Antibiotische Prophylaxe während Neutropenie nach Hochdosistherapie mit autologer Stammzellretransfusion

Diese retrospektive Kohortenstudie wertet die Daten von 336 Patienten aus, die in Neutropenie nach Hochdosistherapie mit autologer Stammzelltransplantation eine antibiotische Prophylaxe erhielten. Es wurden an Lymphomen, Multiplen Myelomen, Sarkomen oder Keimzelltumoren Erkrankte eingeschlossen. Die Prophylaxe mit Colistin (n=137) und Ciprofloxacin (n=164) wurde hinsichtlich der Infektionsraten, mikrobiologischen Ergebnisse und Resistenzraten während Neutropenie verglichen. Es wurde eine Kontrollgruppe (n=35) ohne antibiotische Prophylaxe eingeschlossen. Es zeigte sich eine signifikante Überlegenheit der Prophylaxe in den Infektionsraten (p=0.006), aber kein Unterschied in den Mortalitätsraten (p=0.601). Dies bestätigte sich auch in multivariaten Analysen. Die beiden Prophylaxeregime zeigten untereinander keinen signifikanten Unterschied in den Infektionsraten (p=0.643). Insgesamt konnte ein Vorteil einer Prophylaxegabe mit Hinblick auf die Infektionsraten gezeigt werden

LXRα Regulates oxLDL-Induced Trained Immunity in Macrophages

Reprogramming of metabolic pathways in monocytes and macrophages can induce a proatherosclerotic inflammatory memory called trained innate immunity. Here, we have analyzed the role of the Liver X receptor (LXR), a crucial regulator of metabolism and inflammation, in oxidized low-density lipoprotein (oxLDL)-induced trained innate immunity. Human monocytes were incubated with LXR agonists, antagonists, and oxLDL for 24 h. After five days of resting time, cells were restimulated with the TLR-2 agonist Pam3cys. OxLDL priming induced the expression of LXRα but not LXRβ. Pharmacologic LXR activation was enhanced, while LXR inhibition prevented the oxLDL-induced inflammatory response. Furthermore, LXR inhibition blocked the metabolic changes necessary for epigenetic reprogramming associated with trained immunity. In fact, enrichment of activating histone marks at the IL-6 and TNFα promotor was reduced following LXR inhibition. Based on the differential expression of the LXR isoforms, we inhibited LXRα and LXRβ genes using siRNA in THP1 cells. As expected, siRNA-mediated knock-down of LXRα blocked the oxLDL-induced inflammatory response, while knock-down of LXRβ had no effect. We demonstrate a specific and novel role of the LXRα isoform in the regulation of oxLDL-induced trained immunity. Our data reveal important aspects of LXR signaling in innate immunity with relevance to atherosclerosis formation

Protocol for the induction of innate immune memory in human smooth muscle cells and endothelial cells in vitro

Summary: Non-immune cells, like innate immune cells, can develop a memory-like phenotype in response to priming with microbial compounds or certain metabolites, which enables an enhanced response to a secondary unspecific stimulus. This paper describes a step-by-step protocol for the induction and analysis of trained immunity in human endothelial and smooth muscle cells. We then describe steps for cell culture with cryopreserved vascular cells, subcultivation, and induction of trained immunity. We then provide detailed procedures for downstream analysis using ELISA and qPCR.For complete details on the use and execution of this protocol, please refer to Sohrabi et al. (2020)1 and Shcnack et al.2 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

LXRalpha Regulates oxLDL-Induced Trained Immunity in Macrophages

Reprogramming of metabolic pathways in monocytes and macrophages can induce a proatherosclerotic inflammatory memory called trained innate immunity. Here, we have analyzed the role of the Liver X receptor (LXR), a crucial regulator of metabolism and inflammation, in oxidized low-density lipoprotein (oxLDL)-induced trained innate immunity. Human monocytes were incubated with LXR agonists, antagonists, and oxLDL for 24 h. After five days of resting time, cells were restimulated with the TLR-2 agonist Pam3cys. OxLDL priming induced the expression of LXRalpha but not LXRbeta. Pharmacologic LXR activation was enhanced, while LXR inhibition prevented the oxLDL-induced inflammatory response. Furthermore, LXR inhibition blocked the metabolic changes necessary for epigenetic reprogramming associated with trained immunity. In fact, enrichment of activating histone marks at the IL-6 and TNFalpha promotor was reduced following LXR inhibition. Based on the differential expression of the LXR isoforms, we inhibited LXRalpha and LXRbeta genes using siRNA in THP1 cells. As expected, siRNA-mediated knock-down of LXRalpha blocked the oxLDL-induced inflammatory response, while knock-down of LXRbeta had no effect. We demonstrate a specific and novel role of the LXRalpha isoform in the regulation of oxLDL-induced trained immunity. Our data reveal important aspects of LXR signaling in innate immunity with relevance to atherosclerosis formation