Formation and function of lamellipodial morphology in 3D microenvironments

项目摘要 树突状细胞是免疫系统的哨兵。它们巡视身体寻找抗原，然后迁徙 将他们的发现传递给T细胞和适应性免疫系统的其他细胞。 这些专业的迁徙和搜索者是人类免疫力的关键组成部分，他们的迁徙是 被多种病原体攻击或劫持，包括一些痘和疱疹病毒、结核病和炭疽病。 由于树突状细胞可以激活细胞毒性T细胞攻击癌细胞，它们的迁移在癌症中也起到了作用 免疫治疗策略。许多细胞，包括树突状细胞，通过扩展片状脂蛋白进行迁移。片状脂溢症 是薄的平面突起，已被广泛研究细胞在2D表面上迁移，如玻璃 封面纸条。树突状细胞使用板脂找到一条穿过拥挤的3D环境的路径，并进入LYM- 海绵状血管。对片状脂蛋白及其组成的肌动蛋白网络的研究已有数十年之久。怎么- 以往，最详细的板脂调节和功能的分子模型都是从对细胞的研究中得出的。 因此，我们仍然不知道细胞如何在3D环境中启动和延伸板脂。在这 项目中，我们将研究肌动蛋白核因子是如何组织起来生成片状片状脂膜形态的 缺乏一个表面来引导它们的产生，以及肌动蛋白核蛋白是如何组织起来引导伸展的-- 拥挤的3D环境中的锡安片状病毒。作为树突状细胞外周迁移的模型 组织，我们将研究通过3D纤维胶原基质的迁移。广泛使用的显微技术， 例如共聚焦显微镜，不能以所需的空间和时间分辨率成像3D胶原中的细胞 目的：测量肌动蛋白核子在片状脂体中的组织结构。然而，最近开发的技术，如 作为光片显微镜，才刚刚开始能够做到这一点。由于光片显微镜可以产生 海量数据集、解释甚至简单地可视化如此大量的数据需要复杂的 计算工作流。我们将开发所需的计算工作流程，以研究片状脂体形式 并在3D环境中运行。

Project Summary Dendritic cells are the sentinels of the immune system. They patrol the body looking for antigens and then migrate to a lymph node to communicate what they found to T cells and other cells of the adaptive immune system. These professional migrators and searchers are a critical component of human immunity, and their migration is targeted or hijacked by multiple pathogens including some pox and herpes viruses, tuberculosis, and anthrax. Since dendritic cells can activate cytotoxic T cells to attack cancer cells, their migration also plays a role in cancer immunotherapy strategies. Many cells, including dendritic cells, migrate by extending lamellipodia. Lamellipodia are thin, planar protrusions that have been extensively studied for cells migrating on 2D surfaces, such as glass coverslips. Dendritic cells use lamellipodia to find a path through crowded 3D environments and to enter lym- phatic vessels. Lamellipodia and the actin network that composes them have been studied for decades. How- ever, most molecularly detailed models of lamellipodia regulation and function were derived from studying cells on 2D surfaces, so we still do not know how cells initiate and extend lamellipodia in 3D environments. In this project, we will investigate how actin nucleators organize to generate sheet-like lamellipodial morphologies in the absence of a surface to guide their generation, as well as how actin nucleators organize to direct the exten- sion of lamellipodia within crowded 3D environments. As a model of dendritic cell migration through peripheral tissues, we will study migration though 3D fibrous collagen matrices. Widely available microscopic techniques, such as confocal microscopy, cannot image cells in 3D collagen with the spatial and temporal resolution required to measure the organization of actin nucleators in lamellipodia. However, recently developed techniques, such as light-sheet microscopy, are just beginning to be able to do so. Since light-sheet microscopes can produce massive datasets, interpreting and even simply visualizing such large amounts of data requires sophisticated computing workflows. We will develop the needed computational workflows as we investigate lamellipodia form and function in 3D environments.