Yang Priscilla L, Althage Alana, Chung Josan, Chisari Francis V
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
Proc Natl Acad Sci U S A. 2002 Oct 15;99(21):13825-30. doi: 10.1073/pnas.202398599. Epub 2002 Oct 8.
Hepatitis B virus (HBV) is a prototype for liver-specific pathogens in which the failure of the immune system to mount an effective response leads to chronic infection. Our understanding of the immune response to HBV is incomplete, largely due to the narrow host restriction of this pathogen and the limitations of existing experimental models. We have developed a murine model for studying human HBV replication, immunogenicity, and control. After transfection of hepatocytes in vivo with a replication-competent, over-length, linear HBV genome, viral antigens and replicative intermediates were synthesized and virus was secreted into the blood. Viral antigens disappeared from the blood as early as 7 days after transfection, coincident with the appearance of antiviral antibodies. HBV transcripts and replicative intermediates disappeared from the liver by day 15, after the appearance of antiviral CD8 + T cells. In contrast, the virus persisted for at least 81 days after transfection of NOD/Scid mice, which lack functional T cells, B cells, and natural killer (NK) cells. Thus, the outcome of hydrodynamic transfection of HBV depends on the host immune response, as it is during a natural infection. The methods we describe will allow the examination of viral dynamics in a tightly controlled in vivo system, the application of mutagenesis methods to the study of the HBV life cycle in vivo, and the dissection of the immune response to HBV using genetically modified mice whose immunoregulatory and immune effector functions have been deleted or overexpressed. In addition, this methodology represents a prototype for the study of other known and to-be-discovered liver-specific pathogens.
乙型肝炎病毒（HBV）是肝脏特异性病原体的一个典型例子，免疫系统无法产生有效应答会导致慢性感染。我们对HBV免疫应答的理解并不完整，这在很大程度上是由于该病原体宿主范围狭窄以及现有实验模型存在局限性。我们开发了一种小鼠模型来研究人类HBV的复制、免疫原性和控制情况。用具有复制能力的超长线性HBV基因组在体内转染肝细胞后，合成了病毒抗原和复制中间体，并且病毒分泌到血液中。早在转染后7天，病毒抗原就从血液中消失，这与抗病毒抗体的出现同时发生。在抗病毒CD8 + T细胞出现后，到第15天，肝脏中的HBV转录本和复制中间体消失。相比之下，在缺乏功能性T细胞、B细胞和自然杀伤（NK）细胞的NOD/Scid小鼠转染后，病毒持续存在至少81天。因此，HBV的流体动力学转染结果取决于宿主免疫应答，就如同自然感染时一样。我们所描述的方法将允许在严格控制的体内系统中检查病毒动力学，将诱变方法应用于体内HBV生命周期的研究，并使用免疫调节和免疫效应功能已被删除或过表达的基因改造小鼠来剖析对HBV的免疫应答。此外，这种方法代表了研究其他已知和待发现的肝脏特异性病原体的一个范例。
