the proinflammatory cytokines interleukin (IL)-1, and IL-1, and of the chemokines IL-8 and eotaxin. This immunologic activity was reduced or absent in noninflamed skin from newborn controls and adults. We conclude that there is an accumulation and activation of immune cells in the lesions of erythema toxicum, also present in noninflamed skin of 1-day-old infants, but to a lower level. The physiologic significance of the rash remains to be elucidated. [source]

Proinflammatory action of the antiinflammatory drug infliximab in tumor necrosis factor receptor,associated periodic syndrome

ARTHRITIS & RHEUMATISM, Issue 2 2009
Belinda Nedjai
Objective Tumor necrosis factor receptor (TNFR),associated periodic syndrome (TRAPS) is an autosomal-dominant autoinflammatory condition caused by mutations in the TNFRSF1A gene. Unlike other autoinflammatory diseases in which anti-TNF therapy is largely a successful treatment option, therapy with the anti-TNF drug infliximab is often ineffective in patients with TRAPS. Moreover, in certain cases, infliximab actually triggers severe episodes of inflammation. The aim of this study was to elucidate the mechanisms underlying such a reaction. Methods Peripheral blood mononuclear cells (PBMCs) were obtained from patients with TRAPS. Both caspase 3 activity and NF-,B subunit activity were determined by enzyme-linked immunosorbent assay. Cytokine secretion was assessed using a specific customized human multiplex bead immunoassay kit. Results Unlike findings in controls, cells from a family of 9 patients, all of whom carried the T50M mutation in TNFRSF1A, failed to respond to infliximab through proapoptotic induction of caspase 3 activity. Instead, we observed enhanced antiapoptotic c-Rel subunit activity, accompanied by a significant increase in secretion of the proinflammatory cytokines interleukin- 1, (IL-1,), IL-1 receptor, IL-6, IL-8, and IL-12. Conclusion Altered extracellular conformation of TNFRI, resulting from the T50M mutation in TNFRSF1A, results in failure of PBMCs to induce an apoptotic response to infliximab. We hypothesize that failure to shed infliximab-bound TNF/TNFRI from the cell surface of cells from patients with the T50M mutation triggers c-Rel activation, and that this leads to a marked increase in cytokine secretion and an increased proinflammatory response. In light of these findings, we strongly advise caution when prescribing infliximab as anti-TNF therapy to patients with TRAPS. [source]