Temporal-quantitative control of IRF-3 and NF-kB upon pathogen recognition in single cells and living tissue

诱导i型干扰素（IFN）基因应答病毒感染是先天免疫的一个重要过程。在识别病毒RNA后，一个复杂的信号转导途径最终激活干扰素调节因子3和7以及核因子kB。这些因子介导i型干扰素（IFN）和其他抗病毒基因的转录诱导。引人注目的是，单个细胞在IFN的表达及其时间上表现出一种不可预测的变化。我们最近的工作首次提供了单细胞分辨率下IFN诱导和动作信号传导的综合分析（Rand等人，分子系统生物学，修订版）。然而，IFN表达动态的机制基础尚不清楚。通过提出的研究项目，我想阐明对病原体模式的识别如何在单细胞水平上转化为时空信号动力学。众所周知，i型IFN的不成比例产生可能在无法控制病毒感染和自身免疫性疾病中发挥重要作用。阐明IRF-3 / nf - kb介导诱导的时空动态取决于致病负荷、细胞因子环境或组织结构等可变条件，将有助于了解如何维持对IFN产生的适当控制。因此，我将进行时间分辨定量研究，以研究细胞识别dsRNA后IRF-3和NF-kB的协同调节。有了这个，我将阐明炎症环境的各种条件的影响和活组织中单细胞动力学的相关性。来自这些定量研究的数据将用于创建一个数学模型，目的是能够预测IFN的表达动态。这项工作的总体用途将是允许对感染或接种疫苗后早期免疫反应的过程进行预测性假设。此外，这项工作的结果可以作为相关信号通路的路线图。

The induction of type-I interferon (IFN) genes in response to viral infection is an essential process of innate immunity. Following recognition of viral RNA a complex signal transduction pathway eventually activates IRFs (interferon regulatory factors) 3 and 7 and NF-kB (nuclear factor kB). These factors mediate the transcriptional induction of type-I interferon (IFN) and other antiviral genes. Strikingly, individual cells exhibit a yet unpredictable variation in the expression of IFN and its timing. Our recent work provides for the first time a comprehensive analysis of IFN induction and action signalling at single-cell resolution (Rand et al., Molecular Systems Biology, in revision). However, the mechanistic basis of IFN expression dynamics remains unclear. With the proposed research project I want to elucidate how the recognition of pathogen patterns is translated into spatio-temporal signalling dynamics at single-cell level. It is known that a disproportionate production of type-I IFN can play an important role in the inability to control viral infections and in autoimmune disorders. Elucidating the temporal-spatial dynamics of the IRF-3 / NF-kB-mediated induction depending on variable conditions such as pathogenic load, cytokine environment or tissue structure will help to understand how appropriate control on IFN production is maintained. Therefore, I will perform time-resolved quantitative studies to investigate the concerted regulation of IRF-3 and NF-kB following recognition of dsRNA by the cell. With this I will elucidate the impact of various conditions of an inflammatory environment and the relevance of single-cell dynamics in living tissue. Data from these quantitative studies will be used to create a mathematical model with the aim to be able to predict IFN expression dynamics. The overall use of this work will be to allow predictive assumptions on the course of the early immune response following infection or vaccination. Furthermore, the results of this work can serve as a roadmap for related signalling pathways.