Antigenic characterization of the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor incorporated into nanodiscs.
Antigenic characterization of the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor incorporated into nanodiscs.
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DOI：
10.1371/journal.pone.0170672
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Sodroski J
中科院分区：
文献类型：
--
作者：
Witt KC;Castillo-Menendez L;Ding H;Espy N;Zhang S;Kappes JC;Sodroski J
人类免疫缺陷病毒（HIV-1）进入宿主细胞是由病毒包膜糖蛋白（Envs）介导的，它是由三聚体gp160 Env前体的蛋白水解裂解产生的。成熟的Env三聚体是进入抑制剂和疫苗诱导的中和抗体的主要靶点。环境毒株间变异、构象灵活性和重糖基化有助于逃避宿主免疫反应，并为结构表征和疫苗开发带来挑战。在这里，我们研究了与HIV-1 Env前体重构成纳米圆盘相关的变量，纳米圆盘是由膜支架蛋白包裹的纳米级脂质双层圆盘。我们确定了清洁剂，以及与病毒脂质组成分相似的脂质，它们可以有效地形成环境纳米盘（环境纳米盘）。Env- nds是由全长Env前体和大部分细胞质尾完整的Env前体形成的。戊二醛交联降低了Env-NDs的自结合力。Env- nds显示出HIV-1 Env前体的抗原谱。Env-NDs被广泛中和的抗体识别。值得注意的是，与细胞表面表达的Env相比，gp41膜近端外区域和gp120:gp41界面的中和抗体表位在Env- nds上的暴露程度较高。非中和抗体识别的大多数Env表位被Env- nds掩盖。这种抗原谱在几天内是稳定的，表现出比溶解在洗涤剂中的Env更长的半衰期。阴性选择与弱中和抗体可用于改善Env-NDs的抗原谱。最后，我们发现脂质佐剂可以被纳入Env-NDs。这些结果表明，Env- nds为在膜环境下研究HIV-1 Env三聚体的结构、功能和抗原特性提供了一个潜在的有用平台。
The entry of human immunodeficiency virus (HIV-1) into host cells is mediated by the viral envelope glycoproteins (Envs), which are derived by the proteolytic cleavage of a trimeric gp160 Env precursor. The mature Env trimer is a major target for entry inhibitors and vaccine-induced neutralizing antibodies. Env interstrain variability, conformational flexibility and heavy glycosylation contribute to evasion of the host immune response, and create challenges for structural characterization and vaccine development. Here we investigate variables associated with reconstitution of the HIV-1 Env precursor into nanodiscs, nanoscale lipid bilayer discs enclosed by membrane scaffolding proteins. We identified detergents, as well as lipids similar in composition to the viral lipidome, that allowed efficient formation of Env-nanodiscs (Env-NDs). Env-NDs were created with the full-length Env precursor and with an Env precursor with the majority of the cytoplasmic tail intact. The self-association of Env-NDs was decreased by glutaraldehyde crosslinking. The Env-NDs exhibited an antigenic profile expected for the HIV-1 Env precursor. Env-NDs were recognized by broadly neutralizing antibodies. Of note, neutralizing antibody epitopes in the gp41 membrane-proximal external region and in the gp120:gp41 interface were well exposed on Env-NDs compared with Env expressed on cell surfaces. Most Env epitopes recognized by non-neutralizing antibodies were masked on the Env-NDs. This antigenic profile was stable for several days, exhibiting a considerably longer half-life than that of Env solubilized in detergents. Negative selection with weak neutralizing antibodies could be used to improve the antigenic profile of the Env-NDs. Finally, we show that lipid adjuvants can be incorporated into Env-NDs. These results indicate that Env-NDs represent a potentially useful platform for investigating the structural, functional and antigenic properties of the HIV-1 Env trimer in a membrane context.