Characterization of a novel T cell activating protein in arthritis

关节炎中新型 T 细胞激活蛋白的表征

• 批准号: 8435422
• 负责人: Raphael Hirsch
• 金额: $ 29.99万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8435422
• 关键词: Adult; Apoptotic; Architecture; Arthritis; Birth; Bone Density; Cartilage; Cells; Computers; Development; Disease; Embryonic Development; Follistatin; Follistatin-Related Protein 1; Gene Transfer; Health; Human; IL2RA gene; Inflammation; Inflammatory; Inflammatory Response; Interferons; Interleukin-1; Interleukin-12; Interleukin-17; Interleukin-2; Joints; Mediating; Mediator of activation protein; Monoclonal Antibodies; Mus; Osteoblasts; Osteoclasts; Osteocytes; Osteogenesis; Phenotype; Physiology; Play; Production; Property; Proteins; Rheumatoid Arthritis; Role; Signal Transduction; Structure; T-Cell Activation; T-Cell Depletion; T-Lymphocyte; Time; Wild Type Mouse; X-Ray Computed Tomography; bone; bone strength; cytokine; joint destruction; mineralization; mouse model; novel; protein structure; receptor; response; tomography; tool

DESCRIPTION (provided by applicant): We have discovered that a novel protein, follistatin-like-1 (FSTL-1), is highly expressed in the joints of mice and humans with arthritis, especially at the interface of synovial pannus and eroding bone. A key role for FSTL- 1 in arthritis progression was confirmed by suppression of disease by FSTL-1 neutralization. Our studies indicate that FSTL-1 is a co-stimulator of T cells. We will characterize FSTL-1 and its contribution to inflammatory arthritis in mouse models of disease, with detailed study of T cell activation. The first Aim is to determine the role of FSTL-1 in the normal joint. Our studies demonstrate that FSTL-1 is produced at low levels in the adult mouse joint. FSTL-1 is induced in osteoblasts by TGF-2, a key bone regulatory factor, and FSTL-1 is an arthritis progression factor, but the role of FSTL-1 in normal bone and joint physiology is not characterized. We will determine the cells responsible for FSTL-1 production within the joint during embryogenesis and post-natal development. We will characterize the role of FSTL-1 using a new FSTL-1 hypomorphic (knockdown) mouse by assessing the effect of FSTL-1 under-expression on joint structure at birth and during development to adulthood, bone formation and architecture, bone density and strength, and cartilage integrity. The second Aim is to determine the contribution of FSTL-1 to arthritis. FSTL-1 is induced by IL-12 and FSTL-1 is increased in arthritic joints, where it plays a pro-inflammatory role. These findings suggest that bone is not solely a target of arthritis, but plays an active role in joint destruction. We will characterize the contribution of bone to arthritis progression, focusing on FSTL-1 as a mediator. FSTL-1 will be over-expressed by gene transfer, under-expressed using the FSTL-1 hypomorphic mouse, and neutralized at various times during arthritis using anti-FSTL-1 monoclonal antibody. We will compare the effects of varying FSTL-1 expression on the inflammatory pannus, cartilage and bone formation and erosion, bone formation rate by dynamic histomorphometry, changes in mineralization by micro computer tomography, changes in osteoclastic activity and matrix cells, and expression of pro-inflammatory cytokines induced in response to FSTL-1. The third Aim is to determine how FSTL-1 activates T cells and induces IFN-3 secretion. FSTL-1 promotes inflammation by enhancing IFN-3 signaling. The inflammatory response is dependent on T cells, as T cell depletion abolishes FSTL-1-induced paw inflammation. Furthermore, FSTL-1 prolongs expression of the T cell activation molecule, CD25. To characterize the T cell activating properties of FSTL-1, we will determine the T cell activation phenotype induced by FSTL-1, whether FSTL-1 stabilizes TCR mediated signaling by inducing anti-apoptotic molecules, whether FSTL-1 stimulates T cells directly or indirectly, the receptor for FSTL-1, the protein structure necessary for FSTL-1 activity, and whether FSTL-1 has additional actions on inflammation. Characterization of FSTL- advance understanding of arthritis and may provide new treatment options.

描述（由申请人提供）：我们发现一种新的蛋白质，卵泡抑素样1（FSTL-1），在患有关节炎的小鼠和人类的关节中高度表达，特别是在滑膜血管翳和侵蚀骨的界面处。 FSTL-1 中和对疾病的抑制证实了 FSTL-1 在关节炎进展中的关键作用。我们的研究表明 FSTL-1 是 T 细胞的共刺激剂。我们将在小鼠疾病模型中描述 FSTL-1 及其对炎症性关节炎的影响，并详细研究 T 细胞激活。第一个目的是确定 FSTL-1 在正常关节中的作用。我们的研究表明，成年小鼠关节中 FSTL-1 的产生水平较低。 FSTL-1 在成骨细胞中由关键骨调节因子 TGF-2 诱导，FSTL-1 是关节炎进展因子，但 FSTL-1 在正常骨和关节生理学中的作用尚不清楚。我们将确定胚胎发生和产后发育期间关节内负责 FSTL-1 产生的细胞。我们将使用新型 FSTL-1 亚形（敲低）小鼠，通过评估 FSTL-1 表达不足对出生时和成年发育过程中的关节结构、骨形成和结构、骨密度和强度以及软骨完整性的影响，来表征 FSTL-1 的作用。第二个目标是确定 FSTL-1 对关节炎的影响。 FSTL-1 由 IL-12 诱导，并且 FSTL-1 在关节炎关节中增加，发挥促炎作用。这些发现表明，骨骼不仅是关节炎的目标，而且在关节破坏中发挥着积极作用。我们将描述骨对关节炎进展的贡献，重点关注 FSTL-1 作为介质。 FSTL-1 将通过基因转移过度表达，使用 FSTL-1 低等态小鼠表达不足，并在关节炎期间的不同时间使用抗 FSTL-1 单克隆抗体中和。我们将比较不同 FSTL-1 表达对炎性血管翳、软骨和骨形成和侵蚀、动态组织形态测量的骨形成率、微型计算机断层扫描矿化的变化、破骨细胞活性和基质细胞的变化以及响应 FSTL-1 诱导的促炎细胞因子表达的影响。第三个目标是确定 FSTL-1 如何激活 T 细胞并诱导 IFN-3 分泌。 FSTL-1 通过增强 IFN-3 信号传导促进炎症。炎症反应依赖于 T 细胞，因为 T 细胞耗竭可以消除 FSTL-1 诱导的爪子炎症。此外，FSTL-1 可以延长 T 细胞激活分子 CD25 的表达。为了表征 FSTL-1 的 T 细胞激活特性，我们将确定 FSTL-1 诱导的 T 细胞激活表型、FSTL-1 是否通过诱导抗凋亡分子来稳定 TCR 介导的信号传导、FSTL-1 是否直接或间接刺激 T 细胞、FSTL-1 的受体、FSTL-1 活性所需的蛋白质结构以及 FSTL-1 是否对炎症具有其他作用。 FSTL 的表征 - 增进对关节炎的了解，并可能提供新的治疗选择。