Pim-1调节人肠道病毒71型感染能力的机制研究

Enterovirus (EV71) has repeatedly emerged as a major threat to the public health in the Asia-Pacific regions in the past decade. EV71 had infected over a million children that caused hand-foot-and-mouse disease (HFMD) and had led to hundreds to thousands of deaths in China annually. No effective therapy or vaccine is available to prevent or treat EV71 infection. To promote antiviral drug development, it is urgent to better understand how the host responses combat or facilitate viral infection. .Our team has investigated the host responses to EV71 infection by microarray studies. After validation by quantitative RT-PCR and western blot assays, we have shown that Pim-1 is one of the most elevated proteins which responds to EV71 infection. Knockdown of Pim-1 or inhibition of Pim-1 activity by a specific inhibitor significantly reduced virus yield secreted in culture media, whereas overexpression of Pim-1 increased viral production. Further studies have revealed that Pim-1 plays an important role in facilitating viral package and secretion. In this study, we will investigate the underlying mechanisms of Pim-1 enhancing virus infections via phosphorylation of Hsp90β. Furthermore, we will reveal whether Pim-1 inhibitors could be used as potential antiviral drugs.

肠道病毒71型（EV71）在过去十年多次暴发，已成为亚太地区公共健康的重大威胁。目前尚缺乏有效的药物治疗，故研究宿主与病毒的相互作用，将为抗病毒药物的研究打下理论和实验基础。我们利用基因芯片技术，检测宿主细胞受病毒感染前后的基因表达变化，发现蛋白激酶Pim-1明显上调;敲落Pim-1表达或用Pim-1抑制剂处理能有效抑制病毒增殖，过表达Pim-1则促进病毒增殖。同时我们发现Hsp90β与Pim-1有相似促进病毒包装与释放的现象，并证实Pim-1参与结合并磷酸化Hsp90β，由此推测两者共同参与EV71感染机体的过程。在此前期研究基础上，我们拟结合质谱、基因突变等技术寻找Pim-1磷酸化Hsp90β的具体位点及揭示Hsp90β磷酸化对EV71感染的影响，并通过体内外实验研究Pim-1或与Hsp90β抑制剂联用对EV71增殖影响，试图寻找有效的抗EV71药物并提供可靠的实验依据。

肠病毒A71（EV-A71）感染会导致手足口病（HFMD）和致命的神经系统疾病，目前尚无有效的治疗方法。 宿主因素在建立病毒感染以及确定疾病进展和抗病毒治疗结果方面起着关键作用。 我们发现EV-A71感染中Pim1的表达明显上调。 Pim1的异位表达或沉默通过两种不同的机制促进或抑制EV-A71复制。 Pim1通过增加病毒2A蛋白酶介导的eIF4G裂解来增强病毒IRES活性，并阻断AUF1（IRES的抑制剂）从核转移到细胞质。 更重要的是，我们发现Pim1抑制剂（SGI-1776，AZD-1208和CX-6258）强烈抑制EV-A71的增殖。 尤其是CX-6258， 它显著降低了EV-A71的增殖超过1000倍。另外， 我们还证明Pim1在寨卡病毒感染中也起着重要作用，并阐明了分子机理。 寨卡病毒的NS5蛋白通过Pim1抑制了细胞的天然免疫，而Pim1抑制剂（SGI-1776，AZD-1208和CX-6258）强烈抑制寨卡病毒复制增殖。.此研究意义：（1）阐明了Pim1促进EV-A71及寨卡病毒感染的分子机制；（2）证明了Pim1是一个很好的抗病毒靶标；（3）抗癌药物Pim1抑制剂可作为抗为EV-A71、寨卡病毒感染的潜在药物，为开发抗病毒治疗的药物研发提供了理论和实验依据。