scholarly journals Interleukin-1 synergy with phosphoinositide pathway agonists for induction of interleukin-2 gene expression: molecular basis of costimulation

1990 ◽  
Vol 10 (12) ◽  
pp. 6325-6334
Author(s):  
T J Novak ◽  
D Chen ◽  
E V Rothenberg

The macrophage-derived cytokine interleukin-1 (IL-1) can provide a second signal with antigen to elicit production of interleukin-2 (IL-2) by helper T cells. The pathway(s) involved remains controversial, with protein kinase C and cyclic AMP (cAMP) invoked as possible second messengers. In the murine thymoma EL4.E1, IL-1 could synergize with the phosphoinositide pathway, because the cells made higher levels of IL-2 in the presence of IL-1 than could be induced by phorbol ester plus calcium ionophore alone. IL-1 is unlikely to act through a sustained increase in cAMP in these cells because it did not raise cAMP levels detectably and because IL-1 and forskolin had opposite effects on IL-2 gene expression. Inducible expression of a transfected reporter gene linked to a cloned fragment of the murine IL-2 gene promoter was initially increased by IL-1 costimulation, implying that IL-1 can increase the rate of transcription of IL-2. The minimal promoter elements required for iL-1 responsiveness were located within 321 bp of the IL-2 RNA cap site, and further upstream sequences to -2800 did not modify this response. IL-1 costimulation resulted in enhanced activity of both an inducible NF-kappa B-like factor and one of two distinct AP-1-like factors that bind to IL-2 regulatory sequences. Neither was induced, however, by IL-1 alone. Another AP-1-like factor and NFAT-1, while inducible in other cell types, were expressed constitutively in the EL4.E1 cells and were unaffected by IL-1. These results are discussed in terms of the combinatorial logic of IL-2 gene expression.

1990 ◽  
Vol 10 (12) ◽  
pp. 6325-6334 ◽  
Author(s):  
T J Novak ◽  
D Chen ◽  
E V Rothenberg

The macrophage-derived cytokine interleukin-1 (IL-1) can provide a second signal with antigen to elicit production of interleukin-2 (IL-2) by helper T cells. The pathway(s) involved remains controversial, with protein kinase C and cyclic AMP (cAMP) invoked as possible second messengers. In the murine thymoma EL4.E1, IL-1 could synergize with the phosphoinositide pathway, because the cells made higher levels of IL-2 in the presence of IL-1 than could be induced by phorbol ester plus calcium ionophore alone. IL-1 is unlikely to act through a sustained increase in cAMP in these cells because it did not raise cAMP levels detectably and because IL-1 and forskolin had opposite effects on IL-2 gene expression. Inducible expression of a transfected reporter gene linked to a cloned fragment of the murine IL-2 gene promoter was initially increased by IL-1 costimulation, implying that IL-1 can increase the rate of transcription of IL-2. The minimal promoter elements required for iL-1 responsiveness were located within 321 bp of the IL-2 RNA cap site, and further upstream sequences to -2800 did not modify this response. IL-1 costimulation resulted in enhanced activity of both an inducible NF-kappa B-like factor and one of two distinct AP-1-like factors that bind to IL-2 regulatory sequences. Neither was induced, however, by IL-1 alone. Another AP-1-like factor and NFAT-1, while inducible in other cell types, were expressed constitutively in the EL4.E1 cells and were unaffected by IL-1. These results are discussed in terms of the combinatorial logic of IL-2 gene expression.


1995 ◽  
Vol 15 (2) ◽  
pp. 943-953 ◽  
Author(s):  
R I Scheinman ◽  
A Gualberto ◽  
C M Jewell ◽  
J A Cidlowski ◽  
A S Baldwin

Glucocorticoids are potent immunosuppressants which work in part by inhibiting cytokine gene transcription. We show here that NF-kappa B, an important regulator of numerous cytokine genes, is functionally inhibited by the synthetic glucocorticoid dexamethasone (DEX). In transfection experiments, DEX treatment in the presence of cotransfected glucocorticoid receptor (GR) inhibits NF-kappa B p65-mediated gene expression and p65 inhibits GR activation of a glucocorticoid response element. Evidence is presented for a direct interaction between GR and the NF-kappa B subunits p65 and p50. In addition, we demonstrate that the ability of p65, p50, and c-rel subunits to bind DNA is inhibited by DEX and GR. In HeLa cells, DEX activation of endogenous GR is sufficient to block tumor necrosis factor alpha or interleukin 1 activation of NF-kappa B at the levels of both DNA binding and transcriptional activation. DEX treatment of HeLa cells also results in a significant loss of nuclear p65 and a slight increase in cytoplasmic p65. These data reveal a second mechanism by which NF-kappa B activity may be regulated by DEX. We also report that RU486 treatment of wild-type GR and DEX treatment of a transactivation mutant of GR each can significantly inhibit p65 activity. In addition, we found that the zinc finger domain of GR is necessary for the inhibition of p65. This domain is also required for GR repression of AP-1. Surprisingly, while both AP-1 and NF-kappa B can be inhibited by activated GR, synergistic NF-kappa B/AP-1 activity is largely unaffected. These data suggest that NF-kappa B, AP-1, and GR interact in a complex regulatory network to modulate gene expression and that cross-coupling of NF-kappa B and GR plays an important role in glucocorticoid-mediated repression of cytokine transcription.


1990 ◽  
Vol 10 (11) ◽  
pp. 5967-5976
Author(s):  
H Baumann ◽  
K K Morella ◽  
G P Jahreis ◽  
S Marinković

The transcription rate of the haptoglobin (Hp) gene is stimulated by interleukin-1 (IL-1), IL-6, and dexamethasone in rat hepatoma (H-35) cells. To identify the cis-acting regulatory elements responsive to these hormones, various lengths of 5' Hp gene-flanking regions, including the promoter, were inserted into chloramphenicol acetyltransferase gene expression vectors and transiently introduced into H-35 cells. The first 4 kb of 5' region mediated a severalfold increase in expression after treatment with IL-6 and dexamethasone. No response to IL-1 was detectable. When, however, upstream sequences were deleted to position -165 relative to the transcription start site, a significant stimulation by IL-1 was gained without appreciably affecting the IL-6 response. With the apparent removal of an inhibitory sequence, the promoter-proximal 165-bp region also displayed a severalfold enhanced response to the combination of dexamethasone, IL-1, and IL-6. The sequence from -165 to -147, termed the A-element, was found to be crucial for all hormone regulatory functions. Two copies of the A-element linked to a heterologous promoter responded to the three hormones, but to a lesser degree than in the Hp gene promoter context. The regulatory elements of the rat Hp gene were similarly active in human hepatoma cells. Optimal regulation by IL-6 in HepG2 cells was, however, independent of the A-element. The A-element functioned in these cells exclusively as an IL-1 response sequence. The results suggest that genomic sequences upstream of the rat Hp gene suppress the regulation by specific cytokines more prominently in transient expression assays than in the normal chromosomal context. Moreover, the functional comparison indicated that specific regulatory regions of the rat Hp gene do not function identically in different hepatic cell types.


1990 ◽  
Vol 10 (2) ◽  
pp. 561-568
Author(s):  
H Shimizu ◽  
K Mitomo ◽  
T Watanabe ◽  
S Okamoto ◽  
K Yamamoto

Interleukin-6 (IL-6) is one of the major mediators of inflammation, and its expression is inducible by the other inflammatory lymphokines, interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF-alpha). We demonstrate that a common IL-6 promoter element, termed inflammatory lymphokine-responsive element (ILRE), is important for induction of IL-6 gene expression by IL-1 and TNF-alpha despite possible differences in the mechanisms of action of these lymphokines. Remarkably, the ILRE sequence, located between -73 to -63 relative to the mRNA cap site, is highly homologous to NF-kappa B transcription factor-binding motifs and binds an IL-1-TNF-alpha-inducible nuclear factor; the sequence specificities, binding characteristics, and subcellular localizations of this factor are indistinguishable from those of NF-kappa B. In addition, mutations of the ILRE sequence which impair the binding of this nuclear factor abolished the induction of IL-6 gene expression by IL-1 and TNF-alpha in vivo. These results indicate that a nuclear factor indistinguishable from NF-kappa B is involved in the transcriptional activation of the IL-6 gene by IL-1 and TNF-alpha.


2002 ◽  
Vol 282 (1) ◽  
pp. R173-R183 ◽  
Author(s):  
Min Nian ◽  
Jun Gu ◽  
David M. Irwin ◽  
Daniel J. Drucker

The glucagon-like peptides (GLPs) are synthesized and secreted in a nutrient-dependent manner in rodents; however, the factors regulating human GLP-1 and GLP-2 biosynthesis remain unclear. To understand how nutrients regulate human proglucagon gene expression, we studied the expression of a human proglucagon promoter-growth hormone (GH) transgene in 1.6 human glucagon-GH transgenic mice. Fasting-refeeding significantly decreased and increased the levels of circulating mouse insulin and transgene-derived hGH ( P < 0.05 fasting vs. refeeding) and decreased and upregulated, respectively, the levels of endogenous mouse proglucagon RNA in the ileum but not in the jejunum or colon. High-fiber feeding significantly increased the levels of glucose-stimulated circulating hGH and upregulated levels of mouse intestinal proglucagon gene expression in the jejunum, ileum, and colon ( P < 0.05, 0 vs. 30% fiber diet). In contrast, neither fasting-refeeding nor a high-fiber diet upregulated the expression of the human proglucagon promoter-hGH transgene. These findings demonstrate that human proglucagon gene regulatory sequences specifying tissue-specific expression in gut endocrine cells are not sufficient for recognition of energy-derived signals regulating murine glucagon gene expression in enteroendocrine cells in vivo.


2014 ◽  
Vol 307 (11) ◽  
pp. G1057-G1072 ◽  
Author(s):  
C. A. Cobine ◽  
A. G. Sotherton ◽  
L. E. Peri ◽  
K. M. Sanders ◽  
S. M. Ward ◽  
...  

The effector cells and second messengers participating in nitrergic neuromuscular transmission (NMT) were investigated in the mouse internal anal sphincter (IAS). Protein expression of guanylate cyclase (GCα, GCβ) and cyclic GMP-dependent protein kinase I (cGKI) were examined in cryostat sections with dual-labeling immunohistochemical techniques in PDGFRα+ cells, interstitial cells of Cajal (ICC), and smooth muscle cells (SMC). Gene expression levels were determined with quantitative PCR of dispersed cells from Pdgfrα egfp/+, Kit copGFP/+, and smMHC Cre-egfp mice sorted with FACS. The relative gene and protein expression levels of GCα and GCβ were PDGFRα+ cells > ICC ≫ SMC. In contrast, cGKI gene expression sequence was SMC = ICC > PDGFRα+ cells whereas cGKI protein expression sequence was neurons > SMC ≫ ICC = PDGFRα+ cells. The functional role of cGKI was investigated in cGKI −/− mice. Relaxation with 8-bromo (8-Br)-cGMP was greatly reduced in cGKI −/− mice whereas responses to sodium nitroprusside (SNP) were partially reduced and forskolin responses were unchanged. A nitrergic relaxation occurred with nerve stimulation (NS, 5 Hz, 60 s) in cGKI +/+ and cGKI −/− mice although there was a small reduction in the cGKI −/− mouse. Nω-nitro-l-arginine (l-NNA) abolished responses during the first 20–30 s of NS in both animals. The GC inhibitor ODQ greatly reduced or abolished SNP and nitrergic NS responses in both animals. These data confirm an essential role for GC in NO-induced relaxation in the IAS. However, the expression of GC and cGKI by all three cell types suggests that each may participate in coordinating muscular responses to NO. The persistence of nitrergic NMT in the cGKI −/− mouse suggests the presence of a significant GC-dependent, cGKI-independent pathway.


2021 ◽  
Vol 11 (40) ◽  
pp. 154-155
Author(s):  
Capieaux Etienne ◽  
Donat De Groote ◽  
Pierre Dorfman ◽  
Maurice Jeaner

Background: Metabolic syndrome (MS) is a metabolic disorder associated with obesity, type-II diabetes, and “low grade inflammation”, with the concomitant increased risk of cardiovascular events. As a chronic inflammatory process, MS results in a dysregulation of the cytokine profile. 2L®INFLAM, a Micro-immunotherapy (MI) medication formulated with highly diluted cytokines, is currently prescribed in Belgium for inflammatory diseases and potentially may be helpful for MS patients. Aims: To investigate the impact of 2L®INFLAM on selected gene expression markers (mRNA) in patients suffering from MS, in addition to biological and clinical parameters. Methodology: Four well characterized MS adult patients with stabilized body-weight were advised to take one capsule of 2L®INFLAM per day (by sublingual-oral route) for 6 months (composition in table 1). Concomitantly to biological and clinical examination, genes expression status was assessed by a DNA microarray technology (Oxygen™) comprising 200 genes involved mainly in oxidative stress and inflammation. Whole blood collection was performed before and after treatment (3-6 months) and mRNA levels measured. Gene expression was classified in 3 series (normally expressed, up or down-regulated) and genes related to diabetes predisposition were scored by using a proprietary Diascore (Probiox). Results: Before MI medication, a significant percentage of dysregulated genes (median: 16.3%) as well as a positive Diascore (median: 1.6) were noticed. Impressive correction of dysregulated genes (reaching 90% for one patient) was observed after 3 months of treatment (median: 2.3%) in addition to an improvement of Diascore in 3 MS patients out of 4 (median: 0.5). During the same period, both clinical and biological parameters remained unchanged. Conclusions: MS patients showing a high level of gene dysregulation efficiently normalized after 3 months of 2L®INFLAM (64%-90%), suggesting a biological regulatory effect of MI and a potential benefit of this medication for diabetic patients. Up and down-deregulated gene profiles were specific for each patient and not related to cytokine components of the formula. These preliminary data support the “domino effect” of MI sequential formula to restore in depth the immune homeostasis. DNA microarray technology may represent a promising tool for new provings as well as for biochemical comprehension of the “in vivo” effectiveness of highly diluted immune messengers. Table 1: 2L®INFLAM composition Compounds Dilutions Interleukin-1 (IL-1): 17 CH* Interleukin-1 Ra (IL-1 Ra): 3 CH Interleukin-2 (IL-2): 9 CH Interleukin-4 (IL-4): 7 CH Interleukin-6 (IL-6): 9 CH Interleukin-8 (IL-8): 9 CH Interleukin-10 (IL-10): 4 CH Interleukin-13 (IL-13): 9 CH Ciliary Neuro Trophic Factor (CNTF): 17 CH Leukemia Inhibitory Factor (LIF): 17 CH Oncostatine M (OSM): 9 CH Platelet Derived Growth Factor (PDGF): 5 CH Prostaglandine E2 (PgE2): 200 K** Rantes (Rantes): 17 CH Transforming Growth Factor beta(TGFβ): 5 CH Tumor Necrosis Factor α (TNFα): 17 CH SNA INFLAMa-01 18 C SNA INFLAMb-01 18 CH * CH: Centesimal Hahnemannian (1/100) ** K: Centesimal Korsakovian (1/100)


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