Empirical validation of a novel HLA-disease association theory in skin and rheumatic diseases

皮肤和风湿病中新型 HLA 疾病关联理论的实证验证

• 批准号: 9464174
• 负责人: Joseph Holoshitz
• 金额: $ 38.79万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9464174
• 关键词: Adolescent; Affinity; Affinity Chromatography; Algorithms; Alleles; Antigens; Binding; Bioinformatics; Biological Assay; Cell Differentiation process; Cell Surface Proteins; Cell Surface Receptors; Cells; Code; Complement; Complementarity Determining Regions; Crystallization; Disease; Elements; Event; Gene Expression Profile; Genes; Goals; HLA Antigens; Health; Human; Immobilization; Inflammatory; Inflammatory Arthritis; Intervention; Knowledge; Ligands; Maps; Mass Spectrum Analysis; Molecular Conformation; Mus; Myositis; Ontology; Pathway interactions; Peptides; Peripheral Blood Mononuclear Cell; Phase; Process; Proteins; Quantitative Reverse Transcriptase PCR; Rheumatism; Risk; Role; Severities; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Sjogren' s Syndrome; Solid; Structure; Surface; Systemic Lupus Erythematosus; T-Lymphocyte; Time; Transgenic Mice; Validation; base; crosslink; experimental study; genetic risk factor; interest; macrophage; magnetic beads; novel; novel therapeutic intervention; receptor; skin disorder; synthetic peptide; tandem mass spectrometry; theories; trait; transcriptome; transcriptome sequencing; translational study

ABSTRACT Particular class II human leukocyte antigen (HLA) alleles have been found to be major genetic risk factors in many skin and rheumatic diseases, but the mechanisms underlying the associations are unknown. The prevailing paradigm, which had been based on the MHC restriction paradigm four decades ago, postulates that allele-specific presentation of self or foreign antigens is the culprit; however, this hypothesis remains unverified to this day. The unconventional theory presented here postulates that in addition to presenting peptidic antigens to T cells, HLA-DR molecules express signal transduction ligands that interact with surface receptors and trigger allele-specific signaling events. Under certain environmental conditions or stochastic events, such interactions provoke aberrant cellular events that may increase the risk and/or severity of skin and rheumatic diseases. Based on structural, functional and evolutionary considerations, we propose here that a region on the HLA-DR beta chain, called `cusp' - based on its crystal structure conformation - hosts allele-specific signal transduction ligands. To examine the HLA Cusp theory, we propose to perform a set of experiments to validate key elements in this novel concept. In the 2-year discovery period (R61 phase) we will perform RNA sequencing of cells stimulated by synthetic peptides corresponding to cusp regions coded by representative HLA-DRB1alleles. This will be followed by bioinformatics analyses to determine cusp allele- specific signature transcriptomes and gene ontologies. Additionally, the same allele-specific cusp peptides will be immobilized on solid matrices; cell surface proteins will be allowed to interact with the ligands and eluates will be analyzed by mass spectrometry. Proteins of interest will be expressed and purified, and their interaction with the ligands will be validated by cell-free binding assays. Candidate pathways discovered during the two-year R61 phase will be functionally characterized during year-3 (R33 phase). Here, cusp- activated signal transduction pathways will be mapped, and their biologic significance will be determined in translational experimental settings. At the end of this 3-year project, it is expected that novel, or previously unrecognized, HLA-DRB1allele-coded cusp-activated pathways will have been identified. Due to the involvement of the MHC in diverse biologic processes on the one hand, and the enigmatic mechanistic basis of its association with many health traits and diseases on the other, functional validation of the HLA Cusp theory could have a transformative effect.

抽象的 特定的II类人白细胞抗原（HLA）等位基因已被发现是主要的遗传危险因素 许多皮肤和风湿性疾病，但是关联的基础机制尚不清楚。这 基于MHC限制范式四十年前的盛行范式 罪魁祸首是自我或外国抗原的特定于等位基因的表现。但是，这个假设仍然存在 至今仍未得到证实。这里提出的非常规的理论假设，除了提出 与T细胞的肽抗原，HLA-DR分子表达与表面相互作用的信号转导配体 受体和触发等位基因特异性信号事件。在某些环境条件下或随机条件下 事件，这种相互作用引起了异常的细胞事件，可能会增加皮肤的风险和/或严重程度 和风湿病。根据结构，功能和进化考虑因素，我们在这里提出 HLA -DRβ链上的一个区域，称为“ cusp” - 基于其晶体结构构象 - 主机 等位基因特异性信号转导配体。为了研究HLA尖端理论，我们建议执行一组 在这个新颖概念中验证关键要素的实验。在2年的发现期（R61阶段）中，我们将 通过对应于编码的尖端区域的合成肽刺激的细胞进行RNA测序 代表性HLA-DRB1lears。随后将进行生物信息学分析，以确定尖端等位基因 - 特定的特征转录组和基因本体。另外，相同的等位基因特异性牙肽将 被固定在固体矩阵上；细胞表面蛋白将被允许与配体和洗脱物相互作用 将通过质谱法分析。感兴趣的蛋白质将被表达和纯化，它们 与配体的相互作用将通过无细胞结合测定验证。候选途径发现 在两年的R61期间，将在3年级（R33期）在功能上表征。在这里，cusp- 将映射激活的信号转导途径，并将确定其生物学意义 翻译实验设置。在这个为期三年的项目结束时，预计小说或以前 将确定未识别的HLA-DRB1ALLELERELELELELELELELELELELELELELELELELELELELELELELERELELELELELELELELELELELEL途径。由于 一方面，MHC参与多种生物过程，而神秘的机械基础 它与其他疾病的许多健康特征和疾病的关联 理论可能具有变革性的效果。