Effect of Figaren, an Antiviral Protein from Cucumis figarei, on Cucumber mosaic virus Infection

Local lesion formation on cowpea leaves was more than 50% inhibited by treatment with a 23 kDa RNase-like glycoprotein from Cucumis figarei, figaren, from 24 hr before to 1 hr after inoculation with Cucumber mosaic virus (CMV). CMV accumulation detected by ELISA in tobacco leaves treated with figaren 6 or 0 hr before inoculation with CMV was suppressed. When upper leaves of tobacco plants were treated with figaren and inoculated 10 min later with CMV, mosaic symptoms were delayed for 5–7 days on most of the tobacco plants, and some plants remained asymptomatic. From fluorescence in situ hybridization, infection sites were present in figaren-treated cowpea or melon leaves after inoculation with CMV, though the sites were reduced in number and size compared with those in water-treated control leaves. The amount of CMV RNAs and CMV antigen in melon protoplasts inoculated with CMV and subsequently incubated with figaren similarly increased with time as did that in the control. ELISA and local lesion assays indicated that CMV infection on the upper surfaces of the leaves of tobacco, melon, cowpea and C. amaranticolor whose lower surfaces had been treated with figaren 5–10 min before CMV inoculation was almost completely inhibited. Figaren did not inhibit CMV infection on the opposite untreated leaf halves of melon, cowpea and C. amaranticolor, whereas it almost completely inhibited CMV infection on the untreated halves of leaves of tobacco. CMV infection was not inhibited in the untreated upper or lower leaves of the four plants. These data suggest that figaren does not completely prevent CMV invasion but does inhibit the initial infection processes. It may also induce localized acquired resistance in host plants. Received 10 October 2000/ Accepted in revised form 6 February 2001     

Purification and Partial Characterization of Figaren, an RNase-like Novel Antiviral Protein from Cucumis figarei

An antiviral protein, designated figaren, was purified from leaves of Cucumis figarei and partially characterized. Column chromatography, SDS-polyacrylamide gel electrophoresis and periodic acid-Schiff staining revealed that figaren is a glycoprotein with a molecular weight of 23 kDa. Figaren was stable at pH 2 to 12 and below 90°C. N-terminal amino acid sequencing indicated that figaren contained the conserved region for the S-allele-associated ribonucleases (RNases). In-gel RNase assay showed that figaren digested yeast RNAs. Figaren also digested double-stranded RNAs extracted from Cucumber mosaic virus (CMV)-infected tobacco tissues. Fluorescence in situ hybridization revealed that figaren and RNases (beef pancrease and RNase T₁ at 1 μg/ml similarly inhibited CMV infection in cowpea leaves. Figaren and the RNases at 5-500 ng/ml had similar inhibitory effect on local lesion formation by CMV. These data suggest that figaren is a novel RNase-like antiviral protein. Received 10 October 2000/ Accepted in revised form 6 February 2001     

臭椿抗烟草花叶病毒活性物质的提取及其初步分离

以烟草花叶病毒为供试病毒,采用生物活性跟踪的方法对臭椿抗病毒活性物质进行了提取与初步分离。结果表明,臭椿乙醇提取物、甲醇提取物和丙酮提取物均有较好的抗烟草花叶病毒作用;通过系统溶剂提取、硅胶柱层析分离和活性筛选,从臭椿乙醇提取物的氯仿极性部位获得两个抗烟草花叶病毒活性组分Fr3与Fr6;经硅胶柱层析进一步分离,氯仿/甲醇梯度洗脱,得到4种相对较纯的活性成分C1、C2、C3、C4。生测结果显示,4种活性成分对烟草花叶病毒具有一定程度的抑制作用,但效果均低于原乙醇提取物,在活体条件下对烟草花叶病毒系统侵染的防治作用不明显。     

复方双黄连制剂体外抗菌抗病毒活性研究

【目的】探究复方双黄连制剂体外抗菌抗病毒活性,为复方双黄连的深度开发及家禽、家畜合理选择用药提供科学依据。【方法】将金银花、黄芩、连翘颗粒分别制成浸膏,再将药物浸膏及穿心莲颗粒按照比例制成穿心莲、双黄连（金银花：黄芩：连翘=1：1：2）和复方双黄连（金银花：黄芩：连翘：穿心莲=1：1：2：2）口服液,调节pH为7.0,生药浓度为100%。用大肠杆菌、沙门氏菌、金黄色葡萄球菌的12个菌株进行细菌敏感性检测,采用牛津杯结合试管二倍稀释法筛选出敏感菌株,根据药物的最小抑菌浓度（MIC）探讨其体外抗菌活性;采用二倍稀释法稀释药物,培养恒河猴胚肾细胞（MA-104）、鸡胚成纤维细胞（DF-1）,用CCK-8法检测细胞活力,结合细胞病变（CPE）情况确定3种药物安全浓度,将最大药物安全浓度以二倍稀释法稀释3个梯度,用新城疫病毒、轮状病毒对MA-104和DF-1进行药物+病毒互作、先加药后攻毒和先攻毒后加药3种方式的处理,用CCK-8法检测细胞活力,并结合CPE探讨药物的体外抗病毒活性。【结果】复方双黄连的抗菌效果优于穿心莲和双黄连,其对大肠杆菌、沙门氏菌和金黄色葡萄球菌的MIC分别为0.20~1.56、0.20~1.56和0.78~1.56 mg/mL。CPE和细胞活力的测定结果表明,双黄连、穿心莲、复方双黄连对DF-1细胞的安全浓度范围分别为0~6.25、0~0.78和0~0.78 mg/mL,对MA-104细胞的安全浓度范围分别为0~3.13、0~0.78和0~0.78 mg/mL。新城疫病毒17E株对DF-1细胞的TCID₅₀为10^-6.19/100 μL;牦牛轮状病毒G6P[1]型SDA2株对MA-104细胞的TCID₅₀为10^-6.24/100 μL。复方双黄连通过直接灭活病毒（药物+病毒互作）、阻断病毒吸附（先加药后攻毒）及干扰病毒复制（先攻毒后加药）途径对新城疫病毒的有效抑制率分别为28.82%、55.92%、42.45%,对轮状病毒的有效抑制率分别为48.84%、26.52%、15.40%。【结论】复方双黄连的抗菌抗病毒作用均强于双黄连和穿心莲,且其对大肠杆菌、沙门氏菌的抗菌效果优于金黄色葡萄球菌,研究结果可为复方双黄连在兽医临床应用和深入开发提供科学依据。     

Update on pathogenesis, diagnosis, and treatment of feline herpesvirus type 1

Feline herpesvirus type 1 (FHV-1) infection, but not necessarily chronic or recurrent disease, is common throughout domestic cat populations worldwide. Knowledge of a few essential virological facts permits practitioners to provide appropriate advice to owners of individual pet cats infected with this virus and to assist in the management of shelters and other multicat households in which the virus is enzootic. This article discusses pathogenesis, diagnostic techniques, and clinical signs considered characteristic of infection with FHV-1. Treatment options are considered under the broad categories of supportive care, antiviral agents, and adjunctive therapies.     

Nigrodiquinone A,a Hydroanthraquinone Dimer Containing a Rare C-9–C-7′ Linkage from a Zoanthid-Derived Nigrospora sp. Fungus

One new hydroanthraquinone dimer with a rare C-9–C-7′ linkage, nigrodiquinone A (1), and four known anthraquinone monomers 2–5, were isolated from a fungus Nigrospora sp. obtained from the zoanthid Palythoa haddoni collected in the South China Sea. The structure of 1 was established through extensive NMR spectroscopy, and the absolute configuration was elucidated by comparing computed electronic circular dichroism (ECD) and optical rotations (OR) with experimental results. All the compounds were evaluated for antiviral activity, and 1 was also evaluated for antibacterial activity. Compound 4 displayed mild antiviral activity against coxsackie virus (Cox-B3) with the IC₅₀ value of 93.7 μM, and 5 showed an IC₅₀ value of 74.0 μM against respiratory syncytial virus (RSV).     

家蚕miRNA及其在抗病毒机制中的作用

miRNA广泛存在于真核生物中,并在多种生理过程中发挥着重要的作用。本文简要介绍了家蚕miRNA及其在抗病毒机制中功能作用的研究进展。开展家蚕miRNA在家蚕抗病毒作用机制的研究,不仅有助于全面了解家蚕miRNA的功能及其调控机制,而且对于促进家蚕病毒病的早期诊断、防治和抗病育种具有重要意义。     

梅花鹿γ干扰素克隆表达及抗病毒活性测定

提取经植物血凝素诱导培养的梅花鹿外周血淋巴细胞总RNA,应用RT-PCR方法扩增出梅花鹿γ干扰素成熟蛋白基因并将其克隆到pMD18-T载体上,测序结果表明,扩增片段为梅花鹿γ干扰素成熟蛋白序列,与GenBank上发表的干扰素序列同源性为100%.将其重组到原核表达载体pET32a(+)上,并在大肠埃希菌BL21中实现了高效表达.表达产物以His-Tag融合蛋白的形式存在,表达量约占细菌总蛋白的32.6%.用镍亲和层析法对蛋白进行纯化,并利用VSV-MDBK/IBRV细胞系统分析其生物活性,重组梅花鹿γ干扰素抗病毒活性分别约为7.25×104 U/mL和4.61×104 U/mL.结果表明,重组梅花鹿γ干扰素特异性好,而且抗病毒活性比较稳定.     

从中国商陆分离的PacPAP基因转化番茄对TMV的抗性研究

以中国商陆(Phytolacca acinosa)叶片为材料,经PCR从基因组扩增克隆缺失无毒型抗病毒蛋白基因.采用叶盘法转化番茄,对转基因植株T1代摩擦接种TMV,50d后统计发病情况.结果表明:克隆得到缺失无毒型PAP基因PacPAP,大小为714bp,与美洲商陆抗病毒蛋白基因的同源性为99.7%,GenBank登陆号为AY603353;得到PacPAP整合入番茄基因组中的阳性植株11株,检测的4个转基因番茄株系均达到抗病级别,对照为感病.