Mechanisms and consequences of epithelial cell survival from influenza virus infection.

项目摘要 流感病毒每年在全世界引起显著的发病率和死亡率。该病毒具有广泛的嗜性， 呼吸道的上皮细胞为了清除感染，免疫系统必须对抗这些不同的 可以携带不同水平的病毒或病毒抗原：MHC的细胞具有不同的表达， 抑制性配体，并存在于不同的解剖位置。确定病毒感染者的长期命运 细胞，我们开发了一种新的病毒，能够永久标记报告小鼠中的感染细胞。通过插入 Cre重组酶导入病毒基因组，感染小鼠可永久表达Cre诱导荧光团 标记细胞，并允许长期跟踪和研究受感染的细胞。利用这个工具，我们制作了 令人惊讶的发现是，并非所有先前感染的细胞都被裂解性病毒复制或适应性病毒复制杀死。 免疫反应我们假设CD8 T细胞杀死或赦免受感染的上皮细胞，这取决于细胞 类型、细胞内病毒复制的状态和病毒诱导的抑制性配体表达。我们进一步 假设存活的细胞是肺恢复的关键介质。因为我们可以看到细胞 在感染的整个清除阶段，我们可以利用这个系统来研究上皮细胞， 被CD8 T细胞杀死以及允许感染的机制。本提案的目标是：1）确定 感染细胞逃避CD8 T细胞介导的杀伤的机制2）定义存活细胞的作用 3）绘制被CD8 T细胞清除的感染细胞图，4）阐明 在抗病毒免疫反应面前保护和允许新细胞感染的机制。 重要的是，在这些研究中采用的不可磨灭的标记系统可以扩展到IAV以外的任何 能够接受外来基因插入的病毒。该提案的结果将揭示基本的 抗病毒免疫、细胞抗性和存活以及肺部恢复的机制。

Project Summary Influenza virus causes significant morbidity and mortality worldwide annually. The virus has a broad tropism for epithelial cells in the respiratory tract. To clear the infection the immune system must confront these diverse cells which can be harboring different levels of virus or virus antigen:MHC, have differential expression of inhibitory ligands, and reside in different anatomical locations. To determine the long-term fate of virus infected cells we developed a novel virus capable of permanent labeling of infected cells in reporter mice. By inserting Cre recombinase into the virus genome, infection of mice expressing a Cre-inducible fluorophore permanently labels the cells and allows for long-term tracking and study of infected cells. Using this tool we made the surprising discovery that not all previously infected cells are killed by the lytic virus replication or the adaptive immune response. We hypothesize that CD8 T cells kill or pardon infected epithelial cells depending on cell type, the state of virus replication within the cell, and virus-induced expression of inhibitory ligands. We further hypothesize that surviving cells are critical mediators of pulmonary recovery. Because we can visualize cells throughout the clearance phase of infection we can exploit this system to study the epithelial cells that are killed by CD8 T cells and the mechanisms that permit infection. The goals of this proposal are to: 1) Determine the mechanisms of infected cell evasion from CD8 T cell-mediated killing 2) Define the roles of surviving cells in pulmonary repair and recovery 3) Map the infected cells that are eliminated by CD8 T cells and 4) Elucidate the mechanisms that protect and permit infection of new cells in the face of antiviral immune responses. Importantly, the indelible labeling system employed during these studies can be extended beyond IAV, to any virus that is amenable to foreign gene insertions. Results from this proposal will uncover fundamental mechanisms in antiviral immunity, cellular resistance and survival, and pulmonary recovery.