RUI: Analysis of the Cellular Factors Regulating the Function of the MHC Class II Transactivator (CIITA)

免疫系统的激活对生物体的生存很重要，但必须适当地调节对各种环境因素的反应，如病原体。参与这一调控的一个重要蛋白质是一种被称为第二类反式激活因子(CIITA)的主要调节蛋白。在感染时，CIITA会诱导特定基因亚集的表达，从而激活免疫系统，并导致身体积极抗击病原体。带有CIITA突变的个体不会表现出正常的免疫反应，最终会导致儿童早期因常见感染而死亡。尽管它在触发免疫反应中起着重要的作用，但控制CIITA活动的细胞机制尚不清楚。正在探索的一个机制是磷酸盐的添加或减少对CIITA功能的作用。存在于细胞核中的CIITA是磷酸化的，这与其无法诱导免疫系统基因的表达有关。CIITA也从细胞核输出到细胞质中，尽管这种输出的原理仍有待确定。一种假设是，核CIITA的磷酸化特异性地导致它与将CIITA赶出核的蛋白质相互作用，从而关闭CIITA调控的免疫系统基因的表达。这可能允许有机体快速而准确地控制CIITA活动的程度，从而调节免疫反应的大小。初步研究发现了几种可能与CIITA相互作用的蛋白质，它们可能特异性地参与了CIITA的磷酸化和控制其细胞质/核的定位，从而在调节CIITA功能方面发挥了关键作用。然而，这些蛋白质与CIITA相互作用的方式以及它们在细胞内控制CIITA活性的具体机制尚未确定。该项目检测了这些蛋白质与CIITA相互作用的能力，修改其结构，改变其在细胞中的位置，并调节其在启动免疫系统基因表达方面的功能。了解控制CIITA活性的细胞和分子机制对于设计操纵免疫系统和改变免疫反应的策略至关重要。更广泛的影响：这个项目寻求进一步发展学院第一个积极的、正在进行的实验室研究项目，为本科生提供参与该项目的机会，并获得宝贵的经验和接触分子生物学研究设计、方法学、数据收集和结果解释。在该项目的三年时间框架内，本科生将以暑期或学年实习生的身份密切参与该项目。此外，该项目将成为在生物课程中增加实验研究课程的基础，扩大学生在其学习框架内获得实验室经验的机会。通过将学生和教职员工聚集在一起并提供参与分子生物学研究的机会，该项目将为进一步的课程发展奠定基础，并加强萨拉·劳伦斯学院的本科生科学培训。

Activation of the immune system is important for the survival of an organism however the response to a variety of environmental factors such as pathogens must be properly regulated. An important protein involved in this regulation is a master regulatory protein known as the class II transactivator (CIITA). Upon infection, CIITA acts to induce the expression of a particular subset of genes, thereby activating the immune system and leading to a vigorous effort by the body to combat the pathogen. Individuals with mutations in CIITA do not exhibit a normal immune response and ultimately leads to death in early childhood due to common infections. Despite its prominent role in triggering an immune response, the cellular mechanisms that control CIITA activity are not well understood. One mechanism being explored is the role of addition or subtraction of phosphate on CIITA function. CIITA present in the nucleus of cells is phosphorylated, which correlates with its inability to induce the expression of immune system genes. CIITA is also exported out of the nucleus into the cytoplasm of cells, although the rationale for this export remains to be determined. One hypothesis is that phosphorylation of nuclear CIITA specifically causes it to interact with proteins that drive CIITA out of the nucleus, thereby shutting down CIITA-regulated expression of immune system genes. This may allow the organism to rapidly and precisely control the extent of CIITA activity and therefore mediate the magnitude of an immune response. Preliminary results identified several proteins that potentially interact with CIITA, which may be specifically involved in phosphorylating CIITA and controlling its cytoplasmic/nuclear localization, thereby playing a critical role in regulating CIITA function. However, the means by which these proteins interact with CIITA as well as their specific mechanisms of controlling CIITA activity within a cell have yet to be identified. This project examines the ability of these proteins to interact with CIITA, modify its structure, alter its location in the cell, and regulate its function in initiating the expression of immune system genes. Understanding the cellular and molecular mechanisms that control CIITA activity will be crucial to devising strategies to manipulate the immune system and alter immune responses. Broader Impacts: This project seeks to further develop the first active, on-going laboratory research program at the college, providing an opportunity for undergraduate students to participate in the project and gain valuable experience and exposure to molecular biology research design, methodology, data collection and results interpretation. During the three-year timeframe of this project, undergraduate students will be intimately involved in the program as summer or academic year interns. Furthermore, this project will form the basis for the addition of experimental research courses to the biology curriculum, expanding opportunities for students to gain laboratory experience within the framework of their studies. By bringing together students and faculty and providing opportunities to participate in molecular biology research, this project will establish the foundation for further curricular development and strengthen undergraduate scientific training at Sarah Lawrence College.