CTLA-4 expression by B-1a B cells is essential for immune tolerance
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA678235 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR13053884_1.fastq.gz | Fastqsanger.gz | |||
| SRR13053884_2.fastq.gz | Fastqsanger.gz | |||
| SRR13053885_1.fastq.gz | Fastqsanger.gz | |||
| SRR13053885_2.fastq.gz | Fastqsanger.gz | |||
| SRR13053886_1.fastq.gz | Fastqsanger.gz |
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Project description:The importance of CTLA-4 regulation of T cell function is well recognized. Studies here report the expression of this immune-regulator in murine B-1a cells, and demonstrate the critical roles CTLA-4 plays in maintaining self-tolerance through regulating these early-developing B cells that express a repertoire enriched for auto-reactivity. By selectively deleting CTLA-4 from B cells, we show that the conditional knockout mice spontaneously generate T follicular helper (Tfh) cells and germinal centers (GC) in spleen; produce autoantibodies; and, later in life, develop autoimmune pathologies. This impaired immune homeostasis results from B-1a dysfunction when they lose CTLA-4. Thus, CTLA-4-deficient B-1a cells up-regulate epigenetic and transcriptional activation programs and show increased self-replenishment. These activated cells further internalize surface IgM, differentiate to antigen-presenting cells and, when reconstituted in normal congenic recipients, induce GC responses and Tfh cells expressing a highly selected repertoire. These findings introduce CTLA-4 regulation of B-1a as a crucial immune-regulatory mechanism.
2020-11-14 | GSE161409 | GEO
Project description:CTLA-4 is an important regulator of T-cell function. Here, we report that expression of this immune-regulator in mouse B-1a cells has a critical function in maintaining self-tolerance by regulating these early-developing B cells that express a repertoire enriched for auto-reactivity. Selective deletion of CTLA-4 from B cells results in mice that spontaneously develop autoantibodies, T follicular helper (Tfh) cells and germinal centers (GCs) in the spleen, and autoimmune pathology later in life. This impaired immune homeostasis results from B-1a cell dysfunction upon loss of CTLA-4. Therefore, CTLA-4-deficient B-1a cells up-regulate epigenetic and transcriptional activation programs and show increased self-replenishment. These activated cells further internalize surface IgM, differentiate into antigen-presenting cells and, when reconstituted in normal IgH-allotype congenic recipient mice, induce GCs and Tfh cells expressing a highly selected repertoire. These findings show that CTLA-4 regulation of B-1a cells is a crucial immune-regulatory mechanism.
| S-EPMC7822855 | biostudies-literature
Project description:The MR is an endocytic receptor, which plays an important role in serum homeostasis and antigen presentation. In this study, we firstly describe an important role of the MR as a direct regulator of CD8+ T cell activity. We could demonstrate that the presence of the MR on DCs impaired the cytotoxicity of activated CD8+ T cells both in vitro and in vivo. This regulatory effect was mediated by a direct interaction of the MR with CD45 on the T cells surface, which abolished CD45 activity. MR-mediated suppression of CD45 resulted in the up-regulation of the inhibitory molecule CTLA-4, which in turn was responsible for the reduced T cell activity. MR-mediated inactivation of CD45, up-regulation of CTLA-4 and T cell inactivation could be circumvented by increased signaling via CD28, which was achieved by DC maturation. These implications point out an important role of the MR in maintaining the balance between tolerance and immunity and might have pivotal implications for the development of vaccination strategies aimed at dampening adaptive immunity. DesTCR T cells were incubated with MR-deficient DCs in the presence of FcMR or isotype controls for the indicated time points. Afterwards, CD8+ T cells were isolated by cell sorting (FACSAria), and immediately lysed in Trizol (Invitrogen) before storage at -80°C for RNA isolation.
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Project description:Inflammatory bowel disease (IBD) is a chronic and relapsing immune-mediated disorder characterized by intestinal inflammation and epithelial injury. The underlying causes of IBD are not fully understood, but genetic factors have implicated in genome-wide association studies, including CTLA-4, an essential negative regulator of T cell activation. However, establishing a direct link between CTLA-4 and IBD has been challenging due to the early lethality of CTLA-4 knockout mice. In this study, we identified zebrafish Ctla-4 ortholog and investigated its role in maintaining intestinal immune homeostasis by generating a Ctla-4-deficient (ctla-4-/-) zebrafish line. These mutant zebrafish exhibit reduced weight, along with impaired epithelial barrier integrity and lymphocytic infiltration in their intestines. Transcriptomics analysis revealed upregulation of inflammation-related genes, disturbing immune system homeostasis. Moreover, single-cell RNA-sequencing analysis indicated increased Th2 cells and interleukin 13 expression, along with decreased innate lymphoid cells and upregulated proinflammatory cytokines. Additionally, Ctla-4-deficient zebrafish exhibited reduced diversity and an altered composition of the intestinal microbiota. All these phenotypes closely resemble those found in mammalian IBD. Lastly, supplementation with Ctla-4-Ig successfully alleviated intestinal inflammation in these mutants. Altogether, these findings offer substantial evidence linking CTLA-4 to IBD and establish a new model for investigating pathogenesis and potential treatments.
2024-09-16 | GSE255303 | GEO
Project description:Inflammatory bowel disease (IBD) is a chronic and relapsing immune-mediated disorder characterized by intestinal inflammation and epithelial injury. The underlying causes of IBD are not fully understood, but genetic factors have implicated in genome-wide association studies, including CTLA-4, an essential negative regulator of T cell activation. However, establishing a direct link between CTLA-4 and IBD has been challenging due to the early lethality of CTLA-4 knockout mice. In this study, we identified zebrafish Ctla-4 ortholog and investigated its role in maintaining intestinal immune homeostasis by generating a Ctla-4-deficient (ctla-4-/-) zebrafish line. These mutant zebrafish exhibit reduced weight, along with impaired epithelial barrier integrity and lymphocytic infiltration in their intestines. Transcriptomics analysis revealed upregulation of inflammation-related genes, disturbing immune system homeostasis. Moreover, single-cell RNA-sequencing analysis indicated increased Th2 cells and interleukin 13 expression, along with decreased innate lymphoid cells and upregulated proinflammatory cytokines. Additionally, Ctla-4-deficient zebrafish exhibited reduced diversity and an altered composition of the intestinal microbiota. All these phenotypes closely resemble those found in mammalian IBD. Lastly, supplementation with Ctla-4-Ig successfully alleviated intestinal inflammation in these mutants. Altogether, these findings offer substantial evidence linking CTLA-4 to IBD and establish a new model for investigating pathogenesis and potential treatments.
2024-09-16 | GSE255304 | GEO
Project description:The ability to modulate immune-inhibitory pathways using checkpoint blockade antibodies such as PD-1, PD-L1, and CTLA-4 represents a significant breakthrough in cancer therapy in recent years. This has driven interest in identifying small-molecule-immunotherapy combinations to increase the proportion of responses. Murine syngeneic models, which have a functional immune system, represent an essential tool for pre-clinical evaluation of new immunotherapies. However, immune response varies widely between models and the translational relevance of each model is not fully understood, making selection of an appropriate pre-clinical model for drug target validation challenging. Utilizing RNAseq transcriptomic profiling, we have characterised the changes in gene regulatory pathways and immune populations in CT26 mice after treatment with the combination of anti-PD-L1 and anti-CTLA-4 antibodies. At day 7 post tumor implant, the pathways analysis of differentially expressed genes indicated an enrichment for migration of leukocytes in response to inflammation and communication between innate and adaptive immune cells. Similarly, analysis of upstream regulators suggested that lipopolysaccharide, IL-1B, TNF, IFNG, and NFKB1A pathways associated with inflammation were activated. At day 14, pathways related T-helper cell signalling pathways were upregulated. In addition, upstream regulators of the lipopolysaccharide and IFNG pathway, as well STAT1 and IL21 pathway were enriched, indicative of innate and adaptive immune response to inflammation.
2020-04-16 | E-MTAB-7777 | biostudies-arrayexpress
Project description:Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) plays a pivotal role in preventing autoimmunity and fostering anticancer immunity by interacting with B7 proteins CD80 and CD86. CTLA-4 is the first immune checkpoint targeted with a monoclonal antibody inhibitor. Checkpoint inhibitors have generated durable responses in many cancer patients, representing a revolutionary milestone in cancer immunotherapy. However, therapeutic efficacy is limited to a small portion of patients, and immune-related adverse events are noteworthy, especially for monoclonal antibodies directed against CTLA-4. Previously, small molecules have been developed to impair the CTLA-4: CD80 interaction; however, they directly targeted CD80 and not CTLA-4. In this study, we performed artificial intelligence (AI)-powered virtual screening of approximately ten million compounds to target CTLA-4. We validated primary hits with biochemical, biophysical, immunological, and experimental animal assays. We then optimized lead compounds and obtained inhibitors with an inhibitory concentration of 1 micromole in disrupting the interaction between CTLA-4 and CD80. Unlike ipilimumab, these small molecules did not degrade CTLA-4. Several compounds inhibited tumor development prophylactically and therapeutically in syngeneic and CTLA-4-humanized mice. This project supports an AI-based framework in designing small molecules targeting immune checkpoints for cancer therapy.
2024-02-15 | GSE228560 | GEO
Project description:Transcriptome analysis of human peripheral blood monocytes Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic (changes in gene-expression profile) and functional signatures in vivo in purified human T cells and monocytes. RNA extracted from freshly isolated monocytes from peripheral blood of patients treated with either antiâPD-1 (n = 6), antiâCTLA-4 (n = 5), Combo therapy with antiâPD-1 and antiâCTLA-4 concurrently (Combo, n = 6), and Seq antiâPD-1 in patients with prior antiâCTLA-4 (Seq, n = 3) was analyzed using the Affymetrix GeneChip Human Transcriptome 2.0 exon array. No techinical replicates were performed.
2016-02-16 | E-GEOD-77924 | biostudies-arrayexpress
Project description:BACKGROUND: Giant Cell Arteritis (GCA) causes severe inflammation of the aorta and its branches and is characterized by intense effector T cells infiltration. The roles that immune checkpoints play in pathogenesis of GCA are still unclear.Our aim was to study the immune checkpoints interplay in GCA. METHODS: First, we used VigiBase, the WHO international pharmacovigilance database, to evaluate the relationship between GCA occurrence and immune checkpoint inhibitors (ICI) treatments. We then further dissected the role of ICI in the pathogenesis of GCA, using immunohistochemistry, immunofluorescence, transcriptomics and flow cytometry on peripheral blood mononuclear cells (PBMCs) and aortic tissues of GCA patients and appropriated controls. RESULTS: Using VigiBase, we identified GCA as a significant immune related adverse event associated with anti-CTLA-4 (Cytotoxic T-lymphocyte-associated-protein-4) but not anti-PD-1/PD-L1 treatment. We further dissected a critical role for CTLA-4 pathway in GCA by identification of the dysregulation of CTLA-4-derived gene pathways and proteins in CD4+ T cells (and specifically Tregs) present in blood and aorta of GCA patients versus controls. While Tregs were less abundant and activated/suppressive in blood and aorta of GCA versus controls, they still specifically upregulated CTLA-4. Activated and proliferating CTLA-4+ Ki-67+ Tregs from GCA were more sensitive to anti-CTLA-4 (Ipilimumab)-mediated in vitro depletion versus controls. CONCLUSIONS: We highlighted the instrumental role of CTLA-4 immune checkpoint in GCA which provides a strong rationale for targeting this pathway.
2023-07-03 | GSE236367 | GEO
Project description:Transcriptome analysis of human peripheral blood T cells Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic (changes in gene-expression profile) andfunctional signatures in vivo in purified human T cells. RNA extracted from freshly isolated T cells from peripheral blood of patients treated with either antiâ??PD-1 (n = 6), antiâ??CTLA-4 (n = 5), Combo therapy with antiâ??PD-1 and antiâ??CTLA-4 concurrently (Combo, n = 6), and Seq antiâ??PD-1 in patients with prior antiâ??CTLA-4 (Seq, n = 3) was analyzed using the Affymetrix GeneChip Human Transcriptome 2.0 exon array. No techinical replicates were performed.
2016-02-10 | E-GEOD-77714 | biostudies-arrayexpress