Thymic B lineage cell landscape in Myasthenia gravis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE233180 | GEO | 2025/01/28
REPOSITORIES: GEO
Similar Datasets
Project description:Myasthenia gravis (MG) is a chronic antibody-mediated autoimmune disease disrupting neuromuscular synaptic transmission. Antibodies (Abs) against the acetylcholine receptor (AChR) are detected in approximately 85% of patients. Here, we aimed to study the serum proteome of MG and to identify novel biomarkers reflecting disease activity.
2023-10-24 | PXD040786 | Pride
Project description:This study investigated the genetic basis of an ophthalmoplegic subphenotype of MG (OP-MG) which occurs in a proportion of myasthenics with juvenile symptom onset and African genetic ancestry. This OP-MG subphenotype is characterised by treatment resistant weakness of the extraocular muscles (EOMs) and the pathogenetic mechanism(s) underlying its development is unknown. The aim of this study was to use a hypothesis-generating genome-wide case-control analysis to identify candidate OP-MG susceptibility genes and pathways. Whole genome sequencing (WGS) was performed on 25 AChR-antibody positive myasthenic individuals of African genetic ancestry sampled from the phenotypic extremes: 15 with OP-MG (cases) and 10 individuals with control MG (EOM treatment-responsive).
| EGAS00001003462 | EGA
Project description:Myasthenia gravis (MG) is an autoantibody-mediated autoimmune disorder of the neuromuscular junction. Some patients with MG have pathogenic mAbs that recognize muscle-specific tyrosine kinase (MuSK). Patients respond well to CD20-mediated B-cell depletion therapy (BCDT); most achieve complete stable remission. However, relapse often occurs. To further understand the immunomechanisms underlying relapse we sought to study autoantibody-producing B-cells over the course of BCDT. We developed a monomeric fluorescently labelled antigen to enrich for MuSK-specific B-cells, which was validated with a novel Nalm6 cell line engineered to express a human MuSK autoantibody as B-cell receptor. We found that MuSK-specific B-cells are rare within the circulation (<3 per 10 million cells). From two MuSK-specific B-cells isolated from two distinct patients, we generated human recombinant MuSK mAbs. The autoantibodies originated from plasmablasts, used the IgG4 subclass, recognized the Ig1-like domain of MuSK and showed pathogenic capacity using an in vitro AChR clustering assay. Persistent clones of the mAbs were identified through B-cell repertoire tracing. Clonal variants of 2E6 were detected at several timepoints spanning more than five years months and reemerged after BCDT-mediated remission, appearing several months prior to relapse. These results indicate that a reservoir of rare pathogenic MuSK autoantibody-expressing B cell clones survive BCDT, then reemerge prior to manifestation of clinical relapse. This study provides both a mechanistic understanding of MuSK MG relapse and a valuable candidate biomarker for relapse prediction.
2022-11-07 | GSE215237 | GEO
Project description:The project was focused on the serum proteomic profiling of the neuromuscular autoimmune disease, Myasthenia gravis (MG). The project aimed to identify candidate serum proteins to understand the disease better. To eliminate any typical autoimmune response Rheumatoid arthritis (RA) was included as a reference disease to the sample group.
2024-01-26 | PXD019633 | Pride
Project description:BackgroundThymic epithelial tumors are rare malignant neoplasms that are frequently associated with paraneoplastic syndromes, especially myasthenia gravis. GTF2I is an oncogene mutated in a subgroup of thymomas that is reputed to drive their growth. However, for GTF2I wild-type tumors, the relevant mutations remain to be identified.MethodsWe performed a meta-analysis and identified 4,208 mutations in 339 patients. We defined a panel of 63 genes frequently mutated in thymic epithelial tumors, which we used to design a custom assay for next-generation sequencing. We sequenced tumor DNA from 67 thymomas of patients with myasthenia gravis who underwent resection in our institution.ResultsAmong the 67 thymomas, there were 238 mutations, 83 of which were in coding sequences. There were 14 GTF2I mutations in 6 A, 5 AB, 2 B2 thymomas, and one in a thymoma with unspecified histology. No other oncogenes showed recurrent mutations, while sixteen tumor suppressor genes were predicted to be inactivated. Even with a dedicated assay for the identification of specific somatic mutations in thymic epithelial tumors, only GTF2I mutations were found to be significantly recurrent.ConclusionOur evaluation provides insights into the mutational landscape of thymic epithelial tumors, identifies recurrent mutations in different histotypes, and describes the design and implementation of a custom panel for targeted resequencing. These findings contribute to a better understanding of the genetic basis of thymic epithelial tumors and may have implications for future research and treatment strategies.
| S-EPMC10475716 | biostudies-literature
Project description:To further development of MG-related lncRNA expression differences, we have employed whole lncRNA microarray expression profiling as a discovery platform to identify MG-related lncRNA with the potential to distinguish MG.
2024-08-15 | GSE263220 | GEO
Project description:Myasthenia gravis (MG) is an autoimmune disease affecting the neuromuscular junction, whose clinical hallmark is muscle weakness and early fatigability. Azathioprine (AZA) is commonly used in Myasthenia Gravis therapy. AZA is a purine antagonist, which inhibits the cell cycle in the resting and DNA synthesis phases. It is usually used as an immunosuppressant to block T- and B-cell proliferation. AZA, bioconverted to 6-mercaptopurine by glutathione S-transferase (GST), can be metabolized either through the hypoxanthine phosphoribosyl transferase pathway to active 6-thioguanine nucleotides (6-TGN) or through the thiopurine S-methyltransferase (TPMT) pathway to inactive methyl-thiopurine metabolites. The incorporation of active 6-TGNs into DNA, causing breaks in DNA strands resulting in interference with RNA production and thereby protein synthesis, is responsible for the drug effect. The response to AZA is determined by which metabolic pathway is being favored. While balanced use of both HPRT and TPMT pathways results in responsiveness to AZA, hyperactivity of TPMT skews the balance towards the TPMT pathway and results in unresponsiveness to AZA with no pharmacological effect. In contrast, low TPMT activity skews the balance towards the HPRT pathway, resulting in increasing side-effects due to the accumulation of 6-TGNs. Current treatments for MG therapy are often inadequate because less than 40% of patients achieve complete remission with available drugs. This reflects the lack of drugs acting on target sites for which there is strong evidence of pathogenicity and the inability to identify responder patients. No criteria for responsiveness are available, exposing patients to unpredictable failures and unpredictable side effects. These individuals are at particular risk for adverse drug reaction (ADRs) or therapeutic failure. Genetic profiling with the Affymetrix drug metabolizing enzymes and transports genotyping array offers the ability to determine 1,931 variants and 225 genes involved in drug metabolism and disposition. Accordingly, the study of well-known drug-metabolizing genes can be involved in the specific metabolic pathway of a drug, which is more likely to define genotype-phenotype association and thereby genotype profiles relevant to drug response that can be applied as predictive biomarkers for pharmacological treatment.
2016-05-01 | E-MTAB-4489 | biostudies-arrayexpress
Project description:Myasthenia Gravis (MG) is a chronic autoimmune disorder characterized by severe muscle weakness. However, the seronegative MG patient subgroup, which accounts for about 15% of MG patients, remains challenging diagnosis, and the immunopathology is understudied. Therefore, we performed single-cell RNA-sequencing analysis by peripheral blood and plasma proteome analysis for the seronegative MG patients. Numerical abnormalities were observed in multiple immune cells including B-cells compared to healthy controls (HC) and correlated with disease activities. Additionally, plasma protein of CD22 that was reported to be expressed in the lineage of B-cell maturation, such as mature B-cells and memory B-cells was decreased compared to HC, and had correlation with disease severity, B-cells frequency, and the RNA expression level. These results suggest that the seronegative MG patients have immune disorders centered on B-cells. This is the first large-scale and innovative study to elucidate the immunopathology of the seronegative MG patients.
2024-04-03 | GSE227835 | GEO
Project description:We quantified different methylcytosine genes in CD4+T cells from patients with MG and healthy controls using Infinium HumanMethylation450 BeadChip Assays. Cells were isolated from the peripheral venous blood of 6 MG patients and 6 healthy donors.
2018-04-05 | GSE112696 | GEO
Project description:The thymus is involved in autoimmune Myasthenia gravis (MG) associated with anti-acetylcholine (AChR) antibodies. In MG, thymic regulatory T cells (Treg) are not efficiently suppressive, and conventional T cells (Tconv) are resistant to suppression. To better understand the specific role of the thymus in MG, we compared the phenotype and function of peripheral and thymic Treg and Tconv from controls and MG patients. Suppression assays with thymic or peripheral CD4 + T cells showed that the functional impairment in MG was more pronounced in the thymus than in the periphery. Phenotypic analysis of Treg showed a significant reduction of resting and effector Treg in the thymus but not in the periphery of MG patients. CD31, a marker lost with excessive immunoreactivity, was significantly reduced in thymic but not blood resting Treg. These results suggest that an altered thymic environment may explain Treg differences between MG patients and controls. Since thymic epithelial cells (TECs) play a major role in the generation of Treg, we co-cultured healthy thymic CD4 + T cells with control or MG TECs and tested their suppressive function. Co-culture with MG TECs consistently hampers regulatory activity, as compared with control TECs, suggesting that MG TECs contribute to the immune regulation defects of MG CD4 + T cells. MG TECs produced significantly higher thymic stromal lymphopoietin (TSLP) than control TECs, and a neutralizing anti-TSLP antibody partially restored the suppressive capacity of Treg derived from co-cultures with MG TECs, suggesting that TSLP contributed to the defect of thymic Treg in MG patients. Finally, a co-culture of MG CD4 + T cells with control TECs restored numbers and function of MG Treg, demonstrating that a favorable environment could correct the immune regulation defects of T cells in MG. Altogether, our data suggest that the severe defect of thymic Treg is at least partially due to MG TECs that overproduce TSLP. The Treg defects could be corrected by replacing dysfunctional TECs by healthy TECs. These findings highlight the role of the tissue environment on the immune regulation.
| S-EPMC7218102 | biostudies-literature