A Novel Model of, and Pre-clinical Therapy for, Scleroderma Lung Disease

描述（由申请人提供）：肺间质性疾病-肺部炎症和纤维化的结合-仍然是系统性硬化症或硬皮病患者死亡的主要原因。硬皮病（SLD）的机制尚不清楚，现有治疗方法的效率有限。我们和其他人之前的研究表明，白细胞介素(IL)-4剪接变体，即IL-442的水平升高与SLD患者预后较差有关。我们新的初步数据表明，急性腺病毒介导的小鼠(m) IL-442基因传递到小鼠体内肺部，再现了人类SLD的重要特征，导致淋巴细胞浸润，细胞因子环境紊乱，并倾向于胶原积累。mIL-442在急性基因传递模型中引起的变化与mIL-4不同，包括对基因表达、肺细胞因子环境和细胞浸润的影响。例如，虽然mIL-442引起了上述类似于人类SLD的变化，但它不会诱导肺嗜酸性粒细胞增多或杯状细胞增生（这些特征在哮喘中常见，但在SLD中不常见，并且很容易被野生型mIL-4诱导）。基于这些观察，我们假设IL-442可能在SLD中发挥关键作用，并且靶向IL-442在SLD患者中可能被证明具有治疗作用。考虑到人类SLD是一种慢性疾病，有必要评估肺中IL-442慢性表达引起的分子、细胞和组织学变化。在Specific Aim 1中，我们提出利用慢病毒介导的基因传递建立和研究mIL-442的慢性表达模型。腺病毒介导的系统只允许短期的基因传递，与之相反，慢病毒系统允许基因传递持续数月，直至终生表达。实验将确定mIL-442在动物模型中的慢性表达是否概括了硬皮病肺病的关键特征，包括淋巴细胞炎症（特别是CD8+ T细胞）、纤维化、肺细胞因子环境和细胞表面分子表达的变化，以及对皮质类固醇和其他免疫抑制剂治疗的耐药性。这些实验还将确定mIL-442诱导的关键次级介质，并确定IL-442是通过直接作用于肺，还是通过诱导细胞因子和细胞表面分子的表达间接促进炎症和胶原沉积。Specific Aim 2将通过临床前试验确定针对人(h) IL-442的有效方法。具体来说，实验将评估阻断IL-442的单克隆抗体的功效，以及通过RNA干扰阻断人IL-442的产生。这些实验将为未来针对人IL-442的临床试验奠定基础。本研究的预期结果是：1)更好地理解IL-442的机制作用；2)SLD的临床前开发或新疗法。该结果可能不仅对硬皮病患者有益，而且对哮喘、败血症和结核病患者也有益，IL-442已被认为在所有这些患者中发挥重要作用。

DESCRIPTION (provided by applicant): Interstitial lung disease - a combination of pulmonary inflammation and fibrosis - remains the main cause of death in patients with systemic sclerosis, or scleroderma. The mechanisms of scleroderma lung disease (SLD) are not well understood, and the efficiency of available therapies is limited. Previous studies by us and others have suggested that the levels of a splice variant of Interleukin(IL)-4, so-called IL-442, are elevated in association with poorer outcomes in patients with SLD. Our new Preliminary Data suggest that acute adenovirus-mediated gene delivery of mouse (m) IL-442 to mouse lung in vivo recapitulates important features of human SLD, causing infiltration of lymphocytes, disturbances in cytokine milieu, and a tendency to collagen accumulation. The changes caused by mIL-442 in the acute gene delivery model are different from those caused by mIL-4, including the effects on gene expression, pulmonary cytokine milieu, and cellular infiltration. For example, while causing the mentioned changes resembling of human SLD, mIL-442 does not induce pulmonary eosinophilia or goblet cell hyperplasia (the features that are common in asthma but not in SLD, and that are readily induced by wild-type mIL-4). Based on these observations, we hypothesize that IL-442 may play a key role in SLD, and that targeting of IL-442 in patients with SLD may prove therapeutic. Considering that SLD in humans is a chronic condition, there is a need to assess molecular, cellular, and histological changes caused by chronic IL-442 expression in the lungs. We propose, in Specific Aim 1, to establish and investigate a chronic model of mIL-442 expression utilizing lentivirus-mediated gene delivery. In contrast to the adenovirus-mediated system, which allows only for a short-term gene delivery, the lentiviral system allows for gene delivery lasting for months, up to a life-long expression. The experiments will determine whether chronic expression of mIL-442 in an animal model recapitulates key features of scleroderma lung disease, including lymphocytic inflammation (particularly CD8+ T cells), fibrosis, changes in pulmonary cytokine milieu and expression of cell surface molecules, and resistance to treatment with corticosteroids and other immunosuppressive agents. These experiments will also identify key secondary mediators induced by mIL-442, and determine whether IL-442 promotes inflammation and collagen deposition by directly acting on the lung, or indirectly, by inducing expression of cytokines and cell surface molecules. Specific Aim 2 will identify, through pre- clinical testing, effective means of targeting human (h) IL-442. Specifically, the experiments will assess the efficacy of hIL-442-blocking monoclonal antibodies, and blockade of human IL-442 production through RNA interference. These experiments will form basis for future clinical trials targeting IL-442 in humans. The anticipated outcomes of this research are 1) better understanding of the mechanistic role of IL-442, and 2) pre-clinical development or a novel therapy for SLD. The results are likely to be beneficial for not only patients with scleroderma, but also patients with asthma, sepsis, and tuberculosis, in all of which IL-442 has been suggested to play a significant role.