Cellular Requirements for KSHV Latency in Endothelial Cells

摘要： KS是最早定义疾病的艾滋病之一，世界范围内仍然是最 艾滋病患者常见的肿瘤。KS的主要肿瘤细胞是梭形细胞，这种细胞 表达淋巴管内皮细胞的标志物。晚期肿瘤中所有梭形细胞均维持 卡波西肉瘤疱疹病毒感染。卡波西肉瘤疱疹病毒(KSHV)是一种伽玛病毒。 疱疹病毒，是卡波西肉瘤(KS)的病原体。95%以上的梭形细胞 KS肿瘤仅表达潜伏基因，仅有极低比例的肿瘤表达额外裂解 蛋白质。目前对KS的治疗包括对肿瘤的全面化疗，但不包括 直接瞄准病毒。所有直接治疗疱疹病毒的靶向溶血成分 复制。潜伏的疱疹病毒感染没有治疗方法。由于基因有限 潜伏期的表达很难确定消除潜伏期的病毒治疗靶点 感染。然而，KSHV在潜伏感染期间会显著改变宿主细胞。因此，它 可能有可能在潜伏感染期间针对宿主细胞的病理变化 清除潜伏感染的细胞。我们已经进行了全基因组Crispr/Cas9筛查 TERT永生化内皮细胞以确定基因、细胞基因和信号通路 是潜伏感染的内皮细胞增殖或生存所必需的，但不是它们的 未受感染的同龄人。我们的初步研究已经确定了大量的细胞基因 潜伏感染的细胞增殖和存活所需的似乎对 未感染的内皮细胞。我们建议在原代血管内皮细胞中进一步验证这些研究 细胞。我们还将检查屏幕中确定的特定路径，包括 Rho家族鸟嘌呤交换因子和GTP酶激活蛋白及其相互作用 信号通路。该提案的目标是识别新的细胞目标，这些目标可能是 用于清除潜伏感染KSHV的细胞。

Abstract: KS was one of the first AIDS defining illnesses and world-wide continues to be the most common tumor of AIDS patients. The main tumor cell of KS is the spindle cell, a cell that expresses markers of lymphatic endothelium. All spindle cells in late stage tumors maintain Kaposi's Sarcoma-herpesvirus infection. Kaposi's Sarcoma-herpesvirus (KSHV) is a gamma- herpesvirus and is the etiologic agent of Kaposi's Sarcoma (KS). Over 95% of spindle cells in the KS tumor express only latent genes while only a very low percentage express additional lytic proteins. Current treatments for KS involve general chemotherapy for the tumor but do not directly target the virus. All direct treatment for herpesviruses target elements of lytic replication. There are no treatments for latent herpesvirus infection. Due to the limited gene expression during latency it is difficult to identify viral therapeutic targets for eliminating latent infection. However, KSHV dramatically alters the host cell during latent infection. Therefore, it might be possible to target pathological changes to the host cell during latent infection to eliminate latently infected cells. We have performed a whole genome Crispr/Cas9 screen in tert-immortalized endothelial cells to identify genes cellular genes and signaling pathways that are required for the proliferation or survival of latently infected endothelial cells but not their uninfected counterparts. Our initial studies have identified a large number of cellular genes required for latently infected cells to proliferate and survive that appear to have little effect on uninfected endothelial cells. We propose to further validate these studies in primary endothelial cells. We will also examine specific pathways that were identified in the screen including the Rho family Guanine exchange factors (GEFs) and GTPase activating proteins (GAPs) and their signaling pathways. The goals of the proposal are to identify novel cellular targets that could be used to eliminate cells latently infected with KSHV.