CMV pentameric complex based vaccine strategies for prevention of congenital CMV

摘要 由于先天性心脏病的风险，开发巨细胞病毒(CMV)疫苗是一项重要的公共卫生优先事项 感染。人巨细胞病毒临床株(HCMV)不同于实验室适应株，因为临床株表达 五聚体复合体(PC)和保持感染上皮细胞和内皮细胞的能力不同于实验室菌株 仅限于成纤维细胞。病毒进入表观/内皮细胞的机制不同于GB 进入成纤维细胞的途径，因为它需要病毒蛋白Gh/G1/UL128-131形成内吞 使病毒进入细胞的复合体(PC)。重要的是，经胎盘CMV感染高度依赖于 病毒上皮/内皮细胞嗜性，因为病毒必须感染血管内皮细胞(母体和 胎儿)以及构成胎盘一部分的一层上皮滋养细胞。中和抗体 对PC的作用可能比免疫主导的gB糖蛋白抗体更重要，因为抗- 与GB相比，PC抗体在中和表观/内皮细胞上的病毒方面更有效。重要的是，在 恢复期患者高滴度的抗PC抗体被认为是预防先天性CMV的有效方法。人类 由于物种特异性，CMV不能直接在动物模型中研究。豚鼠是唯一的 小动物模型，允许研究先天性巨细胞病毒，但需要使用特定物种的豚鼠 巨细胞病毒(GPCMV)。在先天性巨细胞病毒的豚鼠模型中，我们定义了一个同源的五聚体复合体 对于上皮性、病毒传播和先天性感染GPCMV是必要的。此外， GPCMV同源PC具有高度的免疫原性，可产生中和病毒感染的抗体 上皮细胞。这项临床前转译研究旨在开发GPCMV PC特异性疫苗策略 (基于亚单位或有缺陷的腺病毒载体)以确定PC或PC亚复合体疫苗策略 可预防豚鼠模型先天性巨细胞病毒感染。重要的是，作为这些研究的一部分，我们将评估 PC疫苗对不同GPCMV株先天性CMV的交叉保护能力。此外， 将评估GB和PC疫苗策略的协同效应。最后，由于在HCMV中，GB和GH 诱导CD4T细胞反应后，将评估T细胞反应的保护性影响。

Abstract Development of a cytomegalovirus (CMV) vaccine is a major public health priority due to the risk of congenital infection. Clinical strains of human CMV (HCMV) differ from lab adapted virus as the clinical strains express a pentameric complex (PC) and retain the ability to infect epithelial and endothelial cells unlike lab strains which are limited to fibroblast cells. The mechanism of virus entry into epi/endothelial cells is different from the gB pathway of entry into fibroblast cells as it requires viral proteins gH/gL/UL128-131 forming an endocytic complex (PC) to enable viral cell entry. Importantly, transplacental CMV infection is highly dependent upon viral epithelial/endothelial tropism since the virus has to infect endothelial cells of blood vessels (maternal and fetal) as well as a layer of epithelial trophoplast cells that constitute part of the placenta. Neutralizing antibodies to the PC are potentially more important than antibodies to the immunodominant gB glycoprotein, since anti- PC antibodies are more effective in neutralizing virus on epi/endothelial cells compared to gB. Importantly, in convalescent patients high anti-PC titers are thought to be effective in preventing congenital CMV. Human CMV cannot be directly studied in an animal model because of species specificity. The guinea pig is the only small animal model that allows the study of congenital CMV but requires the use of species specific guinea pig CMV (GPCMV). In the guinea pig model for congenital CMV, we have defined a homolog pentameric complex as necessary for epithelial tropism, virus dissemination and congenital infection by GPCMV. Furthermore, the GPCMV homolog PC is highly immunogenic and generates antibodies that neutralize virus infection on epithelial cells. This pre-clinical translational study seeks to develop GPCMV PC specific vaccine strategies (either subunit or defective adenovirus vector based) to determine if a PC or PC subcomplex vaccine strategy can prevent congenital CMV in the guinea pig model. Importantly, as part of these studies we will evaluate the ability of PC vaccines to cross protect against congenital CMV from different GPCMV strains. Additionally, the synergy effect of gB and PC vaccine strategies will be evaluated. Finally, since in HCMV both gB and gH induce a CD4 T cell response, the protective impact of the T cell response will be evaluated.