硫酸化茯苓多糖对PRRSV体外感染Marc-145细胞作用的影响

用稀碱法从茯苓中提取茯苓多糖,应用氯磺酸-吡啶法得到硫酸化茯苓多糖。通过观察细胞病变(CPE)效应来评价不同浓度硫酸化茯苓多糖和不同作用方式对猪繁殖与呼吸综合征病毒(PRRSV)感染Marc-145细胞的影响。结果表明,硫酸酯化茯苓多糖预作用于单层细胞12 h后感染104TCID50PRRSV,能明显阻断病毒感染细胞,其阻断病毒感染作用的最小浓度为100 mg/L;而硫酸化茯苓多糖预作用4 h后感染104TCID50的PRRSV阻断感染作用不明显,显示硫酸化茯苓多糖体外对PRRSV感染细胞的阻断感染作用呈一定的浓度和时间依赖性。感染剂量为104TCID50PRRSV后加入不同浓度硫酸化茯苓多糖,也能有效抑制病毒在细胞上的感染与增殖,其作用最小浓度为50 mg/L;而不同浓度多糖与104TCID50病毒在体外共同孵育12 h后加入到单层细胞,多糖直接杀灭PRRSV的最小浓度为100 mg/L。     

桦褐孔菌多糖的提取及体外抗新城疫病毒活性试验

为研究桦褐孔菌多糖抗新城疫病毒活性,本试验采用水提醇沉法提取桦褐孔菌多糖,用苯酚-硫酸比色法,以葡萄糖为标准品测定桦褐孔菌菌核多糖提取率。并将提取的多糖配制成试验所需浓度用于测定其体外抗新城疫病毒活性。MTT法检测预先加多糖、接种病毒后加多糖和多糖与病毒同时加入3种不同方法对新城疫病毒的抗病毒活性。结果初步说明桦褐孔菌多糖具有一定的抗病毒活性,为新型抗新城疫病毒药物或疫苗的研发奠定基础。     

褐藻多糖硫酸脂对小鼠免疫及抗日本乙型脑炎病毒的影响

为了研究褐藻多糖硫酸脂(fucoidan)对小鼠免疫及抗病毒调节作用,研究采用体内和体外试验研究褐藻多糖硫酸脂的免疫调节及抗日本乙型病毒(JEV)作用。结果表明:褐藻多糖硫酸脂能够促进脾脏淋巴细胞增殖,调节CD_4~+T细胞(CD_3~+ CD_4~+)/CD8T细胞(CD_3~+ CD_8~+)/B细胞(B 220+)亚群。说明褐藻多糖硫酸脂能够上调JEV灭活疫苗的抗体水平,同时促进Th1细胞因子IFN-γ及Th2细胞因子IL-4的表达。进一步研究发现褐藻多糖硫酸脂能够直接抑制JEV的复制。说明褐藻多糖硫酸脂具有潜在的抗病毒及免疫调节作用,可作为免疫增强剂及抗日本乙型脑炎的新型药物。     

硫酸多糖抗病毒活性构效关系

近年来随着糖生物学的发展,硫酸多糖独特的抗病毒活性越来越被人们所关注.多糖的功能与结构密切相关,多糖构效关系的研究已经成为人们关注的一个热点.论文对已研究发现的硫酸多糖,从结构出发就构效关系如硫酸基取代度、硫酸基取代位置、分子质量等对抗病毒活性的影响进行详细阐述,以期对新型硫酸多糖的研究与开发提供一定的参考.     

动物抗病毒药物的开发与应用

我国因病毒感染导致动物死亡的比率在所有病因中居第2位,仅次于细菌感染的致死率,占36.8％,且发病率呈上升趋势。很多病毒感染动物,形成多种急、慢性传染病,危害畜牧业健康发展。药物防治作为抗病毒感染的主要手段之一,近年来进展迅速。但由于病毒结构简单,仅由一种核酸（RNA或DNA）和蛋白质组成,缺乏完整的酶系统,有严格的寄生性,需借助宿主细胞的功能而繁殖。病毒只能在敏感的细胞内培养或感染易感动物。抗病毒药物必须通过细胞膜,进入细胞,作用于病毒。不少抗病毒物质对细胞或机体有毒而不能应用,大大限制了抗病毒药物的发展。一种有效的抗病毒药物必须是既能防止病毒吸附于宿主细胞表面,又能特异性抑制病毒复制过程中的某些步骤。理想的药物应当不影响机体细胞的代谢。然而,因为许多代谢步骤为病毒和细胞的功能所共有,所以很难研制出一种无毒的抗病毒药物。许多抗病毒药物在体外细胞培养中虽然是病毒复制的强抑制剂,但在动物体内却有毒性。     

8种中药多糖及其硫酸化衍生物对新城疫病毒的影响

选定8种含有多糖的中药为药效跟踪研究对象,对8种中药进行多糖提取、纯化多糖,氯磺酸-吡啶法进行多糖硫酸化修饰,采用体外鸡胚成纤维细胞培养法研究多糖抗新城疫病毒的活性,MTT法结合CPE观察法检测评价多糖抗新城疫病毒作用。结果显示,8种多糖均具有一定抗病毒活性,以黄芪多糖效果最明显,治疗指数达8,当归多糖、板蓝根多糖次之,紫草及黄精多糖效果不显著,治疗指数低于2。硫酸化修饰使得当归和大黄多糖的抗病毒活性增强,治疗指数高达16,表现强抗NDV作用。     

抗病毒免疫分子IFITMs的研究进展

干扰素诱导跨膜转运蛋白是细胞内具有广谱抗病毒作用的抑制因子.其属于dispanin蛋白家族中的一个亚族并具有多种功能,其中其抗病毒功能是主要的研究热点.由于IFITMs,尤其IFITM3,能抑制禽流感等病毒的早期复制因而近年来得到了广泛的关注.目前研究发现,IFITMS主要通过核内体途径阻止病毒的入侵,从而影响病毒的复制.然而,其具体的抗病毒机制还未完全阐释清楚.本文就近年来IFITMs蛋白抗病毒功能的研究进展对其结构特征、细胞亚定位及其抗病毒机制等方面作一一综述.     

硫酸化银杏叶多糖的制备及对犬细小病毒疫苗免疫增强作用的研究

本研究通过水提醇沉淀法从银杏叶干粉中提取粗多糖,经脱色素、除蛋白等处理得到精制银杏叶多糖,利用氯磺酸—吡啶法制得硫酸化银杏叶多糖,其多糖含量为68.6%,蛋白含量为2.59%,硫酸基含量为16.4%,硫酸基取代度为1.74;通过犬的体内免疫实验,研究硫酸化银杏叶多糖对犬细小病毒活疫苗免疫反应的影响。结果表明,硫酸化银杏叶多糖能够不同程度的提高免疫后血清CPV抗体水平和IL-2的含量。由此表明,硫酸化银杏叶多糖对犬细小病毒活疫苗具有免疫协同作用,这为硫酸化银杏叶多糖作为免疫增强剂的开发奠定了试验基础。     

抗病毒药物在畜禽中的应用

<正>抗病毒药物是用于预防和治疗病毒感染的药物,可抑制病毒复制酶。病毒与细菌不同,缺乏自身繁殖的酶系统,是细胞内寄生的微生物,依赖宿主细胞代谢系统进行生殖复制。而药物在对病毒产生作用的同时也作用于宿主细胞,从而产生毒性作用。主要分抗病毒细胞因子和化学药物,下面对其在兽医临床上的应用分别进行介绍。1抗病毒细胞因子干扰素是活性很强的生物制剂,其比     

畜牧兽医中多糖的应用探讨

多糖是一种高分子化合物,由于其活性非常独特,渐渐引起了畜牧兽医领域的关注.多糖具备一定的抗病毒作用与抗肿瘤作用,人们把多糖运用在畜牧兽医领域,使得其抗病毒作用与抗肿瘤作用得到充分体现.     

甘草多糖和甘草酸对NDV感染鸡胚成纤维细胞能力的影响

从甘草中提取甘草多糖和甘草酸,进行抗病毒活性比较。用MTT法比较了它们对鸡胚成纤维细胞(CEF)生长及以三种加药方式(先药后毒、先毒后药、药毒同时)抵抗新城疫病毒(NDV)感染细胞的影响,并用平均病毒抑制率比较甘草多糖和甘草酸的抗病毒活性。结果表明,先药后毒,甘草多糖能显著抑制NDV感染细胞(P0.05),平均病毒抑制率为60.6%;先毒后药,甘草多糖和甘草酸都能显著抑制NDV感染细胞(P0.05),其中甘草多糖的平均病毒抑制率为74.28%,甘草酸为62.3%。通过平均病毒抑制率比较,表明甘草多糖的抗病毒活性优于甘草酸。     

Anti-influenza A virus activities of mannan-binding lectins and bovine conglutinin

Mannan-binding lectin (MBL) and bovine conglutinin (BKg) belong to the collectin family, which is involved in first-line host defense against various infectious agents. We have previously reported that human MBL inhibited type A influenza viral hemagglutination, infection and spreading to adjacent cells without complement activation. In this study, we investigated the direct antiviral activities of bovine MBL, rabbit MBL and BKg. All collectins used in this study inhibited viral infectivity and hemagglutination at concentrations of 0.02-0.3 microg/ml. They also demonstrated inhibitory activity against viral spreading. Like human MBL, bovine MBL and BKg showed antiviral activities at their physiological concentrations. These results suggest that mammalian MBLs and BKg may inhibit the spread of influenza A virus through the bloodstream.     

Inhibition of African swine fever virus in liquid and feed by medium-chain fatty acids and glycerol monolaurate

Background: The ongoing African swine fever virus(ASFv) epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority. It has been recently identified that feed and feed ingredients, along with drinking water, can serve as transmission vehicles and might facilitate transboundary spread of ASFv. Thus, it is important to test the antiviral activity of regulatory compatible,antiviral feed additives that might inhibit ASFv infectivity in feed. One promising group of feed additive candidates includes medium-chain fatty acids(MCFA) and monoglyceride derivatives, which are known to disrupt the lipid membrane surrounding certain enveloped viruses and bacteria.Results: The antiviral activities of selected MCFA, namely caprylic, capric, and lauric acids, and a related monoglyceride, glycerol monolaurate(GML), to inhibit ASFv in liquid and feed conditions were investigated and suitable compounds and inclusion rates were identified that might be useful for mitigating ASFv in feed environments. Antiviral assays showed that all tested MCFA and GML inhibit ASFv. GML was more potent than MCFA because it worked at a lower concentration and inhibited ASFv due to direct virucidal activity along with one or more other antiviral mechanisms. Dose-dependent feed experiments further showed that sufficiently high GML doses can significantly reduce ASFv infectivity in feed in a linear manner in periods as short as 30 min, as determined by infectious viral titer measurements. Enzyme-linked immunosorbent assay(ELISA) experiments revealed that GML treatment also hinders antibody recognition of the membrane-associated ASFv p72 structural protein, which likely relates to protein conformational changes arising from viral membrane disruption.Conclusion: Together, the findings in this study indicate that MCFA and GML inhibit ASFv in liquid conditions and that GML is also able to reduce ASFv infectivity in feed, which may help to curb disease transmission.     

褐藻岩藻聚糖生物活性的研究进展

褐色海藻富含对人体有益的功能性多糖——硫酸化多糖。多年来,从褐色海藻中分离出的硫酸多糖在药物、保健品、化妆品和功能性食物等领域中具有广阔的应用前景。岩藻聚糖作为褐藻多糖中的一员,其复杂的生物特性已被证明具有开发和进行工业化生产的价值,从而获得对人体有益的成分。由于海藻多糖具有上述特性,故作者主要对从褐色海藻中分离出的岩藻聚糖(又叫多糖硫酸酯)的抗凝血、抗血栓、免疫调节、抗肿瘤等生物活性方面及其在工业生产中应用等方面进行了综述。     

In-vitro antiviral efficacy of ribavirin and interferon-alpha against canine distemper virus

Canine distemper is a highly contagious disease with high incidence and lethality in the canine population. The objective of this study was to evaluate the efficacy of antiviral action with ribavirin (RBV), interferon-alpha (IFNα), and combinations of RBV and IFNα against canine distemper virus (CDV). Vero cells inoculated with CDV were treated with RBV, IFNα, and combinations of these drugs. The efficacy to inhibit viral replication was evaluated by adding the compounds at different times to determine which step of the viral replicative process was affected. Both drugs were effective against CDV in vitro. The IFNα was the most active compound, with an average IC₅₀ (50% inhibitory concentration) value lower than the IC₅₀ of the RBV. Ribavirin (RBV) was more selective than IFNα, however, and neither drug showed extracellular antiviral activity. The combination of RBV and IFNα exhibited antiviral activity for the intra- and extracellular stages of the replicative cycle of CDV, although the intracellular viral inhibition was higher. Both RBV and IFNα showed high antiviral efficacy against CDV, and furthermore, RBV + IFNα combinations have shown greater interference range in viral infectivity. These compounds could potentially be used to treat clinical disease associated with CDV infection.     

动物干扰素研究概况

随着我国养殖业的迅猛发展,各种疾病的发生和危害日益加重,特别是病毒性疫病,已成为传染病的主体。对于病毒性疾病的治疗仍然缺乏有效的药物,且大多数尚无效果可靠的疫苗,再加上新发和再发病不断出现,使得病毒病危害尤为突出,急待寻找提高机体免疫、抵抗病毒感染的替代药物。干扰素(IFN)作为一种细胞因子具有广谱抗病毒、抗肿瘤和免疫调节活性,还可以促进机体免疫反应,提高机体抗病毒感染能力,使病毒在机体存活和复制的几率降到最低。目前发现Ⅰ型、Ⅱ型和Ⅲ型3种类型的IFN,利用3种类型的IFN的抗病毒和调节免疫的功能,研究抑制病毒复制的新型生物制剂,成为人们关注和研究的热点,为病毒性疫病,特别是新发或突发的重大疫病防控提供参考。     

In vitro effect of isoprinosine on rabies virus

The in vitro effect of isoprinosine, an antiviral compound, was evaluated on ERA and VA319 rabies viral strains. Isoprinosine diminished the number of immunofluorescent cells, viral titers, and structures involved in rabies virus replication. Mechanism of antiviral action was probably mediated by modification of the polyribosome conformation and function.     

Evaluation of antiviral activity of phenolic compounds and derivatives against rabies virus

Human rabies is a viral disease with a great impact on public health, mainly on account of its fatal course in the majority of cases. Despite the well-established prophylaxis by immunization, rabies is believed to be responsible for 40,000-70,000 human deaths per year, mostly in endemic areas. Palliative support and experimental protocols to avoid death have been employed with no expressive results, with the exception of a recent human case of recovery from rabies. No antiviral drugs are currently available to fight against this infection. In combination with the prophylaxis, an antiviral drug would be useful for human rabies treatment, providing enhanced protection against the encephalitis caused by the virus. Phenolic compounds are derived from the secondary plant metabolism, although they can also be obtained by synthetic processes. Many studies have shown a great range of pharmacological effects for these substances, including vasodilatation, antiallergenic, antiinflammatory and antiviral properties, among others. In this study, the potential in-vitro anti-rabies activity of 24 synthetic phenolic compounds was evaluated using McCoy cells and PV rabies strain. The cytotoxicity (CC50) was assayed by the MTT method and the antiviral activity (IC50) was estimated by the inhibition of viral cytopathic effects. Isoprinosine and ketamine were used as positive controls. The tested compounds showed selectivity indices (SI=CC50/IC50) ranging from 1.0 to 3.9. Six phenolic compounds failed to inhibit the cytopathic effect to any degree, and four showed SI > or = 3.0. According to these results, some probable structure-activity relationships are suggested. It was observed that the presence of free hydroxyl and ether groups influenced the anti-rabies activity. However, additional studies are required to establish these relationships.     

Stimulation with a class A CpG oligonucleotide enhances resistance to infection with feline viruses from five different families

ABSTRACT: Domestic cats are commonly affected by viral pathogens that induce lengthy infections with fatal outcomes. Prevention of viral propagation is of primordial importance in shelters and catteries, where cats from different backgrounds have narrow contacts. Oligonucleotides (ODN) containing cytosine-phosphate-guanosine motifs of class A (CpG-A) are highly potent synthetic inducers of innate antiviral mechanisms. The aim of this study was to test their ability to modulate innate immune responses and prevent viral replication as stand-alone agents in the domestic cat. CpG-A stimulation of feline peripheral blood mononuclear cells (PBMCs) enhanced their proliferation, increased the presence of co-stimulatory molecules on their surface and influenced their gene expression profiles in an antiviral orientation. Incubation of the supernatants of CpG-A stimulated PBMCs with feline cell lines of epithelial and fibroblastic origin induced expression of the antiviral myxovirus resistance (Mx) gene in these target cells, which also showed enhanced resistance to feline viruses from five distinct families, namely Coronaviridae, Herpesviridae, Caliciviridae, Parvoviridae, and Retroviridae. Most importantly, subcutaneous administration of CpG-A in domestic cats systemically increased the expression of Mx, reaching maximal levels within 24 h. Plasma from treated cats could furthermore inhibit viral replication in vitro. Altogether, our data highlight the promising potential of CpG-A to induce a preventive antiviral state in the cat and to protect feline populations against a broad range of virus infections.