Distinct regulation of pulmonary inflammation by isoforms of Interleukin-33

描述（由申请人提供）： 肺部炎症和纤维化的组合，通常被称为“间质性肺病”（ILD），是使人衰弱的，甚至是致命的。ILD的发生可能有多种原因，在没有经过确认的治疗的情况下，ILD是硬皮病患者死亡的主要原因，而另一种ILD（特发性肺纤维化（IPF））患者的中位生存期仅为2 - 3年。军事暴露、衰老和自身免疫性疾病使ILD在退伍军人中普遍存在。虽然在揭示ILD的机制方面取得了很大进展，但对该病的了解仍然很少。最近的研究结果表明，高内皮微静脉核因子（NFHEV），也称为白细胞介素（IL）-33，在硬皮病和IPF的发病机制。NFHEV/IL-33因其双重生物学特性而被这两个不同的名称所描述。作为一种核因子，它在多种细胞类型中表达，并直接与DNA结合。作为一种细胞因子，蛋白水解激活的细胞外IL-33是Th 2应答的有力诱导剂，例如过敏和哮喘中的那些。IL-33细胞因子的后一种活性处于活跃状态 然而，NFHEV作为一种核因子的前活性尚未得到充分的重视，也没有足够详细的研究或与疾病过程的相关性。我们的数据表明，作为一个核因子，NFHEV驱动ILD。NFHEV在ILD患者的肺中升高，并且相对于IL-33形式占优势。在这些患者中，NFHEV在炎性细胞中表达，特别是成纤维细胞，这是ILD发病机制的核心。与此一致，在ILD的博来霉素模型中，NFHEV的表达在小鼠肺中升高。在细胞培养物和动物模型中NFHEV的基因递送导致MCP-1、IL-6、MMP 3、MMP 10和MMP 13的产生增加，已知所有这些都有助于ILD。NFHEV的基因递送还诱导炎症和局部胶原沉积。尽管患者的细胞外IL-33也可能有所升高，但可溶性T1/ST 2也伴随升高，其中和IL-33细胞因子活性，但对NFHEV的功能没有影响。在博莱霉素模型中，T1/ST 2基因缺陷对ILD的严重程度具有最小的减弱作用（如果有的话）。基于这些数据，该建议的假设是NFHEV是ILD的中心T1/ST 2非依赖性调节剂，通过刺激促炎和促纤维化基因表达发挥作用。如果成功验证NFHEV的这种作用，本研究将为未来开发NFHEV靶向策略奠定基础，从而为ILD提供更好的治疗方法。为了评估这一假设的有效性，将讨论三个具体目标。目的1在博来霉素肺间质疾病模型中，证实NFHEV通过T1/ST 2非依赖性地调节促炎基因和促纤维化基因的表达来减轻肺部炎症和纤维化。目的2是通过确定NFHEV的普遍存在和/或细胞类型特异性缺陷是否在间质性肺病的博来霉素模型中保护免受肺部炎症和纤维化来确定病理生理学上重要的NFHEV表达细胞类型。该目的将利用具有诱导型细胞类型特异性NFHEV基因敲除的小鼠。目的3将利用IPF患者肺部炎症和纤维化的空间异质性，以确定NFHEV表达增加是否与活动性纤维化灶、细胞炎症以及候选NFHEV驱动的促炎因子和促纤维化因子的表达相关。这项工作调查了NFHEV生物学与退伍军人中流行的致命肺部疾病相关的未知方面。这些结果将为将来在退伍军人和普通人群中开发NFHEV靶向治疗奠定基础。因此，这项建议直接解决退伍军人的需要，并有助于退伍军人管理局医疗保健使命。

DESCRIPTION (provided by applicant): Combined pulmonary inflammation and fibrosis, often referred to as "interstitial lung disease" (ILD), is debilitat- ing and even deadly. ILD may develop for a variety of reasons, and with no confirmed therapies, ILD is the main cause of death in patients with scleroderma, whereas median survival is only 2 to 3 years in patients with another ILD, idiopathic pulmonary fibrosis (IPF). Military exposures, aging, and autoimmune diseases make ILD prevalent in Veterans. Although much progress has been made in uncovering the mechanisms of ILD, the disease still remains poorly understood. Recent findings implicate nuclear factor from high endothelial venules (NFHEV), also known as interleukin (IL)-33, in the pathogenesis of scleroderma and IPF. NFHEV/IL-33 is des- ignated by these two different names because of its dual biology. As a nuclear factor, it is expressed in a varie- ty of cell types and binds directly to DNA. As a cytokine, proteolytically activated extracellular IL-33 is a power- ful inducer of Th2 responses, such as those in allergies and asthma. The latter activities of the IL-33 cytokine are under active investigation, whereas the former activities of NFHEV as a nuclear factor have been underap- preciated and not studied in sufficient detail or in association with a disease process. Our data suggest that, as a nuclear factor, NFHEV drives ILD. NFHEV is elevated in the lungs of patients with ILD and predominant over the IL-33 form. In these patients, NFHEV is expressed in inflammatory cells and, notably, fibroblasts, which are central to the pathogenesis of ILD. Consistent with this, the expression of NFHEV is elevated in the lungs of mice in the bleomycin model of ILD. Gene delivery of NFHEV in cell culture and in the animal model leads to increased production of MCP-1, IL-6, MMP3, MMP10, and MMP13, all of which are known to contribute to ILD. Gene delivery of NFHEV also induces inflammation and local collagen deposition. Although extracellular IL-33 in patients may also be somewhat elevated, there is an accompanying elevation in soluble T1/ST2, which neu- tralizes IL-33 cytokine activity but has no effect on the function of NFHEV. Gene deficiency of T1/ST2 has min- imal if any attenuating effect on the severity of ILD in the bleomycin model. Based on these data, the Hypothe- sis of this proposal is that NFHEV is a central T1/ST2-independent regulator of ILD, acting through stimulation of proinflammatory and profibrotic gene expression. If successful in validating this role of NFHEV, this study will lay the groundwork for future development of NFHEV-targeting strategies and thus lead to better therapies for ILD. To assess the validity of this Hypothesis, three Specific Aims will be addressed. Aim 1 is to prove, in the bleomycin model of interstitial lung disease, that NFHEV worsens pulmonary inflammation and fibrosis through T1/ST2-independent regulation of proinflammatory and profibrotic gene expression. Aim 2 is to define pathophysiologically important NFHEV-expressing cell types by determining whether ubiquitous and/or cell type-specific deficiency of NFHEV protects against pulmonary inflammation and fibrosis in the bleomycin mod- el of interstitial lung disease. This Aim will utilize mice with inducible cell type-specific NFHEV gene knockout. Aim 3 will take advantage of the spatial heterogeneity of inflammation and fibrosis in the lungs of human pa- tients with IPF to determine whether increased expression of NFHEV is associated with active fibrotic foci, cel- lular inflammation, and expression of candidate NFHEV-driven proinflammatory and profibrotic factors. This work investigates unknown aspects of NFHEV biology in association with a deadly lung disease prevalent in Veterans. The results will lay the groundwork for future development of NFHEV-targeting therapies in Veterans and in the general population. Thus, this proposal directly addresses the needs of Veterans and contributes to the VA Healthcare Mission.