Gerlach Samantha L, Yeshak Mariamawit, Göransson Ulf, Roy Upal, Izadpanah Reza, Mondal Debasis
Department of Pharmacology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA, 70112.
Biopolymers. 2013 Sep;100(5):471-9. doi: 10.1002/bip.22325.
Human immunodeficiency virus type-1 (HIV-1), the etiologic agent of acquired immune deficiency syndrome (AIDS), is a global pandemic causing millions of deaths annually. Highly active antiretroviral therapy (HAART) greatly enhances lifespan but eventually causes debilitating side effects, in part, due to their chronic administration required to suppress HIV-1 replication. If treatment is discontinued, viral suppression is lost and dormant replication-competent monocytic cell reservoirs become reactivated, leading to viral recrudescence and progression to AIDS. Therefore, novel strategies to circumvent obstacles to HIV-1 therapy are critically needed. We evaluated the potentially therapeutic effects of cycloviolacin O2 (CyO2) on cell viability (MTT assay), membrane disruption (SYTOX Green uptake), p24 production [enzyme-linked immunosorbent assays (ELISA)], and proviral integration (PCR amplification) in U1 cells; a monocytic cell model of HIV-1 latency and reactivation. We demonstrate, for the first time, that CyO2 (0.5-5.0 μM) kills productively infected cells. Sub-toxic concentrations (<0.5 μM) of CyO2 disrupted plasma membranes in both latently-infected and productively-infected U1 cells and enhanced the antiviral efficacy of nelfinavir, a HIV-1 protease inhibitor (HPI). Interestingly, CyO2 also decreased virus production by activated U1 cells; however, this effect was not due to suppression of integrated provirus in U1 cells. This suggested that, in addition to the known pore-forming ability of cyclotides, a novel mode of antiviral activity may exist for CyO2. Our data indicate that CyO2 may be a promising candidate for the targeting HIV-1 reservoirs in monocytes, and their inclusion in adjuvant therapy approaches may augment the efficacy of HPIs and ultimately facilitate virus elimination.
1型人类免疫缺陷病毒（HIV-1）是获得性免疫缺陷综合征（AIDS）的病原体，是一种全球大流行病，每年导致数百万人死亡。高效抗逆转录病毒疗法（HAART）大大延长了患者寿命，但最终会导致使人衰弱的副作用，部分原因是需要长期服用以抑制HIV-1复制。如果停止治疗，病毒抑制作用就会丧失，潜伏的具有复制能力的单核细胞储存库会重新激活，导致病毒复发并发展为AIDS。因此，迫切需要新的策略来克服HIV-1治疗的障碍。我们评估了环肽素O2（CyO2）对U1细胞活力（MTT法）、膜破坏（SYTOX Green摄取）、p24产生[酶联免疫吸附测定（ELISA）]和前病毒整合（PCR扩增）的潜在治疗作用；U1细胞是HIV-1潜伏和激活的单核细胞模型。我们首次证明，CyO2（0.5 - 5.0 μM）可杀死被有效感染的细胞。亚毒性浓度（<0.5 μM）的CyO2破坏了潜伏感染和被有效感染的U1细胞的质膜，并增强了HIV-1蛋白酶抑制剂（HPI）奈非那韦的抗病毒效力。有趣的是，CyO2还降低了激活的U1细胞产生的病毒量；然而，这种作用并非由于抑制了U1细胞中整合的前病毒。这表明，除了环肽已知的成孔能力外，CyO2可能存在一种新的抗病毒活性模式。我们的数据表明，CyO2可能是靶向单核细胞中HIV-1储存库的有前途的候选药物，将其纳入辅助治疗方法可能会增强HPI的疗效，并最终促进病毒清除。
