CHEETAH Center for the Structural Biology of HIV Infection, Restriction, and Viral Dynamics

CHEETAH HIV 感染、限制和病毒动力学结构生物学中心

• 批准号: 10508318
• 负责人: Owen Pornillos
• 金额: $ 118.52万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-11 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10508318
• 关键词: AIDS/HIV problem; APOCEC3G gene; Affect; Antiviral Agents; Antiviral Response; Binding; Biological Assay; Biology of HIV Infection; Capsid; Cell-Free System; Cells; Cryoelectron Microscopy; Detection; Dissociation; Excision; Genetic; Goals; HIV; HIV-1; Human; Immune; Immunologic Factors; In Vitro; Infection; Innate Immune Response; Integration Host Factors; Interferons; Interruption; Learning; Life Cycle Stages; Lipid Bilayers; Lipids; Mediating; Membrane Fusion; Modeling; Molecular Conformation; Myeloid Cells; Pathway interactions; Process; Proteins; Reaction; Recombinants; Regulation; Reverse Transcription; Role; Running; Serine; Signal Transduction; Structure; System; TRIM Gene; TRIM5 gene; Testing; Therapeutic; Transcript; Ubiquitination; Viral; Virion; Virus; Virus Replication; antiretroviral therapy; base; cofactor; design; experimental study; inhibitor; innate immune sensing; insight; novel; phospholipid scramblase; pressure; reconstitution; response; sensor; structural biology; transmission process; viral rebound; viral transmission

PROJECT SUMMARY Although untreated HIV/AIDS infections are fatal, humans nevertheless have an array of powerful innate antiviral responses that help suppress replication and exert strong selective pressures on the virus during transmission and during viral rebound following ART interruption. These observations suggest that innate immune responses could be of therapeutic value if we can understand them better and discover ways to strengthen them. To infect a cell, HIV-1 must run a gauntlet of such innate immune sensors and restrictions. Studies in Project 2, Cellular Defenses Against HIV, will reconstitute and characterize the mechanisms of cellular innate immune sensing and restriction of HIV-1 that occur during the first half of the viral life cycle. Studies in Aim 1 (SERINC Structure, Mechanism, and Antiviral Activity) will build on our recent cryoEM structure of hSERINC3, and our discoveries that restricting SERINCs are nonspecific phospholipid scramblases and that loss of phosphatidyl serine (PS) asymmetry elicits antiviral effects. We hypothesize that SERINCs inhibit HIV-1 entry by altering the natural asymmetry of the virion lipid bilayer. We propose to determine how SERINCs flip lipids, and to test whether SERINCs exert their antiviral activities by altering PS distribution and disrupting Env conformations. Studies in Aim 2 (HIV-1 Recognition and Innate Signaling) will leverage our ability to reconstitute cGAS innate immune sensing of replicating HIV cores in vitro and our discovery that HIV-1 capsid inhibitors can promote innate signaling in infected myeloid cells. We now propose to determine: 1) how viral core structure and stability affect cGAS-mediated detection of reverse transcription, 2) how capsid-binding factors such as PQBP1 contribute to cGAS sensing in myeloid cells, 3) whether and how CA inhibitors can promote cGAS detection of HIV-1, 4) how cell-specific factors regulate cGAS activity, and 5) how the resulting downstream responses restrict HIV-1 infection. Studies in Aim 3 (TRIM Restrictions) will follow from our observation that TRIM5 proteins form hexagonal cages around incoming HIV-1 capsids. Experiments in this Aim are designed to fill fundamental gaps in our understanding of the viral inhibition and signaling processes that follow this initial TRIM5 recognition step, and to discover how host cofactors facilitate or modulate TRIM5 restriction. Studies in Aim 4 (Reconstitution of Other Restrictions) will build on our ability to reconstitute SAMHD1 and APOBEC3G restriction of replicating HIV-1 cores in vitro, and we now propose to reconstitute MxB restriction. These reconstituted reactions will be used to fill gaps in our understanding of restriction mechanisms, cofactors, and regulation, and to examine how capsid inhibitors can enhance MxB activity.

项目摘要 尽管未经治疗的艾滋病毒/艾滋病感染是致命的，但人类仍然有一系列强大的先天抗病毒反应 这有助于抑制复制并在传播过程中和病毒反弹期间对病毒施加强大的选择压力 在艺术中​​断之后。这些观察结果表明，如果我们 可以更好地理解它们，并发现加强它们的方法。要感染细胞，HIV-1必须运行这种先天的手套 免疫传感器和限制。在项目2的研究中，针对艾滋病毒的细胞防御措施将重新构建和表征 病毒生命周期上半年发生的HIV-1的细胞先天免疫传感和限制的机制。 AIM 1（序列结构，机制和抗病毒活性）中的研究将基于我们最近的冷冻结构 HSERINC3，我们发现限制连续体是非特异性磷脂串联酶的发现，损失 磷脂酰丝氨酸（PS）不对称会引起抗病毒作用。我们假设Serincs通过更改抑制HIV-1进入 Virion脂质双层的自然不对称。我们建议确定序列式翻转脂质的方式，并测试是否 Serincs通过改变PS分布和破坏ENV构象来发挥其抗病毒活性。 AIM 2（HIV-1识别和先天信号传导）中的研究将利用我们重建CGA先天免疫的能力 在体外感知复制的HIV核心，我们发现HIV-1 CAPSID抑制剂可以促进先天信号传导 感染的髓样细胞。我们现在建议确定：1）病毒核心结构和稳定性如何影响CGAS介导 检测逆转录，2）capsid结合因子（例如PQBP1）如何促进髓样的CGAS感应 细胞，3）CA抑制剂是否以及如何促进HIV-1的CGA检测，4）细胞特异性因素如何调节CGA 活动和5）产生的下游反应如何限制HIV-1感染。 AIM 3中的研究（修剪限制）将从我们观察到TIRM5蛋白形成六角形笼子周围的观察结果。 传入的HIV-1衣壳。此目标的实验旨在填补我们对病毒的理解的基本空白 遵循此初始TRIM5识别步骤的抑制和信号传导过程，并发现宿主辅助因子如何 促进或调节TRIM5限制。 AIM 4的研究（其他限制的重构）将基于我们重建SAMHD1和APOBEC3G的能力 在体外复制HIV-1核的限制，我们现在建议重建MXB限制。这些重组 反应将用于填补我们对限制机制，辅助因子和调节的理解中的空白，并检查 衣壳抑制剂如何增强MXB活性。