Witvrouw Myriam, Pannecouque Christophe, Fikkert Valery, Hantson Anke, Van Remoortel Barbara, Hezareh Marjan, De Clercq Erik, Brown Stephen J
Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium.
Antivir Chem Chemother. 2003 Nov;14(6):321-8. doi: 10.1177/095632020301400604.
Prostratin, a non-tumour promoting phorbol ester, exhibit a potent anti-HIV activity against human immunodeficiency virus type 1 (HIV-1). However, the antiviral mechanism of prostratin is not well defined. In the present study, we report that prostratin exhibits potent antiviral activity against different strains of HIV-1 (subtypes B and D), a clinical HIV isolate (L1), HIV-2 (ROD and EHO) and SIV (MAC251) with EC50-values ranging from 0.02-0.09 microg/ml. Prostratin was equally active against HIV strains resistant to the polyanionic binding inhibitor dextran sulphate, the fusion inhibitor T-20 (enfuvirtide), nucleoside reverse transcriptase inhibitors (NRTIs) or protease inhibitors (PIs). In contrast, prostratin lost 4.4- and 6.8-fold of its effect against the HIV strains resistant to AMD3100 and the quaternary ammonium salt QAS10+, respectively. As shown by time-of-addition experiments, prostratin needs to be present at the time of viral adsorption to exert its antiviral activity. We selected an HIV strain (NL4.3/PROS) resistant to prostratin in MT-4 cells. The sensitivity of NL4.3/PROS towards prostratin, dextran sulphate and QAS10+ was reduced by 3.2, 4.1 and >50-fold, respectively. However, NL4.3/ PROS was still sensitive to AMD3100, T-20, NRTIs (zidovudine and nevirapine) and a PI (ritonavir). Recombination of the gp160-gene of the NL4.3/PROS strain in a NL4.3 wild-type molecular clone fully rescued its phenotypic resistance. DNA sequencing of the NL4.3/PROS strain revealed mutations throughout the gp120 gene previously associated with resistance towards other HIV entry inhibitors. We concluded that prostratin inhibits the entry step of the replication cycle of HIV by interacting with a cellular target necessary for viral entry.
原锥虫素是一种无促肿瘤作用的佛波酯，对1型人类免疫缺陷病毒（HIV-1）具有强大的抗HIV活性。然而，原锥虫素的抗病毒机制尚未完全明确。在本研究中，我们报告原锥虫素对不同株的HIV-1（B亚型和D亚型）、一株临床HIV分离株（L1）、HIV-2（ROD和EHO）以及猴免疫缺陷病毒（SIV，MAC251）均表现出强大的抗病毒活性，其半数有效浓度（EC50）值范围为0.02 - 0.09微克/毫升。原锥虫素对耐聚阴离子结合抑制剂硫酸葡聚糖、融合抑制剂T-20（恩夫韦肽）、核苷类逆转录酶抑制剂（NRTIs）或蛋白酶抑制剂（PIs）的HIV毒株同样具有活性。相比之下，原锥虫素对耐AMD3100和季铵盐QAS10 +的HIV毒株的作用分别降低了4.4倍和6.8倍。如添加时间实验所示，原锥虫素需要在病毒吸附时存在才能发挥其抗病毒活性。我们在MT-4细胞中筛选出一株对原锥虫素耐药的HIV毒株（NL4.3/PROS）。NL4.3/PROS对原锥虫素、硫酸葡聚糖和QAS10 +的敏感性分别降低了3.2倍、4.1倍和>50倍。然而，NL4.3/PROS对AMD3100、T-20、NRTIs（齐多夫定和奈韦拉平）以及一种PI（利托那韦）仍敏感。NL4.3/PROS株的gp160基因在NL4.3野生型分子克隆中的重组完全恢复了其表型耐药性。NL4.3/PROS株的DNA测序揭示了gp120基因中存在先前与对其他HIV进入抑制剂耐药相关的突变。我们得出结论，原锥虫素通过与病毒进入所需的细胞靶点相互作用来抑制HIV复制周期的进入步骤。
