Vaccines for Prevention of Experimental Congenital CMV

描述（由申请方提供）：预防先天性人巨细胞病毒（HCMV）感染的疫苗仍然是主要的公共卫生优先事项。在先天性感染的动物模型中进行的疫苗研究提供了关于哪种类型的疫苗策略可能对保护胎儿有用的见解。在小动物的巨细胞病毒中，豚鼠巨细胞病毒（GPCMV）模型是唯一有用的，因为这种病毒能够穿过胎盘并感染幼鼠，导致感染和疾病。在最初的授权期，我们已经证明了亚单位疫苗在该模型中的有用性，使用基于糖蛋白B（gB）和UL 83（GP 83）的GPCMV同源物的不同表达策略。在这种竞争的延续，我们建议测试的假设，疫苗介导的保护可以增强，使用几种表达策略。首先，我们建议研究策略，以提高DNA疫苗的保护效力，相比基因枪的方法，包括阳离子脂质体，和一个“启动-加强”的策略，使用DNA疫苗和纯化的gB蛋白。其次，我们将检验以下假设：其他病毒糖蛋白，特别是gM/gN复合物，将是针对先天性GPCMV感染的有效疫苗，并且当该疫苗与gB疫苗联合给药时会产生额外的保护。最后，我们将详细评估2种细胞介导的免疫靶点，UL 83（GP 83）和ie 1同源物在先天性感染模型中的作用。体内试验将评估CD 4+和CD 8+细胞对这些病毒蛋白的反应，CFSE研究将跟踪妊娠动物中的T细胞运输。连续转移研究将检查免疫T细胞在近交系动物中保护母体-胎盘-胎儿单位免受GPCMV感染的作用。将开发豚鼠细胞因子、干扰素γ和IL-12的ELISPOT测定法。我们预计，在这种小动物模型中的这些亚单位疫苗研究将阐明哪些策略可能对先天性HCMV感染的疫苗接种有价值。

DESCRIPTION (provided by applicant): Vaccines for the prevention of congenital human cytomegalovirus (HCMV) infection continue to be a major public health priority. Vaccine studies in animal models of congenital infection provide insights into which types of vaccine strategies are likely to be useful in protecting the fetus. Among the cytomegaloviruses of small animals, the guinea pig cytomegalovirus (GPCMV) model is uniquely useful, because of the ability of this virus to cross the placenta and infect the pup, leading to infection and disease. In the initial grant period, we have demonstrated the usefulness of subunit vaccines in this model, using different expression strategies based on the GPCMV homologs of glycoprotein B (gB) and UL83 (GP83). In this competing continuation, we propose to test the hypotheses that vaccine-mediated protection can be augmented, using several expression strategies. First, we propose to examine strategies for improving the protective efficacy of DNA vaccination, compared to the gene gun approach, including cationic liposomes, and a "prime-boost" strategy using DNA vaccine and purified gB protein. Secondly, we will test the hypothesis that other viral glycoproteins, specifically the gM/gN complex, will be effective vaccines against congenital GPCMV infection, and that additional protection occurs when this vaccine is administered in combination with a gB vaccine. Finally, we will perform detailed assessments of the role of 2 cell-mediated immune targets, the UL83 (GP83) and the ie1 homologs, in the congenital infection model. In vivo assays will evaluate CD4+ and CD8+ cellular responses to these viral proteins, and CFSE studies will track T-cell trafficking in pregnant animals. Adoptive transfer studies will examine the role of immune T cells, in inbred animals, in protecting the maternal-placental-fetal unit from GPCMV infection. ELISPOT assays will be developed for the guinea pig cytokines, interferon gamma and IL-12. We anticipate that these subunit vaccine studies in this small animal model will clarify which strategies may be of value for vaccination against congenital HCMV infection.