IMMUNOSUPPRESSIVE GENE THERAPY FOR RA

越来越多的证据表明关节在病理生理学中起着积极的作用。关节不是身体其他部位发生的重要系统性紊乱的被动受害者，而是它们可能比目前认识到的更大程度地驱动疾病。滑膜在RA中起关节内淋巴结的作用，在这方面可能至关重要。这种范式转变的一个结果是更加重视治疗关节本身，而不是关节外的位点。滑膜中的T细胞-间充质细胞相互作用对于T细胞活化和炎症诱导都特别重要，但相互共活化的潜在机制在很大程度上是未知的。本研究旨在探讨RA滑膜中T细胞与炎症的关系。(1)共刺激CD 28/B7和CD 40/CD 40 L相互作用是T细胞活化和存活所必需的。关节内表达可溶性抑制剂CTLA 4 Ig和CD 40 Ig可提供局部免疫抑制，从而减轻疾病而不损害宿主免疫。这一假设将在使用这些抑制剂的基因转移的RA动物模型中进行测试。(2)我们的研究确定了转录因子NF-κ B在滑膜炎症和增生中的关键作用，但引起持续NF-κ B活化的机制尚不清楚。T细胞-间充质细胞直接接触，特别是CD 40/CD 40 L和CD 28/B7相互作用可能是通过基因递送CD 40 Ig和CTLA 4 Ig在滑膜中激活NF-κ B和炎症的关键。(3)我们的动物研究的一个预期发现是通过CD 40 Ig和CTLA 4 Ig的基因递送抑制单个关节中的NF-κ B抑制滑膜中的NF-κ B活化和炎症。(3)我们的动物研究的一个意想不到的发现是，在单个关节中抑制NF-κ B不仅在治疗的关节中抑制炎症，而且在对侧未治疗的关节中也抑制炎症。这可能有许多治疗分支，但这种效果的基础尚不清楚。滑膜APC、内皮和巨噬细胞中NF-κ B控制的细胞因子和细胞粘附分子的诱导可能对滑膜T细胞中促炎性Th 1应答的发展至关重要，并且滑膜APC、内皮和巨噬细胞中的细胞粘附分子和滑膜APC、内皮和巨噬细胞中的细胞粘附分子可能对滑膜T细胞中促炎性Th 1应答的发展至关重要。我们推测，局部抑制NF-κ B活化可能会使滑膜和循环T细胞中的Th 1/Th 2平衡向抗炎性Th 2亚群转移，从而减轻局部和全身T细胞驱动的炎症。这一假设将在拟议项目中得到检验。(4)密切相关，但不同的目的，这个建议是测试一个新的概念，设计非免疫原性腺病毒（Ad）载体。腺病毒载体是唯一适合基因传递到滑膜，但其免疫原性排除了临床应用。由于T细胞活化是Ad转基因免疫应答的核心，我们将研究通过表达CTLA 4 Ig和CD 40 Ig基因来抑制Ad载体免疫原性的可行性。在感染细胞附近建立免疫保护环境应允许长期表达和重复给药。

There is growing evidence for the active role of the joints in pathophysiology. Instead of the joints being the passive victims of important systemic disturbances occurring elsewhere in the body, they may drive the disease to a much greater extent than is presently appreciated. Synovium, which in RA operates as an intraarticular lymph node, could be critical in this regard. One consequence of this paradigm shift would be to put much greater emphasis on treating the joints themselves, rather than extraarticular loci. T-cell-mesenchymal cell interactions in the synovium are particularly important for both T cell activation and induction of inflammation, but the mechanisms underlying mutual co-activation are largely unknown. The proposed study focuses on the relationship between synovial T cell and inflammation in the RA synovium. (1) Co-stimulatory CD28/B7 and CD40/CD40L interactions are required for T cell activation and viability. Intraarticular expression of soluble inhibitors CTLA4Ig and CD40Ig may provide local immunosupression, thereby alleviating the disease without compromising the host immunity. This hypothesis will be tested in animal models of RA using gene transfer of these inhibitors. (2) Our studies established the pivotal role for the transcription factor NF-kappaB in synovial inflammation and hyperplasia, but the mechanisms causing persistent NF- kappaB activation are not known. Direct T cell-mesenchymal cell contacts, particularly CD40/CD40L and CD28/B7 interactions may be critical for NF-kappaB activation and inflammation in the synovium by gene delivery of CD40Ig and CTLA4Ig. (3) One expected finding of our animal studies was that suppression of NF-kappaB in a single joint inhibiting NF-kappaB activation and inflammation in the synovium by gene delivery of CD40Ig and CTLA4Ig. (3) One unexpected finding of our animal studies was that suppression of NF-kappaB in a single joint inhibited inflammation not only in treated, but also in the contralateral, untreated joints. This may have numerous therapeutic ramifications, but the basis for this effect is not known. The induction of NF-kappaB- controlled cytokines and cell adherence molecules in synovial APC, endothelium, and macrophages may be critically important for development and cell adherence molecules in synovial APC, endothelium, and cell adherence molecules in synovial APC, endothelium, and macrophages may be critically important for development of pro-inflammatory Th1 responses in synovial T cells. We hypothesize that local suppression of NF-kappaB activation may shift the Th1/Th2 balance in synovial and circulating T cells toward the anti-inflammatory Th2 subset, thereby alleviating the local and systemic T cell-driven inflammation. This hypothesis will be tested in the proposed project. (4) Closely related, but distinct objective of this proposal is to test a novel concept for designing non-immunogenic adenoviral (Ad) vectors. Ad vectors are uniquely suitable for gene delivery to the synovium, but its immunogenicity precludes clinical applications. As T cell activation is cental to the development of immune responses to Ad transgene, we will examine the feasibility of suppressing the immunogenicity of Ad vectors by expressing CTLA4Ig and CD40Ig genes. Creating immunoprivileged environment in the vicinity of infected cells should permit long-term expression and repetitive administrations.