The role of UBE2V1 in HIV-1 restriction in primary monocytes

描述（由申请人提供）：单核细胞是树突状细胞和巨噬细胞的前体，这些细胞类型在HIV-1感染和发病机制中起着重要的多方面作用。未分化的原代单核细胞对HIV-1入境后感染具有抵抗力，这可能是由于潜在限制因子的表达。该领域的一个挑战是确定宿主因子并了解其限制原代单核细胞的机制。在我们的初步研究中，我们发现了一种名为UBE2V1（泛素结合酶E2变体1）的细胞蛋白，它可以抑制单核细胞中的HIV-1感染。本R21提案的目的是探索UBE2V1在原代单核细胞中阻断HIV-1感染的功能和机制。我们提出验证翻译后修饰的UBE2V1抑制原代单核细胞中HIV-1复制的假设。我们提出的研究的预期结果是定义一种新的机制，通过UBE2V1的翻译后修饰来调节单核细胞谱系细胞中的HIV-1感染。UBE2V1（也称为UEV1、UEV1A或CROC-1）属于泛素结合酶变异蛋白亚家族，是DNA损伤和细胞分化的调节蛋白。最近的一项研究表明逆转录病毒限制性因子TRIM5通过与泛素偶联酶复合物UBC13-UBE2V1相互作用，作为逆转录病毒衣壳晶格的先天免疫传感器。这一发现表明，UBE2V1是先天免疫反应的一个新组成部分。有趣的是，我们的初步研究表明，UBE2V1的翻译后修饰与原代单核细胞中HIV-1的限制有关。我们提出在两个特定的目的中探索UBE2V1在原代单核细胞中限制HIV-1的作用和机制。目的1。描述ube2v1介导的原代单核细胞中HIV-1早期生命周期的限制。目标2。确定原代单核细胞中负责HIV-1限制性修饰的UBE2V1的关键结构域和残基。我们所提出的研究将为研究参与HIV-1复制的宿主因子的翻译后修饰开辟一个新的领域。我们将通过表征UBE2V1在HIV-1感染中的功能来确定单核细胞谱系细胞中HIV-1限制的分子机制。完成提出的目标有可能推进艾滋病毒宿主相互作用的基本知识。最终，从提出的研究中学到的知识将能够设计新的方法来阻止HIV-1在靶细胞中的复制。

DESCRIPTION (provided by applicant): Monocytes are precursors of dendritic cells and macrophages, and these cell types play an important and multifaceted role in HIV-1 infection and pathogenesis. Undifferentiated primary monocytes are resistant to HIV-1 postentry infection, which is likely due to the expression of a potential restriction factor. A challenge in he field is to identify the host factor and understand its mechanisms underlying HIV-1 restriction of primary monocytes. In our preliminary study, we identified a cellular protein named UBE2V1 (ubiquitin-conjugating enzyme E2 variant 1) that can inhibit HIV-1 infection in monocytic cells. The goal of this R21 proposal is to explore the function and mechanisms of UBE2V1 in blocking HIV-1 infection in primary monocytes. We propose to test the hypothesis that post-translationally modified UBE2V1 inhibits HIV-1 replication in primary monocytes. The expected outcome of our proposed studies is to define a novel mechanism by which post-translational modifications of UBE2V1 regulate HIV-1 infection in monocyte-lineage cells. UBE2V1 (also called UEV1, UEV1A or CROC-1) belongs to the subfamily of ubiquitin-conjugating enzyme variant proteins and acts as a regulatory protein in DNA damage and cell differentiation. A recent study indicated that the retroviral restriction factor TRIM5 functions as an innate immune sensor for the retrovirus capsid lattice by interacting with the ubiquitin-conjugating enzyme complex UBC13-UBE2V1. This finding suggests that UBE2V1 is a novel component of the innate immune response. Interestingly, our preliminary studies indicate that post-translational modification of UBE2V1 is associated with HIV-1 restriction in primary monocytes. We propose to explore the role and mechanisms of UBE2V1 in HIV-1 restriction in primary monocytes in two specific aims. Aim 1. Characterize UBE2V1-mediated restriction of the HIV-1 early lifecycle in primary monocytes. Aim 2. Define the critical domains and residues of the modified UBE2V1 responsible for HIV-1 restriction in primary monocytes. The significant impact of our proposed studies will be to open a new area in the study of post- translational modifications of host factor involved in HIV-1 replication. We will define the molecular mechanism of HIV-1 restriction in monocyte-lineage cells by characterizing the function of UBE2V1 in HIV-1 infection. Accomplishing the proposed aims has the potential to advance basic knowledge of HIV-host interactions. Ultimately, the knowledge learned from the proposed studies will enable design of novel approaches to block HIV-1 replication in target cells.