背景:特发性肺纤维化(IPF)是一种致命的肺部疾病,目前的治疗选择只能减缓临床进展。以前,我们确定了一部分IPF患者,其病程加快与Toll样受体9(TLR9)的成纤维细胞表达相关,所述成纤维细胞表达是通过与其配体线粒体DNA(mtDNA)相互作用介导的.
目的:我们的目的是通过使用两种市售的间接抑制剂和一种专利抑制剂,显示TLR9活化诱导的纤维增殖反应被其拮抗作用所消除,选择性直接小分子抑制剂。
方法:我们采用了两个独立的IPF患者队列,多个体外成纤维细胞培养平台,体内小鼠模型,和离体人类精确切割肺切片系统,以研究TLR9在该疾病中的临床和生物学意义。
结果:在两个独立的IPF队列中,血浆mtDNA以与MCP-1,IL-6,TNFα表达相关的方式激活TLR9,和IP-10恶化了无移植存活率。我们的细胞培养平台显示,TLR9通过TGFβ1和硬底物介导成纤维细胞活化,以及它的对抗,特别是直接抑制,改善这个过程,包括这些TLR9相关药效学终点的产生。我们进一步证明,在我们的肺纤维化的体内和离体模型中,直接TLR9抑制减轻了这些纤维增殖反应。
结论:在这项新颖的研究中,我们发现,在肺纤维化临床前模型中,直接抑制TLR9可减轻纤维化反应.我们的工作证明了直接TLR9拮抗作用在IPF和相关纤维化肺疾病中的治疗潜力。
Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease for which current treatment options only slow clinical progression. Previously, we identified a subset of patients with IPF with an accelerated disease course associated with fibroblast expression of Toll-Like Receptor 9 (TLR9) mediated by interactions with its ligand mitochondrial DNA (mtDNA).
We aimed to show that TLR9 activation induces fibroproliferative responses that are abrogated by its antagonism by using two commercially-available indirect inhibitors and a proprietary, selective direct small molecule inhibitor.
We employed two independent cohorts of patients with IPF, multiple in vitro fibroblast cell culture platforms, an in vivo mouse model, and an ex vivo human precision cut lung slices system to investigate the clinical and biologic significance of TLR9 in this disease.
In two independent IPF cohorts, plasma mtDNA activates TLR9 in a manner associated with the expression of MCP-1, IL-6, TNFα, and IP-10 and worsened transplant-free survival. Our cell culture platform showed that TLR9 mediates fibroblast activation via TGFβ1 and stiff substrates, and that its antagonism, particularly direct inhibition, ameliorates this process, including production of these TLR9 associated pharmacodynamic endpoints. We further demonstrated that direct TLR9 inhibition mitigates these fibroproliferative responses in our in vivo and ex vivo models of pulmonary fibrosis.
In this novel study, we found that direct TLR9 inhibition mitigates fibroproliferative responses in preclinical models of pulmonary fibrosis. Our work demonstrates the therapeutic potential of direct TLR9 antagonism in IPF and related fibrotic lung diseases.