| 1. |
- Hecker, Andreas, et al.
(författare)
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Phosphocholine-Modified Macromolecules and Canonical Nicotinic Agonists Inhibit ATP-Induced IL-1 beta Release
- 2015
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Ingår i: Journal of Immunology. - : AMER ASSOC IMMUNOLOGISTS. - 0022-1767 .- 1550-6606. ; 195:5, s. 2325-2334
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Tidskriftsartikel (refereegranskat)abstract
- IL-1 beta is a potent proinflammatory cytokine of the innate immune system that is involved in host defense against infection. However, increased production of IL-1 beta plays a pathogenic role in various inflammatory diseases, such as rheumatoid arthritis, gout, sepsis, stroke, and transplant rejection. To prevent detrimental collateral damage, IL-1 beta release is tightly controlled and typically requires two consecutive danger signals. LPS from Gram-negative bacteria is a prototypical first signal inducing pro-IL-1 beta synthesis, whereas extracellular ATP is a typical second signal sensed by the ATP receptor P2X7 that triggers activation of the NLRP3-containing inflammasome, proteolytic cleavage of pro-IL-1 beta by caspase-1, and release of mature IL-1 beta. Mechanisms controlling IL-1 beta release, even in the presence of both danger signals, are needed to protect from collateral damage and are of therapeutic interest. In this article, we show that acetylcholine, choline, phosphocholine, phosphocholine-modified LPS from Haemophilus influenzae, and phosphocholine-modified protein efficiently inhibit ATP-mediated IL-1 beta release in human and rat monocytes via nicotinic acetylcholine receptors containing subunits alpha 7, alpha 9, and/or alpha 10. Of note, we identify receptors for phosphocholine-modified macromolecules that are synthesized by microbes and eukaryotic parasites and are well-known modulators of the immune system. Our data suggest that an endogenous anti-inflammatory cholinergic control mechanism effectively controls ATP-mediated release of IL-1 beta and that the same mechanism is used by symbionts and misused by parasites to evade innate immune responses of the host.
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| 2. |
- Richter, Katrin, et al.
(författare)
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Phosphocholine-Modified Lipooligosaccharides of Haemophilus influenzae Inhibit ATP-Induced IL-1 beta Release by Pulmonary Epithelial Cells
- 2018
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Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 23:8
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Tidskriftsartikel (refereegranskat)abstract
- Phosphocholine-modified bacterial cell wall components are virulence factors enabling immune evasion and permanent colonization of the mammalian host, by mechanisms that are poorly understood. Recently, we demonstrated that free phosphocholine (PC) and PC-modified lipooligosaccharides (PC-LOS) from Haemophilus influenzae, an opportunistic pathogen of the upper and lower airways, function as unconventional nicotinic agonists and efficiently inhibit the ATP-induced release of monocytic IL-1 beta. We hypothesize that H. influenzae PC-LOS exert similar effects on pulmonary epithelial cells and on the complex lung tissue. The human lung carcinoma-derived epithelial cell lines A549 and Calu-3 were primed with lipopolysaccharide from Escherichia coli followed by stimulation with ATP in the presence or absence of PC or PC-LOS or LOS devoid of PC. The involvement of nicotinic acetylcholine receptors was tested using specific antagonists. We demonstrate that PC and PC-LOS efficiently inhibit ATP-mediated IL-1 beta release by A549 and Calu-3 cells via nicotinic acetylcholine receptors containing subunits alpha 7, alpha 9, and/or alpha 10. Primed precision-cut lung slices behaved similarly. We conclude that H. influenzae hijacked an endogenous anti-inflammatory cholinergic control mechanism of the lung to evade innate immune responses of the host. These findings may pave the way towards a host-centered antibiotic treatment of chronic airway infections with H. influenzae.
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