Loss of B cell Tolerance is TCR Dependent [amplicon-seq]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE229921 | GEO | 2023/12/29
REPOSITORIES: GEO
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Project description:αβ T cell receptor (TCR) V(D)J genes code for billions of TCR combinations. However only some appear on peripheral T cells in any individual because, to mature, thymocytes must react with low affinity but not high affinity with thymus expressed MHC/peptides. MHC proteins are very polymorphic. Different alleles bind different peptides. Therefore any individual might express many different MHC alleles to ensure that some peptides from an invader are bound to MHC and activate T cells. However, most individuals express limited numbers of MHC alleles. To explore this we compared the TCR repertoires of naïve, CD4 T cells in mice expressing one or two MHC II alleles. Surprisingly, the TCRs in heterozygotes were less diverse that those in the sum of their MHC II homozygous relatives. Our results suggest that thymus negative selection cancels out the advantages of increased thymic positive selection in the MHC heterozygotes.
2024-06-16 | GSE269649 | GEO
Project description:Introduction: Autoreactivity to histones is a pervasive feature of several human autoimmune disorders including systemic lupus erythematosus (SLE). Specific post-translational modifications (PTMs) of histones within neutrophil extracellular traps (NETs) may potentially drive the process by which tolerance to these chromatin-associated proteins is broken. We hypothesized that NETs and their unique histone PTMs might be capable of inducing autoantibodies that target histones. Methods: We developed a novel and efficient method for the in vitro production, visualization, and broad profiling of histone-PTMs of human and murine NETs. We also immunized Balb/c mice with murine NETs and profiled their sera on autoantigen and histone peptide microarrays for evidence of autoantibody production to their immunogen. Results: We confirmed specificity toward acetyl-modified histone H2B as well as to other histone PTMs in sera from patients with SLE known to have autoreactivity against histones. We observed enrichment for distinctive histone marks of transcriptionally silent DNA during NETosis triggered by diverse stimuli. However, NETs derived from human and murine sources did not harbor many of the PTMs toward which autoreactivity was observed in patients with SLE or in MRL/lpr mice. Further, while murine NETs were weak autoantigens in vivo, there was only partial overlap in the IgG and IgM autoantibody profiles induced by vaccination of mice with NETs and those seen in patients with SLE. Conclusions: Isolated in vivo exposure to NETs is insufficient to break tolerance and may involve additional factors that have yet to be identified. Serum samples from 20 systemic lupus erythematosis patients were run on the Human Epigenome Microarray Platform V1.0 (HEMP; a single-color platform), in order to profile their autoantibodies against a library of post-translationally modified histone peptides. These 20 samples were randomly selected from a larger cohort previously profiled (data not shown) on the Utz Lab Whole Protein Autoantigen Array V2.0 (a single-color platform), where 14 were histone-reactive and 6 were histone-nonreactive. Control sera from 9 healthy adults and a positive control comprising a mixture of autoimmune sera with defined reactivities, were also run on HEMP V1.0. Together, these samples comprise the data appearing in Figures 1 and S1 (IgG and IgM isotype reactivity profiles, respectively), identifying IgG reactivity to 9 peptides that significantly distinguish histone-reactive from -nonreactive sera among 96 peptides profiled. For data appearing in Figure 5, serum samples from a total of 6 Balb/c mice, consisting of two treatment groups, NETs (Neutrophil Extracellular Traps) and NETs + CRAMP (cathelicidin-related antimicrobial peptide) were collected monthly over a 3-month period, along with a zero time point. These samples were compared with a positive control consisting of serum collected from a MLR/lpr mice exhibiting lupus-like symptoms, and a negative control with no serum. The 0, 1 and 2 month time points were profiled on the Utz Lab Whole Protein Autoantigen Array V2.0 and are shown in Figure 5A-B, while the 1 and 3 month time points were profiled on HEMP V1.0 arrays and shown in Figure 5E. All samples were run once with no replicates.
2012-01-26 | E-GEOD-32542 | biostudies-arrayexpress
Project description:Introduction: Autoreactivity to histones is a pervasive feature of several human autoimmune disorders including systemic lupus erythematosus (SLE). Specific post-translational modifications (PTMs) of histones within neutrophil extracellular traps (NETs) may potentially drive the process by which tolerance to these chromatin-associated proteins is broken. We hypothesized that NETs and their unique histone PTMs might be capable of inducing autoantibodies that target histones. Methods: We developed a novel and efficient method for the in vitro production, visualization, and broad profiling of histone-PTMs of human and murine NETs. We also immunized Balb/c mice with murine NETs and profiled their sera on autoantigen and histone peptide microarrays for evidence of autoantibody production to their immunogen. Results: We confirmed specificity toward acetyl-modified histone H2B as well as to other histone PTMs in sera from patients with SLE known to have autoreactivity against histones. We observed enrichment for distinctive histone marks of transcriptionally silent DNA during NETosis triggered by diverse stimuli. However, NETs derived from human and murine sources did not harbor many of the PTMs toward which autoreactivity was observed in patients with SLE or in MRL/lpr mice. Further, while murine NETs were weak autoantigens in vivo, there was only partial overlap in the IgG and IgM autoantibody profiles induced by vaccination of mice with NETs and those seen in patients with SLE. Conclusions: Isolated in vivo exposure to NETs is insufficient to break tolerance and may involve additional factors that have yet to be identified. Serum samples from 20 systemic lupus erythematosis patients were run on the Human Epigenome Microarray Platform V1.0 (HEMP; a single-color platform), in order to profile their autoantibodies against a library of post-translationally modified histone peptides. These 20 samples were randomly selected from a larger cohort previously profiled (data not shown) on the Utz Lab Whole Protein Autoantigen Array V2.0 (a single-color platform), where 14 were histone-reactive and 6 were histone-nonreactive. Control sera from 9 healthy adults and a positive control comprising a mixture of autoimmune sera with defined reactivities, were also run on HEMP V1.0. Together, these samples comprise the data appearing in Figures 1 and S1 (IgG and IgM isotype reactivity profiles, respectively), identifying IgG reactivity to 9 peptides that significantly distinguish histone-reactive from -nonreactive sera among 96 peptides profiled. For data appearing in Figure 5, serum samples from a total of 6 Balb/c mice, consisting of two treatment groups, NETs (Neutrophil Extracellular Traps) and NETs + CRAMP (cathelicidin-related antimicrobial peptide) were collected monthly over a 3-month period, along with a zero time point. These samples were compared with a positive control consisting of serum collected from a MLR/lpr mice exhibiting lupus-like symptoms, and a negative control with no serum. The 0, 1 and 2 month time points were profiled on the Utz Lab Whole Protein Autoantigen Array V2.0 and are shown in Figure 5A-B, while the 1 and 3 month time points were profiled on HEMP V1.0 arrays and shown in Figure 5E. All samples were run once with no replicates.
2012-01-26 | E-GEOD-32543 | biostudies-arrayexpress
Project description:We used microarrays to determine how the quality and quantity of peptide-MHC impact TCR-induced gene expression in vivo. Adoptively transferred 5CC7 T cells were stimulated in vivo with different doses if two peptides: MCC peptide is a strong agonist and 102S peptide is a weak agonist for the 5CC7 TCR. After 48hours later, T cells were purified and gene expression was assessed using microarray.
2015-05-15 | E-GEOD-68893 | biostudies-arrayexpress
Project description:Naïve T cells constantly experience TCR signals in response to self-peptides presented by MHC (pMHC) in vivo. The intensity of these basal or tonic TCR signals can be indirectly read out by expression of surrogate markers of tonic TCR signaling, including the Nur77-GFP transgene and Ly6c. The strength of tonic TCR signaling varies broadly across the naïve CD4+ T cell population and is correlated with functional heterogeneity.Cells that experience the most basal TCR signaling (Nur77-GFP hi, Ly6c lo) are hyporesponsive to peptide-MHC stimulation. Here we examine whether tonic TCR stimulation is associated with differences in mRNA expression.
2022-08-22 | GSE206073 | GEO
Project description:Naïve T cells constantly experience TCR signals in response to self-peptides presented by MHC (pMHC) in vivo. The intensity of these basal or tonic TCR signals can be indirectly read out by expression of surrogate markers of tonic TCR signaling, including the Nur77-GFP transgene and Ly6c. The strength of tonic TCR signaling varies broadly across the naïve CD4+ T cell population and is correlated with functional heterogeneity.Cells that experience the most basal TCR signaling (Nur77-GFP hi, Ly6c lo) are hyporesponsive to peptide-MHC stimulation. Here we examine whether tonic TCR stimulation is associated with differences in chromatin accessibility.
2022-08-22 | GSE206072 | GEO
Project description:Antigen-specific regulatory T cells (Tregs) suppress pathogenic autoreactivity and are potential therapeutic candidates for autoimmune diseases such as systemic lupus erythematosus (SLE). Lupus nephritis is associated with autoreactivity to the Smith (Sm) autoantigen and the human leucocyte antigen (HLA)-DR15 haplotype; hence, we investigated the potential of Sm-specific Tregs (Sm-Tregs) to suppress disease. We identified a novel HLA-DR15 restricted immunodominant Sm T cell epitope using biophysical affinity binding assays, then identified high-affinity Sm-specific T cell receptors (TCRs) using high-throughput single-cell sequencing. Using lentiviral vectors, we transduced our lead Sm-specific TCR onto Tregs derived from patients with SLE who were anti-Sm and HLA-DR15 positive. Compared with polyclonal mock-transduced Tregs, Sm-Tregs potently suppressed Sm-specific pro-inflammatory responses in vitro and suppressed disease progression in a humanized mouse model of lupus nephritis. These results show that Sm-Tregs are a promising therapy for SLE.
2023-11-28 | GSE242152 | GEO
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining “immune privilege” remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous guardian peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these guardian peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of guardian peptides was diminished. Fascinatingly, boosting the presence of these guardian peptides reinforced a population of suppressor CD4+ T cells and significantly reduced CNS autoimmune disease. This unexpected discovery of CNS-derived autoimmune guardian peptides may be the molecular key adapting the CNS to receive information and to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
2024-10-11 | GSE240691 | GEO
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
2024-10-11 | GSE272901 | GEO
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
2024-10-11 | GSE276987 | GEO