Department of Microbiology, College of Medicine, Howard University, Washington, DC 20059, USA.
Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, USA.
Viruses. 2021 Oct 6;13(10):2004. doi: 10.3390/v13102004.
The HIV-1 Tat protein interacts with TAR RNA and recruits CDK9/cyclin T1 and other host factors to induce HIV-1 transcription. Thus, Tat-TAR RNA interaction, which is unique for HIV-1, represents an attractive target for anti-HIV-1 therapeutics. To target Tat-TAR RNA interaction, we used a crystal structure of acetylpromazine bound to the bulge of TAR RNA, to dock compounds from the Enamine database containing over two million individual compounds. The docking procedure identified 173 compounds that were further analyzed for the inhibition of HIV-1 infection. The top ten inhibitory compounds with IC ≤ 6 µM were selected and the three least toxic compounds, T6780107 (IC = 2.97 μM), T0516-4834 (IC = 0.2 μM) and T5628834 (IC = 3.46 μM), were further tested for HIV-1 transcription inhibition. Only the T0516-4834 compound showed selective inhibition of Tat-induced HIV-1 transcription, whereas the T6780107 compound inhibited equally basal and Tat-induced transcription and the T5628834 compound only inhibited basal HIV-1 transcription. The compounds were tested for the inhibition of translation and showed minimal (<25%) effect. The T0516-4834 compound also showed the strongest inhibition of HIV-1 RNA expression and p24 production in CEM T cells and peripheral blood mononuclear cells infected with HIV-1 IIIB. Of the three compounds, only the T0516-4834 compound significantly disrupted Tat-TAR RNA interaction. Additionally, of the three tested compounds, T5628834 and, to a lesser extent, T0516-4834 disrupted Tat-CDK9/cyclin T1 interaction. None of the three compounds showed significant inhibition of the cellular CDK9 and cyclin T1 levels. In silico modelling showed that the T0516-4834 compound interacted with TAR RNA by binding to the bulge formed by U23, U25, C39, G26,C39 and U40 residues. Taken together, our study identified a novel benzoxazole compound that disrupted Tat-TAR RNA interaction and inhibited Tat-induced transcription and HIV-1 infection, suggesting that this compound might serve as a new lead for anti-HIV-1 therapeutics.
HIV-1 Tat 蛋白与 TAR RNA 相互作用，并招募 CDK9/周期蛋白 T1 和其他宿主因子诱导 HIV-1 转录。因此，Tat-TAR RNA 相互作用是 HIV-1 所特有的，代表了抗 HIV-1 治疗的一个有吸引力的靶点。为了靶向 Tat-TAR RNA 相互作用，我们使用了乙酰丙嗪与 TAR RNA 突环结合的晶体结构，对接了包含超过两百万个单体化合物的 Enamine 数据库中的化合物。对接程序鉴定了 173 种化合物，进一步分析了它们对 HIV-1 感染的抑制作用。选择了前 10 种抑制性化合物（IC≤6μM），并进一步测试了三种毒性最低的化合物 T6780107（IC=2.97μM）、T0516-4834（IC=0.2μM）和 T5628834（IC=3.46μM）对 HIV-1 转录的抑制作用。只有 T0516-4834 化合物对 Tat 诱导的 HIV-1 转录具有选择性抑制作用，而 T6780107 化合物对基础和 Tat 诱导的转录均具有抑制作用，T5628834 化合物仅抑制基础 HIV-1 转录。这些化合物还被测试了对翻译的抑制作用，显示出最小的（<25%）效果。T0516-4834 化合物还显示出对感染 HIV-1 IIIB 的 CEM T 细胞和外周血单核细胞中 HIV-1 RNA 表达和 p24 产生的最强抑制作用。在这三种化合物中，只有 T0516-4834 化合物显著破坏了 Tat-TAR RNA 相互作用。此外，在这三种测试的化合物中，T5628834 化合物和 T0516-4834 化合物在较小程度上破坏了 Tat-CDK9/周期蛋白 T1 相互作用。这三种化合物均未显著抑制细胞 CDK9 和周期蛋白 T1 水平。计算机模拟显示，T0516-4834 化合物通过与 U23、U25、C39、G26、C39 和 U40 残基形成的突环结合，与 TAR RNA 相互作用。综上所述，我们的研究鉴定了一种新型苯并恶唑化合物，该化合物破坏了 Tat-TAR RNA 相互作用，并抑制了 Tat 诱导的转录和 HIV-1 感染，表明该化合物可能成为抗 HIV-1 治疗的新先导化合物。
