口蹄疫病毒3D蛋白促进TLR3介导的Ⅰ型干扰素产生

口蹄疫是由口蹄疫病毒（FMDV）引起的急性、热性、高度接触性传染病。口蹄疫病毒感染宿主引起一系列严重的炎症反应，而TLR3通路是介导细胞炎性反应的主要途径之一。为研究口蹄疫病毒蛋白对TLR3通路的影响，本研究首先用双荧光素酶报告系统筛选影响TLR3通路的FMDV蛋白；接着用Q-PCR试验验证筛出来的候选蛋白对TLR3通路下游基因表达水平的影响；并用免疫共沉淀试验验证与候选蛋白有相互作用的TLR3通路蛋白；最后用Western blot试验检测候选蛋白对TLR3通路下游分子磷酸化水平的影响。双荧光素酶报告系统结果显示，口蹄疫病毒3D蛋白促进TLR3通路介导的Ⅰ型干扰素的产生并呈剂量依赖性，Q-PCR试验表明，3D能够促进TLR3通路下游基因表达水平；免疫共沉淀试验表明，FMDV 3D与TLR3有相互作用；Western blot试验进一步显示，过表达3D能够促进TLR3下游分子的磷酸化水平。综上，口蹄疫病毒3D蛋白能促进TLR3介导的Ⅰ型干扰素的产生，从而调控天然免疫反应。     

Cell-free DNA-induced alteration of autophagy response and TLR9-signaling: Their relation to amelioration of DSS-colitis

BackgroundThe influence of cell-free DNA (fDNA) administration on the TLR9-autophagy regulatory crosstalk within inflammatory circumstances remains unclear.AimsTo examine the immunobiologic effects of iv. fDNA injection on the TLR9-mediated autophagy response in murine DSS-colitis.MethodsDifferent types of modified fDNAs were administered to DSS-colitic mice. Disease and histological activities, spleen index were measured. Changes of the TLR9-associated and autophagy-related gene expression profiles of lamina proprial cells and splenocytes were assayed by quantitative real-time PCR, and validated by immunohistochemistries. Ultrastructural changes of the colon were examined by transmission electron microscopy (TEM).ResultsA single intravenous injection of colitic fDNA (C-DNA) exhibited beneficial clinical and histological effects on DSS-colitis, compared to normal (N-DNA). C-DNA administration displayed a more prominent impact on the outcome of the TLR9-autophagy response than N-DNA. C-DNA resulted in a decreased spleen index in DSS-colitic mice. C-DNA treatment of normal mice resulted in a downregulation of Beclin1 and ATG16L1 mRNA and protein expression in the colon. These as well as LC3B were downregulated in the spleen. In contrast, the Beclin1, ATG16L1 and LC3B gene and protein expressions were upregulated in both the colon and the spleen by C-DNA injection. Moreover, C-DNA administration to DSS-colitic mice resulted in a remarkable increase of epithelial autophagic vacuoles representing an intensified macroautophagy.ConclusionsThe effect of intravenously administered fDNA on the TLR9-mediated autophagy response is expressly dependent on the origin of fDNA (i.e. inflammatory or not) and on the characteristics of the local immunobiologic milieu (i.e. inflammatory or not, as well).     

安卡鸡TLR4基因外显子2多态性及其与经济性状的关联分析

研究采用PCR-SSCP对安卡鸡TLR4基因外显子2多态性进行检测,并分析其多态性对经济性状的影响。结果表明:安卡鸡TLR4基因存在AA、AB和BB 3种基因型,基因型频率分别为0.3143、0.4000和0.2857,等位基因A、B的频率分别为0.5143和0.4857。χ2适合性检验表明,安卡鸡TLR4基因外显子2等位基因的分布处于Hardy-Weinberg平衡状态。序列分析结果显示,TLR4基因外显子2的114 bp和142 bp处各有1个G/A突变,G114A为沉默突变,没有引起氨基酸改变,G142A为错义突变,氨基酸由谷氨酸转变为赖氨酸。分析这3种基因型与安卡鸡一些重要经济性状间的关联性,表明,3种基因型个体间的生长发育性状、屠宰性状以及常规肉质等重要经济指标差异不显著,安卡鸡TLR4基因外显子2对重要经济性状没有显著的影响。     

水牛TLR4 cDNA全长的克隆及其生物信息学分析

本研究利用RT-PCR方法分段克隆水牛TLR4 cDNA后拼接成全长,并克隆于pMD20-T载体中,同时运用生物信息学软件对其核苷酸序列及编码蛋白质的结构进行分析和预测。结果表明,克隆的TLR4 cDNA ORF全长2526 bp,共编码841个氨基酸,N端具有由25个氨基酸组成的信号肽,该蛋白预测的分子质量为95.98 ku,等电点为6.37;水牛TLR4与GenBank中登录的水牛TLR4(DQ857349)核苷酸序列同源性达99.01%,与黄牛、绵羊、野猪、马、人和黑猩猩的同源性超过80%,与小鼠和狗的同源性次之,分别为72.17%和61.30%,与鸡的最低,仅为53.94%;该蛋白是由胞外区(1-634位氨基酸)、跨膜区(635-657位氨基酸)和胞内区(658-841位氨基酸)3部分构成的跨膜蛋白,胞外区含有12个LRR串联重复结构域、胞内区具有TIR结构域。本试验成功克隆了水牛TLR4 cDNA全长,并获得了核苷酸及其蛋白质的生物信息学分析数据,为进一步研究其功能奠定了基础。     

Toll-like receptor and pro-inflammatory cytokine expression during prolonged hyperinsulinaemia in horses: Implications for laminitis

Equine laminitis, a disease of the lamellar structure of the horse's hoof, can be incited by numerous factors that include inflammatory and metabolic aetiologies. However, the role of inflammation in hyperinsulinaemic laminitis has not been adequately defined. Toll-like receptor (TLR) activation results in up-regulation of inflammatory pathways and the release of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), and may be a pathogenic factor in laminitis. The aim of this study was to determine whether TLR4 expression and subsequent pro-inflammatory cytokine production is increased in lamellae and skeletal muscle during equine hyperinsulinaemia. Standardbred horses were treated with either a prolonged, euglycaemic hyperinsulinaemic clamp (p-EHC) or a prolonged, glucose infusion (p-GI), which induced marked and moderate hyperinsulinaemia, respectively. Age-matched control horses were treated simultaneously with a balanced electrolyte solution. Treated horses developed clinical (p-EHC) or subclinical (p-GI) laminitis, whereas controls did not. Skeletal muscle and lamellar protein extracts were analysed by Western blotting for TLR4, IL-6, TNF-α and suppressor of cytokine signalling 3 (SOCS3) expression. Lamellar protein expression of TLR4 and TNF-α, but not IL-6, was increased by the p-EHC, compared to control horses. A significant positive correlation was found between lamellar TLR4 and SOCS3. Skeletal muscle protein expression of TLR4 signalling parameters did not differ between control and p-EHC-treated horses. Similarly, the p-GI did not result in up-regulation of lamellar protein expression of any parameter. The results suggest that insulin-sensitive tissues may not accurately reflect lamellar pathology during hyperinsulinaemia. While TLR4 is present in the lamellae, its activation appears unlikely to contribute significantly to the developmental pathogenesis of hyperinsulinaemic laminitis. However, inflammation may have a role to play in the later stages (e.g., repair or remodelling) of the disease.     

Functional characterisation of bovine TLR5 indicates species-specific recognition of flagellin

Mammalian toll-like receptor 5 (TLR5) senses flagellin of several bacterial species and has been described to activate the innate immune system. To assess the role of bovine TLR5 (boTLR5) in the cattle system, we cloned and successfully expressed boTLR5 in human embryonic kidney (HEK) 293 cells, as indicated by quantitative PCR and confocal microscopy. However, in contrast to huTLR5-transfected cells, exposure of boTLR5-transfected cells to flagellin neither activated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) nor CXCL8 production. Subsequent comparison of the flagellin response induced in human and bovine primary macrophages revealed that flagellin did not lead to phosphorylation of major signalling molecules. Furthermore, the CXCL8 and TNFα response of primary bovine macrophages stimulated with flagellin was very low compared to that observed in human primary macrophages. Our results indicate that cattle express a functional TLR5 albeit with different flagellin sensing qualities compared to human TLR5. However, boTLR5 seemed to play a different role in the bovine system compared to the human system in recognizing flagellin, and other potentially intracellular expressed receptors may play a more important role in the bovine system to detect flagellin.     

鸡TLR3基因序列特性分析

TLR3 是发现的TLR家族中识别dsRNA 的唯一成员,越来越多的数据显示TLR3基因具有重要的抗病毒感染的功能,而关于鸡TLR3的研究较少.本研究通过生物信息学进行了鸡TLR3基因的序列特性分析.结果表明,鸡TLR3至少有两种转录产物,均包含4个编码外显子,一种预测1个896氨基酸蛋白,另一种为缺失大部分外显子3的...     

Gram-Negative Marine Bacteria: Structural Features of Lipopolysaccharides and Their Relevance for Economically Important Diseases

Gram-negative marine bacteria can thrive in harsh oceanic conditions, partly because of the structural diversity of the cell wall and its components, particularly lipopolysaccharide (LPS). LPS is composed of three main parts, an O-antigen, lipid A, and a core region, all of which display immense structural variations among different bacterial species. These components not only provide cell integrity but also elicit an immune response in the host, which ranges from other marine organisms to humans. Toll-like receptor 4 and its homologs are the dedicated receptors that detect LPS and trigger the immune system to respond, often causing a wide variety of inflammatory diseases and even death. This review describes the structural organization of selected LPSes and their association with economically important diseases in marine organisms. In addition, the potential therapeutic use of LPS as an immune adjuvant in different diseases is highlighted.     

猪TLR4基因单核苷酸多态性对转录的影响

TLR4能识别革兰氏阴性菌脂多糖,并将信号向下游传递,启动天然免疫反应并诱发获得性免疫反应,在机体的防御反应中发挥重要作用。研究利用PCR-RFLP方法对TLR4基因的3个SNPs位点(c.611 T>A、c.962 G>A和c.1027 C>A)进行基因型分析,同时利用荧光定量PCR法检测每个个体TLR4基因的表达量,统计学方法比较不同基因型个体间表达量的差别。发现SNPs c.611 T>A和c.962 G>A显著影响TLR4的转录(P<0.05)。结果表明,SNPs c.611 T>A和c.962 G>A引起的蛋白质合成量变化,影响机体免疫反应。