PICORNAVIRAL 3A PROTEINS AND HOST PROTEIN SECRETION

描述：(改编自《调查者摘要》)：蛋白质分泌 在脊髓灰质炎病毒(PV)感染的早期，宿主细胞的器官被抑制。 初步证据支持脊髓灰质炎病毒3A蛋白的假设 特异性地抑制内质网(ER)之间的蛋白质运输 和高尔基，防止来自急诊室的顺行流量。当单元格 感染了表达3A蛋白的突变PV，该蛋白不抑制 蛋白质分泌，干扰素-b、白介素6和白介素8水平升高 MHC I类分子介导的CD8+CTL抗原递呈增加。因此， 3A的一个重要功能是限制细胞抗病毒反应，从而 影响病毒致病机制的。在该方案中描述了实验，该实验 将研究3A破坏内质网到高尔基体的分子机制 堵车。其他微小核糖核酸病毒3A和2B等位基因的能力调查 将进行家系和血清型测试，以测试 对宿主蛋白分泌的抑制及其致病潜力 病毒。具有不同程度抑制宿主蛋白能力的PV变异体 分泌物将通过一种新的遗传筛选进行选择。这些变种将是 作为候选小核糖核酸病毒的特征和重建为病毒复制体 疫苗。表达PV受体的转基因小鼠将感染 包装复制子抑制或不抑制宿主蛋白分泌和 CD8+CTL反应将使用特定的MHC四聚体进行量化。它是 预计这种方法将允许调节抗原 通过基于微小核糖核酸病毒的载体呈现细胞免疫反应， 这可能是疫苗设计中的关键。

DESCRIPTION: (Adapted from the Investigator's abstract): The protein secretory apparatus of host cells is inhibited early in poliovirus (PV) infection. Preliminary evidence supports the hypothesis that poliovirus 3A protein specifically inhibits protein traffic between the endoplasmic reticulum (ER) and Golgi by preventing anterograde traffic from the ER. When cells are infected with mutant PV that expresses a 3A protein which does not inhibit protein secretion, increased levels of IFN-b, IL-6 and IL-8 are secreted and MHC class I-mediated presentation of antigens to CD8+ CTL is increased. Thus, an important function of 3A is to limit cellular antiviral responses, thereby affecting viral pathogenesis. In this proposal experiments are described which will investigate the molecular mechanism by which 3A disrupts ER-to-Golgi traffic. A survey of the ability of 3A and 2B alleles from other picornaviral families and serotypes will be performed to test the relationship between the inhibition of host protein secretion and the pathogenic potential of these viruses. PV variants with various degrees of ability to inhibit host protein secretion will be selected by a novel genetic screen. These variants will be characterized and reconstructed into viral replicons as candidate picornaviral vaccines. Transgenic mice that express the PV receptor will be infected with packaged replicons that do or do not inhibit host protein secretion and the CD8+ CTL response will be quantified using specific MHC tetramers. It is anticipated that this method will allow the regulation of the antigen presentation to the cellular immune response by picornaviral-based vectors, which could be crucial in vaccine design.