Dexamethasone is a widely used anti-inflammatory agent for a broad spectrum of diseases. The effectiveness of this agent is thought to be due to the capacity to modulate cytokine production in inflammatory cells. We examined the effects of dexamethasone on expressions of interferon gamma (IFN-gamma) and interleukin 4 (IL-4) by human peripheral blood mononuclear cells (PBMCs) in response to interleukin 12 (IL-12). Dexamethasone (10-5 M) inhibited IFN-gamma secretion, through direct suppression of IFN-gamma, IL-12 receptor (IL-12R) -beta1, and -beta2 expressions. Conversely dexamethasone increased IL-4 secretion as well as IL-4 expressions by PBMCs in response to IL-12. In addition, dexamethasone increased expression of suppressor of cytokine signalling (SOCS)-1, which inhibits JAK-STAT pathway of IL-12R signalling. The result of our study suggested that dexamethasone directly inhibited IFN-gamma expression, through suppression of IL-12 signalling and indirectly increases IL-4 expression, through suppression of IFN-gamma expression.
Dexamethasone* ; Humans ; Interferons ; Interleukin-12* ; Interleukin-4* ; Receptors, Interleukin-12

Asthma is a chronic allergic inflammatory disease of lung. The initiation and progression of asthma is dependent on the cytokines interleukin (IL) -4 and IL-13 acting through related receptor complexes. Disease pathogenesis is effected by intracellular signaling pathways that couple primarily to specific motifs within the intracellular domain of the IL-4 receptor alpha chain (IL-4R alpha), a subunit that is common to the IL-4 and IL-13 receptor complexes. Neutralizing anti-cytokine strategies have proven to be highly successful on dissecting relevant effector pathways in experimental allergic disease, and are now entering clinical trials in human allergic disorders. Although there have been only a few clinical studies on the effects of cytokine modulators in asthma, this line of research and development appears promising.
Asthma* ; Cytokines ; Humans ; Interleukin-13 ; Interleukin-4 ; Interleukins ; Lung ; Receptors, Interleukin-13 ; Receptors, Interleukin-4

No abstract available.
Interleukin-4* ; Interleukins* ; Receptors, Interleukin-4* ; Rheumatic Diseases*

No abstract available.
Interleukin-2* ; Interleukins* ; Mucocutaneous Lymph Node Syndrome* ; Receptors, Interleukin-2*

Interleukin-8 (IL-8), which is a member of C-X-C chemokine subfamily, is an important activator and chemoattractant for neutrophils and has been implicated in a variety of inflammatory diseases. Numerous reports show that various cells express IL-8 mRNA and produce IL-8 protein rapidly, including monocytes, T lymphocytes, neutrophils, fibroblasts, endothelial cells and epithelial cells. The human IL-8 gene has a length of 5191 bp and contains four exons separated by three introns. It maps to human chromosome 4q12-q21. The mRNA consists of a 101 bases 5' untranslated region, an open reading frame of 297 bases, and a long 3' untranslated region of 1.2 kb. The 5' flanking region of the IL-8 gene contains potential binding sites for several nuclear factors including activated protein-1 (AP-1), activated protein-2 (AP-2), nuclear factor-gene binding (NF-kappa B), nuclear factor-interleukin-6 (NF-IL-6, also calls CAAT/enhancer-binding proteins, C/EBP), IFN regulatory factor-1 (IRF-1), hepatocyte nuclear factor-1 (HNF-1), and so on. IL-8 gene expression is regulated initially at the level of gene transcription. The rapid induction of IL-8 gene expression is likely mediated by latent transcription factors that bind the IL-8 promoter. AP-1 and NF-IL-6 physically interact with NF-kappa B, and functional cooperativity among these factors appears to be critical for optimal IL-8 promoter activity in different cell types. The IL-8 receptor (IL-8R) is a dimeric glycoprotein consisting of a 59 KDa and a 67 KDa subunit. It has been given the name CDw128. It is expressed in many different cell types including those not responding to IL-8. The receptor density is approximately 20,000/cell in neutrophils, 1,040/cell in monocytes, and 300/cell in T-lymphocytes. The IL-8R is a member of the family of G-protein-coupled receptors. There are at least two different IL-8 receptor types (CXCR1 and CXCR2). The activities of IL-8 are not species-specific. IL-8 affects the adhesion of neutrophils to the endothelium and induces the transendothelial migration of neutrophils. IL-8 also exhibits in vitro chemotactic activities against of T-lymphocytes and basophils. IL-8 gene expression can be regulated by fluid shear stress, which may play an important role in the genesis and development of both inflammation and arterosclerosis.
Gene Expression Regulation ; Interleukin-8 ; chemistry ; genetics ; physiology ; Receptors, Interleukin

We investigated the question of whether cholesterol catabolite can influence expression of inflammatory cytokines via Toll-like receptors (TLR) in monocytic cells. Treatment of THP-1 monocytic cells with 27-hydroxycholesterol (27OHChol) resulted in induction of gene transcription of TLR6 and elevated level of cell surface TLR6. Addition of FSL-1, a TLR6 agonist, to 27OHChol-treated cells resulted in transcription of the IL-1alpha gene and enhanced secretion of the corresponding gene product. However, cholesterol did not affect TLR6 expression, and addition of FSL-1 to cholesterol-treated cells did not induce expression of IL-1alpha . Using pharmacological inhibitors, we investigated molecular mechanisms underlying the expression of TLR6 and IL-1alpha. Treatment with Akt inhibitor IV or U0126 resulted in significantly attenuated expression of TLR6 and IL-1alpha induced by 27OHChol and 27OHChol plus FSL-1, respectively. In addition, treatment with LY294002, SB202190, or SP600125 resulted in significantly attenuated secretion of IL-1alpha . These results indicate that 27OHChol can induce inflammation by augmentation of TLR6-mediated production of IL-1alpha in monocytic cells via multiple signaling pathways.
Cholesterol ; Cytokines ; Inflammation ; Interleukin-1 ; Interleukin-1alpha* ; Toll-Like Receptors*

Purpose: IL-1 is a multifunctional proinflammatory cytokine. As the proliferative effects of IL-6 and IL-6 receptor expressions on prostatic cancer cells in response to IL-1 have not been determined, the effects of IL-1 on prostatic cancer cell lines were investigated. Materials and Methods: PC-3 and DU-145 cells were cultured in RPMI-1640 medium containing 10% fetal bovine serum. Cell cultures were supplemented with various concentrations of IL-1 (0, 1, 10, 20 and 40ng/ml), and the MMT growth assay performed. PC-3 and DU-145 cells were treated for 2, 4, 8, 12 and 24 h both with and without IL-1. IL-6 and IL-6 receptor (IL-6R) mRNA expressions were investigated using RT-PCR, and the IL-6 levels in cultured supernatant measured by ELISA. Results: The viability of both PC-3 and DU-145 cells decreased after IL-1 treatment (10, 20 and 40ng/mul). With 40ng/ml the IL-1, IL-6 and IL-6RmRNA expressions were lower in PC-3 cells, but unchanged in DU-145 cells, whereas the IL-6 protein production was higher in both PC-3 and DU-145 cells. Conclusions: IL-1 inhibited the proliferation of both PC-3 and DU145 cells. In the PC-3 cells, IL-1 decreased the expressions of IL-6 and IL-6R mRNA, but paradoxically increased the IL-6 production. In the DU-145 cells, IL-1 treatment did not affect the IL-6 or IL-6R mRNA expressions, but the IL-6 production was increased. This discrepancy between IL-1-induced IL-6 mRNA and protein production may be mediated by modification to the protein synthesis or an increased cellular excretion.
Cell Culture Techniques ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; Interleukin-1 ; Interleukin-1beta* ; Interleukin-6* ; Interleukins* ; Prostatic Neoplasms* ; Receptors, Interleukin* ; Receptors, Interleukin-6 ; RNA, Messenger

Animals ; Antibodies, Monoclonal ; immunology ; Humans ; Receptors, Interleukin-17 ; immunology

Culture of human peripheral T lymphocytes with irnmobilized anti-CD3 rnAb plus IL-2 resulted in a marked proliferation and the enhancing IL-2Ra mRNA expression. The process of the T cell activation involves a series of biochemical events which ultimately lead to the proliferation and IL-2Ra mRNA expression. Although the above results have been observed, the celluar signal mechanisms between the proliferative response and the IL-2Ra mRNA expression through T cell receptor and IL-2 receptor remains unresolved. In the present study, We have used genistein (the selective PTK inhibitor) or chronic PMA treatment (depletion of intracelluar PKC activity), to investigate the role of PTK or PKC both in a synergistic proliferation and in the enhancing IL-2Ra mRNA expression by IL-2/anti-CD3. Genistein (30 ug/ml) completely blocked IL-2 induced T cell proliferation, and inhibited anti-CD3 induced T cell proliferation (93.4%). But genistein downregulated the IL-2Ra mRNA expression by IL-2, anti-CD3 and IL-2/anti-CD3. The chronic PMA treatment failed to inhibit the proliferation and the IL-2R#u mRNA expression by IL-2 alone. But PKC depleted T cells stimulated with anti-CD3 mAb showed the decrease of the proliferation (68.6%) and IL-2Ra mRNA expression. In activated with IL-2/anti- CD3, the proliferative response showed a half of reduction, but the IL-2Ra mRNA expression were not regulated. These results demonstrate that proliferative response to IL-2 appears to be dependent on PTKs activity and independent of PKC involvement, but the IL-2Ra mRNA expression may be required another signals. PTKs and PKC activity may be important in TCR/CD3 signaling. But IL-2/anti-CD3 are coupled up different signal transduction pathways responsible for the synergistic T cell proliferation and the enhancing IL-2Ru mRNA expression.
Cell Proliferation ; Genistein ; Humans ; Interleukin-2* ; Receptors, Antigen, T-Cell ; Receptors, Interleukin-2 ; RNA, Messenger* ; Signal Transduction ; T-Lymphocytes

BACKGROUND AND OBJECTIVES: The IL-4 receptor (IL-4R) gene has been suggested as a candidate gene for atopic diseases. The IL-4R consists of two subunits: the alpha chain (IL-4Ralpha), which is a high-affinity IL-4 binding site shared with the IL-13R, and the common gamma chain shared with several other cytokine receptors that amplifies signalling of the alpha chain. A Gln551Arg polymorphism of the IL-4Ralpha gene was shown to be a gain-of-function mutation and was associated with atopy. We tested whether a Gln551Arg polymorphism of IL-4Ralpha gene is associated with allergic rhinitis, blood eosinophil counts and total serum IgE levels in the Korean population. SUBJECTS AND METHOD: Blood samples for genetic analysis were obtained from 192 individuals with allergic rhinitis and from 191 healthy subjects without atopic diseases. Polymerase chain reaction-based assay for IL-4Ralpha Gln551Arg was used for genotyping. Serum total IgE levels were determined by using the immunoassay. Eosinophil values were determined by eosinophil numbers per total cell numbers per microL . RESULTS: There were no differences in the frequencies of the genotypes of IL-4Ralpha in the controls and patients (p>0.05). The frequencies of the IL-4Ralpha Arg551 allele were statistically different between controls and patients (p>0.05). Blood eosinophil count and total serum IgE levels were not statistically different in the genotypes of IL-4Ralpha Gln551Arg in allergic rhinitis (p>0.05). CONCLUSION: Our result suggests that the IL-4Ralpha Gln551Arg polymorphism might not give susceptibility to the development of allergic rhinitis in Koreans.
Alleles ; Binding Sites ; Cell Count ; Eosinophils ; Genotype ; Humans ; Immunoassay ; Immunoglobulin E ; Interleukin-4* ; Receptors, Cytokine ; Receptors, Interleukin-4* ; Rhinitis*