B-cell-intrinsic MHCII Signaling is a Diversifying Force of Selection on IgA Repertoires and the Gut Microbiota

B 细胞固有的 MHCII 信号传导是 IgA 库和肠道微生物群选择的多样化力量

基本信息

批准号：
10299067
负责人：
Jason L Kubinak
金额：
$ 43.2万
依托单位：
UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-05-25 至 2026-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10299067
关键词：
Ablation Address Adoptive Transfer Affinity Antibodies Antibody Affinity Antibody Response Antigen Presentation Automobile Driving B-Lymphocytes Benign Bone Marrow CD4 Positive T Lymphocytes Cell Communication Cell Compartmentation Chimera organism Chronic Clone Cells Congenic Mice Data Defect Dependence Ecology Evolution Exons Extravasation Generations Genetic Polymorphism Genetic Variation Genotype Gut associated lymphoid tissue Health Health Promotion Heterozygote Histocompatibility Histocompatibility Antigens Class II Human IL7R gene IgA Deficiency Immune response Immune system Immunoglobulin A Immunologic Memory Individuality Inflammation Inflammatory Integration Host Factors Knowledge Link Lymphocyte MHC Class II Genes Mediating Memory Modeling Mucous Membrane Pathologic Peyer&apos s Patches Phenotype Plasma Cells Play Population Process Promoter Regions Reaction Role Shapes Signal Transduction Structure of germinal center of lymph node Surface T-Cell Development T-Lymphocyte Testing Tissues Vertebrates Work antigen binding base commensal bacteria commensal microbes congenic density dysbiosis experimental study fitness gut microbiota host microbiota immune activation innovation microbial colonization microbial community microbiota microorganism antigen mouse model novel response

项目摘要

Project Summary T-cell-dependent (TD) immunoglobulin A (IgA) responses regulate the composition of the gut microbiota. How B-cell-intrinsic MHCII signaling, which is central to the development of TD IgA responses, influences host- microbiota interactions is unknown. MHCII is widely assumed to promote clonal diversity in effector lymphocyte populations, but this has not been tested. Here, we present evidence in support of the argument that B cell- intrinsic MHCII signaling controls GC dynamics, IgA repertoire diversity, and microbiota composition. Additionally, evidence from our experiments also indicate that both B-cell-intrinsic ablation of MHCII and specific MHC genotypes are associated with enhanced bacterial dissemination from the gut. Based on these observations and previous work by Dr. Kubinak, this R01 seeks to address the hypothesis that B-cell-intrinsic MHCII signaling is a diversifying force of selection promoting clonal diversity in IgA plasma cell pools and individuality in microbiota composition. The objective of Specific Aim #1 is to define the B-cell-intrinsic role of MHCII during GC reactions in the gut; specifically focusing on its role in shaping plasma cell repertoire diversity. A 'Confetti' mouse model will be used to visually demonstrate the effect of MHCII ablation on GC B cell clonal diversity in the gut. IgH sequencing will be used to determine the effect of MHCII polymorphisms and MHC heterozygosity on IgA repertoire diversity in the gut. scRNA sequencing will be used to determine how MHCII influences overlap in clonal diversity between mucosal and systemic plasma cell pools. RAG1-/- bone marrow (BM) chimeras will be used to quantify the effect of MHCII on cross-seeding of gut-derived plasma cells into the BM. Reciprocal BM chimeras will be used to determine the necessity/sufficiency of defects in B-cell-intrinsic MHCII in regulating bacterial dissemination from the gut. The objective of Specific Aim #2 is to test that microbiota composition is an MHCII-dependent phenotype. RAG1-/- and RAG1-/-IL7R-/- BM chimeras will be used to determine the role gut peyer's patches play in driving MHCII-mediated IgA selection in the gut. Microbial colonization experiments in germfree GF RAG1-/- BM chimeras will determine the effect of B-cell-intrinsic MHCII on IgA-targeting of commensal bacteria. A RAG1-/- adoptive transfer model will be used to determine if MHCII surface density influences IgA-mediated targeting of commensals and microbiota composition. Finally, a novel germfree MHC congenic model will be used to explicitly define the role IgA plays in driving individuality in microbiota composition. Results from these studies will address the B-cell-intrinsic role of MHCII in regulating mucosal IgA responses, microbiota composition, and host health. This is a critical gap in our knowledge that is highly relevant to human health. IgA deficiency is the most common form of antibody-deficiency in humans, is strongly linked to genetic variation in MHCII genes, and has been shown to result in dysbiosis that is associated with chronic inflammation. Experiments outlined here are the first to address how MHC genotype influences microbiota composition and bacterial leakage from the gut, a potent driver of chronic immune activation.

项目摘要 T细胞依赖性（TD）免疫球蛋白A（IgA）反应调节肠道菌群的组成。如何 b细胞中的MHCII信号传导是TD IgA响应的核心，它影响宿主 - 微生物群相互作用尚不清楚。广泛认为MHCII可以促进效应淋巴细胞的克隆多样性人群，但这尚未进行测试。在这里，我们提供了证据，以支持B细胞的论点固有的MHCII信号传导控制GC动力学，IGA曲目多样性和微生物群的组成。此外，我们实验的证据还表明，MHCII的B细胞融合和特定 MHC基因型与肠道中细菌传播的增强有关。基于这些 Kubinak博士的观察和先前的工作，此R01试图解决B细胞Intrinsic的假设 MHCII信号传导是促进IgA浆细胞池克隆多样性的选择的多元化力量和菌群组成中的个性。特定目标＃1的目的是定义B细胞intrinsic MHCII在GC反应中的作用；特别关注其在塑造浆细胞库中的作用多样性。 “五彩纸屑”鼠标模型将用于视觉上证明MHCII消融对GC B细胞的影响肠道中的克隆多样性。 IGH测序将用于确定MHCII多态性和MHC的影响肠道中IgA曲目多样性的杂合性。 SCRNA测序将用于确定MHCII 影响粘膜和全身浆细胞池之间克隆多样性的重叠。 rag1 - / - 骨髓（BM）将使用嵌合体来量化MHCII对肠道衍生的浆细胞交叉种子的影响 BM。相互BM Chimeras将用于确定B-Cell Intrinsic中缺陷的必要性/充分性 MHCII调节肠道细菌传播。特定目标2的目的是测试微生物群组成是MHCII依赖性表型。 rag1 - / - 和rag1 - / - il7r-/ - BM Chimeras将用于确定肠道peyer在驱动MHCII介导的IgA选择中的作用。微生物无用的GF RAG1 - / - BM Chimeras的定殖实验将确定B细胞Intrinsic MHCII的效果关于共生细菌的IgA靶向。 rag1 - / - 延迟转移模型将用于确定MHCII是否是MHCII 表面密度会影响IGA介导的共生和微生物群组成的靶向。最后，一本小说免费的MHC先生模型将用于明确定义IGA在推动个性中发挥的作用微生物群的组成。这些研究的结果将涉及MHCII在调节中的B细胞内在作用粘膜IgA反应，微生物群组成和宿主健康。这是我们所知的关键差距与人类健康高度相关。 IgA缺乏是人类抗体缺陷的最常见形式，是与MHCII基因的遗传变异密切相关，并且已证明会导致营养不良患有慢性炎症。这里概述的实验是第一个解决MHC基因型如何影响的实验肠道的菌群组成和细菌泄漏，这是慢性免疫激活的有效驱动因素。