Specificity determinants of the cargo content sorted into cell-derived microvesicles

多细胞生物的正常功能是一个复杂的过程，需要整合自主的细胞活动，包括与组织和器官的局部和远程特异性细胞间信号相互作用。这种无缝功能的核心是细胞外囊泡（ev），特别是外泌体。外泌体是由几乎所有细胞类型分泌的小的膜结合颗粒，大小从30到150纳米不等。每个外泌体含有一组特定的核酸、蛋白质和脂质。外泌体可以与其他细胞相互作用和/或将其内容转移到目标受体细胞，以精确的方式在功能上改变它们。从一种细胞类型分泌的外泌体在远距离“重编程”其他细胞的能力已在组织培养中得到证实。然而，导致细胞产生包含相当独特和特定生物信息的外泌体的机制仍然未知。本研究的主要目的是研究外泌体生成的细胞生物学，重点研究如何将特定的细胞分子分类以装载到外泌体中。我们最近的研究表明，感染（丙型肝炎病毒）和细胞应激（酒精）可以诱导细胞释放与正常条件相比具有完全不同分子组成的外泌体。因此，该研究项目将评估感染和细胞应激条件如何调节细胞释放外泌体中蛋白质、核酸和脂质含量的定性或定量变化。利用体外病毒感染和细胞应激实验模型的结合，我们将进一步破译和描述新发现的特定细胞基因和分子如何决定细胞分子的选择和/或排除在外泌体内装载和释放。回答这些问题将推进新兴的、快速发展的外泌体细胞生物学领域，并扩大我们对细胞基因库和细胞在不同情况下产生特定外泌体的信号机制的理解。除了提供新知识外，本研究的许多方面将为各级学生和学员提供极好的实践机会，因此可以作为发展基础生物学或病毒学事业的关键起点或进步步骤。

The normal functioning of multicellular organisms is a complex process, requiring the integration of autonomous cellular activities involving both local and long-range specific intercellular signaling interactions with tissues and organs. Central to this seamless functioning are extracellular vesicles (EVs), specifically, exosomes. Exosomes are small, membrane-bound particles secreted from almost all cell types ranging in size from 30 to 150 nm. Each exosome contains a specific set of nucleic acids, proteins, and lipids. Exosomes can interact with other cells and/or transfer their content to target recipient cells, functionally altering them in precise ways. The ability of exosomes secreted from one cell type to "reprogram" other cells at a distance has been demonstrated in tissue culture. However, the mechanisms leading to the cellular generation of a repertoire of exosomes containing quite distinct and specific biological messages remain unknown. The main objective of this research is to investigate the cell biology of exosome generation focusing on how specific cellular molecules are sorted for loading into exosomes. We have recently shown that infection (Hepatitis C Virus) and cellular stress (Alcohol) can induce cells to release exosomes with quite distinct molecular composition compared to normal conditions. This research program will, therefore, evaluate how infection and cellular stress conditions modulate the qualitative or quantitative changes in proteins, nucleic acids, and lipids contents of cell-released exosomes. Using a combination of virus infection and cell stress experimental models in-vitro, we will additionally decipher and delineate how newly identified specific cellular genes and molecules determine the selection and/ or exclusion of cellular molecules for loading and release inside exosomes. Answering these questions will advance the nascent, rapidly growing field of exosomal cell biology, and expand our understanding of the repertoire of cellular genes and signaling mechanisms used by cells to generate specific exosomes under different circumstances. In addition to providing new knowledge, many aspects of this research will present excellent hands-on opportunities for students and trainees at all levels, and thus can serve as a critical starting point or advancement step for developing careers in fundamental biology or virology.