"Mechanisms of IL-35 Protection Against Arthritis"

描述（由申请人提供）：风湿性关节炎（RA）是一种慢性关节炎性疾病，表现为慢性滑膜炎和关节的进行性破坏、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维持的。已经开发了模拟关节炎的啮齿动物模型，其中一种模型胶原诱导的关节炎（CIA）需要用异源胶原II免疫。口服耐受性和调节性细胞因子治疗已被认为是治疗关节炎的可能干预措施。一种这样的新治疗剂是调节性细胞因子IL-35;然而，其作用模式尚未确定。IL-35是由IL-12 p35加上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表达为单一多肽。重组小鼠IL-35具有预期的分子量，并且它被IL-12p35和IL-27-EBI3的抗体识别。功能分析表明，IL-35可以完全阻断CIA临床症状的发展。这种疾病抑制似乎是IL-10依赖性的，由异质性调节性T细胞亚群产生，包括CD25 + CD4 + T细胞以及CD39 + CD4 + T细胞。因此，需要进行更多的研究来研究这些调节性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，在本申请中待检验的假设是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。特定目标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产生以治疗CIA，并确定促进IL-35作用所涉及的细胞类型。特定目标2中的研究将定义由IL-35诱导的调节性T细胞亚群，该调节性T细胞亚群负责保护免受CIA，并确定哪种炎性T细胞亚群减少。这些集体研究将为IL-35效应是否可以在RA干预策略中考虑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。 公共卫生相关性：在本申请中，我们提出评估IL-35治疗类风湿性关节炎的治疗潜力。所描述的研究将确定IL-35用于治疗自身免疫性疾病如关节炎的能力和机制。一旦我们了解了它的治疗潜力，未来的研究就可以确定使用病毒或DNA载体递送IL-35来治疗或减少关节炎的最佳方法。

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.