B1 Cell Induction of TH17 Cell Differentiation

描述（由申请人提供）：Th 17细胞表示最近鉴定的辅助性T淋巴细胞亚群，其是促炎性的并且参与自身免疫性恶液质的发病机制。B1细胞代表独特的B淋巴细胞谱系和负责产生天然免疫球蛋白的免疫系统的基本组成部分。该实验室最近发表的工作表明，B1细胞在刺激幼稚T细胞分化为Th 17细胞方面具有独特的效率，而B2细胞的效果很差或根本没有。本提案的长期目标及以后的目标是阐明B1细胞在免疫系统中在B细胞/T细胞相互作用方面的作用和功能。本文所述工作的目标涉及B1细胞诱导Th 17细胞分化的显著能力。具体目的是1）通过ELISA测定上清液、用重组蛋白补充B/T培养物以及通过中和抗体和敲除动物降低细胞因子水平来评估细胞因子和视黄酸的潜在作用，确定B1细胞如何有效地发挥功能以诱导Th 17细胞分化，而B2细胞不能; 2）通过评估B7家族成员，特别是CD 80、CD 86和PD-L2的潜在作用，通过中和抗体和敲除动物减少B7共刺激相互作用，确定B1细胞如何在B2细胞不能有效诱导Th 17细胞分化时有效地起作用，以及通过构建逆转录病毒转导的骨髓嵌合体部分替换缺陷小鼠中的B7家族成员; 3）使用与B细胞和OVA肽和蛋白质一起过继转移至II类缺陷小鼠的OVA特异性OT-II T细胞，测试B1细胞在产生Th 17细胞分化中的体内活性。本研究的结果有望提供有关B1细胞功能的新信息和诱导Th 17细胞分化的因素的新信息，并证明B1细胞可以在体内指导T细胞分化。该项目产生的结果将阐明B1细胞和Th 17细胞之间新的和意想不到的联系，进一步了解B1细胞在与T细胞相互作用期间的作用，并反映B1细胞在免疫系统中的位置和活性。就后者而言，本文所述的工作可能描绘了B细胞的新作用，其中不同的B细胞谱系驱动特定的T细胞极化，将B细胞作为T细胞功能的指导者/管理者。阐明这些点可能提供新的目标和策略，以改善自身免疫性恶液质的进展。公共卫生相关性：Th 17细胞是最近发现的T淋巴细胞亚群，其产生炎症并且与自身免疫性疾病密切相关。B1细胞是B淋巴细胞的一个亚群，特别有价值，因为它们不需要接种疫苗就能产生抗病抗体，但它们也有问题，因为它们也像一些T细胞一样参与自身免疫性疾病。该提案中描述的工作建立在新发现的基础上，即B1细胞特别擅长激活Th 17细胞以产生炎症。该项目中概述的工作旨在更多地了解B1细胞的这种新功能，通过弄清楚为什么B1细胞在刺激静息T细胞成为炎性Th 17细胞方面如此有效，通过确定B1细胞诱导的炎性Th 17细胞是否参与产生自身免疫，以及通过测量B1细胞在动物模型中产生炎性Th 17细胞的能力。这些研究将提供有关如何调节体内炎症细胞数量的信息;这些信息可能有助于治疗类风湿性关节炎等自身免疫性疾病。

DESCRIPTION (provided by applicant): Th17 cells denote a recently identified T lymphocyte helper subset that is proinflammatory and is involved in the pathogenesis of autoimmune dyscrasias. B1 cells represent a distinct B lymphocyte lineage and fundamental component of the immune system that is responsible for the production of natural immunoglobulin. Recent published work from this laboratory has shown that B1 cells are uniquely efficient in stimulating naove T cells to differentiate into Th17 cells, whereas B2 cells do so only poorly or not at all. The long term objective of this proposal and beyond is to elucidate the role and function of B1 cells within the immune system in terms of B cell/T cell interaction. The goals of the work described herein relate to the remarkable capacity of B1 cells to induce Th17 cell differentiation. The specific aims are to 1) Determine how B1 cells function effectively to induce Th17 cell differentiation when B2 cells do not, by evaluating the potential role of cytokines and retinoic acid, through assay of supernatants by ELISA, supplementation of B/T cultures with recombinant proteins, and reduction of cytokine levels via neutralizing antibodies and knock-out animals; 2) Determine how B1 cells function effectively to induce Th17 cell differentiation when B2 cells do not, by evaluating the potential role of B7 family members, specifically CD80, CD86, and PD-L2, through reduction of B7 co-stimulatory interactions via neutralizing antibodies and knock-out animals, and by partial replacement of B7 family members in deficient mice through construction of retrovirally transduced bone marrow chimeras; 3) Test the in vivo activity of B1 cells in producing Th17 cell differentiation using OVA-specific OT-II T cells adoptively transferred to Class II-deficient mice along with B cells and OVA peptide and protein. The results of this study are expected to provide new information about the function of B1 cells and new information about the factors that induce Th17 cell differentiation, as well as demonstrate that B1 cells can direct T cell differentiation in vivo. The results generated as a result of this project will illuminate the new and unexpected connection between B1 cells and Th17 cells, furthering knowledge of the role of B1 cells during interaction with T cells and reflecting on the place and activity of B1 cells within the immune system. In terms of the latter, the work described here may delineate a new role for B cells wherein distinct B cell lineages drive specific T cell polarization, placing B cells as the directors/managers of T cell function. Elucidation of these points is likely to provide new targets and strategies to ameliorate the progression of autoimmune dyscrasias. Public Health Relevance: Th17 cells are a recently discovered subpopulation of T lymphocytes that produces inflammation and that is intimately involved in autoimmune diseases. B1 cells are a subpopulation of B lymphocytes that are especially valuable because they produce disease-fighting antibody without the need for vaccination, but they are problematical because they too, like some T cells, are involved in autoimmune diseases. The work described in this proposal builds on the new discovery that B1 cells are especially good at activating Th17 cells to produce inflammation. The work outlined in this project is designed to learn more about this new function of B1 cells, by figuring out why B1 cells are so effective in stimulating resting T cells to become inflammatory Th17 cells, by determining whether B1 cell-induced inflammatory Th17 cells are involved in producing autoimmunity, and by gauging the ability of B1 cells to produce inflammatory Th17 cells in animal models. These studies will provide information on how to regulate the number of inflammatory cells in the body; this information might then be useful in autoimmune treating diseases like rheumatoid arthritis.