Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 47
Filter
1.
J Nurses Prof Dev ; 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39042849

ABSTRACT

An integrated health system including 12 hospitals, an expansive network of ambulatory settings, and health insurance plans began a systematic review of the existing nursing professional practice model (PPM) created in 2007 to assess current relevancy. The goal was to determine PPM concepts and imagery that represent present-day nursing workforce. This article shares how a formal review of literature, utilization of focus groups, and system-wide shared decision-making influenced creation and evaluation of a revised PPM.

2.
bioRxiv ; 2024 Jun 16.
Article in English | MEDLINE | ID: mdl-38915547

ABSTRACT

INTRODUCTION: Proteome changes associated with APOE4 variant carriage that are independent of Alzheimer's disease (AD) pathology and diagnosis are unknown. This study investigated APOE4 proteome changes in people with AD, mild cognitive impairment, and no impairment. METHODS: Clinical, APOE genotype, and cerebrospinal fluid (CSF) proteome and AD biomarker data was sourced from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Proteome profiling was done using supervised machine learning. RESULTS: We found an APOE4-specific proteome signature that was independent of cognitive diagnosis and AD pathological biomarkers, and increased risk of progression to cognitive impairment. Proteins were enriched in brain regions including the caudate and cortex and cells including endothelial cells, oligodendrocytes, and astrocytes. Enriched peripheral immune cells included T cells, macrophages, and B cells. DISCUSSION: APOE4 carriers have a unique CSF proteome signature associated with a strong brain and peripheral immune and inflammatory phenotype that likely underlies APOE4 carriers' vulnerability to cognitive decline and AD.

3.
Immunol Cell Biol ; 102(6): 437-440, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38693765

ABSTRACT

CAR T cell therapy is showing remarkable results in autoimmune disease with treatment-refractory patients showing durable drug-free remission. Here, we highlight five key papers from 2023 that are driving the development of CAR T cells to improve precision, safety, efficacy and accessibility for the treatment of autoantibody-associated autoimmune diseases.


Subject(s)
Autoimmune Diseases , Immunotherapy, Adoptive , Precision Medicine , Receptors, Chimeric Antigen , Humans , Autoimmune Diseases/therapy , Autoimmune Diseases/immunology , Immunotherapy, Adoptive/methods , Immunotherapy, Adoptive/adverse effects , Receptors, Chimeric Antigen/immunology , Receptors, Chimeric Antigen/metabolism , T-Lymphocytes/immunology , Animals , Receptors, Antigen, T-Cell/metabolism , Receptors, Antigen, T-Cell/immunology
4.
J Rheumatol ; 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37839820

ABSTRACT

As a highly varied disease, Sjögren syndrome (SS; also termed Sjögren disease) is estimated to affect 0.01% to 0.72% of the population, with an overwhelming bias toward the female gender.1 SS causes a significant burden to the quality of life of patients and inhibits their function.

5.
Front Immunol ; 14: 1115548, 2023.
Article in English | MEDLINE | ID: mdl-37006271

ABSTRACT

Introduction: Serum autoantibodies targeting the SSA/Ro proteins are a key component of the classification criteria for the diagnosis of Sjögren's syndrome (SS). Most patients' serum reacts with both Ro60 and Ro52 proteins. Here we compare the molecular and clinical characteristics of patients diagnosed with SS with anti-Ro52 in the presence or absence of anti-Ro60/La autoantibodies. Methods: A cross-sectional study was performed. Patients in the SS biobank at Westmead Hospital (Sydney, Australia) that were positive for anti-Ro52 were included and stratified based on the absence (isolated) or presence (combined) of anti-Ro60/La, measured by line immunoassay. We examined clinical associations and the serological and molecular characteristics of anti-Ro52 using ELISA and mass spectrometry in serological groups. Results: A total of 123 SS patients were included for study. SS patients with isolated anti-Ro52 (12%) identified a severe serological subset characterised by higher disease activity, vasculitis, pulmonary involvement, rheumatoid factor (RhF) and cryoglobulinaemia. Serum antibodies reacting with Ro52 in the isolated anti-Ro52 subset displayed less isotype switching, less immunoglobulin variable region subfamily usage and a lower degree of somatic hypermutation than the combined anti-Ro52 subset. Conclusions: In our cohort of SS patients, isolated anti-Ro52 represents a severe subset of SS, and is associated with the presence of cryoglobulinaemia. We therefore provide clinical relevance to the stratification of SS patients by their sero-reactivities. It is possible that the autoantibody patterns may be immunological epiphenomena of the underlying disease process, and further work is required to unearth the mechanisms of the differential clinical phenotypes.


Subject(s)
Cryoglobulinemia , Sjogren's Syndrome , Humans , Sjogren's Syndrome/diagnosis , Cross-Sectional Studies , Antibodies, Antinuclear , Autoantibodies
6.
Mol Ther ; 31(7): 1979-1993, 2023 07 05.
Article in English | MEDLINE | ID: mdl-37012705

ABSTRACT

Success in the treatment of infants with spinal muscular atrophy (SMA) underscores the potential of vectors based on adeno-associated virus (AAV). However, a major obstacle to the full realization of this potential is pre-existing natural and therapy-induced anti-capsid humoral immunity. Structure-guided capsid engineering is one possible approach to surmounting this challenge but necessitates an understanding of capsid-antibody interactions at high molecular resolution. Currently, only mouse-derived monoclonal antibodies (mAbs) are available to structurally map these interactions, which presupposes that mouse and human-derived antibodies are functionally equivalent. In this study, we have characterized the polyclonal antibody responses of infants following AAV9-mediated gene therapy for SMA and recovered 35 anti-capsid mAbs from the abundance of switched-memory B (smB) cells present in these infants. For 21 of these mAbs, seven from each of three infants, we have undertaken functional and structural analysis measuring neutralization, affinities, and binding patterns by cryoelectron microscopy (cryo-EM). Four distinct patterns were observed akin to those reported for mouse-derived mAbs, but with early evidence of differing binding pattern preference and underlying molecular interactions. This is the first human and largest series of anti-capsid mAbs to have been comprehensively characterized and will prove to be powerful tools for basic discovery and applied purposes.


Subject(s)
Antibodies, Monoclonal , Capsid , Infant , Humans , Animals , Mice , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/genetics , Cryoelectron Microscopy , Capsid/chemistry , Capsid Proteins/chemistry , Dependovirus , Genetic Therapy , Genetic Vectors/genetics
7.
Nurs Open ; 10(6): 3962-3972, 2023 06.
Article in English | MEDLINE | ID: mdl-36808483

ABSTRACT

AIMS: The aim of the study was to explore the physician associate role in patient care, integration and collaboration with team members, within the hospital setting. DESIGN: Convergent mixed methods case study design. METHODS: Questionnaires with some open-ended questions and semi-structured interviews were analysed with descriptive statistics and thematic analysis. RESULTS: Participants included 12 physician associates, 31 health professionals and 14 patients/relatives. Physician associates provide effective, safe and, importantly, continuity of care and patients received patient-centred care. Integration into teams was variable, and there was a lack of knowledge about the physician associate role amongst staff and patients. Views towards physician associates were mostly positive, but support for physician associates differed across the three hospitals. CONCLUSION: This study further consolidates the role of physician associates to multiprofessional teams and patient care and emphasises the importance of providing support to individuals and teams when integrating new professions. Interprofessional learning throughout healthcare careers can develop interprofessional working within multiprofessional teams. IMPACT: Leaders in healthcare will see that clarity about the role of physician associates must be given to staff members and patients. Employers and team members will see the need to properly integrate new professions and team members within the workplace and to enhance professional identities. The research will also impact on educational establishments to provide more interprofessional training. PATIENT AND PUBLIC INVOLVEMENT: There is no patient and public involvement.


Subject(s)
Physicians , Humans , Patient Care , Health Personnel , Hospitals , Patient Care Team
8.
Arthritis Care Res (Hoboken) ; 75(7): 1580-1587, 2023 07.
Article in English | MEDLINE | ID: mdl-36063396

ABSTRACT

Sjögren's disease (SjD) is an archetypal and heterogenous autoimmune disorder that is characterized by exocrine glandular dysfunction. A proportion of patients develop severe extraglandular manifestations, such as cryoglobulinemia, and have an increased risk of lymphoma, both of which can adversely affect quality of life and occasionally mortality. As with most autoimmune disorders, the pathogenesis is poorly understood and difficult to predict, and, frustratingly, there is a lack of targeted therapies to cure this disease. We review the disease manifestations of SjD and propose a staged model for understanding the evolution of pathology. In longitudinal studies, most patients remain relatively stable in terms of their laboratory and clinical parameters. However, in the setting of various risk factors, a proportion of patients develop severe symptoms and/or lymphoma. We discuss potential underlying mechanisms for disease progression and the strengths and limitations of using a staged model to correlate the pathogenesis and spectrum of manifestations in SjD. Ultimately, understanding how and why some patients remain relatively stable, whereas others progress and develop florid systemic disease and a fraction develop lymphoma, is key to developing preventative and therapeutic treatments.


Subject(s)
Autoimmune Diseases , Lymphoma , Sjogren's Syndrome , Humans , Quality of Life , Risk Factors
9.
Immunity ; 55(12): 2386-2404.e8, 2022 12 13.
Article in English | MEDLINE | ID: mdl-36446385

ABSTRACT

The association between cancer and autoimmune disease is unexplained, exemplified by T cell large granular lymphocytic leukemia (T-LGL) where gain-of-function (GOF) somatic STAT3 mutations correlate with co-existing autoimmunity. To investigate whether these mutations are the cause or consequence of CD8+ T cell clonal expansions and autoimmunity, we analyzed patients and mice with germline STAT3 GOF mutations. STAT3 GOF mutations drove the accumulation of effector CD8+ T cell clones highly expressing NKG2D, the receptor for stress-induced MHC-class-I-related molecules. This subset also expressed genes for granzymes, perforin, interferon-γ, and Ccl5/Rantes and required NKG2D and the IL-15/IL-2 receptor IL2RB for maximal accumulation. Leukocyte-restricted STAT3 GOF was sufficient and CD8+ T cells were essential for lethal pathology in mice. These results demonstrate that STAT3 GOF mutations cause effector CD8+ T cell oligoclonal accumulation and that these rogue cells contribute to autoimmune pathology, supporting the hypothesis that somatic mutations in leukemia/lymphoma driver genes contribute to autoimmune disease.


Subject(s)
Autoimmune Diseases , Leukemia, Large Granular Lymphocytic , Animals , Mice , Autoimmune Diseases/genetics , Autoimmune Diseases/pathology , CD8-Positive T-Lymphocytes , Gain of Function Mutation , Leukemia, Large Granular Lymphocytic/genetics , Leukemia, Large Granular Lymphocytic/pathology , Mutation , NK Cell Lectin-Like Receptor Subfamily K/genetics , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism
10.
Clin Rheumatol ; 41(11): 3495-3501, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35871174

ABSTRACT

INTRODUCTION: Anti-Ro52/tripartite motif-containing protein 21 (TRIM21) IgG is one of the most common autoantibodies found in systemic autoimmune diseases and is typically found in conjunction with anti-Ro60 and/or anti-La. A retrospective, cross-sectional study was undertaken to examine the clinical and laboratory features of two serological subsets: patients with anti-Ro52/TRIM21 autoantibodies in the absence of anti-Ro60 and anti-La (isolated anti-Ro52/TRIM21) and patients with anti-Ro52/TRIM21 in the presence of anti-Ro60 and/or anti-La. METHODS: Over a 12-month period, patients tested positive for anti-Ro52/TRIM21 via line immunoassay (LIA) at the Westmead Hospital (Australia) immunopathology laboratory were included. The presence of anti-Ro60 and/or anti-La via same LIA was noted. Associated laboratory and medical records were perused to extract demographic, laboratory, and clinical information. RESULTS: There were 346 patients within the study period, and 39.9% of the patients positive for anti-Ro52/TRIM21 lacked anti-Ro60/anti-La autoantibodies. Isolated anti-Ro52/TRIM21 patients tend to be older, have lower anti-Ro52/TRIM21 titres, have lower rheumatoid factors, and have lower proportions of neutropaenia compared to patients who were positive for anti-Ro52/TRIM21 and anti-Ro60/La. This occurred independent to diagnoses of Sjögren's syndrome or systemic lupus erythematosus. Coexisting neurological syndromes, pulmonary pathologies, and malignancies were more prevalent in the isolated anti-Ro52/TRIM21 subset. CONCLUSIONS: Patients with isolated anti-Ro52/TRIM21 tend to have distinct and important clinical and laboratory associations. It is unclear if these patients evolve or remain a stable subset and how they originate immunologically. Longitudinal and prospective studies are required to ascertain the overall predictive and prognostic value of this stratification. Key Points • Anti-Ro52/TRIM21 is an autoantibody found in autoimmunity and non-immunological conditions. • Sixty percent of anti-Ro52/TRIM21 patients are positive for anti-Ro60. • Isolated anti-Ro52/TRIM21 has reduced anti-Ro52/TRIM21 and rheumatoid factor titres. • Isolated anti-Ro52/TRIM21 is associated with anaemia and malignancies.


Subject(s)
Rheumatoid Factor , Sjogren's Syndrome , Autoantibodies , Cross-Sectional Studies , Humans , Immunoglobulin G , Retrospective Studies
11.
Proc Natl Acad Sci U S A ; 119(28): e2123212119, 2022 07 12.
Article in English | MEDLINE | ID: mdl-35867757

ABSTRACT

Humans lack the capacity to produce the Galα1-3Galß1-4GlcNAc (α-gal) glycan, and produce anti-α-gal antibodies upon exposure to the carbohydrate on a diverse set of immunogens, including commensal gut bacteria, malaria parasites, cetuximab, and tick proteins. Here we use X-ray crystallographic analysis of antibodies from α-gal knockout mice and humans in complex with the glycan to reveal a common binding motif, centered on a germline-encoded tryptophan residue at Kabat position 33 (W33) of the complementarity-determining region of the variable heavy chain (CDRH1). Immunoglobulin sequencing of anti-α-gal B cells in healthy humans and tick-induced mammalian meat anaphylaxis patients revealed preferential use of heavy chain germline IGHV3-7, encoding W33, among an otherwise highly polyclonal antibody response. Antigen binding was critically dependent on the presence of the germline-encoded W33 residue for all of the analyzed antibodies; moreover, introduction of the W33 motif into naive IGHV3-23 antibody phage libraries enabled the rapid selection of α-gal binders. Our results outline structural and genetic factors that shape the human anti-α-galactosyl antibody response, and provide a framework for future therapeutics development.


Subject(s)
Anaphylaxis , Antibodies , Food Hypersensitivity , Immunoglobulin Heavy Chains , Immunoglobulin Variable Region , Tick-Borne Diseases , Trisaccharides , Anaphylaxis/immunology , Animals , Antibodies/chemistry , Antibodies/genetics , Antibody Formation/genetics , Antigen-Antibody Complex/chemistry , Crystallography, X-Ray , Food Hypersensitivity/immunology , Humans , Immunoglobulin Heavy Chains/chemistry , Immunoglobulin Heavy Chains/genetics , Immunoglobulin Variable Region/chemistry , Immunoglobulin Variable Region/immunology , Mice , Mice, Knockout , Peptide Library , Protein Conformation , Tick-Borne Diseases/immunology , Trisaccharides/genetics , Trisaccharides/immunology
12.
Cell Rep ; 38(3): 110259, 2022 01 18.
Article in English | MEDLINE | ID: mdl-35045301

ABSTRACT

CD21low age-associated or atypical memory B cells are autoantibody enriched and poised for plasma cell differentiation. These cells overaccumulate in chronic infections, autoimmune disease, and immunodeficiency, posing the question of what checkpoints normally oppose their accumulation. Here, we reveal a critical role for paralogous calcium-NFAT-regulated transcription factors EGR2 and EGR3 that are induced in self-reactive B cells. CD21low and B1 B cells lacking EGR2 and EGR3 accumulate and circulate in young mice in numbers 10- to 20-fold greater than normal and overexpress a large set of EGR2 ChIP-seq target genes, including known drivers of plasma cell differentiation. Most follicular B cells constitutively express Egr2 proportionally to surface IgM downregulation by self-antigens, and EGR2/3 deficiency abolishes this cardinal feature of B cell anergy. These results explain the cardinal features of B cell anergy, define a key transcriptional checkpoint repressing CD21low B cell formation, and inform how NFATC1 or EGR2 mutations promote B1 cell-derived chronic lymphocytic leukemias.


Subject(s)
B-Lymphocytes/immunology , Clonal Anergy/immunology , Early Growth Response Protein 2/immunology , Early Growth Response Protein 3/immunology , Animals , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , Autoimmunity/immunology , B-Lymphocyte Subsets/immunology , B-Lymphocyte Subsets/metabolism , B-Lymphocytes/metabolism , Early Growth Response Protein 2/metabolism , Early Growth Response Protein 3/metabolism , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Male , Mice , Receptors, Complement 3d/immunology
13.
Immunol Rev ; 307(1): 101-115, 2022 05.
Article in English | MEDLINE | ID: mdl-35001403

ABSTRACT

Autoimmune diseases are characterized by serum autoantibodies, some of which are pathogenic, causing severe manifestations and organ injury. However, autoantibodies of the same antigenic reactivity are also present in the serum of asymptomatic people years before they develop any clinical signs of autoimmunity. Autoantibodies can arise during multiple stages of B cell development, and various genetic and environmental factors drive their production. However, what drives the development of pathogenic autoantibodies is poorly understood. Advances in single-cell technology have enabled the deep analysis of rare B cell clones producing pathogenic autoantibodies responsible for vasculitis in patients with primary Sjögren's syndrome complicated by mixed cryoglobulinaemia. These findings demonstrated a cascade of genetic events involving stereotypic immunoglobulin V(D)J recombination and transforming somatic mutations in lymphoma genes and V(D)J regions that disrupted antibody quality control mechanisms and decreased autoantibody solubility. Most studies consider V(D)J mutations that enhance autoantibody affinity to drive pathology; however, V(D)J mutations that increase autoantibody propensity to form insoluble complexes could be a major contributor to autoantibody pathogenicity. Defining the molecular characteristics of pathogenic autoantibodies and failed tolerance checkpoints driving their formation will improve prognostication, enabling early treatment to prevent escalating organ damage and B cell malignancy.


Subject(s)
Autoantibodies , B-Lymphocytes , Autoimmunity/genetics , Clone Cells , Humans , Mutation/genetics
14.
J Autoimmun ; 124: 102724, 2021 11.
Article in English | MEDLINE | ID: mdl-34464814

ABSTRACT

As iconic and important diagnostic autoantibodies, anti-Ro60 and anti-Ro52/tri-partite motif-containing 21 (TRIM21) make a common appearance in a number of systemic autoimmune disorders such as systemic lupus erythematosus (SLE). These autoantibodies often co-exist together; yet despite their close relationship, there is no evidence that they are physically linked and probably reflect a convergence of separate processes of failed immunological tolerance. Confusingly, they are sometimes classed together as the "SSA" or "Ro" autoantibody system without clear distinction between the two. In this Short Communication, we discuss the diagnostic merits for separate detection and reporting of these two autoantibodies, and discuss avenues for future research. Indeed, further insight into their fascinating origins and pathogenic roles in autoimmunity will surely shed light on how we can prevent and treat devastating autoimmune disorders.


Subject(s)
Antibodies, Antinuclear/metabolism , Lupus Erythematosus, Systemic/immunology , Ribonucleoproteins/immunology , Autoimmunity , Humans , Immune Tolerance , Lupus Erythematosus, Systemic/diagnosis
15.
Immunol Cell Biol ; 99(8): 865-878, 2021 09.
Article in English | MEDLINE | ID: mdl-33988890

ABSTRACT

The level of immunoglobulin M (IgM) displayed on the surface of peripheral blood B cells exhibits a broad dynamic range and has been associated with both development and selection. To determine whether IgM surface expression associates with distinct immunoglobulin heavy-chain (IGH) repertoire properties, we performed deep IgM sequencing of peripheral blood transitional and mature naïve B cells in the upper and lower quartiles of surface IgM expression for 12 healthy donors. Mature naïve B cells within the lowest quartile for surface IgM expression displayed more diverse IGH features including increased complementarity-determining region 3 length, IGHJ6 segment usage and aromatic amino acids compared with mature naïve B cells with high surface IgM. There were no differences between IGH repertoires for transitional B cells with high or low surface IgM. These findings suggest that a selection checkpoint during progression of transitional to mature naïve B cells reduces the breadth of the IGH repertoire among high surface IgM B cells but that diversity is preserved in B cells expressing low levels of surface IgM.


Subject(s)
B-Lymphocytes , Immunoglobulin Heavy Chains , Complementarity Determining Regions/genetics , Humans , Immunoglobulin Heavy Chains/genetics , Immunoglobulin M , Receptors, Antigen, B-Cell
16.
Clin Exp Rheumatol ; 38 Suppl 126(4): 271-282, 2020.
Article in English | MEDLINE | ID: mdl-33025890

ABSTRACT

Primary Sjögren's syndrome (pSS) is often considered a B cell-mediated disease, yet the precise role of B cells in the pathogenesis is not fully understood. This is exemplified by the failure of multiple clinical trials directed at B cell depletion or inhibition. To date, most prognostic markers for severe disease outcomes are autoantibodies, but the underlying mechanisms by which B cells drive diverse disease presentations in pSS likely extend beyond autoantibody production. Here we outline an expanded role of B cells in disease pathogenesis drawing on examples from animal models of SS, and from other autoimmune diseases that share similar clinical or immunological abnormalities. We focus on recent findings from the detailed analysis of pathogenic B cells in patients with pSS to propose strategies for patient stratification to improve clinical trial outcomes. We conclude that an integrated cellular, molecular and genetic analysis of patients with pSS will reveal the underlying pathogenic mechanisms and guide precision medicine.


Subject(s)
Autoimmune Diseases , Sjogren's Syndrome , Animals , Autoantibodies , B-Lymphocytes , Humans , Sjogren's Syndrome/diagnosis
17.
Cell ; 180(5): 878-894.e19, 2020 03 05.
Article in English | MEDLINE | ID: mdl-32059783

ABSTRACT

Pathogenic autoantibodies arise in many autoimmune diseases, but it is not understood how the cells making them evade immune checkpoints. Here, single-cell multi-omics analysis demonstrates a shared mechanism with lymphoid malignancy in the formation of public rheumatoid factor autoantibodies responsible for mixed cryoglobulinemic vasculitis. By combining single-cell DNA and RNA sequencing with serum antibody peptide sequencing and antibody synthesis, rare circulating B lymphocytes making pathogenic autoantibodies were found to comprise clonal trees accumulating mutations. Lymphoma driver mutations in genes regulating B cell proliferation and V(D)J mutation (CARD11, TNFAIP3, CCND3, ID3, BTG2, and KLHL6) were present in rogue B cells producing the pathogenic autoantibody. Antibody V(D)J mutations conferred pathogenicity by causing the antigen-bound autoantibodies to undergo phase transition to insoluble aggregates at lower temperatures. These results reveal a pre-neoplastic stage in human lymphomagenesis and a cascade of somatic mutations leading to an iconic pathogenic autoantibody.


Subject(s)
Autoantibodies/genetics , Autoimmune Diseases/genetics , B-Lymphocytes/immunology , Lymphoma/genetics , Animals , Autoantibodies/immunology , Autoimmune Diseases/immunology , Autoimmune Diseases/pathology , B-Lymphocytes/pathology , CARD Signaling Adaptor Proteins/genetics , Carrier Proteins/genetics , Clonal Evolution/genetics , Clonal Evolution/immunology , Cyclin D3/genetics , Guanylate Cyclase/genetics , Humans , Immediate-Early Proteins/genetics , Immunoglobulin Variable Region/genetics , Immunoglobulin Variable Region/immunology , Inhibitor of Differentiation Proteins/genetics , Lymphoma/immunology , Lymphoma/pathology , Mice , Mutation/genetics , Mutation/immunology , Neoplasm Proteins/genetics , Sequence Analysis, DNA/methods , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , Tumor Necrosis Factor alpha-Induced Protein 3/genetics , Tumor Suppressor Proteins/genetics , V(D)J Recombination/genetics
18.
J Exp Med ; 217(2)2020 02 03.
Article in English | MEDLINE | ID: mdl-31841125

ABSTRACT

Antibody-mediated autoimmune diseases are a major health burden. However, our understanding of how self-reactive B cells escape self-tolerance checkpoints to secrete pathogenic autoantibodies remains incomplete. Here, we demonstrate that patients with monogenic immune dysregulation caused by gain-of-function mutations in PIK3CD, encoding the p110δ catalytic subunit of phosphoinositide 3-kinase (PI3K), have highly penetrant secretion of autoreactive IgM antibodies. In mice with the corresponding heterozygous Pik3cd activating mutation, self-reactive B cells exhibit a cell-autonomous subversion of their response to self-antigen: instead of becoming tolerized and repressed from secreting autoantibody, Pik3cd gain-of-function B cells are activated by self-antigen to form plasmablasts that secrete high titers of germline-encoded IgM autoantibody and hypermutating germinal center B cells. However, within the germinal center, peripheral tolerance was still enforced, and there was selection against B cells with high affinity for self-antigen. These data show that the strength of PI3K signaling is a key regulator of pregerminal center B cell self-tolerance and thus represents a druggable pathway to treat antibody-mediated autoimmunity.


Subject(s)
Antibody Formation/genetics , Autoantibodies/immunology , Class I Phosphatidylinositol 3-Kinases/genetics , Gain of Function Mutation , Immune Tolerance/immunology , Plasma Cells/immunology , Animals , Autoantibodies/blood , Autoantigens/immunology , Autoimmunity/genetics , Class I Phosphatidylinositol 3-Kinases/blood , Class I Phosphatidylinositol 3-Kinases/metabolism , Female , Germinal Center/immunology , Humans , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Signal Transduction/genetics
19.
Immunol Rev ; 292(1): 61-75, 2019 11.
Article in English | MEDLINE | ID: mdl-31556969

ABSTRACT

The adaptive immune system is tasked with producing antibodies that recognize a wide scope of potential pathogens, including those never before encountered, and concurrently avoiding formation of antibodies binding host tissues. The diverse repertoire of antibodies produced by V(D)J recombination inevitably includes autoantibodies that bind to self-antigens, estimated to be as much as 70% of nascent antibodies on immature B cells. Early theoretical models of tolerance hypothesized that such self-reactive clones could not possibly be allowed to survive and mature. However from the first direct view of the fate of nascent B cells carrying a self-binding antibody it was clear that many "forbidden clones" circulate to secondary lymphoid tissues, where they adopt an IgMlow IgD+ cell surface phenotype and are prevented from secreting autoantibodies by a series of tolerance checkpoints referred to as "clonal anergy." Since anergic B cells can be reactivated to secrete pathogenic autoantibodies in certain settings, the advantage of controlling self-reactive antibodies by clonal anergy has until recently remained enigmatic. Here we review this topic and recent advances showing that anergic B cells are recruited into the germinal center to mutate away from self-reactivity, undergoing "clonal redemption" into cells making antibodies with exquisite specificity for foreign immunogens.


Subject(s)
B-Lymphocytes/immunology , Clonal Anergy/immunology , Immune Tolerance/immunology , Immunity/immunology , Animals , Autoantibodies/immunology , Autoantigens/immunology , Autoantigens/metabolism , B-Lymphocytes/metabolism , Germinal Center/immunology , Germinal Center/metabolism , Humans , Receptors, Antigen, B-Cell/immunology , Receptors, Antigen, B-Cell/metabolism
20.
Cancer Cell ; 35(2): 297-314.e8, 2019 02 11.
Article in English | MEDLINE | ID: mdl-30753827

ABSTRACT

Promoter CpG islands are typically unmethylated in normal cells, but in cancer a proportion are subject to hypermethylation. Using methylome sequencing we identified CpG islands that display partial methylation encroachment across the 5' or 3' CpG island borders. CpG island methylation encroachment is widespread in prostate and breast cancer and commonly associates with gene suppression. We show that the pattern of H3K4me1 at CpG island borders in normal cells predicts the different modes of cancer CpG island hypermethylation. Notably, genetic manipulation of Kmt2d results in concordant alterations in H3K4me1 levels and CpG island border DNA methylation encroachment. Our findings suggest a role for H3K4me1 in the demarcation of CpG island methylation borders in normal cells, which become eroded in cancer.


Subject(s)
CpG Islands , DNA Methylation , DNA, Neoplasm/metabolism , Histones/metabolism , Neoplasms/metabolism , 5-Methylcytosine/analogs & derivatives , 5-Methylcytosine/metabolism , Animals , Cell Line, Tumor , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Female , Gene Expression Regulation, Neoplastic , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Histones/genetics , Humans , Male , Methylation , Mice, Inbred C57BL , Mice, Knockout , Myeloid-Lymphoid Leukemia Protein/genetics , Myeloid-Lymphoid Leukemia Protein/metabolism , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Neoplasms/genetics , Promoter Regions, Genetic
SELECTION OF CITATIONS
SEARCH DETAIL
...