Understanding the connection between exposure to mercury, auto-immunity and tolerance in B cells.

了解汞暴露、自身免疫和 B 细胞耐受性之间的联系。

• 批准号: 9979868
• 负责人: ALLEN J ROSENSPIRE
• 金额: $ 44.96万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9979868
• 关键词: Address; Affect; Animal Model; Animals; Antibodies; Antigens; Appearance; Attenuated; Autoantibodies; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autoimmunity; B cell repertoire; B-Cell Development; B-Lymphocytes; Binding; Biochemical; Biological Markers; Blood; Cell membrane; Cells; Complex; Cytoskeletal Proteins; Cytoskeleton; Data; Development; Elements; Environment; Environmental Exposure; Exposure to; Flow Cytometry; Generations; Genetic; Genetic Predisposition to Disease; Goals; Hen Egg Lysozyme; Human; Image; Immune; Immune response; Immunoglobulins; Immunologist; Immunomodulators; Individual; Intoxication; Lead; Light; Link; Maps; Mass Spectrum Analysis; Measures; Mediating; Membrane Proteins; Mercury; Modeling; Molecular; Molecular Abnormality; Molecular Target; Mouse Strains; Mus; Nature; PTPN6 gene; PTPRC gene; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Population; Predisposition; Process; Protein Tyrosine Kinase; Protein Tyrosine Phosphatase; Proteins; Proteome; Proteomics; Publishing; Receptor Signaling; Receptors, Antigen, B-Cell; Reporting; Shapes; Signal Pathway; Signal Transduction; Source; Sulfhydryl Compounds; Surface; Surveys; T-Lymphocyte; Techniques; Technology; Testing; Transgenic Mice; Western Blotting; Xenobiotics; attenuation; autoreactive B cell; base; cofilin; design; drinking water; ds-DNA; environmental agent; epidemiology study; experimental study; immunogenic; improved; molecular dynamics; novel; prevent; rapid technique; response; sex; theories

ABSTRACT Mercury (Hg) is a xenobiotic that is widespread in the environment. Mercury is also a potent immunomodulator that has been implicated as a factor contributing to autoimmune disease in animal models and humans. A recent epidemiological study has now convincingly shown that, in otherwise healthy individuals who were only exposed to low levels of Hg through typical environmental sources, there is a correlation between blood Hg levels and the appearance in the blood of antibodies to double-stranded DNA, an autoimmune biomarker. This finding indicates that under the proper circumstances, exposure to environmental Hg promotes autoimmunity, a precursor to autoimmune disease. Since the discovery of B cells, immunologists have appreciated that, in light of the Clonal Selection Theory, during the normal course of B cell development, large numbers of immature B cells must be generated that produce immunoglobulin that is reactive to many self-antigens (auto- antibodies). However, in the course of normal development, the vast majority of immature auto-reactive B cells are prevented from maturing by processes collectively known as tolerance. Autoimmune disease arises when the mechanisms that promote tolerance are disrupted. For B cells, it is firmly established that tolerance depends to a large extent on signals generated by the B cell receptor (BCR) in immature B cells. Our preliminary and recently published studies have shown that Hg interferes with signal generation by the BCR in immature B cells, through mechanisms that likely involve the tyrosine kinase Lyn, the tyrosine phosphatases SHP-1 and CD45 and elements of the cytoskeleton. Our overall hypothesis is that environmental exposure to Hg disrupts BCR signaling in Hg-exposed compared with non-exposed animals, resulting in the disruption of B cell tolerance in exposed animals. This in turn should lead to the appearance of an excess of mature auto- reactive B cells in Hg-exposed animals that have the potential to cause autoimmune disease. We propose to test this hypothesis by generating anti-hen egg lysozyme (HEL)/hen egg lysozyme double transgenic mice which are designed to be normally tolerant to HEL, and them exposing them or not to Hg, in order to break HEL tolerance (Aim 1). We will expand on our preliminary data to further elucidate the molecular mechanisms that enable Hg to interfere with BCR signaling. We will utilize mouse strains with different genetic susceptibilities to Hg intoxication to directly investigate how Hg interferes with the function of the tyrosine kinase Lyn and the tyrosine phosphatases SHP-1 and CD45 during BCR signaling under the influence of different genetic backgrounds (Aim 2). We will use complementary proteomic and multicolor phosphoflow cytometric approaches to determine how Hg interacts with elements of the cytoskeleton, so as to attenuate BCR signaling (Aim 3).

抽象的 汞（HG）是一种在环境中普遍存在的异生元。汞也是一种有效的免疫调节剂 这被认为是在动物模型和人类中导致自身免疫性疾病的一个因素。一个 最近的流行病学研究现在令人信服地表明，在健康的人中 通过典型的环境来源暴露于低水平的HG，血液HG之间存在相关性 水平和外观在双链DNA抗体的血液中，一种自身免疫性生物标志物。这 发现表明，在适当的情况下，暴露于环境HG会促进自身免疫性， 自身免疫性疾病的前身。自从发现B细胞以来，免疫学家对此表示赞赏， 克隆选择理论的光，在B细胞发育的正常过程中，大量 必须生成未成熟的B细胞，该细胞产生对许多自我抗原反应的免疫球蛋白（自动 - 抗体）。但是，在正常发育过程中，绝大多数未成熟的自身反应性B细胞 阻止通过统称为耐受性的过程成熟。自身免疫性疾病会发生 促进公差的机制被破坏。对于B细胞，牢固确定了公差 在很大程度上取决于未成熟B细胞中B细胞受体（BCR）产生的信号。我们的 初步和最近发表的研究表明，HG会干扰BCR的信号生成 未成熟的B细胞，通过可能涉及酪氨酸激酶Lyn的机制，酪氨酸磷酸酶 SHP-1和CD45以及细胞骨架的元素。我们的总体假设是环境暴露 与非暴露动物相比 暴露动物的细胞耐受性。反过来，这将导致出现过量的成熟自动 hg暴露动物中有可能引起自身免疫性疾病的活性B细胞。我们建议 通过产生抗Hen卵溶菌酶（HEL）/Hen Egg溶菌酶双重转基因小鼠来检验该假设 其设计通常耐受HEL，并且它们暴露于HG或不暴露于HG，以便打破 HEL耐受性（AIM 1）。我们将扩展我们的初步数据，以进一步阐明分子机制 这使HG能够干扰BCR信号。我们将利用具有不同遗传的小鼠菌株 HG中毒的敏感性直接研究HG如何干扰酪氨酸的功能 在BCR信号传导期间，激酶Lyn和酪氨酸磷酸酶SHP-1和CD45在 不同的遗传背景（AIM 2）。我们将使用互补的蛋白质组学和多色磷脂 细胞仪方法确定汞如何与细胞骨架元素相互作用，以便减弱 BCR信号传导（AIM 3）。