Source and homeostatic functions of anti-adduct IgM in humans

人类抗加合物 IgM 的来源和稳态功能

基本信息

批准号：
10680950
负责人：
Emmanuel Zorn
金额：
$ 24.68万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-06-22 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10680950
关键词：
Address Adult Age Months Antigens Apoptotic Area Autoimmune Diseases Autoimmune Thrombocytopenias B-Lymphocytes B-cell receptor repertoire sequencing Binding Biological Assay Biological Process Bone Marrow Cell membrane Cell secretion Cell surface Cells Characteristics Chemicals Clone Cells Collection Complement Complex Epitopes Exposure to Flow Cytometry Gut associated lymphoid tissue Housekeeping Human Humoral Immunities Hypersensitivity Immunity Immunoglobulin G Immunoglobulin Isotypes Immunoglobulin M Incidence Individual Inflammation Knowledge Link Malondialdehyde Maps Memory Memory B-Lymphocyte Neonatal Newborn Infant Patients Phagocytes Phenotype Phosphorylcholine Plasma Cells Play Process Property Proteins Reaction Regulation Research Role Serum Source Specificity Spleen Systemic Lupus Erythematosus Thymus Gland Tissues adduct chemical group cytokine early childhood enzyme linked immunospot assay experimental study high dimensionality in vivo macromolecule natural antibodies neonate oxidation oxidized low density lipoprotein pathogen pathogenic bacteria pathogenic virus prevent single-cell RNA sequencing transcriptome uptake

项目摘要

Project Summary Serum IgM have crucial “housekeeping” functions such as the clearance of apoptotic cells and cellular debris, preventing their accumulation in tissue. However, despite their important role, IgM have been largely understudied in comparison to other immunoglobulin isotypes, especially IgG. A central characteristic of serum IgM linked to their biological function is their reactivity to simple chemical moieties exposed on cell membranes and macromolecules. For instance, IgM bind to phosphorylcholine on apoptotic cells to promote their elimination. These moieties form adducts when attached to proteins or other macromolecules. Remarkably, only a few chemical adducts recognized by serum IgM have been identified thus far. Whether these are examples of a much larger group of chemical radicals targeted by serum IgM is unknown. To address this knowledge gap, we developed a high-dimensional platform to assess monoclonal IgM and serum IgM reactivity to 87 ubiquitous adducts. Results showed that: 1) monoclonal “polyreactive” IgM cloned from memory blood B cells and binding to apoptotic cells, hence displaying a typical “natural antibody” profile, react in fact to specific adducts; 2) the anti-adduct IgM repertoire is highly restricted in newborns and only includes reactivity to a limited number of adducts; 3) IgM reactivity diversifies abruptly around 6 months of age, marking a transition from a restricted neonatal repertoire to a broad adult repertoire and 4) this transition appears to coincide with exposure to environmental antigens. Overall, these studies uncovered a much more complex anti-adduct IgM immunity than was initially anticipated. Yet, several important questions remain unanswered: What are the functional niches of anti-adduct B cells/PC? Do anti-adduct B cells constitute a distinct subset with specific phenotypic characteristics? What is the role of anti-adduct IgM in efferocytosis and regulation of inflammation? Are these functions dependent on the IgM specificity to individual adducts? Our proposed studies will address these salient questions through the characterization of anti-adduct B cell and PC at the single-cell level. Specific aim-1. To characterize anti-adduct memory B cells and plasma cells and map their niches We will first detect anti-adduct memory IgM+ B cells and IgM-secreting cells in the bone marrow, spleen, thymus and gut-associated lymphoid tissue in order to identify their main niches. We will then characterize the phenotype of anti-adduct memory IgM+ B cells using flow cytometry and single-cell-RNA-seq combined with BCR-seq to profile their transcriptome and evaluate their clonal composition in vivo. Specific aim-2. To determine the role of anti-adduct IgM in regulation of efferocytosis and inflammation In specific aim 2 we will examine the capacity of IgM mab specific to individual adducts to opsonize apoptotic cells and enhance their clearance by different types of phagocytes. We will also investigate the role of complement in this function. In a second part, we will examine whether apoptotic cells opsonized by IgM reactive to different adducts trigger distinct cytokine secretion upon their uptake by phagocytes.

项目摘要血清IgM具有至关重要的“管家”功能，例如凋亡细胞的清除和细胞碎片，防止它们在组织中的积累。但是，涂料它们的重要作用，IgM在很大程度上是与其他免疫球蛋白同种型，尤其是IgG相比，对研究进行了研究。系列的中心特征与其生物学功能相关的IgM是它们对暴露在细胞膜上的简单化学部分的反应性和大分子。例如，IgM与凋亡细胞上的磷酸胆碱结合以促进其进化。这些部分在蛋白质或其他大分子附着时形成加合物。值得注意的是，只有少数到目前为止，已经确定了血清IgM识别的化学加合物。这些是否是由血清IgM靶向的更大的化学自由基尚不清楚。为了解决这个知识差距，我们开发了一个高维平台，以评估单克隆IgM和血清IgM对87无处不在的反应性加合物。结果表明：1）单克隆“多反应” IgM从记忆血液B细胞克隆并结合对于凋亡细胞，因此显示出典型的“天然抗体”曲线，实际上对特定的加合物有反应。 2）抗媒介IgM曲目在新生儿受到很高的限制，仅包括对有限数量的反应性加合物； 3）IgM反应性在6个月大左右突然多样化，这标志着限制的过渡新生儿曲目遍布广泛的成人曲目，4）这种过渡似乎与暴露环境抗原。总体而言，这些研究发现了比相比最初是预料的。但是，几个重要的问题仍未得到解决：抗adduct B细胞/PC？ DO抗adduct B细胞构成具有特定表型的独特子集特征？抗添加剂IgM在炎症的肿瘤和调节中的作用是什么？是这些函数取决于IGM对单个addcts的特异性？我们提出的研究将解决这些显着性通过在单细胞水平上表征抗adduct B细胞和PC的问题。特定的目标1。为了表征抗添加物记忆B细胞和浆细胞并绘制其壁ni 我们将首先检测到抗胶合记忆IgM+ B细胞和骨髓中的IgM分泌细胞，Sleen，胸腺和肠道相关的淋巴组织，以鉴定其主要壁ni。然后，我们将表征表型使用流式细胞术和单细胞-RNA-Seq与BCR-Seq结合到TO的抗添加记忆IgM+ B细胞介绍其转录组并在体内评估其克隆组成。特定的目标-2。确定抗添加IgM在调节肿瘤和炎症调节中的作用在特定目标2中，我们将检查特定于个体加合物的IgM MAB的能力细胞并通过不同类型的吞噬细胞增强清除率。我们还将调查补充此功能。在第二部分中，我们将检查凋亡细胞是否通过IgM反应性调子在吞噬细胞摄取时，对不同的加合物引发了不同的细胞因子秘密。