Molecular and functional correlates of HIV-1 transmission in MTCT

描述(申请人提供)：培训项目我的职业目标是通过将免疫学与细胞生物学相结合，在一家顶级研究机构担任独立研究员，以加深对人类健康和疾病的了解。对疾病过程的分子理解对于开发新的治疗和预防方法至关重要。这项建议旨在研究HIV-1母婴传播(MTCT)过程中病毒进入的分子和生物学机制。完成这项建议的目标，不仅将提高我们对HIV传播和慢性感染过程中env进化的理解，也将帮助我实现我的职业目标。研究HIV传播的潜在机制将加深我对假设驱动、以患者为导向的研究的理解，在加州大学马萨诸塞州医学院分子医学项目的工作将使我能够与马萨诸塞州各地的知名科学家建立牢固而持久的关系。 研究计划在艾滋病毒的粘膜传播期间，与源患者中的准种或感染个体中随时间演变的准种相比，传播株的多样性明显受到限制。目前尚不清楚这种瓶颈效应是否是随机的，或者是由于宿主因素和/或病毒特性介导的主动选择。我将使用MTCT模型评估HIV病毒进入期间主动选择与随机选择的相对贡献，在该模型中，婴儿感染的传播对和时间很容易确定。我将使用两个具有良好特征的、独特的HIV-1感染妇女队列的系列样本，她们在出生时或通过母乳喂养传播HIV-1。这些队列包括患有慢性艾滋病毒-1感染(CI)的妇女和在产后获得原发艾滋病毒-1感染(急性感染，AI)的妇女。我将结合系统发育序列分析(结合单基因组扩增和高通量深度测序)和功能分析(CD4和辅助受体的使用、细胞嗜性和病毒进入表型)来评估方正病毒与母体病毒变异的关系。通过比较CI和AI队列中的母源病毒和方正病毒，我将量化随机和主动选择的相对贡献，确定选择压力何时可能作用于HIV-1包膜(Env)蛋白，并确定方正HIV环境变种是否比非传播变种更适合MTCT。识别传播的Env变异体共有的生物学特性并定位这些特性的遗传基础将提高我们对HIV-1进入的理解，并有可能识别Env介导的病毒进入的关键成分。这些研究的结果将揭示靶向特定的环境功能特性(嗜性、传染性)是否有望阻止妇女和儿童的原发艾滋病毒感染，有助于指导开发新的策略来预防妇女和婴儿的原发艾滋病毒感染。

DESCRIPTION (provided by applicant): Training Program My career goal is to further the understanding of human health and disease by integrating immunology with cell biology as an independent investigator at a top research institution. A molecular understanding of disease processes is critical for developing new treatment and prevention methods. This proposal aims to investigate the molecular and biological mechanisms underlying viral entry during mother-to-child transmission (MTCT) of HIV-1. Accomplishing the aims of this proposal will not only improve our understanding of the evolution of env during HIV transmission and chronic infection, but will also help me achieve my career goals. Studying the mechanisms underlying HIV transmission will enhance my understanding of hypothesis-driven, patient-oriented research, and working in the Program in Molecular Medicine at UMass Medical School will allow me to build strong and lasting relationships with prominent scientists throughout Massachusetts. Research Plan During mucosal transmission of HIV, the diversity of transmitted strains is markedly restricted compared to the quasispecies in the source patient or that evolves over time in infected individuals. It remains unclear whether this bottleneck effect is stochastic (random) o due to active selection mediated by host factors and/or viral characteristics. I will evaluate the relative contributions of active vs. stochastic selection during HIV viral entry using a model of MTCT, where transmission pairs and timing of infant infection are readily identified. I will use serial samples from two well-characterized, unique cohorts of HIV-1 infected women who transmitted HIV-1 at birth or through breastfeeding. These cohorts include women with chronic HIV-1 infection (CI) and women who acquired primary HIV-1 infection post-partum (acutely infected, AI). I will combine phylogenetic sequence analyses (combining single genome amplification with high-throughput deep sequencing) and functional assays (CD4 and co-receptor use, cell tropism, and viral entry phenotype) to assess the relationship of founder viruses to maternal viral variants. By comparing maternal viral variants to founder viruses in the CI and AI cohorts, I will quantify the relative contributions of stochastic and active selection, determine when selective pressures may act on the HIV-1 Envelope (Env) protein, and determine whether founder HIV env variants are better adapted for MTCT than non-transmitted variants. Identifying the biologic properties common to transmitted Env variants and mapping the genetic bases of these properties will improve our understanding of HIV-1 entry, and have the potential to identify critical components of Env-mediated entry for viral entry. These results of these studies will reveal whether targeting specific Env functional properties (tropism, infectivity) hold promise for blocking primary HIV infection of women and children, helping to guide the development of novel strategies to prevent primary HIV-1 infection of women and infants.