Specific post-translational histone mod. of neutrophil extracellular traps as immunogens & potential SLE Ab targets.
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ABSTRACT:
ORGANISM(S): Escherichia coli Bos taurus Mus musculus Homo sapiens Oryctolagus cuniculus Gallus gallus
PROVIDER: GSE32544 | GEO | 2012/01/26
SECONDARY ACCESSION(S): PRJNA147919
REPOSITORIES: GEO
Similar Datasets
Project description:This SuperSeries is composed of the following subset Series: GSE32542: Murine serum reactivity to common autoantigens in response to immunization with neutrophil extracellular traps GSE32543: Human and murine serum reactivity to specific histone posttranslational modifications in neutrophil extracellular traps Refer to individual Series
2012-01-26 | E-GEOD-32544 | biostudies-arrayexpress
Project description:IntroductionAutoreactivity 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.MethodsWe 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.ResultsWe 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 immunoglobulin G (IgG) and IgM autoantibody profiles induced by vaccination of mice with NETs and those seen in patients with SLE.ConclusionsIsolated in vivo exposure to NETs is insufficient to break tolerance and may involve additional factors that have yet to be identified.
| S-EPMC3392818 | biostudies-literature
Project description:BackgroundNucleic acid binding proteins are frequently targeted as autoantigens in systemic lupus erythematosus (SLE) and other interferon (IFN)-linked rheumatic diseases. The AIM-like receptors (ALRs) are IFN-inducible innate sensors that form supramolecular assemblies along double-stranded (ds)DNA of various origins. Here, we investigate the ALR absent in melanoma 2 (AIM2) as a novel autoantigen in SLE, with similar properties to the established ALR autoantigen interferon-inducible protein 16 (IFI16). We examined neutrophil extracellular traps (NETs) as DNA scaffolds on which these antigens might interact in a pro-immune context.MethodsAIM2 autoantibodies were measured by immunoprecipitation in SLE and control subjects. Neutrophil extracellular traps were induced in control neutrophils and combined with purified ALR proteins in immunofluorescence and DNase protection assays. SLE renal tissues were examined for ALR-containing NETs by confocal microscopy.ResultsAIM2 autoantibodies were detected in 41/131 (31.3%) SLE patients and 2/49 (4.1%) controls. Our SLE cohort revealed a frequent co-occurrence of anti-AIM2, anti-IFI16, and anti-DNA antibodies, and higher clinical measures of disease activity in patients positive for antibodies against these ALRs. We found that both ALRs bind NETs in vitro and in SLE renal tissues. We demonstrate that ALR binding causes NETs to resist degradation by DNase I, suggesting a mechanism whereby extracellular ALR-NET interactions may promote sustained IFN signaling.ConclusionsOur work suggests that extracellular ALRs bind NETs, leading to DNase resistant nucleoprotein fibers that are targeted as autoantigens in SLE.FundingThese studies were funded by NIH R01 DE12354 (AR), P30 AR070254, R01 GM 129342 (JS), K23AR075898 (CM), K08AR077100 (BA), the Jerome L. Greene Foundation and the Rheumatology Research Foundation. Dr. Antiochos and Dr. Mecoli are Jerome L. Greene Scholars. The Hopkins Lupus Cohort is supported by NIH grant R01 AR069572. Confocal imaging performed at the Johns Hopkins Microscopy Facility was supported by NIH Grant S10 OD016374.
| S-EPMC9129876 | biostudies-literature
Project description:Low back pain following spine surgery is a major complication due to excessive epidural fibrosis, which compresses the lumbar nerve. The mechanisms of epidural fibrosis remain largely elusive. In the drainage samples from patients after spine operation, neutrophil extracellular traps (NETs) and NETs inducer high-mobility group box 1 were significantly increased. In a mouse model of laminectomy, NETs developed in the wound area post epidural operation, accompanied with macrophage infiltration. In vitro, macrophages ingested NETs and thereby increased the elastase from NETs via the receptor for advanced glycation end product. Moreover, NETs boosted the expression of fibronectin in macrophages, which was dependent on elastase and could be partially blocked by DNase. NF-κB p65 and Smad pathways contributed to the increased expression fibronectin in NETs-treated macrophages. In the mouse spine operation model, post-epidural fibrosis was significantly mitigated with the administration of DNase I, which degraded DNA and cleaved NETs. Our study shed light on the roles and mechanisms of NETs in the scar formation post spine operation.
| S-EPMC7599244 | biostudies-literature
Project description:Coronavirus disease 2019 (COVID-19) is a novel, viral-induced respiratory disease that in ?10-15% of patients progresses to acute respiratory distress syndrome (ARDS) triggered by a cytokine storm. In this Perspective, autopsy results and literature are presented supporting the hypothesis that a little known yet powerful function of neutrophils-the ability to form neutrophil extracellular traps (NETs)-may contribute to organ damage and mortality in COVID-19. We show lung infiltration of neutrophils in an autopsy specimen from a patient who succumbed to COVID-19. We discuss prior reports linking aberrant NET formation to pulmonary diseases, thrombosis, mucous secretions in the airways, and cytokine production. If our hypothesis is correct, targeting NETs directly and/or indirectly with existing drugs may reduce the clinical severity of COVID-19.
| S-EPMC7161085 | biostudies-literature
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:The mechanisms of bacterial killing by neutrophil extracellular traps (NETs) are unclear. DNA, the largest component of NETs is believed to merely be a scaffold with minimal antimicrobial activity through the charge of the backbone. Here, we report that NETs DNA is beyond a scaffold and produces hydroxyl free radicals through the spatially concentrated G-quadruplex/hemin DNAzyme complexes, driving bactericidal effects. Immunofluorescence staining showed colocalization of G-quadruplex and hemin in extruded NETs DNA, and Amplex UltraRed assay portrayed its peroxidase activity. Proximity labeling of bacteria revealed localized concentration of radicals resulting from NETs bacterial trapping. Ex vivo bactericidal assays revealed that G-quadruplex/hemin DNAzyme is the primary driver of bactericidal activity in NETs. NETs are DNAzymes that may have important biological consequences.One-sentence summaryG-quadruplex/hemin DNAzymes may be major contributors to biological consequences of neutrophil extracellular traps.
| S-EPMC10634746 | biostudies-literature
Project description:Fibrosis is a major health burden across diseases and organs. To remedy this, we study wound-induced hair follicle neogenesis (WIHN) as a model of non-fibrotic healing that recapitulates embryogenesis for de novo hair follicle morphogenesis after wounding. We previously demonstrated that TLR3 promotes WIHN through binding wound-associated dsRNA, the source of which is still unclear. Here, we find that multiple distinct contexts of high WIHN all show a strong neutrophil signature. Given the correlation between neutrophil infiltration and endogenous dsRNA release, we hypothesized that neutrophil extracellular traps (NETs) likely release nuclear spliceosomal U1 dsRNA and modulate WIHN. However, rather than enhance regeneration, we find mature neutrophils inhibit WIHN such that mice with mature neutrophil depletion exhibit higher WIHN. Similarly, Pad4 null mice, which are defective in NET production, show augmented WIHN. Finally, using single-cell RNA sequencing, we identify a dramatic increase in mature and activated neutrophils in the wound beds of low regenerating Tlr3-/- mice. Taken together, these results demonstrate that although mature neutrophils are stimulated by a common pro-regenerative cue, their presence and NETs hinder regeneration.
| S-EPMC8572775 | biostudies-literature
Project description:Inflammation after trauma is both critical to normal wound healing and may be highly detrimental when prolonged or unchecked with the potential to impair physiologic healing and promote de novo pathology. Mechanical strain after trauma is associated with impaired wound healing and increased inflammation. The exact mechanisms behind this are not fully elucidated. Neutrophil extracellular traps (NETs), a component of the neutrophil response to trauma, are implicated in a range of pro-inflammatory conditions. In the current study, we evaluated their role in linking movement and inflammation. We found that a link exists between the disruption and amplification of NETs which harbors the potential to regulate the wound's response to mechanical strain, while leaving the initial inflammatory signal necessary for physiologic wound healing intact.
| S-EPMC6821718 | biostudies-literature