HIV-1 CA Inhibitors Are Antagonized by Inositol Phosphate Stabilization of the Viral Capsid in Cells.
HIV-1 CA Inhibitors Are Antagonized by Inositol Phosphate Stabilization of the Viral Capsid in Cells.
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DOI：
10.1128/jvi.01445-21
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发表时间：
2021-11-23
影响因子：
5.4
通讯作者：
Aiken C
中科院分区：
文献类型：
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作者：
Sowd GA;Shi J;Aiken C
HIV-1衣壳由CA蛋白组成，是新型抗逆转录病毒药物来那帕韦(LCV)的靶标。CA抑制剂分别阻断宿主因子结合和改变衣壳稳定性以防止核进入和逆转录(RTN)。衣壳的稳定性在体外是通过与宿主细胞代谢物六磷酸肌醇(IP6)结合而介导的。靶细胞中IP6的缺失对HIV-1感染的影响很小。我们推测，改变衣壳浓度的CA抑制剂可能揭示了IP6缺失对靶细胞中HIV-1感染的影响。为了验证这一点，我们研究了IP6耗尽对CA抑制剂PF74和LCV抑制感染的影响。在影响HIV-1核进入的低剂量化合物中，没有观察到IP6耗尽对抗病毒活性的影响。在IP6耗竭的细胞中，观察到在影响衣壳稳定性的抑制剂浓度下，抗病毒活性增加，这与RTN抑制增加相关。体外纯化核心的脱涂层和内源性RTN检测提供了额外的支持。我们的结果表明，肌醇磷酸盐稳定了靶细胞中的HIV-1衣壳，从而抑制了衣壳靶向抗病毒化合物的抗病毒效果。我们认为，靶向IP6结合位点与CA抑制剂结合将导致强大的抗逆转录病毒治疗(ART)。HIV-1感染和随后的CD4+T细胞耗尽导致艾滋病。对感染者进行抗逆转录病毒治疗可防止进展为艾滋病。HIV-1衣壳最近已成为抗逆转录病毒治疗的靶子。衣壳类抑制剂通过多个步骤阻止HIV-1感染，提供了比目前的ART更好的优势。细胞代谢产物六磷酸肌醇(IP6)与HIV-1衣壳结合，在体外稳定它。然而，这种相互作用在靶细胞中的作用尚不清楚。我们的结果表明，IP6稳定了进入细胞的HIV-1衣壳，从而限制了破坏衣壳稳定的抗病毒药物的抗病毒效率。我们提出了衣壳蛋白抑制物功能的模型，并提出靶向IP6结合位点与目前正在开发的衣壳蛋白抑制剂将导致更强大的ART。
The HIV-1 capsid, composed of the CA protein, is the target of the novel antiretroviral drug lenacapavir (LCV). CA inhibitors block host factor binding and alter capsid stability to prevent nuclear entry and reverse transcription (RTN), respectively. Capsid stability is mediated in vitro by binding to the host cell metabolite inositol hexakisphosphate (IP6). IP6 depletion in target cells has little effect on HIV-1 infection. We hypothesized that capsid-altering concentrations of CA inhibitors might reveal an effect of IP6 depletion on HIV-1 infection in target cells. To test this, we studied the effects of IP6 depletion on inhibition of infection by the CA inhibitors PF74 and LCV. At low doses of either compound that affect HIV-1 nuclear entry, no effect of IP6 depletion on antiviral activity was observed. Increased antiviral activity was observed in IP6-depleted cells at inhibitor concentrations that affect capsid stability, correlating with increased RTN inhibition. Assays of uncoating and endogenous RTN of purified cores in vitro provided additional support. Our results show that inositol phosphates stabilize the HIV-1 capsid in target cells, thereby dampening the antiviral effects of capsid-targeting antiviral compounds. We propose that targeting of the IP6-binding site in conjunction with CA inhibitors will lead to robust antiretroviral therapy (ART). IMPORTANCE HIV-1 infection and subsequent depletion of CD4+ T cells result in AIDS. Antiretroviral therapy treatment of infected individuals prevents progression to AIDS. The HIV-1 capsid has recently become an ART target. Capsid inhibitors block HIV-1 infection at multiple steps, offering advantages over current ART. The cellular metabolite inositol hexakisphosphate (IP6) binds the HIV-1 capsid, stabilizing it in vitro. However, the function of this interaction in target cells is unclear. Our results imply that IP6 stabilizes the incoming HIV-1 capsid in cells, thus limiting the antiviral efficiency of capsid-destabilizing antivirals. We present a model of capsid inhibitor function and propose that targeting of the IP6-binding site in conjunction with capsid inhibitors currently in development will lead to more robust ART.