Modulation of Host Cell Exosome Content and Function by EBV LMP1

 描述(申请人提供)：外切体是癌细胞高水平释放的小囊泡，是肿瘤环境的重要修饰物，有助于疾病的进展。外切体包含有关其起源细胞的分子信息，可以从包括血液、尿液和唾液在内的许多生物液中分离出来。最近发现，来自乳腺癌细胞或乳腺癌患者血液的外切体可以导致非癌细胞形成肿瘤。这些发现表明，外切体在癌症发展或疾病进展中起着关键作用，并为基于外切体的诊断和治疗创造了新的机会。根据我们的研究和其他研究的数据，致癌病毒利用和修改宿主细胞外切体途径也变得越来越明显，这些变化可能导致疾病。例如，被人类肿瘤病毒EB病毒(EBV)感染的细胞释放富含病毒产物的外体，如主要病毒癌基因潜伏膜蛋白1(LMP1)和病毒编码的miRNAs。我们之前已经证明，LMP1改变了从感染细胞释放的外切体的数量，并且这些LMP1修饰的外切体可以对邻近的未感染细胞发挥致癌信号功能。尽管LMP1修饰的外切体的细胞间传递很重要，但人们对这种病毒蛋白如何真正进入和操纵宿主外切体途径知之甚少。这些研究的总体目标是确定LMP1驱动外切体内容重组和改变外切体功能的机制。我们假设LMP1胞外转运通过改变胞内途径和膜微区来调节胞外小体的组成和生物学特性。为了测试这一点，我们的目标是：1)研究LMP1改变外切体成分的机制；确定LMP1修饰的外切体在细胞内通讯和细胞转化中的功能。

 DESCRIPTION (provided by applicant): Exosomes are small vesicles released at high levels from cancer cells that are important modifiers of the tumor environment and contribute to disease progression. Exosomes contain molecular information about their cells of origin and can be isolated from many biological fluids including blood, urine, and saliva. It has recently been discovered that exosomes from breast cancer cells or the blood of patients with the disease can cause non- cancerous cells to form tumors. These findings suggest a critical role of exosomes in cancer development or disease progression, and create new opportunities for exosome-based diagnostics and therapies. Based on data from our studies and others, it is also becoming clear that cancer causing viruses utilize and modify the host cell exosome pathway, and these changes may contribute to disease. For example, cells infected with the Epstein-Barr virus (EBV), a human tumor virus, release exosomes that are enriched in viral products like the major viral oncogene latent membrane protein 1 (LMP1) and virally-encoded miRNAs. We have previously shown that LMP1 alters the cargo of exosomes released from infected cells and that these LMP1-modifed exosomes can exert oncogenic signaling functions on neighboring uninfected cells. In spite of the importance of inter-cellular transmission of LMP1-modifeid exosomes, very little is known about how this viral protein actually enters and manipulates the host exosome pathway. The overall goal of these studies is to determine the mechanisms that LMP1 drives exosome content reorganization and alters the functions of exosomes. We hypothesize that LMP1 exosomal trafficking modulates the components and biological properties of exosomes by altering endocytic routes and membrane microdomains. To test this, we aim to: 1.) investigate the mechanism through which LMP1 alters exosome components; 2.) determine the functions of LMP1-modified exosomes in intracellular communication and cellular transformation.