MOLECULAR ANALYSIS OF POLIOVIRUS NEUTRALIZING EPITOPES

这项研究的目的是为了促进一个更 脊髓灰质炎病毒中和位点的详细分子描述 以及病毒引起的免疫反应。 的组合 遗传学和免疫学方法被提出来测试 预测来自结构分析的中和 A）扩展了结构描述， 先前鉴定的脊髓灰质炎病毒血清型1的中和位点， B）鉴定潜在的新中和位点，和C） 衣壳蛋白中的功能特征区域 这对病毒的存活至关重要 为了实现这些目标， 建议进行几项研究： 1)病毒突变体将使用位点特异性 诱变方法 分子生物学和抗原 将研究这些突变体的特性。 2)衣壳蛋白中的区域似乎是 超变的或突变约束的将被识别为 对六种天然存在的脊髓灰质炎病毒血清1型毒株进行测序。 这些菌株在13个月的时间内通过以下方法连续分离： 疾病控制中心从发生在 阿米什人中爆发麻痹性脊髓灰质炎流行病 社区 本研究将指出氨基酸谱 替换和病毒内存活的区域 突变可能发生。 3)将研究VP4衣壳蛋白的免疫原性。 虽然其他三种衣壳蛋白的免疫原性 已经被广泛研究，对VP4的抗体应答是 可能在脊髓灰质炎病毒中起重要作用 发病机制 这里提出的研究提供了一个独特的机会， 我们的理解超越了氨基酸的识别 形成一个中和决定因素， 关于：抗体如何与中和位点相互作用， 病毒表面的不同区域有什么功能作用 （包括中和位点）用于病毒的生物学， 病毒是如何突变成为中和抗性的， 产生抗原变体，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。 此外该 这项建议的健康相关性来自其对以下方面的贡献： 了解病毒对宿主保护的分子基础 疫苗和这些知识的潜在应用 合理设计病毒疫苗（例如HTLV和HIV毒株， 和甲型肝炎）和改进现有的病毒疫苗 (such作为脊髓灰质炎病毒）。

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).