Immune alterations in end-stage renal patients receiving hemodialysis are complex and predispose patients to infections. Anticoagulation may also play an immunomodulatory role in addition to the accumulation of uremic toxins and the effects of the dialysis procedure. Accordingly, it has been recently shown that the infection rate increases in patients under regional citrate anticoagulation (RCA) compared with systemic heparin anticoagulation (SHA).
View Article and Find Full Text PDFis a common cause of hospital-acquired pneumonia associated with high mortality. Adequate clinical treatment is impeded by increasing occurrence of antibiotic resistances. Understanding the underlying mechanisms of its virulence during infections is a prerequisite to finding alternative treatments.
View Article and Find Full Text PDFIn vitro cocultures of macrophages and apoptotic cells (ACs) provide a practical and useful tool to study efferocytosis. Here, we describe a method for automated quantification and imaging of recognition and engulfment of apoptotic cells by primary macrophages using imaging flow cytometry (IFC). IFC-based analysis allows us to successfully quantify efferocytosis, clearly distinguishing phagocytic from nonphagocytic macrophages and, more importantly, from those in recognition stage, which is not achievable by standard flow cytometrical analysis.
View Article and Find Full Text PDFThe proinflammatory alarmins S100A8 and S100A9 are among the most abundant proteins in neutrophils and monocytes but are completely silenced after differentiation to macrophages. The molecular mechanisms of the extraordinarily dynamic transcriptional regulation of and genes, however, are only barely understood. Using an unbiased genome-wide CRISPR/Cas9 knockout (KO)-based screening approach in immortalized murine monocytes, we identified the transcription factor C/EBPδ as a central regulator of and expression.
View Article and Find Full Text PDFIt remains largely unclear how thymocytes translate relative differences in T cell receptor (TCR) signal strength into distinct developmental programs that drive the cell fate decisions towards conventional (Tconv) or regulatory T cells (Treg). Following TCR activation, intracellular calcium (Ca) is the most important second messenger, for which the potassium channel K18.1 is a relevant regulator.
View Article and Find Full Text PDFBackground: Scavenger receptor CD163 is exclusively expressed on monocytes/macrophages and is widely used as a marker for alternatively activated macrophages. However, the role of CD163 is not yet clear.
Objectives: We sought to examine the function of CD163 in steady-state as well as in sterile and infectious inflammation.
The inflammatory responsiveness of phagocytes to exogenous and endogenous stimuli is tightly regulated. This regulation plays an important role in systemic inflammatory response syndromes (SIRSs). In SIRSs, phagocytes initially develop a hyperinflammatory response, followed by a secondary state of hyporesponsiveness, a so-called "tolerance.
View Article and Find Full Text PDFIsolation and characterization of antigen-containing endosomes remains difficult utilizing standard purification techniques. Here, we describe a method, which allows isolation of antigen-loaded endosomes, that is based on flow cytometrical analysis and sorting. We specifically isolated antigen-containing endosomes from cells that had taken up fluorochrome-labeled ovalbumin via mannose receptor-mediated endocytosis.
View Article and Find Full Text PDFThe molecular mechanisms regulating noncanonical protein transport across cellular membranes are poorly understood. Cross-presentation of exogenous antigens on MHC I molecules by dendritic cells (DCs) generally requires antigen translocation from the endosomal compartment into the cytosol for proteasomal degradation. In this study, we demonstrate that such translocation is controlled by the endocytic receptor and regulated by ubiquitination.
View Article and Find Full Text PDF