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

描述(申请人提供)：间质性肺部疾病-肺部炎症和纤维化的组合-仍然是系统性硬化症或硬皮病患者的主要死亡原因。硬皮病肺病(SLD)的发病机制尚不清楚，现有治疗方法的有效性有限。我们和其他人之前的研究表明，在SLD患者中，IL-4的剪接变体，即所谓的IL-442的水平升高，与较差的预后相关。我们的新的初步数据表明，体内急性腺病毒介导的小鼠IL-442基因转移到小鼠肺内重现了人类SLD的重要特征，导致淋巴细胞渗透，细胞因子环境紊乱，并有胶原沉积的趋势。在急性基因传递模型中，mIL-442引起的改变不同于mIL-4引起的改变，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引起上述类似于人类SLD的变化，但不会导致肺嗜酸性粒细胞增多或杯状细胞增生(这些特征在哮喘中很常见，但在SLD中不常见，而且很容易被野生型mIL-4诱导)。基于这些观察，我们假设IL-442可能在SLD中起关键作用，靶向治疗SLD患者可能被证明是有效的。考虑到人类SLD是一种慢性疾病，有必要评估由肺部慢性IL-442表达引起的分子、细胞和组织学变化。在特定的目标1中，我们建议利用慢病毒介导的基因传递来建立和研究mIL-442表达的慢性模型。腺病毒介导的系统只允许短期的基因传递，而慢病毒系统允许持续数月的基因传递，直到终身表达。这些实验将确定mIL-442在动物模型中的慢性表达是否概括了硬皮病肺部疾病的关键特征，包括淋巴细胞性炎症(特别是CD8+T细胞)、纤维化、肺细胞因子环境的变化和细胞表面分子的表达，以及对皮质类固醇和其他免疫抑制剂治疗的抵抗。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。具体目标2将通过临床前测试确定靶向人(H)IL-442的有效方法。具体地说，这些实验将评估阻断hIL-442的单抗的有效性，以及通过RNA干扰阻断人类IL-442的产生。这些实验将为未来针对IL-442的人体临床试验奠定基础。这项研究的预期结果是：1)更好地了解IL-442的机制作用；2)SLD的临床前开发或新的治疗方法。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好处，所有这些患者中IL-442都被认为发挥了重要作用。

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.