EGAS00001000099-sc-2019-08-19T11:01:42Z - samples
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ABSTRACT:
PROVIDER: EGAD00001005263 | EGA |
REPOSITORIES: EGA
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Project description:Primary T cell immunodeficiency disorders have a heterogeneous genetic basis. This study will focus on one case characterised by severe T cell lymphopenia in the index case. We aim to sequence the complete exomes of this individual, her three unaffected siblings and parents in an effort to identify the causative genetic mutation responsible for this disorder. We will perform exome capture using Agilent SureSelect system, followed by sequencing on the HiSeq platform. Our study has the potential to uncover genes important for T cell development and novel therapeutic strategies to treat T cell immunodeficiencies.
| EGAS00001000099 | EGA
Project description:Combined immunodeficiencies are a heterogeneous collection of primary immune disorders that exhibit defects in T cell development or function, along with impaired B cell activity even in light of normal B cell maturation. CARMIL2 (RLTPR) is a protein involved in cytoskeletal organization and cell migration which also plays a role in CD28 co-signaling of T cells. Mutations in this protein have recently been reported to cause a novel primary immunodeficiency disorder with variable phenotypic presentations. Here we deposit genotyping data for seven patients from three unrelated, consanguineous multiplex families that presented with dermatitis, eosophagitis and recurrent skin and chest infections with evidence of combined immunodeficiency. By using this genotyping data to perform autozygome-guided analysis, and coupling it with the results of whole exome sequencing, we uncovered two mutations not previously reported (p.R50T and p.L846Sfs) in CARMIL2.
2018-01-25 | E-MTAB-6440 | biostudies-arrayexpress
Project description:<p>The etiologies of primary immunodeficiencies often yield novel insights about the immune system. Although a genetic etiology has been suspected for patients with abnormally low CD4+ T cells in the absence of HIV infection or any known causes of lymphopenia, no genetic mutation has been described to date for any case of primary CD4 lymphopenia. In this study, we characterized a non-consanguineous family with two non-HIV infected boys exhibiting an inverted CD4 to CD8 T cell ratio and a history of recurrent chronic viral infections since birth. Consistent with a decreased thymic output of CD4+ T cells, the percentage of CD31+ cells in the CD4+ naive population of these patients was decreased. In addition, the activation of T cells was significantly impaired in the patient upon TCR stimulation. Given the mother's T cells show completely skewed X chromosome inactivation, we suspected that the nature of this disease is X-linked. We performed X-chromosome exon-capture targeted single-end Solexa sequencing on two brothers and the mother and found a 10 base pair deletion at an intron-exon junction of Magnesium Transporter 1 (MAGT1), a Mg<sup>2+</sup> specific transporter. We confirmed that this deletion leads to altered splicing, frameshift, early termination of the mRNA, and deficient protein expression in the lymphocytes of the two patients. Moreover, knockdown of this transporter in T cells isolated from healthy donors can recapitulate the observed T cell activation defect while its ectopic expression in the patients' lymphocytes can restore T cell stimulation. Our discovery highlights the significance of this transporter to T cell function.</p>
| phs000365 | dbGaP
Project description:Overall, this work describes the largest cohort of patients with RAG mutations and an associated phenotype consisting of combined immunodeficiency and granulomatous lesions and/or autoimmunity (CID-G/AI). By using multiple methods (microarray, ELISA and multiplex bead technology), we have consistently identified a distinctive signature of anti-cytokine antibodies in patients with RAG-dependent immunodeficiencies, especially in those with CID-G/AI and a history of severe viral infections. These autoantibodies were not detected in a large panel of patients with other forms of primary immunodeficiency, and may therefore represent a novel biomarker panel of this condition.
2015-07-08 | GSE70618 | GEO
Project description:Overall, this work describes the largest cohort of patients with RAG mutations and an associated phenotype consisting of combined immunodeficiency and granulomatous lesions and/or autoimmunity (CID-G/AI). By using multiple methods (microarray, ELISA and multiplex bead technology), we have consistently identified a distinctive signature of anti-cytokine antibodies in patients with RAG-dependent immunodeficiencies, especially in those with CID-G/AI and a history of severe viral infections. These autoantibodies were not detected in a large panel of patients with other forms of primary immunodeficiency, and may therefore represent a novel biomarker panel of this condition. Known autoantigens, cytokines, chemokines, growth factors and receptors were printed onto microarrays. All targets were printed in triplicate. Arrays were probed with diluted plasma and autoantibodies were detected with a AF647 conjugated anti-human IgG secondary.
2015-07-08 | E-GEOD-70618 | biostudies-arrayexpress
Project description:STING gain-of-function (GOF) mutations lead to T cell lymphopenia, in the context of severe combined immunodeficiency (SCID) for STING GOF V154M mice. This T cell lymphopenia, which is of central origin, has been described as type I IFN independent and associated with dysfunctions of the rare mature T cells found in the periphery. To better describe the biological mechanisms of these dysfunctions, we performed a transcriptomic analysis by RNA-seq on sorted splenic CD4+ and CD8+ mature T cells from STING GOF mice. We highlighted an unexpected T cell exhaustion phenotype that could partly explain their dysfunctions. Acquired very early in life, but only once the peripheral environment is reached, the phenotype appeared to depend neither on type I IFNs, nor on the intrinsic activation of STING in T or stromal cells. Mechanistically, the few mature T cells reaching the periphery seem to be rapidly impacted by the lymphopenic environment through increased antigenic and IL-7 stimulations that could lead to their exhaustion. By using STING GOF long term-hematopoietic stem cells (LT-HSC) transplantations with supportive wild-type bone marrow (BM) cells, we prevented the T cell exhaustion of STING GOF T cells in the resulting non lymphopenic context. With the support of lymphopenic RAG1 hypomorphic mice developing the phenotype, our data uncover a lymphopenia-mediated T cell exhaustion mechanism in STING GOF mice, for which a synergistic effect of the mutation is also envisaged.
2024-01-07 | E-MTAB-13658 | biostudies-arrayexpress
Project description:Hematopoietic stem and progenitor cells (HSPCs), including the multipotent progenitors (MPPs), are responsible for replenishing immune cells. They reside in bone marrow (BM) endosteal and (peri)-vascular niches, which provide all cellular and molecular components required for their lifelong maintenance and fate. Among them, the CXCL12 chemokine and one of its receptor, CXCR4, exert a dominant role in promoting HSPC retention and quiescence. These processes are deregulated in the WHIM Syndrome (WS), a rare immunodeficiency caused by inherited heterozygous autosomal gain-of-function CXCR4 mutations that affect homologous desensitization of the receptor. Clinically, WS is notably characterized by severe, chronic circulating lymphopenia whose mechanisms remain to be elucidated. Using a mouse model carrying a naturally occurring WS-linked Cxcr4 mutation, we explored the possibility that the lymphopenia in WS originates from defects at the MPP level in BM. The global strategy consists in performing high-throughput RNA-seq analyses of the different MPP subsets bearing or not the WS-linked Cxcr4 mutation to investigate the impact of the gain-of-Cxcr4-function on the molecular identity of MPP subsets.
2021-09-02 | GSE182992 | GEO
Project description:This study reports two unrelated patients with a combined immunodeficiency. Whole-exome sequencing of both patients, their healthy parents and siblings identified a single de novo missense variant in ITPR3 (NM_002224.3:c.7570C>T, p.Arg2524Cys) in both index cases. While the mRNA level in patients remained the same as in healthy siblings and controls, the level of protein expression was diminished. It was also shown that the ITPR3 heterozygous p.Arg2524Cys mutation impairs calcium flux function in dermal fibroblast of one patient and in a knock-in Jurkat T cell line. Two additional patients with related phenotypes and the same mutation were further identified and described in the study. The present dataset corresponds to the RNAseq performed on PBMC of patient 2 of the study and healthy controls.
2023-01-02 | E-MTAB-12432 | biostudies-arrayexpress
Project description:Megakaryoblastic leukemia 1 (MKL1) promotes the regulation of essential cell processes, including actin cytoskeletal dynamics by co-activating serum response factor. Recently, the first human case with MKL1 deficiency, leading to a novel primary immunodeficiency, was identified. We report a second family with two siblings with a homozygous frameshift mutation in MKL1. The index case deceased as an infant from progressive and severe pneumonia by Pseudomonas aeruginosa and poor wound healing. The younger sib was preemptively transplanted shortly after birth. The immunodeficiency was marked by a pronounced actin polymerization defect and a strongly reduced motility and chemotactic response by MKL1-deficient neutrophils. Apart from the lack of MKL1, subsequent proteomic and transcriptomic analyses of patient neutrophils revealed actin and several actin-related proteins to be downregulated, confirming a role for MKL1 as transcriptional co-regulator. Degranulation was enhanced upon suboptimal neutrophil activation, while production of reactive oxygen species was normal. Neutrophil adhesion was intact but without proper spreading. The latter could explain the observed failure in firm adherence and transendothelial migration under flow conditions. No apparent defect in phagocytosis and bacterial killing was found. Also monocyte-derived macrophages showed intact phagocytosis; lymphocyte counts and proliferative capacity were normal. Non-hematopoietic primary patient fibroblasts demonstrated defective differentiation into myofibroblasts but normal migration and filamentous actin (F-actin) content, most probably due to compensatory mechanisms of MKL2, which is not expressed in neutrophils. Our findings extend current insight into the severe immune dysfunction in MKL1 deficiency, with cytoskeletal dysfunction and defective extravasation of neutrophils as most prominent features.
2020-03-16 | GSE134644 | GEO
Project description:The transcription factor FOXN1 is a master regulator of thymic epithelial cell development and function. Here we demonstrate that FOXN1 expression is differentially regulated during organogenesis and participates in multi-molecular nuclear condensates essential for the factor's transcriptional activity. FOXN1's C-terminal sequence regulates the diffusion velocity within these aggregates and modulates the binding to proximal gene regulatory regions. These dynamics are significantly altered in a patient's FOXN1 mutant modified in its C-terminal sequence. This mutant is transcriptionally inactive and acts as a dominant negative factor displacing wild-type FOXN1 from condensates and causing athymia and severe lymphopenia in heterozygotes. Expression of the mutated mouse ortholog, Foxn1, selectively impairs mouse thymic epithelial cell (TEC) differentiation, revealing a gene dose dependency for individual TEC subtypes. We have therefore identified the cause for a primary immunodeficiency disease and determined the mechanism by which this FOXN1 gain-of-function mutant mediates its dominant negative effect.
2021-10-29 | PXD025552 | Pride