MOLECULAR ANALYSIS OF POLIOVIRUS NEUTRALIZING EPITOPES

拟议研究的目的是为更多的 脊髓灰质炎病毒中和部位的详细分子描述 以及病毒引发的免疫反应。一种组合 建议采用遗传学和免疫学方法来测试 从中和的结构分析得出的预测 站点，从而A)扩展了对 先前已确定的1型脊髓灰质炎病毒中和部位， B)确定潜在的新中和部位，以及c) 衣壳蛋白中具有功能特征的区域 对病毒的生存至关重要。为了实现这些目标， 建议进行几项研究： 1)病毒突变体将使用特定的位点构建 诱变方法。分子生物学与抗原性 这些突变体的特性将被研究。 2)衣壳蛋白内的区域 超可变或突变约束将由 对6株自然发生的脊髓灰质炎病毒1型毒株进行测序。 这些菌株是在13个月的时间里通过 美国疾病控制中心根据 阿米什地区一起麻风性脊髓灰质炎疫情暴发 社区。这项研究将显示氨基酸的光谱 替换和病毒内可存活的区域 突变是可能发生的。 3)研究VP4衣壳蛋白的免疫原性。 尽管其他三种衣壳蛋白的免疫原性 已经被广泛研究过，对VP4的抗体反应是 未定性，可能在脊髓灰质炎病毒中发挥重要作用 发病机制。 这里提出的研究提供了一个独特的机会来扩展 我们的理解超越了对氨基酸的识别 这形成了一个中和的决定因素，并解决了 关注：抗体如何与中和位点相互作用， 病毒表面的不同区域起什么功能作用 (包括中和部位)为病毒的生物学服务， 病毒如何变异成为耐中和和 产生抗原性变异，新的血清型是如何形成的。 这些问题对于彻底理解 病毒致病的分子机制。此外， 这项提议与健康有关的原因是它对 对病毒保护宿主的分子基础的认识 疫苗和这一知识在疫苗中的潜在应用 合理设计病毒疫苗(如HTLV和HIV毒株， 和甲型肝炎)和改进现有的病毒疫苗 (如脊髓灰质炎病毒)。

The aim of the proposed research is to contribute to a more detailed molecular description of the poliovirus neutralizing sites and the immune response induced by the virus. A combination of genetic and immunological approaches are proposed to test predictions derived from a structural analysis of the neutralizing sites, thereby A) extending the structural description of the previously identified neutralizing sites for poliovirus serotype 1, B) identifying potentially new neutralizing sites, and C) functionally characterizing regions in the capsid proteins that are critical for the viability of the virus. To achieve these goals, several studies are proposed: 1) Viral mutants will be constructed using site-specific mutagenesis methods. The molecular biology and antigenic characteristics of these mutants will be studied. 2) Regions within the capsid proteins that appear to be hypermutable or mutationally constrained will be identified by sequencing six naturally-occuring poliovirus serotype 1 strains. These strains were sequentially isolated over a 13 month period by the Centers for Disease Control from cases that occurred during an epidemic outbreak of paralytic poliomyelitis within the Amish community. This study will indicate the spectrum of amino acid substitutions and the regions within the virus that viable mutations can occur. 3) The immunogenicity of the VP4 capsid protein will be studied. Although the immunogenicity of the other three capsid proteins have been extensively studied, the antibody response to VP4 is uncharacterized and may play important roles in poliovirus pathogenesis. The studies proposed here provide an unique opportunity to extend our understanding beyond the identification of the amino acids that form a neutralizing determinant and to address issues concerning: how antibodies interact with the neutralizing sites, what functional roles do different regions on the virus surface (including the neutralizing sites) serve for the biology of the virus, how viruses mutate to become neutralization resistant and generate antigenic variants, how are new serotypes formed. These issues are important for a thorough understanding of the molecular mechanisms of viral pathogenesis. In addition, the health relatedness of this proposal derives from its contribution to the understanding the molecular basis of host protection by viral vaccines and the potential application of this knowledge to the rational design of vaccines for viruses (e.g. HTLV and HIV strains, and hepatitis A) and for the improvement of existing viral vaccine (such as poliovirus).