【作者】 戎其飞；

【导师】 黄峻；

【作者基本信息】 南京医科大学 ， 内科学， 2007， 博士

【摘要】 研究背景：既往研究表明，乙肝病毒(HBV)在肝外组织的复制引起诸如乙肝相关性病毒性心肌炎等多种肝外表现，但是乙肝病毒如何传染肝外组织引起如乙肝相关性病毒性心肌炎等临床表现，其发病机理仍然不清。目的：为了探讨人内皮祖细胞(EPCs)和人及鼠骨髓间充质干细胞(MSCs)是否能被HBV感染，具有携带HBV而修复肝外损伤的组织，进一步研究乙肝病毒肝外表现的发病机理。同时，探讨HBV传染的种属同源性问题。方法：在本研究中，我们用乙肝病毒高拷贝阳性血清感染人脐带血内皮祖细胞、人和SD大鼠骨髓间充质干细胞及SD乳鼠心肌细胞，并将感染的祖／干细胞移植入心肌梗死模型和急性肾缺血模型的SD大鼠。免疫组化、流式细胞仪、PCR和透射电镜检测体外培养的细胞，同时免疫组化和免疫荧光检测SD大鼠的各脏器组织。结果：本研究发现，在体外培养系统中用乙肝病毒对祖／干细胞、SD乳鼠心肌细胞和人脐静脉内皮细胞(HUVECs)进行干预，人内皮祖细胞可通过吞噬乙肝病毒而引起感染，骨髓间充质干细胞也可被HBV感染，但不感染人脐静脉内皮细胞和SD乳鼠心肌细胞。在人内皮祖细胞和骨髓间充质干细胞可检测到HBV DNA和变异的乙肝病毒颗粒，并在以后的维持培养中逐渐下降以至于消失。同时，乙肝表面抗原(HBsAg)和核心抗原(HBcAg)也在内皮祖细胞、人和鼠的骨髓间充质干细胞表达。但是，HBV共价闭合环状DNA(HBV cccDNA)始终是阴性。在体研究发现，在心肌梗死周边部和继发性损伤的肾、肺和肝组织，免疫组化和免疫荧光均发现乙肝抗原的表达。结论：乙肝病毒不能感染乳鼠的心肌细胞，但能感染SD大鼠间充质干细胞和人间充质干细胞，病毒对不同种属的干细胞的感染可能是人畜共患性疾病的感染基础。内皮祖细胞和人骨髓间充质干细胞可被乙肝病毒感染，但不在这两种细胞中复制，并将乙肝病毒携带至被修复的组织，这充分说明内皮祖细胞和骨髓间充质干细胞带乙肝病毒修复组织的功能是乙肝病毒性心肌炎和其他乙肝肝外表现的发病机理之一。意味着干细胞具有带病毒修复组织的功能，这也可能是病毒性疾病和病毒相关性肿瘤疾病的发病机理之一。更多还原

【Abstract】 BackgroundHepatitis B virus (HBV) replication has been reported to be involved inmany extrahepatic viral disorders; however, the mechanism by whichHBV is trans-infected into extrahepatic tissues such as HBV associatedmyocarditis remains largely unknown.ObjectiveIn order to explore whether neogenetic Sprague-Dawley rat cardiacmyocytes, Sprague-Dawley rat bone marrow mesenchymal stemcells(rMSCs), human bone marrow mesenchymal stem cells (hMSCs)and human cord blood endothelial progenitor cells (EPCs) could beinfected by Hepatitis B virus in vitro, and whether hMSCs and EPCshave a function to carry hepatitis B virus to repair damaged tissues invivo.Methods We cultured rat cardiac myocytes, EPCs and MSCs withhepatitis B virus positive serum and then transplantated them intoSprague-Dawley mice of acute myocardial infarction and acute renal ischemic model.ResultsIn this study, we showed that human bone marrow mesenchymal stemcells and human cord blood endothelial progenitor cells, but not ratcardiac myocytes and human umbilical vein endothelial cells could beeffectively infected by uptake of HBV in vitro. Exposure of the cells withHBV resulted in HBV DNA and viral particles were detected in hMSCsand EPCs at day 3 after HBV challenge, which declined thereafter.Consistently, HBV envelope surface and core antigens were first detectedin the cells at day 3 after virus challenge. Significantly, HBV cccDNAwas not detected in EPCs at any time point. In addition, the core antigencan be detected in rat bone marrow mesenchymal stem cells. Furthermore,intravenous transplantation of HBV-treated hMSCs and EPCs intomyocardial infarction and acute renal ischemia mouse model resulted inincorporation of both the stem cells and HBV into heart tissues at theinfarct border zone and other injured extrahepatic tissues such as kidney,lung and liver.ConclusionsNeogenetic Sprague-Dawley rat cardiac myocytes could not be infected,and rat and human bone marrow mesenchymal stem cells could beinfected by hepatitis B virus. It suggests that infection of stem cells byviruses may be one of the mechanisms of emerging zoonotic diseases. These results also strongly support that both EPCs and MSCs serve asvirus carrier mediating HBV trans-infection into the injured tissues. Thefindings might provide a novel mechanism for HBV-associatedmyocarditis and other HBV-related extrahepatic diseases as well. Itsuggests that stem cell have a function to carry viruses to repair sometissues and this may be one of the mechanisms of virus relevant diseaseincluding virus relevant tumor diseases.更多还原