乙型肝炎病毒（HBV）所致慢性感染难以治愈，拮抗细胞凋亡抑制蛋白（cIAPs）被发现可以清除小鼠模型内慢性HBV感染，但机制尚未完全阐明。本课题组前期研究发现慢乙肝患者肝组织cIAPs表达显著增加，且与ALT水平正相关；其拮抗剂APG-1387静脉注射可快速清除小鼠模型内病毒DNA和抗原。由此我们推测, HBV感染或炎症因子可能通过上调肝细胞cIAPs的表达来抑制细胞凋亡，促进感染肝细胞存活；体内拮抗cIAPs 功能可能促进T细胞介导的免疫杀伤效应和抗体中和作用而清除病毒。本项目拟利用体外试验和动物模型，探讨HBV感染对cIAPs表达的调节作用，以及APG-1387诱导感染肝细胞凋亡效应和对HBV特异性T细胞和B细胞应答的影响。研究成果将阐明HBV感染慢性化的分子机制和cIAPs拮抗剂清除HBV感染的效应机制，为APG-1387用于临床抗病毒治疗提供实验和理论依据。

The chronic hepatitis caused by hepatitis B virus (HBV）infection is hard to cure by current antiviral therapies. A recent study reported that the antagonist of cellular inhibitors of apoptosis proteins (cIAPs) was able to eliminate chronic HBV infection in mouse model. However, the antiviral mechanism of cIAPs antagonist remains largely unknown. Our prelimilary data identified that cIAPs expression was significantly up-regulated in liver tissue of chronic hepatitis B patients and positively correlated with ALT levels. Moreover, we confirmed that a specific antagonist of cIAPs, APG-1387, was also able to clear HBV infection in mouse models of chronic hepatitis B. Hence, we speculated that under chronic HBV infection, HBV itself or inflammatory cytokines were able to induce cIAP2 expression in hepatocyts, which promoter cell survival during T- cell mediated immune clearcance of HBV. Morover, APG-1387 treatment could induce neutralizing antibodies and increase the sensitivity of heptocytes to immunity induced apoptosis, then destruct the HBV-infected hepatocytes to clear HBV. The current project is supposed to investigate the regulatory effect of HBV infection on cIAPs expression, and how APG-1387 induce apoptosis in HBV-infected hepatocytes specifically and its regulation on HBV specific T and B cell responses in vitro and animal models in vivo. The findings hopefully would elucidate the novel molecular mechanisms of HBV persistence and cIAPs agonist-mediated clearance of HBV. Therefore, it will provide experimental and theoretical evidences for clinical application of cIAPs antagonist APG-1387 in the antiviral therapy of chronic HBV infection.

乙型肝炎病毒（HBV）所致慢性感染难以治愈，拮抗细胞凋亡抑制蛋白（cIAPs）被发现可以清除小鼠模型内慢性HBV感染，但机制尚未完全阐明。本课题研究发现慢乙肝患者肝组织cIAPs表达显著增加，且与ALT水平正相关；HBV感染或炎症因子如IFN-γ，TNF-α等可以上调肝细胞cIAPs的表达，采用APG-1387抑制cIAPs表达可以增强肝细胞对TNF-α诱导凋亡的敏感性，提示HBV感染可以通过上调肝细胞内cIAPs的表达来抑制免疫杀伤诱导的细胞凋亡，促进感染肝细胞存活。利用高压尾静脉注射的小鼠模型，APG-1387静脉注射可以快速诱导血清病毒抗原和HBV DNA的清除，肝内病毒复制中间体消失，且停药后无反弹，但未观察到与替诺福韦的协同清除效应。机制研究发现，APG-1387处理可以诱导血清ALT/AST的一过性升高和局灶性炎症，免疫荧光证实HBV感染的肝细胞发生凋亡。此外，APG-1387治疗可以显著增加肝内浸润的CD4+和CD8+淋巴细胞数量，同时增强HBV特异性T细胞分泌IFN-γ，TNF-α和IL-2的功能。以上结果证实cIAPs拮抗剂APG-1387能增强机体抗病毒免疫应答，诱导HBV感染肝细胞凋亡而清除病毒。本研究阐明了HBV感染慢性化的分子机制和cIAPs拮抗剂清除HBV感染的效应机制，为APG-1387用于临床抗病毒治疗提供实验和理论依据。