IRF4 haploinsufficiency in a family with Whipple’s disease
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE102862 | GEO | 2017/10/30
SECONDARY ACCESSION(S): PRJNA415625
REPOSITORIES: GEO
Similar Datasets
Project description:The germinal center (GC) reaction is a coordinated and dynamic ensemble of cells and processes that mediate the maturation and selection of high-affinity GC B cells (GCBs) from lower-affinity precursors and ultimately results in plasma cell and memory cell fates that exit the GC. It is of great interest to identify intrinsic and extrinsic factors that control the selection process. The transcription factor IRF4, induced upon BCR and CD40 signaling, is essential for the acquisition of plasma cell and GCB cell fates. We hypothesized that beyond this early requirement, IRF4 continuously operates at later phases of the B cell response. We show that IRF4 is expressed in GCBs at levels greater than seen in resting cells and plays a role in efficient selection of high-affinity GCBs. Halving Irf4 gene copy number in an Ag-specific murine B cell model, we found that Ag presentation, isotype switching, GC formation and zonation, somatic hypermutation rates, and proliferation were comparable with cells with a full Irf4 allelic complement. In contrast, Irf4 haploinsufficient GCBs exhibited impaired generation of high-affinity cells. Mechanistically, we demonstrate suboptimal Blimp-1 regulation among high-affinity Irf4 haploinsufficient GCBs. Furthermore, in cotransfer settings, we observed a marked disadvantage of Irf4 haploinsufficient cells for GC entry, evidential of ineffective recruitment of T cell help. We propose that, analogous to its role in early GC entry, IRF4 continues to function in the late phase of the Ab response to promote productive T follicular helper cell interactions and to activate optimal Blimp-1 expression during GC selection and affinity maturation.
| S-EPMC9085970 | biostudies-literature
Project description:Most humans are exposed to Tropheryma whipplei (Tw). Whipple's disease (WD) strikes only a small minority of individuals infected with Tw (<0.01%), whereas asymptomatic chronic carriage is more common (<25%). We studied a multiplex kindred, containing four WD patients and five healthy Tw chronic carriers. We hypothesized that WD displays autosomal dominant (AD) inheritance, with age-dependent incomplete penetrance. We identified a single very rare non-synonymous mutation in the four patients: the private R98W variant of IRF4, a transcription factor involved in immunity. The five Tw carriers were younger, and also heterozygous for R98W. We found that R98W was loss-of-function, modified the transcriptome of heterozygous leukocytes following Tw stimulation, and was not dominant-negative. We also found that only six of the other 153 known non-synonymous IRF4 variants were loss-of-function. Finally, we found that IRF4 had evolved under purifying selection. AD IRF4 deficiency can underlie WD by haploinsufficiency, with age-dependent incomplete penetrance.
| S-EPMC5915175 | biostudies-literature
Project description:Single cell RNA seq (scRNA-seq) has emerged as a powerful tool to determine the composition of heterogeneous cell states in a tissue. We found that Irf4+/- antigen specific B cells were functionally impaired in affinity maturation. The goal of this study was to determine whether Irf4+/- antigen specific B cells exhibited distinct cellular composition compared to wild type cells. Sequence data from 8360 cells revealed a similar distribution and numbers of cell states between cells of Irf4+/- or Irf4+/+ genotypes.
2021-10-04 | GSE185188 | GEO
Project description:IRF4 Haploinsufficiency Impairs Affinity Maturation
| PRJNA767888 | ENA
Project description:In rice (Oryza sativa L.), chilling-induced male sterility increased when plants experienced low water temperature (Tw, 18 °C for 14 days) before panicle initiation. The number of mature pollen grains after chilling at the booting stage (12 °C for 5 days) was only approximately 45% of total pollen grains in low-Tw plants, whereas it was approximately 71% in normal-Tw plants (Tw not controlled; approximately 23 °C under air temperature of 26 °C/21 °C, day/night). Microarray and quantitative PCR analyses showed that many stress-responsive genes (including OsFKBP65 and genes encoding a large heat shock protein OsHSP90.1, heat-stress transcription factors, and many small heat shock proteins) were strongly up-regulated by chilling in normal-Tw spikelets, but were not or rather down-regulated by chilling in low Tw spikelets. OsAPX2 and genes encoding some other antioxidative enzymes were also significantly down-regulated by low Tw in the chilled spikelets. In low-Tw plants, lipid peroxidation products (malondialdehyde equivalents) were significantly increased in the spikelets after chilling, and ascorbate peroxidase activity in the chilled spikelets was significantly lower than that in normal-Tw plants. Our data suggest that an OsFKBP65-related chilling response, which protects proteins from oxidative damage, is indispensable for chilling tolerance but is lost in low-Tw spikelets.
2014-12-22 | GSE59221 | GEO
Project description:Background: Salmonella Typhi and Salmonella Paratyphi A are the agents of enteric (typhoid) fever; both can establish chronic carriage in the gallbladder. Chronic Salmonella carriers are typically asymptomatic, intermittently shedding bacteria in the feces, and contributing to disease transmission. Detecting chronic carriers is of public health relevance in areas where enteric fever is endemic, but there are no routinely used methods for prospectively identifying those carrying Salmonella in their gallbladder. Methodology/Principal Findings: Here we aimed to identify biomarkers of Salmonella carriage using metabolite profiling. We performed metabolite profiling on plasma from Nepali patients undergoing cholecystectomy with confirmed S. Typhi or S. Paratyphi A gallbladder carriage (and non-carriage controls) using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) and supervised pattern recognition modeling. We were able to significantly discriminate Salmonella carriage samples from non-carriage control samples. We were also able to detect differential signatures between S. Typhi and S. Paratyphi A carriers. We additionally compared carriage metabolite profiles with profiles generated during acute infection; these data revealed substantial heterogeneity between metabolites associated with acute enteric fever and chronic carriage. Lastly, we found that Salmonella carriers could be significantly distinguished from non-carriage controls using only five metabolites, indicating the potential of these metabolites as diagnostic markers for detecting chronic Salmonella carriers. Conclusions/Significance: Our novel approach has highlighted the potential of using metabolomics to search for diagnostic markers of chronic Salmonella carriage. We suggest further epidemiological investigations of these potential biomarkers in alternative endemic enteric fever settings.
2018-01-17 | MTBLS579 | MetaboLights
Project description:Wilson disease (WD) is an autosomal recessive disease caused by mutations in ATP7B encoding a copper transporter. Consequent copper accumulation results in a variable WD clinical phenotype involving hepatic, neurologic, and psychiatric symptoms, without clear genotype-phenotype correlations. The goal of this study was to analyze alterations in DNA methylation at the whole-genome level in liver and blood from patients with WD to investigate epigenomic alterations associated with WD diagnosis and phenotype. We used whole-genome bisulfite sequencing (WGBS) to examine distinct cohorts of WD subjects to determine whether DNA methylation could differentiate patients from healthy subjects and subjects with other liver diseases and distinguish between different WD phenotypes. WGBS analyses in liver identified 969 hypermethylated and 871 hypomethylated differentially methylated regions (DMRs) specifically identifying patients with WD, including 18 regions with genome-wide significance. WD-specific liver DMRs were associated with genes enriched for functions in folate and lipid metabolism and acute inflammatory response and could differentiate early from advanced fibrosis in WD patients. Functional annotation revealed that WD-hypermethylated liver DMRs were enriched in liver-specific enhancers, flanking active liver promoters, and binding sites of liver developmental transcription factors, including Hepatocyte Nuclear Factor 4 alpha (HNF4A), Retinoid X Receptor alpha (RXRA), Forkhead Box A1 (FOXA1), and FOXA2. DMRs associated with WD progression were also identified, including 15 with genome-wide significance. However, WD DMRs in liver were not related to large-scale changes in proportions of liver cell types. DMRs detected in blood differentiated WD patients from healthy and disease control subjects, and distinguished between patients with hepatic and neurologic WD manifestations. WD phenotype DMRs corresponded to genes enriched for functions in mental deterioration, abnormal B cell physiology, and as members of the polycomb repressive complex 1 (PRC1). 44 DMRs associated with WD phenotype tested in a small validation cohort had a predictive value of 0.9. We identified a disease-mechanism relevant epigenomic signature of WD that reveals new insights into potential biomarkers and treatments for this complex monogenic disease.
2019-02-14 | GSE117593 | GEO
Project description:In this work we analyzed the genomic diversity of several Tropheryma whipplei strains by microarray based-comparative genomic hybridization. Fifteen clinical isolates originating from biopsy samples recovered from different countries were compared with the T. whipplei Twist strain. For each isolate, the genes were defined as either present or absent/divergent using the GACK analysis software. Genomic changes were then further characterized by PCR and sequencing. Obtained results revealed a limited genetic variation between these T. whipplei isolates with at most 2.24 % of the probes exhibiting differential hybridization against the Twist strain. The main variation was found in genes encoding for the WiSP family proteins supporting the view of these membrane proteins as key actors of immune evasion. This work also evidenced a 19.2 kb-pair deletion within T. whipplei DIG15 strain. This deletion takes place in the same region as the large genomic rearrangement previously described between Twist and TW08/27 which can thus be considered as a major hot-spot for intra-specific T. whipplei differentiation. Analysis of this deleted region confirmed the role of WND-domains in generating T. whipplei diversity Keywords: Comparative genomic hybridization
2007-04-06 | GSE7453 | GEO
Project description:Wilson’s disease (WD) is a rare genetic disease caused by mutations in the ATP7B gene. These mutations impact the expression and/or function of the copper-transporting ATP7B protein, leading to massive toxic accumulation of copper in the liver and brain. Due to its low incidence and highly variable clinical presentations, WD is challenging to diagnose. Here, we explored the plasma proteome of the Atp7b-/- mouse, a genetic and phenotypic model of WD, to provide new insights into the pathogenic mechanisms of WD and discover potential biomarkers for WD diagnosis. A mass spectrometry (MS)-based proteomics workflow combining unbiased discovery analysis followed by targeted quantification was developed. Analysis of two independent groups of samples (discovery and validation cohorts) highlighted seven plasma proteins for which abundance was significantly modified (more than 2-fold) between Atp7b-/- mice and wild-type littermates. To assess the clinical significance and specificity of these seven proteins as potential biomarkers for WD, we adapted our targeted proteomics assay to allow the quantification of human orthologues in plasma from WD patients (treated with copper chelators), non-alcoholic steatohepatitis patients (disease-control group), and healthy donors. The plasma proteome changes observed in the Atp7b-/- mouse were not confirmed in treated WD patients, with the exception of alpha-1 antichymotrypsin, levels of which were decreased in WD patients compared to healthy individuals. Plasma ceruloplasmin was investigated in both the Atp7b-/- mouse model and human patients, and was found to be significantly decreased in the human form of WD only.
2020-04-14 | PXD011007 | Pride
Project description:Human iPSC-derived cardiomyocytes (hiPSC-CMs) exhibit functional immaturity, potentially impacting their suitability for assessing drug proarrhythmic potential. We previously devised a Traveling Wave (TW) system to promote maturation in 3D cardiac tissue. To align with current drug assessment paradigms (CiPA and JiCSA), necessitating a 2D monolayer cardiac tissue, we integrated the TW system with a multi-electrode array. This gave rise to a hiPSC-derived closed-loop cardiac tissue (iCT), enabling spontaneous TW initiation and swift pacing of cardiomyocytes from various cell lines. The TW-paced cardiomyocytes demonstrated heightened sarcomeric and functional maturation, exhibiting enhanced response to isoproterenol. Moreover, these cells showcased diminished sensitivity to verapamil and maintained low arrhythmia rates with ranolazine—two drugs associated with a low risk of torsades de pointes (TdP). Notably, the TW group displayed increased arrhythmia rates with high and intermediate risk TdP drugs (quinidine and pimozide), underscoring the potential utility of this system in drug assessment applications..
2024-01-07 | GSE251914 | GEO