汉滩病毒核蛋白与热休克蛋白GRP94、HSP27的相互作用

为研究汉滩病毒(Hantaan virus, HTNV)感染诱导乳鼠脑组织热休克蛋白GRP94、HSP27与病毒蛋白的相互关系,选出生2～3d的昆明乳鼠实验性感染汉滩病毒,取8d后发病乳鼠脑组织部分制石蜡切片,用免疫组化结合共聚焦显微镜检测组织中病毒抗原及GRP94、HSP27的表达,部分制匀浆液,用ELISA、免疫共沉淀方法分析病毒抗原和GRP94、HSP27的关系.结果示汉滩病毒感染诱导乳鼠脑组织神经细胞高表达GRP94且与细胞内病毒抗原有共定位关系,但未见HSP27诱导高表达;免疫共沉淀显示汉滩病毒核心抗原(HINV-NP)与GRP94、HSP27呈非共价复合物形式存在.该结果为进一步探讨HSPs在病毒感染复制中的作用以及抗病毒感染方面提供了有意义的实验资料.     

汉滩病毒感染诱导热休克蛋白70表达

为了解汉滩病毒感染后细胞的应激反应及HSP70的表达与病毒复制的关系,在汉滩病毒A9株感染Vero-E6细胞后,用免疫组织化学及核酸分子原位杂交法,对细胞HSP70基因的表达进行了检测.结果表明,汉滩病毒感染细胞4h后即可诱导Vero-E6细胞表达HSP70,表达可持续至感染后5d,且HSP70在细胞内的分布也有改变.提示汉滩病毒可直接诱导HSP70的高表达.     

汉滩病毒感染诱导热休克蛋白70表达

为了解汉滩病毒感染后细胞的应激反应及ＨＳＰ７０的表达与病毒复制的关系,在汉滩病毒Ａ９株感染Ｖｅｒｏ－Ｅ６细胞后,用免疫组织化学及核酸分子原位杂交法,对细胞ＨＳＰ７０基因的表达进行了检测。结果表明,汉滩病毒感染细胞４ｈｙ后即可诱导Ｖｅｒｐ－Ｅ６细胞表达ＨＳＰ７０,表达可持续至感染后５ｄ且ＨＳＰ７０在细胞内的分布也有改变。提示汉滩病毒可直接诱导ＨＳＰ７０的高表达。     

汉坦病毒感染诱导乳鼠脑神经细胞表达热休克蛋白70

生后2～3天的昆明乳鼠,每只腹腔接种0.05mL100个半数致死量的陈株汉坦病毒,于接种后不同时间点处死动物,取其脑组织常规固定,石蜡包埋制备5μm连续组织切片,用免疫组化法检测组织中的病毒抗原及热休克蛋白70的表达,用共聚焦显微镜观察二者之间的关系。结果发现,感染了病毒的组织能够稳定地检测到热休克蛋白70的表达,而病毒阴性的组织则检测不到热休克蛋白70的表达,且二者有共定位关系,其分布与组织病变一致。这与在病毒感染的VeroE6细胞及EHF病人尸检组织中得到的结果一致,说明病毒感染可诱导热休克蛋白70的表达,后者可能具有保护组织避免或减轻损伤的作用。     

热休克蛋白HSP70和gp96在抗病毒感染中的作用

热休克蛋白(HSP)是一组在进化上高度保守、具有重要生理功能的蛋白质家族,是生物在应激条件下产生的一种非特异性防御产物,在调节免疫应答和抗病毒反应中起重要作用。现简要介绍HSP70、gp96(HSP96,GRP94)这两种HSP与病毒感染的关系及在抗病毒感染中的作用。     

汉坦病毒感染诱导乳鼠脑神经细胞表达热休克蛋白70

生后2－3天的昆明乳鼠,每只腹腔接种0.05mL100个半数致死量的陈株汉坦病毒,于接种后不同时间点处死动物,取其脑组织常规固定,石蜡包埋制备5μm连续组织片,用免疫组化法检测组织中的病毒抗原及热休克蛋白70的表达,用共聚焦显微镜观察二者之间的关系。结果发现,感染了病毒的组织能够稳定地检测到热休克蛋白70的表达,而病毒阴性的组织则检测不到热休克蛋白70的表达,且二者有共定位关系,其分布与组织病变一致。这与在病毒感染的VeroE6细胸及EHF病人尸检组织中得到的结果一致,说明病毒感染可诱导热休克蛋白70的表达,后者可能具有保护组织避免或减轻损伤的作用。     

热休克蛋白27增强A型流感病毒NS1对β干扰素的抑制作用

热休克蛋白27(Heat shock protein 27,HSP27)是一种具有多重功能的小热休克蛋白,它在一些病毒的生命周期中也发挥着重要作用。为研究HSP27对流感病毒感染的调节作用,首先在原核及真核细胞中克隆并表达了人源的HSP27蛋白,并验证了HSP27和A型流感病毒NS1蛋白能够相互结合。通过荧光素酶检测试验发现,HSP27可以抑制病毒感染细胞中β干扰素(IFN-β)的表达,但不依赖于其自身的磷酸化状态,而且HSP27与NS1共同对于IFN-β的表达具有叠加抑制效果。进一步的结果表明HSP27可能通过RIG-I样RNA解旋酶(RLH)途径中MDA5因子抑制IFN-β的表达。研究表明,HSP27在被感染细胞的天然免疫中发挥一定作用,有助于进一步阐明宿主因子对于流感病毒感染的调节机理。     

应用蛋白组学方法筛选和鉴定乙型肝炎病毒PreS1结合蛋白

前S1蛋白（PreS1）在乙型肝炎病毒与宿主的相互作用中起至关重要的作用．为筛选乙型肝炎病毒PreS1结合蛋白,进一步探讨其在病毒感染过程中的作用,原核表达、纯化了PreS1-谷胱甘肽-S-转移酶（glutathione-S-transferase,GST）融合蛋白,利用此蛋白与HepG2细胞裂解液进行Pull-down实验,其产物进行双向凝胶电泳分离. 结果发现2个PreS1特异结合蛋白,经质谱鉴定为分子伴侣蛋白——葡萄糖调节蛋白78(GRP78)和葡萄糖调节蛋白75(GRP75)．通过免疫共沉淀和Western印迹分析证实,PreS1与GRP75之间存在相互作用．实验结果表明,GRP75为新发现乙型肝炎病毒PreS1特异结合蛋白,其与PreS1结合后的生理功能以及在HBV感染过程中的作用值得深入研究．     

GRP94的功能及其与肿瘤的相关性

葡萄糖调节蛋白94（gloucose requlated protein 94,GRP94）是HSP90家族的成员,主要定位于内质网中.GRP94作为分子伴侣参与蛋白质的折叠、转运和分泌外,还参与了细胞凋亡以及抗原的提呈.GRP94与肿瘤的发生以及进展密切相关,肿瘤的分化程度越低,GRP94的表达也越高.GRP94又可将肿瘤特异性抗原提呈给专业提呈细胞启动特异性的免疫反应.GRP94在肿瘤的发生及转归中发挥了重要的作用.     

汉滩病毒感染小鼠腹腔巨噬细胞模型的建立

目的:建立汉滩病毒感染的小鼠腹腔巨噬细胞模型。方法:PBS灌洗6~8周龄C57BL/6小鼠腹腔,分离获取小鼠腹腔巨噬细胞后,以100 TCID50汉滩病毒76-118株感染小鼠腹腔巨噬细胞,通过间接免疫荧光、ELISA和Realtime PCR检测病毒感染情况。结果:病毒感染3 d后,间接免疫荧光和ELISA检测到病毒核衣壳蛋白的表达,Realtime PCR检测到病毒核酸的表达。结论:建立了汉滩病毒感染小鼠腹腔巨噬细胞的模型,为进一步阐明汉滩病毒的发病机制奠定了基础。     

Evidence of prognostic relevant expression profiles of heat-shock proteins and glucose-regulated proteins in oesophageal adenocarcinomas

A high percentage of oesophageal adenocarcinomas show an aggressive clinical behaviour with a significant resistance to chemotherapy. Heat-shock proteins (HSPs) and glucose-regulated proteins (GRPs) are molecular chaperones that play an important role in tumour biology. Recently, novel therapeutic approaches targeting HSP90/GRP94 have been introduced for treating cancer. We performed a comprehensive investigation of HSP and GRP expression including HSP27, phosphorylated (p)-HSP27^(Ser15), p-HSP27^(Ser78), p-HSP27^(Ser82), HSP60, HSP70, HSP90, GRP78 and GRP94 in 92 primary resected oesophageal adenocarcinomas by using reverse phase protein arrays (RPPA), immunohistochemistry (IHC) and real-time quantitative RT-PCR (qPCR). Results were correlated with pathologic features and survival. HSP/GRP protein and mRNA expression was detected in all tumours at various levels. Unsupervised hierarchical clustering showed two distinct groups of tumours with specific protein expression patterns: The hallmark of the first group was a high expression of p-HSP27^{(Ser15, Ser78, Ser82)} and low expression of GRP78, GRP94 and HSP60. The second group showed the inverse pattern with low p-HSP27 and high GRP78, GRP94 and HSP60 expression. The clinical outcome for patients from the first group was significantly improved compared to patients from the second group, both in univariate analysis (p = 0.015) and multivariate analysis (p = 0.029). Interestingly, these two groups could not be distinguished by immunohistochemistry or qPCR analysis. In summary, two distinct and prognostic relevant HSP/GRP protein expression patterns in adenocarcinomas of the oesophagus were detected by RPPA. Our approach may be helpful for identifying candidates for specific HSP/GRP-targeted therapies.     

病毒性心肌炎所致小鼠心力衰竭心肌组织内质网应激相关的凋亡关系的研究

目的：探讨病毒性心肌炎心力衰竭小鼠心肌组织内质网应激介导的凋亡途径。方法：40只雄性Balb／c小鼠分为病毒性心肌炎组和正常对照组（n=20）,病毒性心肌炎组应用柯萨奇B3病毒制作BALB／c小鼠病毒性心肌炎模型,观察小鼠的一般情况,7d行血流动力学检查后处死取心脏标本,用TUNEL法检测心肌细胞凋亡,RT-PCR检测心肌细胞内质网伴侣蛋白葡萄糖调节蛋白（GAP）78和GRP04的mRNA表达水平。结果：①与正常对照组相比,病毒性心肌炎组小鼠血流动力学指标明显降低（P〈0．01）;②TUNEL染色显示病毒性心肌炎心力衰竭小鼠心肌组织凋亡明显增多（P〈0．01）;③病毒性心肌炎组小鼠内质网伴侣蛋白GRP78和GRP94的mRNA表达水平均明显高于对照组（P〈0．01）。结论：病毒性心肌炎心力衰竭小鼠内质网应激可能介导了心肌细胞凋亡。     

Betanodavirus up-regulates chaperone GRP78 via ER stress: roles of GRP78 in viral replication and host mitochondria-mediated cell death

Whether viral pathogens that induce ER stress responses benefit the host or the virus remains controversial. In this study we show that betanodavirus induced ER stress responses up-regulate GRP78, which regulates the viral replication and host cellular mitochondrial-mediated cell death. Betanodavirus (redspotted grouper nervous necrosis virus, RGNNV) infection resulted in the following increased ER stress responses in fish GF-1 grouper fin cells: (1) IRE-1 and ATF-6 sensors at 48 h post-infection (p.i.) that up-regulated chaperone protein GRP78; (2) activation of caspase-12; and (3) PERK phosphorylation and down-regulation of Bcl-2. Analyses of GRP78 functions during viral replication using either loss-of-function or gain-of-function approaches showed that GRP78 over-expression also enhanced viral replication and induced cell death. Then, we found that zfGRP78 localization gradually increased in mitochondria after RGNNV infection by EGFP tagging approach. Furthermore, zfGRP78 can interact with viral RNA-dependent RNA polymerase (RdRp) by using immunofluorescent and immunoprecipitation assays. Finally, we found that blocking GRP78-mediated ER signals can reduce the viral death factors protein α and protein B2 expression and decrease the Bcl-2 down-regulation mediated mitochondria-dependent cell death, which also enhances host cellular viability. Taken together, our results suggest that RGNNV infection and expression can trigger ER stress responses, which up-regulate the chaperone GRP78 at early replication stage. Then, GRP78 can interact with RdRp that may enhance the viral replication for increasing viral death factors’ expressions at middle-late replication stage, which can enhance mitochondrial-mediated cell death pathway and viral spreading. These results may provide new insights into the mechanism of ER stress-mediated cell death in RNA viruses.     

Hantaan virus infection causes an acute neurological disease that is fatal in adult laboratory mice

Hantaan virus, the etiological agent of Korean hemorrhagic fever, is transmitted to humans from persistently infected mice (Apodemus agrarius), which serve as the primary reservoir. Here we demonstrate that several strains of adult Mus musculus domesticus (C57BL/6, BALB/c, AKR/J, and SJL/J) were susceptible to Hantaan virus infection when infected intraperitoneally. First clinical signs were loss of weight, ruffled fur, and reduced activity, which were followed by neurological symptoms, such as paralyses and convulsions. Within 2 days of disease onset, the animals died of acute encephalitis. PCR analysis indicated a systemic infection with viral RNA present in all major organs. Immunohistochemical and in situ hybridization analyses of postmortem material detected viral antigen and RNA in the central nervous system (predominantly brain), liver, and spleen. In the central nervous system, viral antigen and RNA colocalized with perivascular infiltrations, the predominant pathological finding. To investigate the involvement of the interferon system in Hantaan virus pathogenesis, we infected alpha/beta interferon receptor knockout mice. These animals were more susceptible to Hantaan virus infection, indicating an important role of interferon-induced antiviral defense mechanisms in Hantaan virus pathogenesis. The present model may help to overcome shortcomings in the development of therapeutic and prophylactic measurements against hantavirus infections.     

Robust expression of p27Kip1 induced by viral infection is critical for antiviral innate immunity

Influenza A virus (IAV) infection regulates the expression of numerous host genes. However, the precise mechanism underlying implication of these genes in IAV pathogenesis remains largely unknown. Here, we employed isobaric tags for relative and absolute quantification (iTRAQ) to identify host proteins regulated by IAV infection. iTRAQ analysis of mouse lungs infected or uninfected with IAV showed a total of 167 differentially upregulated proteins in response to the viral infection. Interestingly, we observed that p27Kip1, a potent cyclin‐dependent kinase inhibitor, was markedly induced by IAV both at mRNA and protein levels through in vitro and in vivo studies. Furthermore, it was shown that innate immune signalling positively regulated p27Kip1 expression in response to IAV infection. Ectopic expression of p27Kip1 in A549 cells dramatically inhibited IAV replication, whereas, p27Kip1 knockdown significantly enhanced the virus replication. in vivo experiments demonstrated that p27Kip1 knockout (KO) mice were more susceptible to IAV than wild‐type (WT) mice: exhibiting higher viral load in lung tissue, faster body‐weight loss, reduced survival rate and more severe organ damage. Moreover, we found that p27Kip1 overexpression facilitated the degradation of viral NS1 protein, caused a dramatic STAT1 activation and promoted the expression of IFN‐β and several critical antiviral interferon‐stimulated genes (ISGs). Increased p27Kip1 expression also restricted infections of several other viruses. Conversely, IAV‐infected p27Kip1 KO mice exhibited a sharp increase in NS1 protein accumulation, reduced level of STAT1 activation and decreased expression of IFN‐β and the ISGs in the lung compared to WT animals. These findings reveal a key role of p27Kip1 in enhancing antiviral innate immunity.     

Human cytomegalovirus specifically controls the levels of the endoplasmic reticulum chaperone BiP/GRP78, which is required for virion assembly

The endoplasmic reticulum (ER) chaperone BiP/GRP78 regulates ER function and the unfolded protein response (UPR). Human cytomegalovirus infection of human fibroblasts induces the UPR but modifies it to benefit viral replication. BiP/GRP78 protein levels are tightly regulated during infection, rising after 36 h postinfection (hpi), peaking at 60 hpi, and decreasing thereafter. To determine the effects of this regulation on viral replication, BiP/GRP78 was depleted using the SubAB subtilase cytotoxin, which rapidly and specifically cleaves BiP/GRP78. Toxin treatment of infected cells for 12-h periods beginning at 36, 48, 60, and 84 hpi caused complete loss of BiP but had little effect on viral protein synthesis. However, progeny virion formation was significantly inhibited, suggesting that BiP/GRP78 is important for virion formation. Electron microscopic analysis showed that infected cells were resistant to the toxin and showed none of the cytotoxic effects seen in uninfected cells. However, all viral activity in the cytoplasm ceased, with nucleocapsids remaining in the nucleus or concentrated in the cytoplasmic space just outside of the outer nuclear membrane. These data suggest that one effect of the controlled expression of BiP/GRP78 in infected cells is to aid in cytoplasmic virion assembly and egress.