Intrahepatic T cell responses to hepatotropic viruses in transgenic mice with inducible viral gene expression in the liver

嗜肝病毒（HBV、HCV）急性感染的清除依赖于CD 8 + T细胞。这种抗病毒T细胞应答的失败导致慢性病毒感染;并且这种T细胞反应性的重建是治疗性疫苗接种的关键目标。需要信息丰富的临床前模型来开发疫苗接种策略，该疫苗接种策略在肝脏中引发具有功能性抗病毒活性的CD 8 + T细胞应答。本申请的目的是使用转基因小鼠模拟病毒感染，实现病毒基因在肝脏中的选择性（瞬时）表达。这些小鼠将通过杂交两个小鼠品系产生：第一个品系在肝脏中从批准的白蛋白启动子/甲胎蛋白增强子控制区选择性地表达他莫昔芬诱导型Cre重组酶/人雌激素受体（hEr）融合蛋白。第二个系携带“敲入"抗原盒的普遍表达的ROSA 26基因座，其需要Cre介导的重组步骤来激活。抗原盒将被FRT位点标记，这有助于ES细胞中抗原的有效交换。将两个品系杂交将产生双转基因品系，其中病毒基因的表达限于肝脏并且是可诱导的。该系统将提供一种新的临床前研究工具，以研究在肝脏中瞬时表达HBV和HCV抗原的致敏或致敏抗病毒CD 8 + T细胞的归巢。该系统可以很容易地修改，以研究细胞因子（或其信号）的影响，在建立功能性CD 8 + T细胞免疫的肝脏。

The clearance of the acute infection of hepatotropic viruses (HBV, HCV) is CD8+ T cell-dependent. The failure of this anti-viral T cell response leads to chronic virus infection; and the reconstitution of this T cell reactivity is the key objective of therapeutic vaccination. Informative preclinical models are required to develop vaccination strategies that prime CD8+ T cell responses with functional anti-viral activity in the liver. The objective of this application is to achieve the select ble (transient) expression of viral genes in the liver using transgenic mice to mimic viral infection. These mice will be generated by crossing two mouse lines: the first line expresses a tamoxifen-inducible Cre recombinase/human estrogen receptor (hEr) fusion protein selectively in the liver from an approved albumin promoter/a-fetoprotein enhancer control region. The second line carries a 'knock in' into the ubiquitously expressed ROSA26 locus of an antigen cassette which requires a Cre-mediated recombination step for activation. The antigen cassette will be tagged by FRT sites, which facilitates the efficient exchange of antigens in ES cells. Crossing both lines will generate a double transgenic line, in which expression of the viral genes is restricted to the liver and inducible. This system will provide a novel preclinical research tool to study priming, or homing of primed anti-viral CD8+ T cells in the liver that transiently expresses antigens of HBV and HCV. The system can be readily modified to study the influence of cytokines (or their signals) in the establishment of functional CD8+ T cell immunity in the liver.