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: 9197259
• 负责人: DAVID M ROTHSTEIN
• 金额: $ 37.74万
• 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 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9197259
• 关键词: Acute; Address; Allograft Tolerance; Allografting; Anatomy; Antigen Presentation; Autoimmune Diseases; Autoimmunity; B-Lymphocyte Subsets; B-Lymphocytes; Biological; Cell physiology; Cells; Collagen-Induced Arthritis; Computer Assisted; Data; Detection; Eragrostis; Exhibits; Experimental Autoimmune Encephalomyelitis; Graft Rejection; Graft Survival; Hour; Human; Humoral Immunities; IgG3; Image; Imagery; Immune response; Immunobiology; Immunofluorescence Immunologic; In Situ; In Vitro; Inflammation; Insulin-Dependent Diabetes Mellitus; Interleukin-10; Knockout Mice; Knowledge; Lead; Locales; Location; Lymphoid; Mediating; Minority; Modeling; Mus; Organ; Phenotype; Plasma Cells; Play; Population; Regulation; Reporting; Role; Shapes; Source; Spleen; Splenic Red Pulp; System; T-Lymphocyte; T-Lymphocyte Subsets; Therapeutic; Time; Tissue imaging; Transplantation; Work; allograft rejection; base; cell motility; chemokine; clinically relevant; cytokine; falls; humoral immunity deficiency; improved; in vivo; insight; kidney allograft; mouse model; novel; prevent; programs; public health relevance; response; simulation

 DESCRIPTION (provided by applicant): It is now clear that B cells play an important role regulating immune responses. B cell deficiency or depletion in mice can worsen autoimmunity and prevent allograft tolerance by various agents thought to target T cells. Moreover, we showed that regulatory B cells (Bregs) can be induced and are responsible for prolonged graft survival mediated by anti-TIM-1. These studies suggest that Bregs play an important role in allograft tolerance. This is echoed by the "B cell profile" observed in tolerant human renal allograft recipients. However, our understanding of Bregs is hampered because they are rare and their only specific marker is IL-10, which thus far, has only been detected after stimulation ex vivo. Transfer of various B cell subsets can inhibit inflammation and prevent allograft rejection in an IL-10 dependent fashion. However, these subsets suppress because they contain the highest proportion of IL-10+ B cells in a given model, rather than representing a true Breg phenotype. Of note, these subsets are generally small (each making up 2-15% of total B cells), and IL-10+ cells are still only 5-15% in each subset. Thus, current studies only account for a minority of IL-10+ B cells. In contrast, <1% of follicular (FO) B cells express IL-10, but because of 50-70% of all B cells are FO B cells, these are a major source of IL-10+ B cells. This has made study of Bregs by transfer of B cell subpopulations challenging, and the solution lies in identifying IL-10+ B cells directly without the need for ex vivo culture and simulation. These same issues have contributed to a remarkable lack of understanding of how Bregs function in vivo. Mice receiving Bregs have largely been treated as a "black box". We do not know which IL-10 + B subsets function as Bregs, where they arise, and how and where they effect suppressor function. Such understanding is key to developing clinically relevant approaches to enhance Breg number and function, and to avoid their inadvertent depletion. We now show that IL-10 expression by B cells can in fact be identified without in vitro simulation, and that most IL-10+ B cells are actually, B1a, MZ, and FO B cells, and even Plasma Cells. Moreover, IL-10+ B cells can be directly visualized in situ. Our lead data confirm that IL-10+ B cells populate the splenic MZ, follicle, and red pulp. Based on these data we now aim to determine how Bregs actually function in vivo to prevent rejection in Breg-dependent allograft models. Different subsets of B cells have different roles and localization within the secondary lymphoid organs (SLO). Therefore in Aim 1 we will determine which IL-10+ B cell subpopulations exhibit the Breg activity and whether different subsets have subspecialized functions. In Aim 2, we will determine where within the SLO Bregs actually act to inhibit the alloimmune response. In Aim 3, we will directly determine whether Bregs suppress T cells through direct cognate interactions. We utilize state of the art imaging and inducible KO mice not previously applied to Breg studies. This work will greatly enhance our understanding of Breg immunobiology and provide therapeutic insights highly relevant to allograft tolerance.

 描述（由适用提供）：现在很明显，B细胞起着调节免疫调查的重要作用。小鼠的B细胞缺乏症或耗竭会使自身免疫性恶化，并防止各种被认为靶向T细胞的药物的同种异体移植耐受性。此外，我们表明可以诱导调节性B细胞（BREG），并负责由抗TIM-1介导的延长移植物存活。这些研究表明，布雷格在同种异体移植耐受性中起着重要作用。在耐受的人肾同种异体接受者中观察到的“ B细胞轮廓”回应了这一点。但是，我们对布雷格的理解受到阻碍，因为它们很少见，并且它们的唯一特定标记是IL-10，到目前为止，仅在刺激后才检测到。各种B细胞子集的转移可以抑制注射并防止同种异体移植以IL-10依赖性方式排斥。但是，这些子集抑制它们是因为它们在给定模型中包含最高比例的IL-10+ B细胞，而不是代表真正的Breg表型。值得注意的是，这些子集通常很小（每个子集占总B细胞的2-15％），而IL-10+细胞在每个子集中仍然只有5-15％。这是当前的研究仅解释IL-10+ B细胞的少数。相反，<1％的卵泡（FO）B细胞表达IL-10，但由于所有B细胞的50-70％是FO B细胞，这些是IL-10+ B细胞的主要来源。这已经通过转移B细胞亚群的挑战对Breg进行了研究，该解决方案在于直接识别IL-10+ B细胞而无需过体外培养和模拟。这些相同的问题也导致人们对布雷格在体内发挥作用的理解不足。接受布雷格的小鼠在很大程度上被视为“黑匣子”。我们不知道哪些IL-10 + B子集作为Bregs，它们的出现以及如何影响抑制器功能。这种理解是开发临床相关方法以增强布雷格数量和功能的关键，并避免它们无意的耗竭。我们现在表明，B细胞的IL-10表达实际上可以在没有体外模拟的情况下鉴定出来，并且大多数IL-10+ B 细胞实际上是B1A，MZ和FO B细胞，甚至是浆细胞。此外，IL-10+ B细胞可以直接在原位可视化。我们的铅数据证实IL-10+ B细胞填充了脾脏MZ，Folicle和Red Pulp。基于这些数据，我们旨在确定Bregs在体内的实际功能，以防止在Breg依赖性同种异体移植模型中排斥。 B细胞的不同子集具有不同的作用和次要淋巴器官（SLO）的位置。因此，在AIM 1中，我们将确定哪些IL-10+ B细胞亚群表现出Breg活性以及不同子集是否具有亚指定函数。在AIM 2中，我们将确定Bregs内部的位置实际作用以抑制同种免疫反应。在AIM 3中，我们将直接确定Bregs是否通过直接的同源相互作用抑制T细胞。我们利用艺术成像状态，并诱发了以前未应用于布雷格研究的KO小鼠。这项工作将大大增强我们对布雷格免疫生物学的理解，并提供与同种异体耐受性高度相关的治疗见解。