Chronic infection with Schistosoma mansoni parasites is associated with reduced allergic sensitization in humans, while schistosome eggs protects against allergic airway inflammation (AAI) in mice. One of the main secretory/excretory molecules from schistosome eggs is the glycosylated T2-RNAse Omega-1 (ω1). We hypothesized that ω1 induces protection against AAI during infection.
View Article and Find Full Text PDFDendritic cell (DC) activation and function are underpinned by profound changes in cellular metabolism. Several studies indicate that the ability of DCs to promote tolerance is dependent on catabolic metabolism. Yet the contribution of AMP-activated kinase (AMPK), a central energy sensor promoting catabolism, to DC tolerogenicity remains unknown.
View Article and Find Full Text PDFObesity-associated metabolic inflammation drives the development of insulin resistance and type 2 diabetes, notably through modulating innate and adaptive immune cells in metabolic organs. The nutrient sensor liver kinase B1 (LKB1) has recently been shown to control cellular metabolism and T cell priming functions of DCs. Here, we report that hepatic DCs from high-fat diet-fed (HFD-fed) obese mice display increased LKB1 phosphorylation and that LKB1 deficiency in DCs (CD11cΔLKB1) worsened HFD-driven hepatic steatosis and impaired glucose homeostasis.
View Article and Find Full Text PDFIn response to different stimuli, dendritic cells (DCs) undergo metabolic reprogramming to support their function. Here we describe how fluorescent dyes and antibody-based approaches can be used to assess various metabolic parameters of DCs including glycolysis, lipid metabolism, mitochondrial activity, and the activity of important sensors and regulators of cellular metabolism, mTOR and AMPK. These assays can be performed using standard flow cytometry and will allow for the determination of metabolic properties of DC populations at single-cell level and to characterize metabolic heterogeneity within them.
View Article and Find Full Text PDFInflammatory bowel disease (IBD) is a chronic relapsing inflammation of the intestinal tract with currently not well-understood pathogenesis. In addition to the involvement of immune cells, increasing studies show an important role for fibroblasts in the pathogenesis of IBD. Previous work showed that glycolysis is the preferred energy source for fibroblasts in fibrotic diseases.
View Article and Find Full Text PDFHow mechanistic target of rapamycin complex 1 (mTORC1), a key regulator of cellular metabolism, affects dendritic cell (DC) metabolism and T cell-priming capacity has primarily been investigated in vitro, but how mTORC1 regulates this in vivo remains poorly defined. Here, using mice deficient for mTORC1 component raptor in DCs, we find that loss of mTORC1 negatively affects glycolytic and fatty acid metabolism and maturation of conventional DCs, particularly cDC1s. Nonetheless, antigen-specific CD8 T cell responses to infection are not compromised and are even enhanced following skin immunization.
View Article and Find Full Text PDFBackground: The parasitic trematode evades host immune defenses through secretion of various immunomodulatory molecules. Fatty Acid Binding Proteins (FABPs) are among the main excreted/secreted proteins and have been shown to display anti-inflammatory properties. However, little is currently known regarding their impact on dendritic cells (DCs) and their subsequent capacity to prime specific CD4 T cell subsets.
View Article and Find Full Text PDFAs cancer immunotherapy gains importance, the determination of a patient's ability to react to his/her tumor is unquestionably relevant. Though the presence of T cells that recognize specific tumor antigens is well established, the total frequency of tumor-reactive T cells in humans is difficult to assess, especially due to the lack of broad analysis techniques. Here, we describe a strategy that allows this determination, in both CD4 and CD8 compartments, using T cell proliferation induced by tumor cell-lysate pulsed dendritic cells as the readout.
View Article and Find Full Text PDFLiver Kinase B1 (LKB1) plays a key role in cellular metabolism by controlling AMPK activation. However, its function in dendritic cell (DC) biology has not been addressed. Here, we find that LKB1 functions as a critical brake on DC immunogenicity, and when lost, leads to reduced mitochondrial fitness and increased maturation, migration, and T cell priming of peripheral DCs.
View Article and Find Full Text PDFDendritic cells (DCs) are professional antigen-presenting cells that play a crucial role in the priming and differentiation of CD4 T cells into several distinct subsets including effector T helper (Th) 1, Th17 and Th2 cells, as well as regulatory T cells (Tregs). It is becoming increasingly clear that cellular metabolism shapes the functional properties of DCs. Specifically, the ability of DCs to drive polarization of different Th cell subsets may be orchestrated by the engagement of distinct metabolic pathways.
View Article and Find Full Text PDFDendritic cells (DC) are professional antigen presenting cells, uniquely able to induce naïve T cell activation and effector differentiation. They are, likewise, involved in the induction and maintenance of immune tolerance in homeostatic conditions. Their phenotypic and functional heterogeneity points to their great plasticity and ability to modulate, according to their microenvironment, the acquired immune response and, at the same time, makes their precise classification complex and frequently subject to reviews and improvement.
View Article and Find Full Text PDFCardiac autonomic neuropathy is a neglected diabetic chronic complication for which genetic predictors are rarely reported. Oxidative stress is implicated in the pathogenesis of microvascular complications, and glutathione peroxidase 4 is involved in the detoxification of peroxides and of reactive oxygen species. Thus, the association of a functional variant in the gene encoding glutathione peroxidase 4 (rs713041) with this diabetic complication was investigated in 341 individuals with type 1 diabetes evaluated for cardiac autonomic neuropathy status (61.
View Article and Find Full Text PDFAlthough inflammasome plays a well-known role in animal models of renal injury, limited studies in humans are available, and its participation in diabetic kidney disease (DKD) remains unknown. Aim of this study was to elucidate the contribution of inflammasome genetics in the development of DKD in type-1 diabetes (T1D). The association of functional variants in inflammasome genes with DKD was assessed by multivariate analysis in a retrospective and in a prospective cohort.
View Article and Find Full Text PDFBackground And Aim: Glutathione peroxidase (GPX) is a class of antioxidant enzymes that catalyze the reduction of hydrogen peroxide to water. GPX1 is the most abundant isoform and is expressed in all kidney cells. Isoprostane and advanced oxidation protein products (AOPP) were identified as markers of oxidative stress in patients with kidney disease.
View Article and Find Full Text PDFBackground: A functional variant in the promoter region of the gene encoding tumor necrosis factor (TNF; rs1800629, -308G>A) showed to confer susceptibility to T1D. However, TNF rs1800629 was found, in several populations, to be in linkage disequilibrium with HLA susceptibility haplotypes to T1D. We evaluated the association of TNF rs1800629 with T1D in a cohort of Brazilian subjects, and assessed the impact of HLA susceptibility haplotypes in this association.
View Article and Find Full Text PDFBackground: Given the important contribution of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system to the generation of reactive oxygen species induced by hepatitis C virus (HCV), we investigated two single nucleotide polymorphisms (SNPs) in the putative regulatory region of the genes encoding NADPH oxidase 4 catalytic subunit (NOX4) and its regulatory subunit p22phox (CYBA) and their relation with metabolic and histological variables in patients with HCV.
Methods: One hundred seventy eight naïve HCV patients (49.3% male; 65% HCV genotype 1) with positive HCV RNA were genotyped using specific primers and fluorescent-labeled probes for SNPs rs3017887 in NOX4 and -675 T → A in CYBA.
Oxidative stress plays a pivotal role in the pathophysiology of diabetic nephropathy, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system is an important source of reactive oxygen species in hyperglycemic conditions in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, is increased in patients with diabetic nephropathy. We investigated associations of variants in the CYBA gene, encoding the regulatory subunit p22(phox) of NADPH oxidase, with diabetic nephropathy and plasma AOPP and myeloperoxidase (MPO) concentrations in type 1 diabetic patients.
View Article and Find Full Text PDFBackground: Oxidative stress is involved in development of diabetes complications. Extracellular superoxide dismutase (EC-SOD, SOD3) is a major extracellular antioxidant enzyme and is highly expressed in arterial walls. Advanced oxidation protein products (AOPP) and 8-iso-prostaglandin (isoprostane) are markers of oxidative stress.
View Article and Find Full Text PDFAims/hypothesis: Oxidative stress is involved in the pathogenesis of diabetic nephropathy. The antioxidant enzyme catalase plays a key role in redox regulation in the kidney. We investigated associations of catalase gene (CAT) polymorphisms and plasma catalase activity with diabetic nephropathy in type 1 diabetic patients.
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