Combination therapy using siRNA nanocompelex and PD-L1 inhibitor for alcoholic liver fibrosis

项目摘要 肝纤维化是一个创伤愈合过程，其特征是过量的细胞外基质的积累， 基质（ECM）在肝脏中。酒精滥用是肝纤维化/肝硬化的最常见原因之一， 西方发达国家，占肝硬化病例的50%以上。如果不治疗，肝脏 肝纤维化将发展为肝硬化，这是不可逆转的，影响了近633，233名成年人， 美国的不幸的是，到目前为止还没有标准的肝纤维化治疗方法。因此，我们认为， 迫切需要有效的抗纤维化药物 I型胶原在纤维化肝脏中的积累主要是由于I型胶原的半衰期增加。 其mRNA在活化的肝星状细胞（HSC）中。我们最近证明，阻断PCBP 2 使用siRNA表达可有效降低胶原α1（I）mRNA的稳定性， 随后逆转HSC中酒精和甜菜碱诱导的纤维化。我们还发现了 IGF 2 R特异性肽，可用于将货物特异性递送至活化的HSC。我们将 改进我们目前的纳米复合物系统，以增强PCBP 2 siRNA向活化的 HSC。 肝星状细胞的活化和增殖是肝脏的中心事件 纤维化最近，实验和临床研究表明，诱导细胞凋亡， 激活肝星状细胞是一种合理的和潜在的抗肝纤维化的方法。发现HSC 通过HSC表面的PD-L1抑制T细胞和B细胞。PD-L1在活化的 HSC，导致激活的HSC针对T细胞应答的强免疫调节活性。 活化的HSC对浸润的CD 8 + T细胞具有抑制作用，对CD 4 + CD 25 + T细胞具有诱导作用。 调节性T（Treg）细胞。激活的HSC的免疫调节活性可以被抗- PD-L1抗体阻断PD-1/PD-L1相互作用。因此，我们假设抗PD-L1 抑制剂可用于恢复纤维化肝脏中浸润T细胞的活性，以清除活化的T细胞。 过表达PD-L1的HSC。 我们的策略是开发一种联合疗法，以逆转积累的I型胶原蛋白， PCBP 2 siRNA和使用PD-L1抑制剂诱导活化HSC的凋亡。我们的核心假设 酒精性肝纤维化可以通过靶向肝纤维化形成中的两个不同的关键步骤来逆转。

Project Summary Liver fibrosis is a wound healing process characterized by the accumulation of excess extracellular matrix (ECM) in the liver. Alcohol abuse is one of the most common causes of liver fibrosis/cirrhosis in western developed countries, accounting for more than 50% of cirrhosis cases. If left untreated, liver fibrosis will develop into liver cirrhosis, which is irreversible and affects nearly 633,233 adults in the United States. Unfortunately, there is no standard treatment for liver fibrosis till now. Therefore, effective antifibrotic medicines are needed urgently The accumulation of type I collagen in fibrotic liver is primarily due to an increase in the half-life of its mRNA in activated hepatic stellate cells (HSCs). We recently demonstrated that blocking PCBP2 expression using siRNA can efficiently decrease the stability of the collagen α1(I) mRNA and subsequently reverse alcohol- and cytokine-induced fibrogenesis in HSCs. We also discovered an IGF2R-specific peptide that can be used to specifically deliver cargos to activated HSCs. We will improve our current nanocomplex system to enhance the delivery of the PCBP2 siRNA to activated HSCs. It has been well established that the activation and proliferation of HSCs is the central event in liver fibrogenesis. Recently, experimental and clinical studies have shown that inducing apoptosis of activated HSCs in fibrotic liver is a rational and potential anti-fibrotic approach. It was found that HSCs inhibit T cells and B cells through PD-L1 on the surface of HSCs. PD-L1 is overexpressed in activated HSCs, leading to the strong immune modulatory activity of the activated HSCs against T-cell response. Activated HSCs exert inhibitory effects on infiltrating CD8+ T cells and induction effects on CD4+CD25+ regulatory T (Treg) cells. The immune modulatory activity of activated HSCs can be reversed by anti- PD-L1 antibodies to block the PD-1/PD-L1 interaction. We therefore hypothesize that anti-PD-L1 inhibitor can be utilized to restore the activity of infiltrating T cells in the fibrotic liver to clear activated HSCs which overexpress PD-L1. Our strategy is to develop a combination therapy to reverse the accumulated type I collagen using PCBP2 siRNAs and induce apoptosis of activated HSCs using PD-L1 inhibitors. Our central hypothesis is that alcoholic liver fibrosis can be reversed by targeting two different key steps in liver fibrogenesis.