In Vivo Detection And Mechanisms of Regulatory B cell Function in Transplantation

移植中调节性 B 细胞功能的体内检测和机制

• 批准号: 10598490
• 负责人: DAVID M ROTHSTEIN
• 金额: $ 47.59万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10598490
• 关键词: Acute; Address; Agreement; Allograft Tolerance; Allografting; Antibody Formation; Autoimmune; Autoimmune Diseases; Autoimmunity; B-Cell Acute Lymphoblastic Leukemia; B-Cell Development; B-Lymphocyte Subsets; B-Lymphocytes; Bone Marrow; Cell Count; Cell physiology; Cells; Cellular Immunity; Cellular biology; Chronic; Consensus; Detection; Exhibits; Experimental Autoimmune Encephalomyelitis; Frequencies; Funding; Genetic Transcription; Graft Rejection; Graft Survival; Heart Transplantation; Human; Immune; Immune response; Immunity; In Vitro; Inbred Mouse; Inflammation; Interleukin-10; Kidney Transplantation; Knowledge; Maintenance; Mediating; Minor; Minority; Modeling; Mus; Phenotype; Plasma Cells; Play; Process; Proteins; Regulation; Regulatory T-Lymphocyte; Reporter; Reporting; Role; Self Tolerance; Signal Transduction; System; T-Lymphocyte; Therapeutic; Transplant Recipients; Transplantation; Vascular Diseases; Work; allograft rejection; cytokine; humoral immunity deficiency; improved; in vivo; infancy; insight; isoimmunity; kidney allograft; loss of function; microbiota; mouse model; mutant; novel; prevent; systemic autoimmunity; targeted treatment; transcriptome sequencing; tumor

B cells play an important role regulating immune responses. B cell deficiency or depletion in mice can worsen autoimmunity and prevent allograft tolerance. We showed that TIM-1 is a broad marker for IL-10+ regulatory B cells (Bregs) and that anti-TIM-1 induces tolerance through induction of IL-10+ Bregs. Based on this discovery, our collaborator Dr. Kuchroo, has just shown that TIM-1 regulates various inhibitory molecules on B cells in addition to IL-10, and that mice specifically lacking B cell-TIM-1 develop spontaneous systemic autoimmunity. This unequivocally demonstrates a critical role for Bregs in maintaining tolerance. In general agreement, tolerant human renal allograft recipients demonstrate a “Breg profile” and peri-transplant depletion of B cells increased acute rejection and vasculopathy after renal and cardiac transplantation, respectively. Despite these advances, our understanding of Bregs remains in its infancy. First, there is no agreement even about which B cells carry out Breg function, why Bregs in different studies belong to different subsets, or even whether plasma cells (PCs), and not B cells per se, actually carry out Breg function. Second, little is known about how Bregs are regulated in vivo, or what signals can be used to expand them. Based on our and our collaborator’s advances, this proposal, will directly address both of these major gaps. The field has been hampered because Bregs are rare and their prior best marker, IL-10, was only detected after stimulation of B cells ex vivo. Transfer of various B cell subsets can inhibit inflammation in transplant and autoimmune models. However, these subsets are suppressive because they contain a relatively high proportion of IL-10+ B cells in a given model, rather than representing a true Breg phenotype. Only 5-15% of B cells in such subsets express IL-10, and each subset comprises <20% of all IL-10+ B cells. As a result, the field has identified a myriad of different Breg "subsets” (often minor or immature), and there is no consensus as to their function. However, using IL- 10-GFP reporter mice, we recently demonstrated that IL-10+ B cells can be directly identified without in vitro culture. Moreover, on a protein level, canonical Follicular B cells (FOB), Marginal Zone B cells (MZB) and PCs each account for ~30% of all B-lineage IL-10. We hypothesize that Bregs belonging to these canonical subsets that have distinct localization in the SLO, have different functions. In AIM 1, using purified IL-10+ or TIM-1+ Bregs belonging to these 3 subsets, we will now directly determine whether they regulate the same or different aspects of the immune response (e.g. humoral vs. cellular). While PCs were reported to be essential for Breg function, we found that mice unable to generate PCs due to B cell-specific deletion of BLIMP-1 exhibit a regulated phenotype with improved allograft survival and less severe EAE, and a marked increase in both frequency and number of IL-10+ and TIM-1+ Bregs. Therefore, in Aim 2, we will identify how changes in BLIMP-1, PCs, and the microbiota interact to regulate Breg numbers in vivo. This work will greatly enhance our understanding of B cell and Breg biology and provide therapeutic insights highly relevant to allograft tolerance.

B细胞在调节免疫应答中起重要作用。小鼠的B细胞缺乏或耗竭可加重 自身免疫和防止同种异体移植耐受。我们发现TIM-1是IL-10+调节性B的广泛标志物， 细胞（BCLs），并且抗TIM-1通过诱导IL-10+ BCLs诱导耐受性。基于这一发现， 我们的合作者Kuchroo博士刚刚表明，TIM-1调节B细胞上的各种抑制分子， 此外，IL-10，和小鼠特异性缺乏B细胞-TIM-1发展自发性全身性自身免疫。 这明确地表明了贝加尔湖在维持容忍方面的关键作用。大家普遍同意， 耐受性人肾移植受者表现出“布雷格谱”和移植前后B细胞耗竭 增加肾移植和心脏移植后的急性排斥反应和血管病变。尽管有这些 虽然我们的研究取得了很大进展，但我们对Bibliography的了解仍处于起步阶段。首先，甚至对于哪一个B都没有达成一致意见 细胞执行布雷格功能，为什么不同研究中的布雷格属于不同的子集，甚至是否 浆细胞（PC）而不是B细胞本身实际上执行布雷格功能。第二，我们对它是如何运作的知之甚少。 bt3在体内受到调节，或者可以使用什么信号来扩展它们。基于我们和我们的合作者 这一提议的进展将直接解决这两个主要差距。该领域受到阻碍， B细胞是罕见的，并且它们先前最好的标记物IL-10仅在离体刺激B细胞后检测到。 各种B细胞亚群的转移可以抑制移植和自身免疫模型中的炎症。然而，在这方面， 这些亚群是抑制性的，因为它们在给定的细胞内含有相对高比例的IL-10+ B细胞。 模型，而不是代表真正的布雷格表型。在这些亚群中只有5-15%的B细胞表达IL-10， 并且每个亚组包含<20%的所有IL-10+ B细胞。因此，该领域已经确定了无数不同的 布雷格“子集”（往往是次要的或不成熟的），并没有共识，以他们的功能。然而，使用IL- 10-GFP报告小鼠，我们最近证明，IL-10+ B细胞可以直接识别，而无需体外 文化此外，在蛋白质水平上，典型滤泡B细胞（FO B）、边缘区B细胞（MZ B）和PC 每种占所有B-谱系IL-10的约30%。我们假设，属于这些典型子集的 在SLO中有不同的定位，有不同的功能。在AIM 1中，使用纯化的IL-10+或TIM-1+ bepaly手机投注属于这3个子集，我们现在将直接确定它们是否调节相同或不同的 免疫应答的各个方面（例如体液与细胞）。虽然据报道PC对于布雷格来说是必不可少的 功能，我们发现由于B细胞特异性缺失BLIMP-1而不能产生PC的小鼠表现出 调节表型，提高移植物存活率，减轻EAE严重程度， IL-10+和TIM-1+ Bcl 3的频率和数量。因此，在目标2中，我们将确定 BLIMP-1、PC和微生物群相互作用以调节体内布雷格数量。这项工作将大大提高我们的 了解B细胞和布雷格生物学，并提供与同种异体移植耐受高度相关的治疗见解。