TLR Signaling Pathways in the Zebrafish

描述(由申请人提供)：对感染的第一反应，包括Toll样受体(TLR)介导的过程，对于对抗病原体入侵和增强适应性免疫反应至关重要。斑马鱼是通过TLR途径研究感染先天免疫反应的理想脊椎动物模型。作为一种低等脊椎动物，斑马鱼的免疫系统比哺乳动物简单，在发育的前30-60天，斑马鱼完全依靠先天免疫反应来保护自己免受病原体的攻击。这提供了一个时间窗口，在这个窗口中，可以表征进食、游泳和以其他方式与环境相互作用的有机体的先天免疫，并且很容易暴露于病原体以启动免疫反应。我们的实验室已经对TLR介导的斑马鱼信号进行了广泛的分析。此外，我们实验室还建立了细菌和病毒感染模型。在我们的研究过程中，我们发现斑马鱼TICAM1同源蛋白，哺乳动物中的一种TLR接头蛋白，可以激活斑马鱼I型干扰素，就像它在哺乳动物中所做的那样，但通过另一种机制。因此，这些正词源证明了功能守恒，而不是机械守恒。值得注意的是，这意味着新的TLR介导的信号通路在先天免疫中可能是活跃的。我们推测斑马鱼TLR信号可能在机制上与哺乳动物不同。此外，这些差异可能导致在高等脊椎动物(如人类)中发现新的TLR途径。对这些新途径的阐明可能会为传染病的替代疗法和治疗方法提供洞察。在这个方案中，我们打算实现以下特定目标：1.分析斑马鱼接头蛋白在免疫防御病原体中的作用2.确定斑马鱼接头蛋白的关键结构域并通过体内功能分析鉴定TLR接头蛋白缺失突变体3.寻找在体内产生免疫应答的新的TLR信号通路组件。传染病继续在世界范围内的人类状况中发挥重要作用，因此，疫苗、抗生素和干预策略正在不断发展。这些方法在很大程度上被证明是有效的；然而，由于微生物的适应和环境引发的新疾病的出现，研究控制传染病的替代方法至关重要。这项研究的一个关键焦点涉及免疫系统本身，特别是它的功能可以被增强、延伸和延长的方式。最近认识到先天免疫反应的内在重要性，而不仅仅是它在随后的获得性免疫反应中的调节作用，这表明该系统在预防传染病方面发挥着关键作用。

DESCRIPTION (provided by applicant): The first response to infection, which includes Toll-like receptor (TLR) mediated processes, is crucial for fighting pathogen invasion and for potentiating the adaptive immune response. The zebrafish is an ideal vertebrate model to study innate immune response to infection through the TLR pathways. As a lower vertebrate, the zebrafish has a simpler immune system than mammals, and in the first 30 - 60 days of development the zebrafish relies solely on the innate immune response for protection against pathogens. This provides a window in time in which it is possible to characterize innate immunity in an organism that is eating, swimming, and otherwise interacting with its environment, and can easily be exposed to pathogens to initiate an immune response. Our laboratory has conducted extensive analysis of TLR-mediated signaling in the zebrafish. In addition, bacterial and viral infection models have been developed in our lab. During the course of our studies, we discovered that the zebrafish TICAM1 orthologue, a TLR adaptor protein in mammals, can activate zebrafish type I interferon as it does in mammals, but through an alternative mechanism. Thus, these orthologues demonstrate functional, but not mechanistic conservation. Significantly, this implies that novel TLR-mediated signaling pathways may be active in innate immunity. We hypothesize that zebrafish TLR signaling may be mechanistically divergent from mammals. Furthermore, these differences may lead to the discovery of novel TLR pathways in higher vertebrates, such as humans. The elucidation of these novel pathways may provide insight into alternative therapies and treatments for infectious disease. In this proposal, we intend to fulfill the following SPECIFIC AIMS: 1. Analyze the role of zebrafish adaptor proteins in immune defense against pathogens 2. Determine the critical domains of zebrafish adaptor proteins and characterize the TLR adaptor protein deletion mutants through in vivo functional analysis 3. Identify novel TLR signaling pathway components that generate an immune response in vivo. Infectious diseases continue to play a major role in the human condition worldwide and as a result vaccines, antibiotics, and intervention strategies are continually being developed. These methods have largely proven effective; however, due to microbial adaptation and environment- triggered emergence of new diseases, it is critical to investigate alternative methods for controlling infectious diseases. A critical focus of this investigation involves the immune system itself, specifically ways in which its function can be augmented, extended, and prolonged. Recent recognition of the intrinsic importance of the innate immune response beyond its regulatory role in the subsequent adaptive immune response suggests that this system plays a crucial role in protection against infectious diseases.