神经介素B及其受体NMBR参与抗A型流感病毒H1N1亚型感染的信号通路

NMB/NMBR通过调节A型流感病毒（IAV/H1N1/PR8）感染诱导的细胞因子表达而参与抗IAV的先天性免疫反应。为探究其发挥抗IAV/H1N1感染的信号通路，本文用PR8和WSN毒株分别感染MLE-12细胞和小鼠，用NF-κB抑制剂BAY11-7028单独或联合NMB处理MLE-12细胞，小鼠后腿肌内注射NMB和NMBRA，采用RT-PCR和qRT-PCR分析NMB、NMBR、IL-6、IFN-α和NP基因表达变化，采用Western blot分析NMB、NMBR、P65/p-P65、IκBα和NP蛋白表达的变化。结果显示，BAY11-7028可促使PR8和WSN感染的MLE-12细胞中NMB、NMBR、IL-6和IFN-α基因表达水平均下降和NP基因表达水平上升，并降低NMB、NMBR和p-P65蛋白表达水平和提升IκBα和NP蛋白表达水平。然而，NMB联合BAY 11-7028诱导PR8或WSN感染后的细胞中IL-6和NP表达出现极显著下降和IFN-α显著上升。此外，NMB抑制PR8和WSN感染的小鼠肺组织内p-P65和NP蛋白表达水平和促进IκBα蛋白表达水平；NMBRA联合NMB抵消NMB对PR8或WSN感染后的这些蛋白表达水平的调节作用。综上表明，NMB/NMBR通过调节PR8和WSN感染的MLE-12细胞和小鼠体内的NF-κB信号通路上P65蛋白磷酸化和IκBα的表达，进而影响下游细胞因子IL-6和IFN-α基因的表达，从而发挥抗IAV/H1N1感染的先天性免疫应答反应。     

Characterization of bovine ileal epithelial cell line for lectin binding,susceptibility to enteric pathogens,and TLR mediated immune responses

In this study, primary and immortalized bovine intestinal epithelial cells (BIECs) were characterized for the expression of surface carbohydrate moieties. Primary BIEC-c4 cells showed staining greater than 90 % for 16 lectins but less than 50 % staining for four lectins. Immortalized BIECs showed significantly different lectin binding profile for few lectins compared to BIEC-c4 cells. BIEC-c4 cells were studied for infectivity to E. coli, Salmonella enterica, bovine rotavirus, bovine coronavirus, and bovine viral diarrhea virus. Bovine strain E. coli B41 adhered to BIEC-c4 cells and Salmonella strains S. Dublin and S. Mbandaka showed strong cell invasion. BIEC-c4 cells were susceptible to bovine rotavirus. LPS stimulation upregulated IL-10, IL-8, and IL-6 expression and Poly I:C upregulated TLR 8 and TLR 9 expression. This study provides important knowledge on the glycoconjugate expression profile of primary and immortalized BIECs and infectivity and immune responses of primary BIECs to bacterial and viral pathogens or ligands.     

Management of yellow dwarf disease in Europe in a post‐neonicotinoid agriculture

Barley/cereal yellow dwarf viruses (YDVs) cause yellow dwarf disease (YDD), which is a continuous risk to cereals production worldwide. These viruses cause leaf yellowing and stunting, resulting in yield reductions of up to 80%. YDVs have been a consistent but low‐level problem in European cereal cultivation for the last three decades, mostly due to the availability of several effective insecticides (largely pyrethroids and more recently neonicotinoids) against aphid vectors. However, this has changed recently, with many insecticides being lost, culminating in a recent European Union (EU) regulation prohibiting outdoor use of the neonicotinoid‐insecticide compounds. This change is coupled with the growing challenge of insecticide‐resistant aphids, the lack of genetic resources against YDVs, and a knowledge deficit around the parameters responsible for the emergence and spread of YDD. This means that economic sustainability of cereal cultivation in several European countries including France and United Kingdom is now again threatened by this aphid‐vectored viral disease. In this review, we summarize the current knowledge on the YDV pathosystem, describe management options against YDD, analyse the impacts of the neonicotinoid ban in Europe, and consider future strategies to control YDV. © 2020 Society of Chemical Industry     

3株鸽源新城疫病毒的分子特征及对鸽的致病性

2011―2013年在新城疫流行病学调查中分离到3株鸽源新城疫病毒(SDS,SD01和SD02),为了进一步了解其生物学特性和遗传进化规律,对3株病毒进行了测序和生物活性分析,并对分离株SDS对鸽的致病性进行了评价。结果表明,毒株SDS基因组全长为15192 bp,基因排列方式为3′-NP-P-M-F-HN-L-5′,3个分离株F蛋白裂解位点氨基酸序列均为¹¹²RRQKRF¹¹⁷,具有典型的新城疫强毒的分子特征。系统进化分析表明这3个毒株与基因Ⅵ型NDV毒株聚于一簇,属于ClassⅡ系Ⅵb基因型。3个分离株F蛋白的融合肽和七肽重复区,HN蛋白的抗原中和表位存在多处突变,与单克隆抗体1E5、2F10的反应性也发生改变,表明3个分离株与疫苗株LaSota有明显的抗原差异。SDS攻毒试验结果显示,试验鸽自攻毒后5 d出现明显的临床症状,滴鼻组和肌肉注射组的死亡率分别为60%和70%;病死鸽剖检可见脑膜充血出血,腺胃乳头、腺胃肌胃交界及肠道出血,肝脏肿大,脾有淤血斑。滴鼻组在攻毒后5~14 d于喉头和泄殖腔检出排毒,而肌肉注射组在攻毒后3~14 d于喉头和泄殖腔有排毒。     

太子参须提取物对鸭流感病毒体外试验初探

为尝试性探究太子参须提取物对鸭H9N2亚型流感病毒体外生长的抑制作用,本文基于TCID50试验检测鸭H9N2亚型流感病毒体外感染不同处理组的MDCK细胞。结果表明,太子参须提取物高低剂量组(75%、25%)和黄芪多糖阳性对照组均对鸭H9N2亚型流感病毒体外生长产生抑制,且太子参须提取物高剂量组(75%)的抑制作用最优。结论:太子参须提取物对鸭H9N2亚型流感病毒在MDCK细胞上的体外增殖具有一定抑制作用,且呈相应剂量关系。     

Effect of rifaximin on gut-lung axis in mice infected with influenza A virus

Gut-lung axis injury is a common finding in patients with respiratory diseases as well as in animal model of influenza virus infection. Influenza virus damages the intestinal microecology while affecting the lungs. Rifaximin, a non-absorbable derivative of rifamycin, is an effective antibiotic that acts by inhibiting bacterial RNA synthesis. This study aimed to determine whether rifaximin-perturbation of the intestinal microbiome leads to protective effects against influenza infection, via the gut-lung axis. Our results showed that influenza virus infection caused inflammation of and damage to the lungs. The expression of tight junction proteins in the lung and colon of H1N1 infected mice decreased significantly, attesting that the barrier structure of the lung and colon was damaged. Due to this perturbation in the gut-lung axis, the intestinal microbiota became imbalanced as Escherichia coli bacteria replicated opportunistically, causing intestinal injury. When influenza infection was treated with rifamixin, qPCR results from the gut showed significant increases in Lactobacillus and Bifidobacterium populations, while Escherichia coli populations markedly decreased. Furthermore, pathology sections and western blotting results illustrated that rifaximin treatment strengthened the physical barriers of the lung-gut axis through increased expression of tight junction protein in the colon and lungs. These results indicated that rifaximin ameliorated lung and intestine injury induced by influenza virus infection. The mechanisms identified were the regulation of gut flora balance and intestinal and lung permeability, which might be related to the regulation of the gut-lung axis. Rifaximin might be useful as a co-treatment drug for the prevention of influenza virus infection.     

甘薯褪绿矮化病毒RNase3蛋白的原核表达及抗血清制备

以本实验室保存的重组质粒为模板,利用PCR方法扩增获得了甘薯褪绿矮化病毒SPCSV的RNase3基因,RNase3基因由690个核苷酸组成,编码229个氨基酸。将RNase3基因克隆到原核表达载体pET-28a(+),转化大肠杆菌BL21(DE3),经IPTG诱导,对诱导产物进行SDS-PAGE分析。结果表明,RNase3在大肠杆菌中能高效表达,融合蛋白分子量约为26.5kD。以表达的融合蛋白为抗原,免疫家兔,制备了SPCSV-RNase3的特异性抗血清。ACP-ELISA检测结果表明,制备的抗血清对RNase3融合蛋白的效价达10万倍。     

小麦TaeEF1β基因的克隆、同源性及表达分析

真核翻译延伸因子(eukaryotic translation elongation factor,eEFs)是一种重要的多功能调控蛋白,eEF1β是eEF1的组成部分,在蛋白质生物合成过程中发挥着重要的作用。本文通过RT-PCR扩增克隆小麦(Triticum aestivum L.)的eEF1β基因,并命名为TaeEF1β。氨基酸同源性分析发现,TaeEF1β具有高度保守性,且其保守结构域位于137~226 aa处。qRT-PCR结果表明,中国小麦花叶病毒(Chinese wheat mosaic virus,CWMV)侵染小麦植株后,可以诱导TaeEF1β基因转录水平的上调表达。另外,本文也进一步分析了TaeEF1β基因在小麦根、茎、叶的表达水平和CWMV侵染不同时间点的表达情况。     

Detection and characterization of a rhabdovirus causing mortality in black bullhead catfish,Ameiurus melas

This study fully describes a severe disease outbreak occurred in 2016 in black bullhead catfish farmed in Italy. Affected fish showed nervous clinical signs as well as emaciations and haemorrhagic petechiae on the skin at the fin bases, abdomen and gills. Viral isolation in cell culture allowed the subsequent identification of a rhabdovirus, tentatively named ictalurid rhabdovirus (IcRV), through electron microscopy, immunofluorescence and whole genome sequencing (WGS). The newly isolated virus, together with 14 additional viral strains stored in our repository and detected during similar mortality episodes in the period 1993–2016, was phylogenetically analysed on the basis of the nucleoprotein and the glycoprotein nucleotide and amino acid sequences. The genetic distances among Italian IcRV strains were also estimated. Our results show that all the IcRV strains belong to the genus Sprivivirus and are closely related to the tench rhabdovirus (TenRV). Italian catfish production is constantly decreasing, mainly due to viral infections, which include the newly characterized IcRV. Data presented in this work will assist to investigate the molecular epidemiology and the diffusive dynamics of this virus and to develop adequate surveillance activities.     

一例日本囊对虾暴发性死亡的病原分析

为了阐明山东省潍坊市一对虾养殖场发生日本囊对虾暴发性死亡的原因,采用分子生物学检测方法,对发病对虾进行了白斑综合征病毒(white spot syndrome virus,WSSV)、桃拉综合征病毒(Taura syndrome virus,TSV)、黄头病毒(yellow head virus,YHV)、传染性皮下及造血组织坏死病毒(infectious hypodermal and hematopoietic necrosis virus,IHHNV)、传染性肌肉坏死病毒(infectious myonecrosis virus,IMNV)、偷死野田村病毒(covert mortality nodavirus,CMNV)及急性肝胰腺坏死病(acute hepatopancreatic necrosis disease,AHPND)7种病原的检测,且对发病对虾进行了常规组织病理学观察。同时采用16S r DNA细菌鉴定方法及浸泡回接感染实验对分离自发病对虾体内的可疑病原菌进行了分子鉴定及毒力测试。结果显示,发病对虾样品核酸检测呈现WSSV强阳性,IHHNV和CMNV为弱阳性,其他4种病原为阴性。组织病理学观察发现,在对虾的胃、鳃等上皮组织中存在WSSV包涵体,头部肌肉纤维出现离散。对分离编号为2901、2902、2903的3株优势可疑病原菌鉴定结果显示,3株菌分别与印度格里蒙菌、交替单胞菌及溶藻弧菌相似,相似度分别为99%、99%及100%。攻毒结果显示,3株可疑病原菌的LC50分别为9.8×107、1.1×108与2.3×108 CFU/m L,各细菌毒力均较弱,非导致对虾出现暴发性死亡的病原。研究表明,导致本次日本囊对虾暴发性死亡的病因与混合感染病原WSSV、IHHNV、CMNV有关,其中WSSV感染是造成日本囊对虾暴发性死亡的主因,研究结果可为解析当前养殖日本囊对虾疾病暴发及其成因提供参考。