Mechanism of Humoral Immune Defects in Autoimmune Polyglandular Syndrome Type 1

自身免疫性多腺体综合征1型体液免疫缺陷的机制

• 批准号: 9304961
• 负责人: Kang Chen
• 金额: $ 19.25万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9304961
• 关键词: Address; Antibodies; Antibody Formation; Antibody Repertoire; Antifungal Agents; Autoantibodies; Autoimmune Diseases; Autoimmune Process; Autoimmunity; Avidity; B-Cell Activation; B-Lymphocytes; Biological Assay; Biology; Candida albicans; Candidiasis; Cell Communication; Cells; Cellular Immunity; Chemicals; Chronic Mucocutaneous Candidiasis; Clinical; Clinical Immunology; Complex; Cutaneous; Data; Defect; Disease; Dot Immunoblotting; Effector Cell; Endocrine Glands; Enzyme-Linked Immunosorbent Assay; Enzymes; Exhibits; Eye; Flow Cytometry; Gastrointestinal tract structure; Generations; Genes; Genetic Transcription; Genomics; German population; Goals; Health; Human; Immune; Immune System Diseases; Immune System and Related Disorders; Immune response; Immunity; Immunoglobulin Class Switching; Immunoglobulin G; Immunoglobulin Somatic Hypermutation; Immunoglobulin Switch Recombination; Immunologic Deficiency Syndromes; Immunologics; Impairment; In Vitro; Infection; Interleukin-17; Knowledge; Lymphoid; Lymphoid Tissue; Measures; Mediating; Methodology; Mission; Modeling; Mus; Mutation; Nuclear Localization Signal; Organ; Pathogenesis; Pathogenicity; Patients; Peripheral; Predisposition; Production; Public Health; Regulation; Research; Role; Side; Skin; Structure of germinal center of lymph node; Syndrome; T cell response; T-Lymphocyte; Testing; Therapeutic; Time; United States National Institutes of Health; Uracil; Work; acquired immunodeficiency; activation-induced cytidine deaminase; autoreactive B cell; autoreactivity; base; burden of illness; chromatin immunoprecipitation; congenital immunodeficiency; cytokine; disability; effective therapy; in vivo; innovation; insight; interleukin-22; loss of function mutation; mouse model; mutant; neutralizing antibody; next generation sequencing; novel; response; therapy development

Project Summary Autoimmune Polyglandular Syndrome type 1 (APS-1) is caused by mutations in the Autoimmune Regulator (Aire) gene, which normally promotes central and peripheral T cell tolerance. APS-1 patients exhibit autoimmune disorders in multiple organs and a predisposition to chronic mucocutaneous candidiasis (CMC). A lack of mechanistic under- standing of the basis of candidiasis and its paradoxical association with autoimmunity hampers effective treatment of APS-1. Patients with candidiasis often have defects in cell-mediated immunity. APS-1 patients produce class- switched IgG autoantibodies against T helper 17 (TH17) cytokines, which may neutralize and impair protective anti- fungal immunity. This highlights humoral immune dysfunction as a potentially important contributing factor to CMC in APS-1. Our long-term goal is to understand the immune dysregulation in autoimmune and immunodeficiency disor- ders and to develop mechanism-guided therapeutic strategies. The objective in this application is to elucidate the mechanism of humoral immune defects in APS-1. Our preliminary studies show that AIRE is expressed specifically in human and mouse germinal center (GC) B cells in secondary lymphoid organs in vivo, and in B cells undergoing antibody diversification in vitro. AIRE deficiency in B cells causes elevated class switch recombination (CSR) and somatic hypermutation (SHM). AIRE suppresses CSR when introduced into AIRE-deficient B cells. AIRE interacts in B cells with activation-induced cytidine deaminase (AID), the enzyme essential for SHM and CSR. Aire‒/‒ mice have aberrant expansion of GC B cell and T cell responses in systemic and mucosal lymphoid tissues. These findings support the central hypothesis that APS-1 involves aberrantly increased antibody maturation caused by B cell- intrinsic defects in AIRE-mediated AID regulation and B cell-extrinsic defects in the selection against autoreactive antibodies due to excessive GC response. Our rationale is that the elucidation of the mechanism of humoral immune defects in APS-1 will prompt more specific treatment of APS-1. The hypothesis will be tested by pursing two specific aims. Employing quantitative real-time PCR, flow cytometry, chromatin immunoprecipitation, genomic uracil dot blot and next-generation sequencing, studies in Aim 1 will determine the abnormalities in antibody maturation and the antibody repertoire in APS-1 and the mechanism by which AIRE regulates AID in B cells. Studies in Aim 2 will use competitive ELISA as well as mouse models of cutaneous Candida albicans infection to determine the role of B cell- intrinsic and -extrinsic AIRE deficiency in APS-1-associated candidiasis. This study proposes innovative and cutting- edge methodologies to test novel and mechanistic hypotheses in APS-1 pathogenesis. The work will have sustained and broad impact on the field of basic and clinical immunology, as it will not only advance the understanding of the disease APS-1 and AID-mediated regulation of antibody maturation, but also offer insights into the enigmas of an increasing number of immunodeficiencies that co-present with autoimmunity, thus paving the way to better treat the- se diseases.

项目摘要 自身免疫多腺体综合征1型（APS-1）是由自身免疫调节因子（Aire）突变引起的。 该基因通常促进中枢和外周T细胞耐受。APS-1患者表现出自身免疫性疾病 在多个器官和易患慢性粘膜皮肤念珠菌病（CMC）。缺乏机械性的- 念珠菌病的基础及其与自身免疫的矛盾联系阻碍了对 APS-1。念珠菌病患者往往有缺陷的细胞介导的免疫。APS-1患者产生类- 针对T辅助细胞17（TH 17）细胞因子的转换IgG自身抗体，这可能中和和损害保护性抗- 真菌免疫这突出了体液免疫功能障碍作为CMC的潜在重要促成因素， APS-1。我们的长期目标是了解自身免疫性和免疫缺陷性疾病中的免疫失调， ders和开发机制指导的治疗策略。本申请的目的是阐明 APS-1的体液免疫缺陷机制。我们的初步研究表明，AIRE表达特异性 在体内次级淋巴器官中的人和小鼠生殖中心（GC）B细胞中，以及在经历 体外抗体多样化。B细胞中的AIRE缺陷引起升高的类别转换重组（CSR）， 体细胞超突变（SHM）。当引入AIRE缺陷型B细胞时，AIRE抑制CSR。AIRE与 B细胞具有活化诱导的胞苷脱氨酶（AID），这是SHM和CSR所必需的酶。Aire mice/Aire mice有 全身和粘膜淋巴组织中GC B细胞和T细胞反应的异常扩增。这些发现 支持APS-1涉及由B细胞引起的异常增加的抗体成熟的中心假设， AIRE介导的AID调节中的内在缺陷和抗自身反应性选择中的B细胞-外在缺陷 抗体由于过度GC反应。我们的理论基础是阐明体液免疫的机制， APS-1中的缺陷将促使对APS-1进行更具体的治疗。这一假设将通过两个具体的 目标。采用实时荧光定量PCR、流式细胞术、染色质免疫沉淀、基因组尿嘧啶斑点杂交 和下一代测序，目标1中的研究将确定抗体成熟的异常， APS-1中的抗体库以及AIRE调节B细胞中AID的机制。目标2中的研究将使用 竞争性ELISA以及皮肤白色念珠菌感染的小鼠模型，以确定B细胞的作用， APS-1相关念珠菌病中内源性和外源性AIRE缺陷。本研究提出了创新和切割- 边缘方法来测试APS-1发病机制中的新的机制假设。这项工作将持续 对基础和临床免疫学领域的广泛影响，因为它不仅将促进对 疾病APS-1和艾滋病介导的抗体成熟调节，但也提供了深入了解的奥秘， 越来越多的免疫缺陷与自身免疫共同存在，从而为更好地治疗 这些疾病。

项目成果

Stress Forces First Lineage Differentiation of Mouse Embryonic Stem Cells; Validation of a High-Throughput Screen for Toxicant Stress.

• DOI: 10.1089/scd.2018.0157
• 发表时间: 2019-01
• 期刊: Stem cells and development
• 影响因子: 4
• 作者: Quanwen Li;E. Louden;Jordan Z Zhou;S. Drewlo;Jing Dai;E. Puscheck;Kang Chen;D. Rappolee