Development of a DNA Vaccine against RSV

本项目的目标是开发和研究一种抗呼吸道合胞病毒（RSV）的DNA疫苗。呼吸道合胞病毒感染几乎所有两岁以下的儿童，而且没有可用的疫苗。本项目旨在设计一种含有RSV F基因免疫重要区域和修饰霍乱毒素基因的重组DNA载体。预期DNA免疫原在肌肉注射时可诱导局部和全身免疫反应。由于DNA质粒诱导Th1细胞应答，这种方法特别适用于RSV，其中Th1免疫应答在诱导保护性免疫中非常关键。该项目吸引人的方面包括DNA质粒的设计和开发的简单性，以及诱导细胞、体液和粘膜免疫反应的潜力。将使用DNA载体（来自基因治疗系统的phCMV1）构建DNA质粒，将RSV F的区域和修饰的霍乱毒素基因克隆到该载体中。phCMV1 DNA载体包含一个CMV启动子、内含子a和一个强终止子。DNA将被纯化并在小鼠体内传递

The Proposed project goal is to develop and study a DNA vaccine against Respiratory Syncytial Virus (RSV). RSV infects almost all children under two years of age and there is no vaccine available. This project aims to engineer a recombinant DNA vector containing immunologically important regions of the RSV F gene and modified cholera toxin gene. It is expected that the DNA immunogen will induce local and systemic immune response when administered intramuscularly. Since DNA plasmids induce a Th1 cell response, this approach is particularly well suited against RSV where Th1 immune response is very critical in inducing protective immunity. Attractive aspects of the project include the simplicity of the design and development of the DNA plasmid, potential to induce cellular, humoral and the mucosal immune responses. The DNA plasmid will be constructed using a DNA vector (phCMV1 from Gene Therapy Systems) into which regions of RSV F and modified cholera toxin genes will be cloned. The phCMV1 DNA vector contains a CMV promoter, intron A and a strong terminator. DNA will be purified and delivered in mice intramuscularly. Additionally, to test the establishment of Th1 cell response, mice will be immunized with combination of DNA vaccine and recombinant RSV F protein. The humoral and cellular immune responses resulting from immunizations will be analyzed. The ability of the immunogen to protect mice from RSV infection will be evaluated by challenging mice with live RSV. The upper and lower respiratory tract infections will be assessed by studying virus load in upper mucosa and the lungs. This study will lead to an understanding of the DNA vaccination and mucosal immune response and contribute to design and development of a safer and more effective vaccine against RSV and other viruses infecting the mucosa.