Potentiation of regulatory T cell stability and function via a neuropilin-1:semaphorin-4a axis
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE41185 | GEO | 2013/09/06
SECONDARY ACCESSION(S): PRJNA176124
REPOSITORIES: GEO
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Project description:Regulatory T cells (Treg) represent a critical immunoregulatory component of the immune system. The signals that maintain Treg stability and potentiate their function remain obscure. Here we show that the immune cell surface ligand semaphorin-4a (Sema4a) Sema treated and NRP1 knock outs were compared to untreated wild type T cell controls
2013-09-06 | E-GEOD-41185 | biostudies-arrayexpress
Project description:Tissue stem cells are hierarchically organized, but the signals that selectively preserve their functional integrity are largely unknown. Semaphorin 4A (Sema4A) is a specific regulator of myeloid-biased hematopoietic stem cells (myHSC), which are positioned at the top of the HSC hierarchy. Through single-cell transcriptomics, we compare the effect of Sema4A knock-out on the myHSCs.
2023-06-04 | E-MTAB-12890 | biostudies-arrayexpress
Project description:Tissue stem cells are hierarchically organized, but the signals that selectively preserve their functional integrity are largely unknown. Semaphorin 4A (Sema4A) is a specific regulator of myeloid-biased hematopoietic stem cells (myHSC), which are positioned at the top of the HSC hierarchy. Through single-cell transcriptomics, we compare the effect of Sema4A knock-out on the myHSCs.
2022-01-21 | E-MTAB-11359 | biostudies-arrayexpress
Project description:Tissue stem cells are hierarchically organized. Those that are most primitive serve as key drivers of regenerative response but the signals that selectively preserve their functional integrity are largely unknown. Here, we identify a secreted factor, Semaphorin 4A (Sema4A), as a specific regulator of myeloid-biased hematopoietic stem cells (myHSC), which are positioned at the top of the HSC hierarchy. Lack of Sema4A leads to exaggerated myHSC (but not downstream “balanced” HSC) proliferation after acute inflammatory stress, indicating that Sema4A enforces myHSC quiescence. Strikingly, aged Sema4A knock-out myHSC expand but almost completely lose reconstitution capacity. The effect of Sema4A is non cell-autonomous, since upon transplantation into Sema4A-deficient environment, wild-type myHSC excessively proliferate but fail to engraft long-term. Sema4A constrains inflammatory signaling in myHSC and acts via a surface receptor Plexin-D1. Our data support a model whereby the most primitive tissue stem cells critically rely on a dedicated signal from the niche for self-renewal and life-long persistence.
2024-12-11 | GSE281145 | GEO
Project description:Regulatory T cells (Treg cells) have a crucial role in the immune system by preventing autoimmunity, limiting immunopathology, and maintaining immune homeostasis. However, they also represent a major barrier to effective anti-tumour immunity and sterilizing immunity to chronic viral infections. The transcription factor Foxp3 has a major role in the development and programming of Treg cells. The relative stability of Treg cells at inflammatory disease sites has been a highly contentious subject. There is considerable interest in identifying pathways that control the stability of Treg cells as many immune-mediated diseases are characterized by either exacerbated or limited Treg-cell function. Here we show that the immune-cell-expressed ligand semaphorin-4a (Sema4a) and the Treg-cell-expressed receptor neuropilin-1 (Nrp1) interact both in vitro, to potentiate Treg-cell function and survival, and in vivo, at inflammatory sites. Using mice with a Treg-cell-restricted deletion of Nrp1, we show that Nrp1 is dispensable for suppression of autoimmunity and maintenance of immune homeostasis, but is required by Treg cells to limit anti-tumour immune responses and to cure established inflammatory colitis. Sema4a ligation of Nrp1 restrained Akt phosphorylation cellularly and at the immunologic synapse by phosphatase and tensin homologue (PTEN), which increased nuclear localization of the transcription factor Foxo3a. The Nrp1-induced transcriptome promoted Treg-cell stability by enhancing quiescence and survival factors while inhibiting programs that promote differentiation. Importantly, this Nrp1-dependent molecular program is evident in intra-tumoral Treg cells. Our data support a model in which Treg-cell stability can be subverted in certain inflammatory sites, but is maintained by a Sema4a-Nrp1 axis, highlighting this pathway as a potential therapeutic target that could limit Treg-cell-mediated tumour-induced tolerance without inducing autoimmunity.
| S-EPMC3867145 | biostudies-literature
Project description:Although Semaphorin 3G has some roles in the development of vessels, the roles in immune system are not characterized. We aimed to study how Semaphorin 3G affects the function of macrophages.
2022-05-17 | GSE176438 | GEO
Project description:Background: Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system and the leading cause of lasting neurological disabilities in young adults. Increasing evidence suggests that early treatment prevents the development of disability. However, there have been no reliable serum markers to assist the early diagnosis. In addition, interferon (IFN)-β, which is the major treatment for MS, is not always effective. Therefore, the development of simple serological test to help the early diagnosis and predict responsiveness to IFN-β is of clinical importance. On the other hand, a transmembrane-type semaphorin, Sema4A, has been implicated in experimental autoimmune encephalomyelitis (EAE) by regulating helper T (Th) cell differentiation. Thus, we aimed to identify the implications of Sema4A in diagnosis and pathogenesis of MS. Methods: We assayed serum Sema4A in 59 patients with relapsing-remitting MS (RRMS), 22 patients with clinically isolated syndrome (CIS) and 126 patients with other neurological diseases (OND) by developing a sandwich ELISA. To identify a source of soluble Sema4A and characteristics of MS patients with high levels of Sema4A, we analyzed peripheral blood mononuclear cells (PBMCs) from MS patients and healthy controls by flow cytometry (FACS) and gene chip analysis. The effect of Sema4A was examined in vitro and in vivo using an EAE model. Findings: Sema4A was significantly increased in sera of patients with MS and CIS compared to controls. Sema4A expression was increased on the surface of DCs in MS patients and shed from these cells in a metalloproteinase-dependent manner, affecting the Th17skewing. In addition, patients with high Sema4A levels exhibited more severe disabilities, and IFN-β treatment was not beneficial to those patients. Interpretation: Measuring Sema4A is a practical laboratory test to help diagnose MS and to predict responsiveness to IFN-β therapy. Microarray analysis showed that metalloproteinases such as ADAM 10 and MMPs 1, 3, 9, 12 and 25, which are reported to be involved in the pathogenesis of MS, were increased in PBMCs from MS patients with high Sema4A levels compared to those with low Sema4A and healthy controls. However, ADAM 17 and MMP 2 and 7 did not correlate with Sema4A levels. Taken together, these findings strongly suggest that Sema4A, abundantly expressed on monocytes and DCs in MS patients, is enzymatically cleaved and shed in a portion of the patients, which contributes to the high soluble Sema4A detected by the ELISA. Multiple sclerosis patients were classified according to Serum Sema4A levels. RNA from peripheral blood from 4 healthy controls, 3 MS patients with high serum Sema4A levels and 3 MS patients with low serum Sema4A levels was extracted and hybridized on Affymetrix microarrays. We sought to see whether there is corrlated genes with serum Sema4A levels or not, especially for genes for varions proteases.
2011-06-01 | E-GEOD-26484 | biostudies-arrayexpress
Project description:Semaphorin 4A (Sema4A) exerts a stabilizing effect on human Treg cells in PBMC and CD4+ T cell cultures by engaging Plexin B1. Sema4A deficient mice display enhanced allergic airway inflammation accompanied by fewer Treg cells, while Sema4D deficient mice displayed reduced inflammation and increased Treg cell numbers even though both Sema4 subfamily members engage Plexin B1. The main objectives of this study were: 1. To compare the in vitro effects of Sema4A and Sema4D proteins on human Treg cells; and 2. To identify function-determining residues in Sema4A critical for binding to Plexin B1 based on Sema4D homology modeling. We report here that Sema4A and Sema4D display opposite effects on human Treg cells in in vitro PBMC cultures; Sema4D inhibited the CD4+CD25+Foxp3+ cell numbers and CD25/Foxp3 expression. Sema4A and Sema4D competitively bind to Plexin B1 in vitro and hence may be doing so in vivo as well. Bayesian Partitioning with Pattern Selection (BPPS) partitioned 4505 Sema domains from diverse organisms into subgroups based on distinguishing sequence patterns that are likely responsible for functional differences. BPPS groups Sema3 and Sema4 into one family and further separates Sema4A and Sema4D into distinct subfamilies. Residues distinctive of the Sema3,4 family and of Sema4A (and by homology of Sema4D) tend to cluster around the Plexin B1 binding site. This suggests that the residues both common to and distinctive of Sema4A and Sema4D may mediate binding to Plexin B1, with subfamily residues mediating functional specificity. We mutated the Sema4A-specific residues M198 and F223 to alanine; notably, F223 in Sema4A corresponds to alanine in Sema4D. Mutant proteins were assayed for Plexin B1-binding and Treg stimulation activities. The F223A mutant was unable to stimulate Treg stability in in vitro PBMC cultures despite binding Plexin B1 with an affinity similar to the WT protein. This research is a first step in generating potent mutant Sema4A molecules with stimulatory function for Treg cells with a view to designing immunotherapeutics for asthma.
| S-EPMC8953949 | biostudies-literature
Project description:Background: Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system and the leading cause of lasting neurological disabilities in young adults. Increasing evidence suggests that early treatment prevents the development of disability. However, there have been no reliable serum markers to assist the early diagnosis. In addition, interferon (IFN)-β, which is the major treatment for MS, is not always effective. Therefore, the development of simple serological test to help the early diagnosis and predict responsiveness to IFN-β is of clinical importance. On the other hand, a transmembrane-type semaphorin, Sema4A, has been implicated in experimental autoimmune encephalomyelitis (EAE) by regulating helper T (Th) cell differentiation. Thus, we aimed to identify the implications of Sema4A in diagnosis and pathogenesis of MS. Methods: We assayed serum Sema4A in 59 patients with relapsing-remitting MS (RRMS), 22 patients with clinically isolated syndrome (CIS) and 126 patients with other neurological diseases (OND) by developing a sandwich ELISA. To identify a source of soluble Sema4A and characteristics of MS patients with high levels of Sema4A, we analyzed peripheral blood mononuclear cells (PBMCs) from MS patients and healthy controls by flow cytometry (FACS) and gene chip analysis. The effect of Sema4A was examined in vitro and in vivo using an EAE model. Findings: Sema4A was significantly increased in sera of patients with MS and CIS compared to controls. Sema4A expression was increased on the surface of DCs in MS patients and shed from these cells in a metalloproteinase-dependent manner, affecting the Th17skewing. In addition, patients with high Sema4A levels exhibited more severe disabilities, and IFN-β treatment was not beneficial to those patients. Interpretation: Measuring Sema4A is a practical laboratory test to help diagnose MS and to predict responsiveness to IFN-β therapy. Microarray analysis showed that metalloproteinases such as ADAM 10 and MMPs 1, 3, 9, 12 and 25, which are reported to be involved in the pathogenesis of MS, were increased in PBMCs from MS patients with high Sema4A levels compared to those with low Sema4A and healthy controls. However, ADAM 17 and MMP 2 and 7 did not correlate with Sema4A levels. Taken together, these findings strongly suggest that Sema4A, abundantly expressed on monocytes and DCs in MS patients, is enzymatically cleaved and shed in a portion of the patients, which contributes to the high soluble Sema4A detected by the ELISA.
2011-06-01 | GSE26484 | GEO
Project description:Genomic and epigenomic studies support that adenocarcinomas of the gallbladder develop according to a metaplasia-biliary intraepithelial neoplasia (BilIN)-adenocarcinoma histogenic sequence, in which metaplasia and BilIN are non-cancerous lesions of the epithelium. Moreover, recent genomic data suggest that adenocarcinoma can develop in a BilIN-dependent or -independent way, pointing toward patient-specific tumourigenic processes. Spatial transcriptomic data addressing these processes are still missing. Here, using GeoMx digital spatial profiling (NanoString), we characterized the spatial transcriptome of normal gallbladder epithelium, BilINs and adenocarcinoma coexisting within the same samples. To address intra-patient variability we profiled the whole transcriptome of a high number of regions of interest (ROIs) per sample in two patients (Patient #1, 81 year old woman: 24 ROIs; Patient #2, 53-year old man:32 ROIs), with each ROI covering approximately 200 cells of normal epithelium, low-grade BilIN, high-grade BilIN or adenocarcinoma. Our results showed that each type of lesion displayed little transcriptomic variability within the same patient, but differed significantly between patients. They also suggested that adenocarcinoma can derive from high-grade BilIN or from low-grade BilIN, with co-existing high-grade BilIN evolving via a distinct process in the latter case. We also provide strong evidence for patient-specific tumourigenic mechanisms, characterized by distinct sequences of signalling pathway activation. Among those pathways, we functionally investigated SEMAPHORIN 4A (SEMA4A) and provided evidence that repression of SEMA4A expression, as is observed in the gallbladder samples of the two patients, can enhance cell migration and survival, and perturb polarisation of the epithelial cells. In conclusion, our results support that gallbladder adenocarcinoma develops according to patient-specific processes that can be promoted by repression of SEMA4A. They underscore the need to gain gene expression data in addition to histological information to evaluate the risk of low-grade preneoplastic lesions.
2024-03-01 | GSE259311 | GEO