Division of Virology, Defence Research & Development Establishment (DRDE), Gwalior, MP, India.
J Med Virol. 2010 May;82(5):817-24. doi: 10.1002/jmv.21663.
The resurgence of Chikungunya virus (CHIKV) in the form of unprecedented and explosive epidemics in India and the Indian Ocean islands after a gap of 32 years is a major public health concern. Currently, there is no specific therapy available to treat CHIKV infection. In the present study, the in vitro prophylactic and therapeutic effects of chloroquine on CHIKV replication in Vero cells were investigated. Inhibitory effects were observed when chloroquine was administered pre-infection, post-infection, and concurrent with infection, suggesting that chloroquine has prophylactic and therapeutic potential. The inhibitory effects were confirmed by performing a plaque reduction neutralization test (PRNT), real-time reverse transcriptase (RT)-PCR analysis of viral RNA levels, and cell viability assays. Chloroquine diminished CHIKV infection in a dose-dependent manner, with an effective concentration range of 5-20 microM. Concurrent addition of drug with virus, or treatment of cells prior to infection drastically reduced virus infectivity and viral genome copy number by >/=99.99%. The maximum inhibitory effect of chloroquine was observed within 1-3 hr post-infection (hpi), and treatment was ineffective once the virus successfully passed through the early stages of infection. The mechanism of inhibition of virus activity by chloroquine involved impaired endosomal-mediated virus entry during early stages of virus replication, most likely through the prevention of endocytosis and/or endosomal acidification, based on a comparative evaluation using ammonium chloride, a known lysosomotropic agent.
时隔 32 年，基孔肯雅病毒（CHIKV）以空前规模和极具爆发性的流行态势在印度和印度洋岛屿重现，这引起了重大的公共卫生关注。目前，尚无专门针对 CHIKV 感染的治疗方法。本研究旨在探究氯喹在 Vero 细胞中对 CHIKV 复制的体外预防和治疗效果。结果表明，氯喹在感染前、感染后和同时给药时均具有抑制作用，这表明氯喹具有预防和治疗潜力。通过进行噬斑减少中和试验（PRNT）、实时 RT-PCR 分析病毒 RNA 水平和细胞活力测定实验，验证了抑制效果。氯喹呈剂量依赖性地降低 CHIKV 感染，有效浓度范围为 5-20μM。药物与病毒同时添加或在感染前处理细胞可使病毒感染力和病毒基因组拷贝数降低>99.99%。氯喹的最大抑制效果出现在感染后 1-3 小时（hpi），一旦病毒成功通过感染的早期阶段，治疗就不再有效。氯喹抑制病毒活性的机制涉及在病毒复制的早期阶段破坏内体介导的病毒进入，这可能是通过防止内吞作用和/或内体酸化来实现的，这是基于对氯化铵（一种已知的溶酶体靶向剂）的比较评估。
