Elucidating Non-Virus Encoded HIV Capture through Artificial Virus Nanoparticles

描述（由申请人提供）：最近的研究表明GM3（一种含有末端¿-2,3连接唾液酸残基的神经节苷脂）可以介导人类免疫缺陷病毒1 （HIV-1）和树突状细胞（dc）之间的糖蛋白独立相互作用，因此可以诱导树突状细胞捕获病毒的包膜糖蛋白独立。这一重要捕获机制的许多方面仍然未知，由于缺乏适当的工具来表征病毒膜中GM3的浓度和空间分布，以及具有明确定义的表面组成的适当病毒模型系统，对其系统研究受到挑战。本研究旨在通过开发新的贵金属纳米颗粒为基础的工具来研究非病毒编码的表面功能在HIV-1发病机制中的作用，从而克服这些挑战。我们将利用贵金属纳米颗粒独特的电磁特性来量化GM3的表面密度及其在外周血单个核细胞（PBMCs）衍生病毒上的空间分布（目前尚不清楚）。HIV-1颗粒中GM3含量的定量信息将构成人工病毒纳米颗粒（avn）实施的基础，avn含有包裹在磷脂双层膜中的金核，其脂质组成模仿天然病毒的脂质组成。作为人造的、可工程的纳米颗粒，avngm3的表面是可以调谐的

DESCRIPTION (provided by applicant): Recent studies have indicated that GM3 (a ganglioside that contains a terminal ¿-2,3 linked sialic acid residue) can mediate glycoprotein independent interactions between human immunodeficiency virus 1 (HIV-1) and dendritic cells (DCs) and can, thus, induce an envelope glycoprotein-independent capture of the virus by DCs. Many aspects of this important capture mechanism remain unknown and its systematic investigation is challenged by a lack of appropriate tools to characterize the concentration and spatial distribution of GM3 in the virus membrane and of appropriate virus model systems with clearly defined surface composition. This proposal seeks to overcome these challenges by developing new noble metal nanoparticle-based tools for investigating the role of non-virus encoded surface functionalities in the pathogenesis of HIV-1. We will take advantage of the unique electromagnetic properties of noble metal nanoparticles to quantify the - as yet unknown - surface density of GM3 and its spatial distribution on viruses derived from peripheral blood mononuclear cells (PBMCs). Quantitative information about the GM3 content in HIV-1 particles will form the basis for the implementation of artificial virus nanoparticles (AVNs) that contain a gold core wrapped in a phospholipid bilayer membrane whose lipid composition mimics that of the native virus. As artificial, engineerable nanoparticles, it is possible to tune AVN GM3 surface concentration in a systematic fashion without the risk of including any other host or virus encoded surface functionalities. The AVNs introduced herein combine the advantageous material properties of metal NPs with the programmable functionality of biological membranes, are conveniently generated in large quantities, provide large optical cross-sections in fluorescent and darkfield optical microscopy, and can be localized with high resolution in both electron and optical microscopy. AVNs are, thus, ideal tools to determine the contribution of GM3 in the capture of HIV-1 particles on DCs and will enable us to probe the probe the intricate mechanisms underlying the GM3- dependent HIV-1 invasion of DCs. The specific aims of this application are: Aim1: To define the role of GM3 in interactions of primary HIV-1 isolates with DCs using nanoparticle enabled assays Aim2: To develop artificial virus nanoparticles (AVNs) that mimic GM3-mediated HIV-1 capture Aim3: To elucidate the molecular mechanisms underlying GM3-CD169 mediated binding and uptake of HIV-1 particles within DCs using AVNs.