CYTOKINE MILIEU AND IMMUNE RESPONSE TO RSV

呼吸道合胞病毒（RSV）疫苗的开发， 得到了高度重视。启动临床试验的主要障碍 对新候选疫苗的试验是对 由福尔马林灭活的RSV疫苗引起的疫苗增强型疾病。 我们 研究小组已经描述了RSV的BALB/c小鼠模型，其中 可以研究RSV疫苗免疫增强的免疫学机制。 我们已经证明，用灭活的RSV抗原致敏小鼠， RSV攻击后的Th 2样细胞因子mRNA表达模式（显性 IL-4表达），以及通过鼻或胃肠外途径 途径诱导RSV后Th 1样细胞因子mRNA表达模式 激发（显性IFN-γ表达）。 这一发现使我们 提出假设，Th 2细胞亚群的选择性激活是 负责RSV疫苗对疾病的免疫增强。主题 该建议是为了解决细胞因子环境对细胞因子的影响。 两只小鼠中对RSV免疫和攻击的免疫应答模式 还有人类具体目标是：（1）确定当地的影响力 和全身细胞因子环境对RSV免疫应答的影响， 在小鼠中激发; 2）确定是否抗原特异性或机制 抗原提呈是选择性激活的主要因素， RSV感染小鼠T细胞亚群及细胞因子表达的变化 3）通过评价细胞因子来检验小鼠模型的有效性 RSV感染儿童的表达模式。目标1和2将是 通过使用特定基因的“敲除”转基因小鼠， 细胞因子和α-表达单个RSV的重组牛痘载体 蛋白质和特异性鼠细胞因子。人类研究需要 RSV治疗的临床试验基础设施的优势，以及 正在进行的减毒活RSV疫苗试验，以获得血清，PBMC， 鼻和气管分泌物用于细胞因子分析。分析检测 人体研究的方法将包括直接细胞因子的EIA 测量和定量RNA PCR用于细胞因子信息。验证 小鼠作为评估对RSV的免疫应答模式的模型将 加速候选RSV疫苗的临床前开发。定义如何 细胞因子环境影响对RSV疫苗接种的免疫应答， 挑战将影响RSV疫苗设计和交付的策略。

Development of a vaccine for respiratory syncytial virus (RSV) has received a high priority. The major impediment to initiating clinical trials with new candidate vaccines is an incomplete understanding of the vaccine-enhanced illness caused by formalin-inactivated RSV vaccines. Our group has described a BALB/c mouse model of RSV in which details of the immunologic mechanisms of RSV vaccine-immunopotentiation can be studied. We have shown that priming mice with inactivated RSV antigen induces a Th2-like cytokine mRNA expression pattern after RSV challenge (dominant IL-4 expression), and that live RSV priming by the nasal or parenteral route induces a Th1-like cytokine mRNA expression pattern after RSV challenge (dominant IFN-gamma expression). This finding has led us to propose the hypothesis that selective activation of the Th2 cell subset is responsible for RSV vaccine immunopotentiation of disease. The theme of this proposal is to address the impact of the cytokine milieu on the pattern of immune response to RSV immunization and challenge in both mice and humans. The specific aims are to: l) define the influence of the local and systemic cytokine environment on the response to RSV immunization and challenge in mice; 2) determine whether antigen specificity or mechanism of antigen presentation is the major factor in the selective activation of T cell subsets and pattern of cytokine expression in RSV-infected mice; and 3) test the validity of the mouse model by evaluating cytokine expression patterns in RSV-infected children. Aims l and 2 will be approached by using transgenic mice with "knock-outs" in specific cytokines, and recombinant vaccinia vectors that cc-express individual RSV proteins and specific murine cytokines. The human studies will take advantage of a clinical trial infrastructure for RSV therapeutics, and ongoing vaccine trials of live attenuated RSV to obtain serum, PBMC, nasal, and tracheal secretions for cytokine analysis. The assay detection methods for the human studies will include EIA for direct cytokine measurement, and quantitative RNA PCR for cytokine message. Validating the mouse as a model for evaluating patterns of immune response to RSV will accelerate preclinical development of candidate RSV vaccines. Defining how the cytokine milieu influences the immune response to RSV vaccination and challenge will impact strategies for RSV vaccine design and delivery.