Attenuation of CMV Vector Pathogenicity and Transmission by Altering Viral Tropis

该项目的总体目标是开发一种基于恒河猴巨细胞病毒的减毒疫苗，用于预防 猴免疫缺陷病毒(RhCMV/SIV)，不能在与 巨细胞病毒的传播和疾病。我们已经证明，RhCMV/SIV活疫苗是一种有效的疫苗，可以诱导 SIV对恒河猴的保护性免疫。为了将我们的发现转化为人类巨细胞病毒 (HCMV)/艾滋病毒疫苗，对包括免疫受损个人在内的所有潜在性行为者都是安全的， CMV疫苗载体需要在不失去诱导保护性免疫的能力的情况下进行减毒。巨细胞病毒 可以在宿主的多种细胞和FIss中复制，包括：腺组织中的上皮细胞 (唾液腺和乳房)、肺、肾以及肝脏的肝细胞和中央的神经元。 神经系统(CNS)。髓系细胞和内皮细胞也被认为是CMV在 主持人。项目2的总体目标是调节CMV在这些关键细胞类型中的复制能力 以在不影响疫苗效力的情况下增加安全性。我们假设，消除所有 上皮细胞亲和性基因将降低致病性，并消除病毒进入唾液和尿液的现象。 因此，在本项目的第一个具体目标中，我们将删除RhCMV上皮细胞趋化基因，以进一步 消除病毒在这种细胞类型中复制的能力。作为一种额外的方法来衰减 ，我们将使用一种新的方法来灭活与CMV相关的组织中的病毒。 通过使用基于microRNA的策略特异性地灭活本质CMV来疾病和传播 中枢神经系统、肝脏和髓系细胞中病毒复制过程中的基因。这些RhCMV/SIV嗜性缺陷病毒 将分析SIV在恒河猴体内的免疫原性和特异性2.在最后 我们将把这些发现转化为人类巨细胞病毒/艾滋病毒载体，并将在一种新的 建立人性化小鼠模型。这些研究将导致设计一种人巨细胞病毒/艾滋病毒疫苗 将为临床研究做好准备。 相关性(请参阅说明)： 尽管研究人员一直专注于开发有效的艾滋病毒疫苗，但自 自20世纪80年代初艾滋病流行以来，一种有效的艾滋病毒疫苗一直难以找到。我们有 研究表明，含有SIV抗原的巨细胞病毒(CMV)活载体可以有效地诱导保护性免疫 恒河猴的免疫力。为了设计一种既保持疗效又足够安全的CMV载体 在人类中的普遍使用，我们建议确定是否通过基因修改CMV来限制其能力 在与疾病和传播相关的细胞类型中复制，同时保留其在细胞中持续存在的能力 对于增强免疫力很重要，这将导致安全有效的艾滋病毒/艾滋病疫苗载体。

The overall goal ofthis project is to develop an attenuated rhesus cytomegalovirus-based vaccine against simian immunodeficiency virus (RhCMV/SIV) that is unable to replicate in cells and tissues associated with CMV transmission and disease. We have shown that live RhCMV/SIV is an effecfive vaccine that induces SIV protective immunity in rhesus macaques. In order to translate our findings into a human CMV (HCMV)/HIV vaccine that would be safe for all potenfial pafients including immunocompromised individuals, the CMV vaccine vector needs to be attenuated without losing the ability to induce protective immunity. CMV can replicate in a wide variety of cells and fissues in the host, including: epithelial cells in glandular tissue (salivary glands and breast), lung, kidney, as well as hepatocytes in the liver and neurons in the central nervous system (CNS). Myeloid and endothelial cells are also considered persistent sites for CMV in the host. The overall goal of Project 2 is to modulate the ability of CMV to replicate in these crifical cell types in order to increase safety without compromising vaccine efficacy. We hypothesize that eliminafion of all the epithelial cell tropic genes will reduce pathogenicity and eliminate viral shedding into saliva and urine. Therefore, in the first specific aim of this project, we will delete RhCMV epithelial cell tropism genes to further abrogate the ability of the virus to replicate in this cell type. As an additional method to attenuate the RhCMV/SIV vaccine, we will use a novel approach to inactivate virus in tissues associated with CMV disease and disseminafion by using a microRNA-based strategy to specifically inacfivate essenfial CMV genes during viral replication in CNS, liver, and myeloid cells. These RhCMV/SIV tropism deficient viruses will be analyzed for SIV immunogenicity and attenuafion in rhesus macaques in Specific Aim 2. In the last specific aim, we will translate these findings into a human CMV/HIV vector that will be tested in a newly established humanized mouse model. These studies will result in the design of an HCMV/HIV vaccine that will be ready for clinical studies. RELEVANCE (See instructions): Although investigators have been focused on the development of an effective vaccine for HIV since the emergence ofthe AIDS epidemic in the early 1980s, an effecfive HIV vaccine has been elusive. We have shown that a live cytomegalovirus (CMV) vector containing SIV antigens can effectively induce protecfive immunity in rhesus macaques. In order to design a CMV vector which retains efficacy, but is safe enough for general use in humans, we propose to determine whether genetically modifying CMV to limit its ability to replicate in cell types associated with disease and transmission, while retaining its ability to persist in cells important for elicifing immunity, will lead to a safe and effective vector for an HIV/AIDS vaccine.