Interactions Between HIV and SIV with DC-SIGN & DC-SIGNR

描述：(申请人提供)HIV-1进入细胞需要 病毒包膜蛋白、CD4和辅助受体之间的相互作用。边装订边 是有效感染病毒所必需的，将病毒附着到 细胞表面可以通过与各种分子的相互作用来调节，只有 其中一些已经被很好地描述了。附着在细胞表面上 Se可能是进入途径中的一个限制性步骤。在体外，细胞感染 HIV-1诱导的LINE和PBMC可通过在 病毒接种或通过将病毒离心到细胞表面。感染性疾病 激活的T细胞也可以通过首先将HIV-1与树突状细胞(DC)结合来增强。去除未结合的病毒后，添加激活的T细胞 导致病毒非常有效地传播到这些细胞靶点。 最近，一种被称为DC-SIGN的LI型整合膜蛋白被证明是 介导HIV-1与DC的结合。DC-SIGN包含C型(即 钙依赖的)凝集素结构域，介导这一过程。因为DC 从外周粘膜组织转移到淋巴结，已经被提出 HIV使用DC作为携带者，使病毒能够进入淋巴组织。 更广泛地说，DC-SIGN的发现增加了其他 存在高度特异的病毒附着因素。事实上，我们已经发现 DC-SIGNR与DC-SIGN的氨基酸同源性为77%，也 支持HIV绑定和传播。DC-SIGNR在内皮细胞上的表达 淋巴结、肝脏和胎盘中的细胞，而DC-SIGN在 DC和体内某些类型的巨噬细胞。DC-SIGN和DC-SIGNR的能力 以高亲和力结合病毒，增强淋巴细胞感染，以及它们的 细胞在粘膜表面和胎盘中的表达 发生导致我们假设这些蛋白质促进病毒结合到 细胞，一旦结合，病毒粒子被修饰和/或保护，以及 最终更有效地呈现给启动病毒的关键靶细胞 在宿主中的传播和传播。在这项提案中，我们将继续 四个具体的目标，将探索结构，功能和表达 DC-SIGN和DC-SIGNR的模式。此外，我们将开发出 将使我们能够测试DC-SIGN在性传播病毒中的作用 使用恒河猴模型。我们建议采取高度协作的 利用DOMS和Hoxie实验室的技能和专业知识的方法 作为与其他实验室的合作，所以这些问题可以 通过追求4个具体目标，快速有效地解决问题。

DESCRIPTION:(provided by applicant)The entry of HIV-1 into cells requires interactions between the viral Env protein, CD4 and a coreceptor. While binding to CD4 is required for efficient virus infection, attachment of virus to the cell surface can be mediated by interactions with a variety of molecules, only some of which have been well characterized. Attachment to the cell surface per se can be a limiting step in the entry pathway. In vitro, infection of cell lines and PBMC by HIV-1 can be enhanced by inclusion of polycations in the virus inoculum or by centrifuging virus onto the cell surface. Infection of activated T-cells can also be enhanced by first binding HIV-1 to dendritic cells (DCs). After removing unbound virus, addition of activated T cells results in very efficient transmission of virus to these cellular targets. Recently, a type lI integral membrane protein termed DC-SIGN has been shown to mediate binding of HIV-1 to DCs. DC-SIGN contains a C-type (i.e. calcium-dependent) lectin domain that mediates this process. Because DCs migrate from peripheral mucosal tissues to lymph nodes, it has been proposed that HIV uses DCs as carriers, allowing the virus to access lymphoid tissue. More generally, the discovery of DC-SIGN raises the possibility that other highly specific virus attachment factors exist. Indeed, we have found that DC-SIGNR, which shares 77 percent amino acid identity with DC-SIGN, also supports HIV binding and transmission. DC-SIGNR is expressed on endothelial cells in lymph nodes, liver, and the placenta, while DC-SIGN is expressed on DCs and some types of macrophages in vivo. The ability of DC-SIGN and DC-SIGNR to bind virus with high affinity, to augment lymphocyte infection, and their expression on cells in mucosal surfaces and the placenta where transmission occurs leads us to hypothesize that these proteins facilitate viral binding to cells, and that once bound, virions are modified and/or protected, and ultimately presented more efficiently to key target cells that initiate viral propagation and dissemination in the host. In this proposal, we will pursue four Specific Aims that will explore the structure, function, and expression patterns of DC- SIGN and DC-SIGNR. Furthermore, we will develop reagents that will enable us to test the role of DC-SIGN in sexual transmission of virus using the rhesus macaque model. We propose to take a highly collaborative approach employing the skills and expertise of the Doms and Hoxie labs, as well as collaborations with other laboratories so that these questions can be addressed quickly and efficiently through the pursuit of 4 Specific Aims.