Molecular and functional correlates of HIV-1 transmission in MTCT

描述（由申请人提供）：培训计划我的职业目标是通过将免疫学与细胞生物学相结合，进一步了解人类健康和疾病，作为顶级研究机构的独立研究员。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。该提案旨在研究HIV-1母婴传播（MTCT）过程中病毒进入的分子和生物学机制。实现这一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演变的理解，而且还将帮助我实现我的职业目标。研究HIV传播的潜在机制将增强我对假设驱动，以患者为导向的研究的理解，并在麻省大学医学院分子医学项目中工作将使我能够与整个马萨诸塞州的杰出科学家建立牢固而持久的关系。 研究计划在HIV的粘膜传播过程中，与源患者中的准种或受感染个体中随时间演变的准种相比，传播菌株的多样性明显受到限制。目前还不清楚这种瓶颈效应是否是随机的（随机）或由于主动选择介导的宿主因素和/或病毒的特性。我将使用MTCT模型评估HIV病毒进入过程中主动选择与随机选择的相对贡献，其中传播对和婴儿感染的时间很容易确定。我将使用来自两个特征良好、独特的HIV-1感染妇女队列的连续样本，这些妇女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HIV-1感染（CI）的妇女和产后获得原发性HIV-1感染（急性感染，AI）的妇女。我将结合联合收割机系统发育序列分析（将单基因组扩增与高通量深度测序相结合）和功能测定（CD 4和辅助受体使用、细胞嗜性和病毒进入表型）来评估创始病毒与母体病毒变异体的关系。通过比较CI和AI队列中的母体病毒变体与创始病毒，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，并确定创始HIV env变体是否比非传播变体更适合MTCT。确定传播的Env变异体的共同生物学特性并绘制这些特性的遗传基础将提高我们对HIV-1进入的理解，并有可能确定Env介导的病毒进入的关键组分。这些研究的结果将揭示靶向特定Env功能特性（向性、感染性）是否有望阻断妇女和儿童的原发性HIV感染，有助于指导预防妇女和婴儿原发性HIV-1感染的新策略的开发。

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.