Immune Responses to CMV DNA Vaccination

CMV DNA 疫苗接种的免疫反应

• 批准号: 6824224
• 负责人: Thomas G Evans
• 金额: $ 51.01万
• 依托单位: VICAL, INC.
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6824224
• 关键词: MHC class I antigen; T lymphocyte; active immunization; antibody titering; antigen antibody reaction; cell proliferation; clinical research; clinical trial phase I; clinical trial phase II; cytokine; cytomegalovirus; enzyme linked immunosorbent assay; flow cytometry; human subject; immune response; immunity; leukocyte activation /transformation; longitudinal human study; method development; neutralizing antibody; patient oriented research; technology /technique development; vaccine development; vaccine evaluation; vector vaccine; virus antigen; virus diseases

DESCRIPTION (provided by applicant): Vical Incorporated of San Diego, CA is developing a bivalent CMV DNA vaccine for use in prevention of CMV disease and its consequences in transplantation. The vaccine, VCL-CBO 1, contains two plasmids, one encoding the major surface protein gB, and the other encoding the tegument protein pp65, and is formulated in the poloxamer CRL1005 to increase the induction of T cell and B cell responses. Immune responses to natural CMV infection have been used a model for the measurement of CIM" and CD8 T cells, but whether these assays will be applicable as surrogate markers of immunity in CMV vaccine trials has not been fully investigated. The objective of this Hyperaccelerated Award application will be to use the blood samples collected during the Vical Phase 1 and Phase 2 Trials to develop appropriate GLP assays that can be used to monitor vaccine responses in both CMV seropositive and CMV seronegative subjects, and to develop correlates of immunologic response with clinical and virologic outcomes. The specific AIMS will be to: 1) Determine the level of induction of T cell responses induced by VCL-CB01 using a peptide-based ELISPOT technique and intracellular cytokine cytometry (ICC) method, comparing the two methods to each other and to conventional lymphoproliferative assays. We will differentiate between the natural fluctuations in the CMV T-cell response and vaccine induced responses in CMV seropositives by longitudinal measurement of responses to the vaccine-encoded antigen, pp65, and another CMV antigen not included in the vaccine (IE1). 2) Compare and contrast DNA-vaccine induced T cell responses with those resulting from natural infection in seronegative and seropositive subjects through the use of multiparameter flow cytometry, MHC Class I tetramer binding studies and mapping of pp65 epitopes to the level of the 15-mers used in these assays. 3) Examine and develop novel methods for the measurement of neutralizing antibodies to CMV. These studies will be significant to the field in many ways. First, we will establish a relationship between vaccination and responses to natural infection that have been studied in a limited number of systems. We will discover whether the immunodominant responses to vaccination are similar to those induced by natural infection. We will study the immune responses to vaccination in the setting of potent natural immunity, which may be important in the area of therapeutic vaccines. We will determine in part the memory and effector phenotype of the T cells induced by DNA vaccination, and be able to compare these phenotypes to those induced by natural infection by other pathogens or by other vaccination modalities in the future. Lastly, we will further the field of measurement of CMV neutralization, which will be critical in the area of maternal-fetal disease prevention and possible universal vaccination.

描述（由申请人提供）：加利福尼亚州圣地亚哥的 Vical 公司正在开发一种二价 CMV DNA 疫苗，用于预防 CMV 疾病及其移植后果。该疫苗 VCL-CBO 1 含有两种质粒，一种编码主要表面蛋白 gB，另一种编码外皮蛋白 pp65，并配制在泊洛沙姆 CRL1005 中，以增强 T 细胞和 B 细胞反应的诱导。对天然 CMV 感染的免疫反应已被用作测量 CIM 和 CD8 T 细胞的模型，但这些测定是否可用作 CMV 疫苗试验中免疫的替代标记尚未得到充分研究。本次超加速奖申请的目的是使用 Vical 第一阶段和第二阶段试验期间收集的血液样本来开发适当的 GLP 测定，可用于监测两个阶段的疫苗反应 CMV 血清阳性和 CMV 血清阴性受试者，并建立免疫反应与临床和病毒学结果的相关性。 具体目的是： 1) 使用基于肽的 ELISPOT 技术和细胞内细胞因子细胞计数 (ICC) 方法确定 VCL-CB01 诱导的 T 细胞反应的诱导水平，将两种方法相互比较并与传统的淋巴增殖测定进行比较。我们将通过纵向测量对疫苗编码抗原 pp65 和疫苗中未包含的另一种 CMV 抗原 (IE1) 的反应，区分 CMV T 细胞反应的自然波动和疫苗诱导的 CMV 血清阳性反应。 2) 通过使用多参数流式细胞术、MHC I 类四聚体结合研究以及将 pp65 表位映射到这些测定中使用的 15-mers 水平，将 DNA 疫苗诱导的 T 细胞反应与血清阴性和血清阳性受试者中自然感染引起的反应进行比较和对比。 3) 研究并开发测量 CMV 中和抗体的新方法。 这些研究在很多方面对该领域具有重要意义。首先，我们将建立疫苗接种与自然感染反应之间的关系，这一关系已在有限数量的系统中进行了研究。我们将发现疫苗接种的免疫显性反应是否与自然感染引起的免疫反应相似。我们将在有效的自然免疫环境中研究疫苗接种的免疫反应，这在治疗性疫苗领域可能很重要。我们将部分确定 DNA 疫苗接种诱导的 T 细胞的记忆和效应表型，并能够将这些表型与其他病原体自然感染或其他疫苗接种方式诱导的表型进行比较。最后，我们将进一步推进 CMV 中和测量领域，这对于母胎疾病预防和可能的普遍疫苗接种领域至关重要。