Biophysical Signatures in HIV-1 Env Correlating with Mother-to-Child Transmission

HIV-1 包膜的生物物理特征与母婴传播相关

• 批准号: 8730847
• 负责人: Kelly Keisen Lee
• 金额: $ 21.63万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8730847
• 关键词: Address; Antigens; Biological; Biological Assay; Breast Feeding; CCR5 gene; CD209 gene; CD4 Positive T Lymphocytes; Cells; Collaborations; Complement; Complex; Crystallization; Crystallography; Deuterium; Differential Scanning Calorimetry; Environment; Exhibits; Fingerprint; Glycoproteins; HIV; HIV Envelope Protein gp120; HIV Infections; HIV-1; Heating; Hydrogen; Immune response; Infant; Infection; Lactic acid; Link; Mass Spectrum Analysis; Measurement; Mediating; Membrane Glycoproteins; Methods; Mothers; Mutation; Play; Population; Property; Proteins; Recombinants; Reporting; Resistance; Resolution; Site; Structure; Techniques; Testing; Tropism; Ursidae Family; Vaccine Design; Vaccines; Variant; Vertical Disease Transmission; Viral; Virion; Virus; Virus Inactivation; biophysical techniques; design; env Glycoproteins; experience; glycoprotein structure; glycosylation; insight; macrophage; monomer; novel; public health relevance; receptor; receptor binding; resilience; structural biology; trait; transmission process

DESCRIPTION: One of the hallmarks of HIV is its extreme mutability, which leads to broad diversification of the viral quasispecies following infection. During mucosal transmission, the virus experiences the opposite phenomenon as well, undergoing a stringent narrowing of genotypic diversity, such that the majority of new infections are established by a single transmitted, "founder" (T/F) variant from the quasispecies. The physical determinants of transmission remain poorly defined. While many studies have traced T/F signature traits to Env, the surface glycoprotein that mediates infection, most have examined the biological consequences of underlying differences without being able to address what specifically differentiates one Env from another because classical methods are poorly suited to analyze structural variation of glycoproteins. The requirements for crystallography make it necessary to truncate and deglycosylate the glycoprotein, removing the very features such as variable loops and glycosylation that make each variant distinct and that can modulate structure within core, conserved regions. We propose to apply novel biophysical and structural approaches to compare the structure of Env glycoproteins from T/F variants of HIV with Env from donor variants using transmission pairs identified in a well-characterized mother-to-child-transmission (MTCT) study. We have developed the use of hydrogen/deuterium-exchange mass spectrometry (HDX-MS) to probe intact glycoprotein structure under native conditions. This approach provides the sensitivity and resolution necessary to identify variant-specific differences, producing a fingerprint of local structural order and stability throughout the glycoprotein. In AIM 1, we will apply HDX-MS to analyze Env from matched transmission pairs identified in a Nairobi Breastfeeding MTCT study. The transmission pairs provide a powerful means to pinpoint sequence differences that may be linked with structural and phenotypic differences relevant to transmission of T/F variants. We hypothesize that structural properties in T/F Env may exist including greater stability that confer a selective advantage to T/F variants. We anticipate that greater Env stability may result in complexes that are resistant to inactivation In AIM 2, using infectivity assays, we will test whether T/F variants exhibit enhanced resistance to heat inactivation and inactivation by low pH and lactic acid, factors that may be present at sites of transmission such as the infant gastrointenstinal tract. The combination of structural biology and virological expertise in the Lee and Overbaugh labs applied to examine the matched transmission pairs can provide significant new insights into the physical determinants of virus transmissibility and provide structural details relevant to vaccine immunogen design.

产品说明：艾滋病毒的一个特点是它的极端变异性，这导致感染后病毒准种的广泛多样性。在粘膜传播期间，病毒也经历相反的现象，经历基因型多样性的严格缩小，使得大多数新感染由来自准种的单一传播的“创始者”（T/F）变体建立。传播的物理决定因素仍然定义不清。虽然许多研究已经将T/F特征追踪到介导感染的表面糖蛋白Env，但大多数研究都检查了潜在差异的生物学后果，而无法解决具体区分一种Env与另一种Env的原因，因为经典方法不适合分析糖蛋白的结构变异。晶体学的要求使得有必要截短和去糖基化糖蛋白，去除使每个变体不同并且可以调节核心保守区域内的结构的非常特征，例如可变环和糖基化。我们建议应用新的生物物理和结构的方法来比较的结构Env糖蛋白从T/F变异体的HIV与Env从供体变异体使用传输对确定在一个良好的特点母婴传播（MTCT）的研究。我们已经开发了使用氢/氘交换质谱（HDX-MS）在天然条件下探测完整的糖蛋白结构。这种方法提供了必要的灵敏度和分辨率，以确定变异特异性差异，产生指纹的局部结构顺序和稳定性的整个糖蛋白。在AIM 1中，我们将应用HDX-MS分析来自内罗毕母乳喂养MTCT研究中确定的匹配传播对的Env。传递对提供了一种强有力的手段来查明可能与T/F变体的传递相关的结构和表型差异相关的序列差异。我们假设T/F Env中可能存在结构特性，包括赋予T/F变体选择性优势的更大稳定性。我们预计，更大的Env稳定性可能会导致复合物对灭活具有抗性。在AIM 2中，使用感染性测定，我们将测试T/F变体是否对热灭活和低pH和乳酸灭活表现出增强的抗性，这些因素可能存在于传播部位，如婴儿胃肠道。Lee和Overbaugh实验室的结构生物学和病毒学专业知识相结合，用于检查匹配的传播对，可以为病毒传播性的物理决定因素提供重要的新见解，并提供与疫苗免疫原设计相关的结构细节。