"Mechanisms of IL-35 Protection Against Arthritis"

描述（由申请人提供）：类风湿关节炎（RA），一种关节慢性炎症性疾病，表现为慢性滑膜炎和关节进行性破坏，白细胞浸润，软骨破坏和骨侵蚀。据信，这种破坏是由自身反应性T细胞贡献的促炎细胞因子支持和延续的。已经开发出模拟关节炎的啮齿动物模型，其中一种模型，胶原诱导关节炎（CIA），需要异源胶原II免疫。口服耐受性和调节细胞因子治疗已被认为是治疗关节炎的可能干预措施。其中一种新的治疗方法是调节性细胞因子IL-35；然而，其行动方式尚未确定。IL-35是由IL-12p35和IL-27 EBI3亚基组成的异源二聚体细胞因子。我们最近使用真核表达系统将IL-35表达为单个多肽。重组小鼠IL-35具有预期的分子量，可被IL-12p35和IL-27-EBI3抗体识别。功能分析显示，IL-35可完全阻断CIA临床症状的发展。这种疾病抑制似乎是il -10依赖性的，由异质调节性T细胞亚群产生，包括CD25+ CD4+ T细胞，以及CD39+ CD4+ T细胞。因此，有必要进一步研究这些调节性T细胞的性质，并了解哪些单核细胞对IL-35的作用有反应。鉴于这些发现，在本应用中需要验证的假设是，IL-35干预将通过刺激调节性T细胞来降低疾病严重程度并限制CIA的疾病进展。为了验证这一假设，提出了两个具体目标。Specific Aim 1的研究将确定IL-35是否以旁分泌/自分泌方式刺激内源性IL-35的产生以治疗CIA，并确定促进IL-35作用的细胞类型。特异性目标2的研究将定义IL-35诱导的负责保护CIA的调节性T细胞亚群，并确定哪些炎症T细胞亚群被减少。这些集体研究将为是否可以在RA干预策略中考虑il - 35eff以及是否可以定义替代调节性T细胞以促进IL-35在人类中的治疗作用提供基础。

DESCRIPTION (provided by applicant): Rheumatoid arthritis (RA), a chronic inflammatory disease of the joints, manifests as a chronic synovitis and progressive destruction of the joints, leukocyte infiltrates, and cartilage destruction and bone erosion. It is believed this destruction is supported and perpetuated by proinflammatory cytokines contributed by autoreactive T cells. Rodent models have been developed that mimic arthritis, and one such model, collagen-induced arthritis (CIA), requires immunization with heterologous collagen II. Oral tolerance and treatments with regulatory cytokines have been suggested as possible interventions to treat arthritis. One such new therapeutic is the regulatory cytokine, IL-35; however, its mode of action has yet to be determined. IL-35 is a heterodimer cytokine composed of IL-12p35 plus IL-27 EBI3 subunits. We recently expressed IL-35 as a single polypeptide using eukaryotic expression systems. The recombinant mouse IL-35 has the expected molecular weight, and it is recognized with antibodies to IL-12p35 and IL-27-EBI3. Functional analysis reveals that IL-35 can completely block development of clinical symptoms of CIA. This disease suppression does appear to be IL-10-dependent, produced by heterogeneous regulatory T cell subsets, including CD25+ CD4+ T cells, as well as CD39+ CD4+ T cells. Thus, additional studies are warranted to investigate the nature of these regulatory T cells and learn which mononuclear cells are responsive to IL-35's action. Given these findings, the hypothesis to be tested in this application is that IL-35 intervention will reduce disease severity and limit disease progression of CIA by the stimulation of regulatory T cells. To test this hypothesis, two Specific Aims are proposed. Studies in Specific Aim 1 will determine if IL-35 in a paracrine/autocrine fashion stimulates endogenous IL-35 production for treatment of CIA and determine the cell types involved to facilitate IL-35's action. Studies in Specific Aim 2 will define the regulatory T cell subset induced by IL-35 that is responsible for protection against CIA and determine which inflammatory T cell subset is diminished. These collective studies will provide the foundation of whether IL-35 eff can be considered in RA intervention strategies and whether alternative regulatory T cells can be defined that would facilitate IL-35's therapeutic impact in humans. PUBLIC HEALTH RELEVANCE: Herein this application we propose to evaluate the therapeutic potential of IL-35 to treat rheumatoid arthritis. The described studies will ascertain the ability and mechanisms used by IL-35 to treat autoimmune diseases such as arthritis. Once we understand its therapeutic potential, future studies can then determine optimal means to deliver IL-35 using viral or DNA vectors to treat or reduce arthritis.