Somatic mutations in lymphocytes in patients with immune-mediated aplastic anemia
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PROVIDER: EGAS00001004994 | EGA |
REPOSITORIES: EGA
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Project description:In this study, we investigated somatic mutations of CD4+ and CD8+ T cells in patients with immune-mediated aplastic anemia (AA). To understand the role of mutations, we performed single-cell level analysis of 6 longitudinal samples of 2 AA patients carrying STAT3 or KRAS and other mutations in CD8+ T cells. The analysis was performed using V(D)J and 5' gene expression platform (10X Genomics). STAT3 mutated clone was clearly distinguishable from other CD8+ T cells and showed a cytotoxic phenotype, attenuated by successful immunosuppressive treatment. Our results suggest that somatic mutations in T cells can alter T cell phenotype warranting further investigation of their role in the pathogenesis of immune-mediated AA.
2021-03-24 | E-MTAB-9969 | biostudies-arrayexpress
Project description:Alopecia areata (AA) is among the most prevalent autoimmune diseases, but the development of innovative therapeutic strategies has lagged due to an incomplete understanding of the immunological underpinnings of disease. Here, we performed single-cell RNA sequencing (scRNAseq) of skin-infiltrating immune cells from the graft-induced C3H/HeJ mouse model of AA, coupled with antibody-based depletion to interrogate the functional role of specific cell types in AA in vivo. Since AA is predominantly T cell-mediated, we focused on dissecting lymphocyte function in AA. Both our scRNAseq and functional studies established CD8+ T cells as the primary disease-driving cell type in AA. Only the depletion of CD8+ T cells, but not CD4+ T cells, NK, B, or γδ T cells, was sufficient to prevent and reverse AA. Selective depletion of regulatory T cells (Treg) showed that Treg are protective against AA in C3H/HeJ mice, suggesting that AA failure of Treg-mediated immunosuppression is not a major disease mechanism. Focused analyses of CD8+ T cells revealed five subsets, whose heterogeneity is defined by an ‘effectorness gradient’ of interrelated transcriptional states that culminate in increased effector function and tissue residency. scRNAseq of human AA skin showed that CD8+ T cells in human AA follow a similar trajectory, underscoring that shared mechanisms drive disease in both murine and human AA. Our study represents a comprehensive, systematic interrogation of lymphocyte heterogeneity in AA, and uncovers a framework for AA-associated CD8+ T cells with implications for the design of future therapeutics.
2023-07-25 | GSE233906 | GEO
Project description:Signal-transducer-and-activator-of-transcription-3 (STAT3) is a central regulator of immune homeostasis. STAT3 levels are strictly controlled and STAT3 impairment contributes to several diseases including the monogenic autosomal-dominant hyper-IgE syndrome (AD-HIES). We investigated patients of four consanguineous families with an autosomal-recessive disorder resembling the phenotype of AD-HIES, with symptoms of immunodeficiency, recurrent infections, skeletal abnormalities, and elevated IgE. Patients presented with reduced STAT3 expression and diminished Th17 cell numbers, in absence of STAT3 mutations. We identified homozygous nonsense mutations in ZNF341, encoding a zinc-finger transcription factor. Wildtype-ZNF341 bound to and activated the STAT3 promoter, whereas the mutant variants showed impaired transcriptional activation, partly due to nuclear translocation failure. In summary, nonsense mutations in ZNF341 account for the STAT3-like phenotype in four autosomal-recessive kindred. Thus, ZNF341 is a previously unrecognized regulator of immune homeostasis.
2018-05-02 | GSE107719 | GEO
Project description:Signal-transducer-and-activator-of-transcription-3 (STAT3) is a central regulator of immune homeostasis. STAT3 levels are strictly controlled and STAT3 impairment contributes to several diseases including the monogenic autosomal-dominant hyper-IgE syndrome (AD-HIES). We investigated patients of four consanguineous families with an autosomal-recessive disorder resembling the phenotype of AD-HIES, with symptoms of immunodeficiency, recurrent infections, skeletal abnormalities, and elevated IgE. Patients presented with reduced STAT3 expression and diminished Th17 cell numbers, in absence of STAT3 mutations. We identified homozygous nonsense mutations in ZNF341, encoding a zinc-finger transcription factor. Wildtype-ZNF341 bound to and activated the STAT3 promoter, whereas the mutant variants showed impaired transcriptional activation, partly due to nuclear translocation failure. In summary, nonsense mutations in ZNF341 account for the STAT3-like phenotype in four autosomal-recessive kindreds. Thus, ZNF341 is a previously unrecognized regulator of immune homeostasis.
2018-05-04 | GSE109030 | GEO
Project description:TGFb signaling is a major pathway associated with poor clinical outcome in patients with
advanced metastatic cancers and non-response to immune checkpoint blockade, particularly in the immune-excluded tumor phenotype. While previous pre-clinical studies demonstrated that converting tumors from an excluded to an inflamed phenotype and curative anti-tumor immunity require attenuation of both PD-L1 and TGFb signaling, the underlying cellular mechanisms remain unclear. Recent studies suggest that stem cell-like CD8 T cells (TSCL) can differentiate into non-exhausted CD8 T effector cells that drive durable anti-tumor immunity. Here, we show that TGFb and PD-L1 restrain TSCL expansion as well as replacement of progenitor exhausted and dysfunctional CD8 T cells with non-exhausted IFNghi CD8 T effector cells in the tumor microenvironment (TME). Blockade of TGFb and PD-L1 generated IFNghi CD8 T effector cells with enhanced motility, enabling both their accumulation in the TME and increased interaction with other cell types. Ensuing IFNg signaling markedly transformed myeloid, stromal, and tumor niches to yield a broadly immune-supportive ecosystem. Blocking IFNg completely abolished the effect of anti-PD-L1/ TGFb combination therapy. Our data suggest that TGFb works in concert with PD-L1 to prevent TSCL expansion and replacement of exhausted CD8 T cells with fresh CD8
T effector cells, thereby maintaining the CD8 T cell compartment in a dysfunctional state.
2023-06-16 | MSV000092193 | MassIVE
Project description:Immune checkpoint inhibitors interfere with T cell exhaustion but often fail to cure or control cancer long-term in patients. Using a genetic screen in C57BL/6J mice, we discovered a mutation in host H2-Aa that caused strong immune-mediated resistance to mouse melanomas. H2-Aa encodes an MHC class II α chain, and its absence in C57BL/6J mice eliminates all MHC-II expression. H2-Aa deficiency, specifically in dendritic cells (DC), led to a quantitative increase in type 2 conventional DC (cDC2) and a decrease in cDC1. H2-Aa–deficient cDC2, but not cDC1, were essential for melanoma suppression and effectively cross-primed and recruited CD8 T cells into tumors. Lack of T regulatory cells, also observed in H2-Aa deficiency, contributed to melanoma suppression. Acute disruption of H2-Aa was therapeutic in melanoma-bearing mice, particularly when combined with checkpoint inhibition, which had no therapeutic effect by itself. Our findings suggest that inhibiting MHC-II may be an effective immunotherapeutic approach to enhance immune responses to cancer.
2024-10-22 | GSE266960 | GEO
Project description:Major efforts are underway to identify agents that can potentiate effects of immune checkpoint inhibition. Here, we show that ascorbic acid (AA) treatment caused genome wide demethylation and enhanced expression of endogenous retroviral elements in lymphoma cells. AA also increased 5-hydroxymethylcytosine (5hmC) levels of CD8+ T cells and enhanced their cytotoxic activity in a lymphoma co-culture system. High-dose AA treatment synergized with anti-PD1 therapy in a syngeneic lymphoma mouse model, resulting in marked inhibition of tumor growth compared with either agent alone. Analysis of the intra-tumoral epigenome revealed increased 5hmC with AA treatment, consistent with in vitro findings. Analysis of the tumor immune microenvironment revealed that AA strikingly increased intra-tumoral infiltration of CD8+ T cells and macrophages, suggesting enhanced tumor immune recognition. The combination treatment markedly enhanced intra-tumoral infiltration of macrophages and CD8+ T lymphocytes, granzyme B production by cytotoxic cells (cytotoxic T cells and Natural Killer cells), and IL-12 production by antigen presenting cells compared with single agent anti-PD1. These data indicate that AA potentiates anti-PD1 checkpoint inhibition through synergistic mechanisms. The study provides compelling rationale for testing combinations of AA and anti-PD1 agents in lymphoma patients as well as in pre-clinical models of other malignancies.
2020-01-27 | GSE141444 | GEO
Project description:Major efforts are underway to identify agents that can potentiate effects of immune checkpoint inhibition. Here, we show that ascorbic acid (AA) treatment caused genome wide demethylation and enhanced expression of endogenous retroviral elements in lymphoma cells. AA also increased 5-hydroxymethylcytosine (5hmC) levels of CD8+ T cells and enhanced their cytotoxic activity in a lymphoma co-culture system. High-dose AA treatment synergized with anti-PD1 therapy in a syngeneic lymphoma mouse model, resulting in marked inhibition of tumor growth compared with either agent alone. Analysis of the intra-tumoral epigenome revealed increased 5hmC with AA treatment, consistent with in vitro findings. Analysis of the tumor immune microenvironment revealed that AA strikingly increased intra-tumoral infiltration of CD8+ T cells and macrophages, suggesting enhanced tumor immune recognition. The combination treatment markedly enhanced intra-tumoral infiltration of macrophages and CD8+ T lymphocytes, granzyme B production by cytotoxic cells (cytotoxic T cells and Natural Killer cells), and IL-12 production by antigen presenting cells compared with single agent anti-PD1. These data indicate that AA potentiates anti-PD1 checkpoint inhibition through synergistic mechanisms. The study provides compelling rationale for testing combinations of AA and anti-PD1 agents in lymphoma patients as well as in pre-clinical models of other malignancies.
2020-01-27 | GSE141397 | GEO
Project description:Alopecia areata (AA) is one of the most common autoimmune conditions, presenting initially with loss of hair without overt skin changes. The unremarkable appearance of the skin surface contrasts with the complex immune activity occurring at the hair follicle. AA pathogenesis is due to the loss of immune privilege of the hair follicle leading to autoimmune attack. Although the literature has focused on CD8+ T cells, vital roles for CD4+ T cells and antigen-presenting cells have been suggested. Here, we use single-cell sequencing to reveal distinct expression profiles of immune cells in AA. We found clonal expansions of both CD4+ and CD8+ T cells, with shared clonotypes across varied transcriptional states. These data were used to generate highly predictive models of human AA disease. Finally, single-cell sequencing of T cells in human AA recapitulated the clonotypic findings and the gene expression of the predictive models.
2020-08-10 | GSE145095 | GEO
Project description:In this work, we investigated the frequency and oligoclonal expansion of effector CD28-CD57+ memory cells in CD8+ T cell compartments and the T-cell Receptor (TCR) Vβ repertoire in acquired aplastic anemia (AA) to provide additional evidence to the immune hypothesis in AA pathophysiology. Using flow cytometry, deep sequencing, and computational methods, we examined the blood of 32 AA patients and 29 appropriate controls for Vβ usage; eight of these patients showing CD8+CD57+ expansion and three healthy subjects were subjected to TCR deep sequencing to confirm the clonality. We showed that CD8+CD57+ cells were frequently expanded with oligoclonal characteristics in AA, and patients and healthy donors shared CD8+ clonotypes by complementarity-determining region 3 sequences analysis.
2018-05-05 | GSE101660 | GEO