Project description:anti-CD3 + anti-CD46 stimulation for 2hr Patient has a mutation in CD46 that leads to reduced cell surface CD46 expression and suffers from episodes of atypical hemolytic uremic syndrome (aHUS), common variable immune deficiency (CVID) and recurrent infections
Project description:Recent data indicate that intracellularly activated and autocrine-functioning complement activation fragments - in conjunction with an NLRP3 inflammasome - is critical for normal human Th1 induction and contraction. More specifically, engagement of of the C3aR and CD46 by autocrine generated C3a and C3b, respectively, drives the metabolic reprogramming needed for IFN-gamma secrtion by human CD4+ T cells. It was not clear whether autocrine complement and/or the NLRP3 inflammasome are also needed for normal human cytotoxic CD8+ T cell (CTL) responses. During this study, we used CTLs isolated from patients with either CD46 deficiency or with NLRP3 hyperactivity to determine that CD46 is also required for normal IFN-gamma secretion as well as killing activity in CTLs, whilst a canonical NLRP3 inflammasome is not required for these key functions. The CD46-deficient patient utilized in this study has a mutation in the CD46 gene that leads to reduced cell surface CD46 expression and a dysfunction in Th1 induction. The patient suffers from episodes of atypical hemolytic uremic syndrome (aHUS) and common variable immune deficiency (CVID) and recurrent infections.
Project description:In this experiment, we explore if circulating microRNAs are altered in patients with atypical hemolytic uremic syndrome (aHUS). To do so, we analyze 4 different pooled samples of aHUS (Pool 1-4) in the arrays and 2 pools of age and gender-matched control samples (Pool F and Pool M). aHUS pools consist of patients samples with different characteristics regarding the presence of complement gene mutations: Pool 1: patients without identified mutations (n=5) Pool 2: patients with mutations in CFH (n=5) Pool 3: patients with mutations in MCP (n=5) Pool 4: patients with mutations in C3 or CFB (n=5) In the case of the control samples, pool F consists of 10 samples of healthy women and pool M consists of 10 samples of healthy men. In conclusion, circulating miRNAs levels are altered in aHUS compared with controls. This alteration is variable and could be mediated by the presence of the complement genetic defect.
Project description:Shiga toxin type 2 (Stx2) is the main virulence factor produced by Stx-producing Escherichia coli (STEC) responsible for hemorrhagic colitis and the life-threatening sequela hemolytic uremic syndrome.
Project description:Analysis of differentiated Caco-2 intestinal epithelial cell line cocultured with probiotics L. acidophilus NCFM™, B. lactis 420, L. salivarius Ls-33 bacterial cells or treated with cell-free supernatant, and with E. coli O157:H7 cell-free supernatant. Lactobacillus and Bifidobacterium are important genera suggested to be beneficial for human health and E. coli O157:H7 is a pathogen causing hemorrhagic colitis and hemolytic uremic syndrome. Results provide insight into the mechanisms underlying the beneficial effects of probiotics on intestinal epithelial cells and a comparison to pathogenic E. coli.
Project description:Hemolytic uremic syndrome caused by an invasive Streptococcus pneumoniae infection (SP-HUS) is a rare and severe disease that primarily affects children under two years of age. The pathophysiology of SP-HUS remains poorly understood, and treatment is largely supportive. Complement factor H (FH) is a key regulator of the alternative pathway of the complement system. It has been hypothesized that loss of sialic acids from FH’s N-glycans may impair its regulatory functions, thereby potentially leading to complement-mediated endothelial cell damage in SP-HUS. In this study, we investigated the N-glycosylation patterns of FH across three N-glycosylation sites for four SP-HUS patients and compared it to healthy controls using LC-MS/MS-based glycopeptide profiling.
Project description:Changes in endothelial phenotype induced by E. coli-derived Shiga toxins (Stx) are believed to play a critical role in the pathogenesis of hemolytic uremic syndrome. Stx inactivate host ribosomes, but also alter gene expression at concentrations that minimally affect global protein synthesis. The effect of Stx on the gene expression profile of human microvascular endothelial cells was examined using the Affymetrix HG-U133A platform. Data were processed using 13 different methods and revealed 369 unique differentially expressed genes, 318 of which were up-regulated and 51 of which were down-regulated. These studies implicated activation of the CXCR4/CXCR7/SDF-1 chemokine pathway in Stx-mediated pathogenesis.
Project description:The microarray data provided here belong to a study that describes two different Shiga toxin (Stx) induced models of hemolytic uremic syndrome (HUS) in mice. Although several rodent models of HUS were published, it still remains difficult to reproduce all clinical features of human HUS. Here, two different Stx2 regimes combined with volume resuscitation were tested in C57BL/6J wild type mice. Animals were euthanized because of kidney injury after 3 or 7 days respectively. Kidneys were removed for histological evaluation and RNA extraction. Kidney injury was confirmed histologically and by laboratory parameters in plasma. Data for the respective vehicle treated groups are also provided here.
Project description:Changes in endothelial phenotype induced by E. coli-derived Shiga toxins (Stx) are believed to play a critical role in the pathogenesis of hemolytic uremic syndrome. Stx inactivate host ribosomes, but also alter gene expression at concentrations that minimally affect global protein synthesis. The effect of Stx on the gene expression profile of human microvascular endothelial cells was examined using the Affymetrix HG-U133A platform. Data were processed using 13 different methods and revealed 369 unique differentially expressed genes, 318 of which were up-regulated and 51 of which were down-regulated. These studies implicated activation of the CXCR4/CXCR7/SDF-1 chemokine pathway in Stx-mediated pathogenesis. Primary human dermal microvascular endothelial cells were treated with vehicle or Shiga toxin (10 fM, 24 h, n = 6) and changes in steady-state mRNA levels were determined by hybridization to Affymetrix HG-U133A arrays