Different roles of fetal- and adult-derived IgA secreting cells against GI infection

胎儿和成人 IgA 分泌细胞对抗胃肠道感染的不同作用

• 批准号: 10722743
• 负责人: Momoko Yoshimoto
• 金额: $ 24.09万
• 依托单位: WESTERN MICHIGAN UNIV SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-18 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10722743
• 关键词: Adult; Affinity; Antibodies; Antigens; Autoimmune Diseases; B-Lymphocytes; B-cell receptor repertoire sequencing; Bacteria; Binding; Bone Marrow; CD4 Positive T Lymphocytes; Cell Lineage; Cell physiology; Cell secretion; Cells; Characteristics; Chromium; Citrobacter rodentium; Clinical; Data; Defect; Development; Disease; Embryo; Embryonic Development; Endothelial Cells; Endothelium; Exclusion; Fetal Liver; Gene Expression; Genetic; Goals; Hematopoietic Cell Production; Hematopoietic stem cells; Heterogeneity; Homeostasis; Hypersensitivity; IgA Deficiency; Immune; Immunity; Immunoglobulin A; Immunoglobulin Class Switching; Immunoglobulin Somatic Hypermutation; Immunoglobulins; Immunologic Deficiency Syndromes; Infection; Infection prevention; Inflammatory Bowel Diseases; Injury; Intestinal Mucosa; Intestines; Invaded; Investigation; Knowledge; Lamina Propria; Lymphopoiesis; Molecular; Mucosal Immunity; Mucous body substance; Mus; Pathology; Pathway interactions; Patients; Peritoneal; Play; Positioning Attribute; Predisposition; Production; Reaction; Reporting; Role; Spleen; Structure of germinal center of lymph node; Symptoms; System; T-Cell Depletion; T-Lymphocyte; Testing; Tomatoes; Transplantation; Visualization; Work; base; enteric infection; fetal; fetal infection; gut homeostasis; in vivo; intestinal homeostasis; microbial; microbiome; microbiota; mouse model; pathogen; polyclonal antibody; prevent; progenitor; recurrent infection; response; segregation; single-cell RNA sequencing; Adult; Affinity; Antibodies; Antigens; Autoimmune Diseases; B-Lymphocytes; B-cell receptor repertoire sequencing; Bacteria; Binding; Bone Marrow; CD4 Positive T Lymphocytes; Cell Lineage; Cell physiology; Cell secretion; Cells; Characteristics; Chromium; Citrobacter rodentium; Clinical; Data; Defect; Development; Disease; Embryo; Embryonic Development; Endothelial Cells; Endothelium; Exclusion; Fetal Liver; Gene Expression; Genetic; Goals; Hematopoietic Cell Production; Hematopoietic stem cells; Heterogeneity; Homeostasis; Hypersensitivity; IgA Deficiency; Immune; Immunity; Immunoglobulin A; Immunoglobulin Class Switching; Immunoglobulin Somatic Hypermutation; Immunoglobulins; Immunologic Deficiency Syndromes; Infection; Infection prevention; Inflammatory Bowel Diseases; Injury; Intestinal Mucosa; Intestines; Invaded; Investigation; Knowledge; Lamina Propria; Lymphopoiesis; Molecular; Mucosal Immunity; Mucous body substance; Mus; Pathology; Pathway interactions; Patients; Peritoneal; Play; Positioning Attribute; Predisposition; Production; Reaction; Reporting; Role; Spleen; Structure of germinal center of lymph node; Symptoms; System; T-Cell Depletion; T-Lymphocyte; Testing; Tomatoes; Transplantation; Visualization; Work; base; enteric infection; fetal; fetal infection; gut homeostasis; in vivo; intestinal homeostasis; microbial; microbiome; microbiota; mouse model; pathogen; polyclonal antibody; prevent; progenitor; recurrent infection; response; segregation; single-cell RNA sequencing

Abstract IgA is the most abundant immunoglobulin produced in the lamina propria (LP) of the intestine and protects the host against microbial invasions into intestinal mucosa by coating and excluding them. Selective IgA deficiency is the most common immunodeficiency, and more than 50% of patients are asymptomatic. However, other patients develop various diseases such as inflammatory bowel diseases, allergies, autoimmune diseases, and recurrent infections. Despite the essential roles of IgA, it still remains unknown what causes the different clinical manifestations of this disease. One of the barriers to understanding the pathology of selective IgA deficiency is a gap of knowledge about the heterogeneity of developmental origin of the IgA-secreting cells. Our long-term goal is to fill this knowledge gap and to determine the roles of IgA+ cells of different origins in the mucosal immunity. There are two known pathways in producing IgA secreting cells: T-cell independent (TI) and T-cell dependent (TD) pathways. TI-IgA is a low-affinity polyclonal antibody that coats bacteria and maintains the microbiome homeostasis, while TD-IgA undergoes somatic hypermutation and reacts against specific antigens. The precursors of these TI- and TD-IgA have been controversial, but it has recently been demonstrated that TI IgA+ cells are derived from peritoneal B-1b cells while TD IgA+ cells are from germinal center B-2 cells. It is generally considered that these B-1b and B-2 cells are ultimately produced by hematopoietic stem cells (HSCs) that reside in the bone marrow (BM). However, our and others' prior work has shown that B-1b cells are also produced by HSC-independent fetal progenitors during embryonic development. Our lineage tracing data indicated that IgA+ cells in the lamina propria (LP) are derived from embryonic day (E) 7.5 endothelial cells (ECs), three days before the first HSC production in the embryo. Our lineage tracing system using EC-derived (Cdh5CreERT2) and HSC- derived (Fgd5CreERT2) enables us to segregate IgA+ cells in the LP of different origins. Thus, the central hypothesis of this project is that IgA+ cells in the LP consists of cells with different origins: fetal (EC)- and HSC- derived and that IgA+ cells of different origins have different roles against gut injury and infections. To test our hypothesis, in Aim1, we will examine TI- and TD- class switching of fetal- and HSC-derived B cells. We will also visualize these fetal- and HSC-derived TI- and TD- IgA+ cells using scRNA-sequencing and BCR repertoire- sequencing and will display the molecular differences of these cells. In Aim 2, we will examine the protective roles of fetal- and HSC-derived IgA+ cells against GI infection with C. rodentium. The results obtained from this proposal will establish a new paradigm of the developmental origin of IgA+ cells and their functions in the gut homeostasis and infections.

抽象的 IGA是肠道层（LP）中产生的最丰富的免疫球蛋白，并保护 通过涂层和排除它们的托管微生物入侵肠道粘膜的宿主。选择性IgA缺陷 是最常见的免疫缺陷，超过50％的患者无症状。但是，其他 患者患有各种疾病，例如炎症性肠病，过敏，自身免疫性疾病和 复发感染。尽管IgA具有重要的作用，但仍然未知是什么原因导致不同的临床 这种疾病的表现。理解选择性IgA缺乏病理的障碍之一是 关于IGA分泌细胞发育起源的异质性的知识差距。我们的长期 目标是填补这一知识差距，并确定粘膜不同起源的IgA+细胞的作用 免疫。 产生IgA分泌细胞有两种已知途径：T细胞独立（Ti）和T细胞依赖性 （TD）途径。 TI-IGA是一种低亲和力多克隆抗体，可覆盖细菌并保持微生物组 稳态，而TD-IGA经历了体细胞超成名，并反应于特定的抗原。这 这些TI-和TD-IGA的前体是有争议的，但最近已证明Ti Iga+ 细胞源自腹膜B-1B细胞，而TD IgA+细胞来自生发中心B-2细胞。通常是 认为这些B-1B和B-2细胞最终是由驻留的造血干细胞（HSC）产生的 在骨髓（BM）中。但是，我们和其他人的先前工作表明，B-1B细胞也是由 在胚胎发育过程中，HSC独立的胎儿祖细胞。我们的谱系跟踪数据表明IgA+ 固有层（LP）中的细胞源自胚胎日（E）7.5内皮细胞（EC），三天前 胚胎中的第一个HSC生产。我们使用EC衍生（CDH5CREERT2）和HSC-的谱系跟踪系统 得出的（FGD5CREERT2）使我们能够在不同起源的LP中隔离IgA+细胞。因此，中央 该项目的假设是LP中的IgA+细胞由具有不同起源的细胞组成：胎儿（EC）和HSC-- 衍生并且不同起源的IgA+细胞在肠道损伤和感染中具有不同的作用。测试我们的 假设在AIM1中，我们将检查胎儿和HSC衍生的B细胞的TI-和TD-类切换。我们也会 使用scrna-sequering和bcr repertoire-可视化这些胎儿和HSC衍生的Ti-iga+细胞 测序并将显示这些细胞的分子差异。在AIM 2中，我们将检查保护性 胎儿和HSC衍生的IgA+细胞对gi感染的作用。 从该提案中获得的结果将建立IgA+细胞发育起源的新范式 以及它们在肠道稳态和感染中的功能。