THE ROLE OF CYTOMEGALOVIRUS PHOSPHOPROTEIN 65 IN VIRUS REPLICATON IN VIVO

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 巨细胞病毒(CMV)蛋白pp65调节宿主的免疫反应。同时，它也是细胞免疫反应的主要抗病毒靶点。Pp65是恒河猴CMV(RhCMV)和人CMV(HCMV)被膜中含量最丰富的成分，是衣壳和被膜之间的富含蛋白质的一层，释放到细胞质中。有趣的是，pp65对于这两种病毒的体外生长都不是必需的。这使我们能够产生pp65缺陷的RhCMV，以检查是否1)蛋白质的免疫调节功能对病毒在体内的生存至关重要；或2)pp65的免疫原性在功能免疫存在的情况下限制了病毒的复制。用突变的RhCMV感染恒河猴(RMS)，可以检测pp65在体内CMV感染中的重要性。因此，我们将用pp65缺失的重组病毒感染CMV-NAéve RM，并评估该病毒是否能够建立原发和慢性感染，如果是，与之前在感染野生型RhCMV期间所观察到的病毒学和免疫学参数进行比较。根据这项实验的结果，我们将评估pp65缺失的病毒是否能够再次感染这些动物。如果体内有效感染需要pp65编码的功能，我们预计缺失病毒的复制要么无法检测到，要么不如野生型RhCMV那么健壮。相反，如果pp65的免疫原性对宿主免疫反应控制病毒感染的能力至关重要，我们预测pp65缺失的病毒的复制将大于野生型RhCMV。这些实验的结果对CMV疫苗和抗病毒治疗的设计以及CMV作为疫苗载体的发展都有意义。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The cytomegalovirus (CMV) protein pp65 modulates the host immune response. At the same time it is also the primary antiviral target of cellular immune responses. pp65 is the most abundant component of the Rhesus CMV (RhCMV) and human CMV (HCMV) tegument, a protein-rich layer between the capsid and the envelope that is released into the cytoplasm. Interestingly, pp65 is not required for in vitro growth of either virus. This allowed us to generate a pp65-deficient RhCMV to examine whether 1) The protein's immunomodulatory functions are critical for virus survival in vivo; or 2) The demonstrated immunogenicity of pp65 limits virus replication in the presence of functional immunity. Infection of rhesus macaques (RMs) with mutant RhCMV will allow examination of the importance of pp65 for CMV infection in vivo. Therefore we will infect CMV-na¿ve RM with a pp65-deleted recombinant virus and evaluate whether this virus is able to establish primary and chronic infection and, if so, how virological and immunological parameters compare to previous observations made during infection with wild type RhCMV. Depending on the outcome of this experiment, we will then evaluate whether pp65-deleted virus is able to re-infect these animals. If pp65-encoded functions are required for productive in vivo infection, we expect replication of the deletion virus to be either undetectable or less robust than that measured for wild type RhCMV. Conversely, if the pp65 immunogenicity is crucial to the ability of the host immune response to control virus infection we predict that replication of the pp65-deleted virus will be greater than that for wild type RhCMV. The outcome of these experiments has implications both for the design of CMV vaccines and antiviral treatments as well as the development of CMV as a vaccine vector.