水稻稻瘟病菌特异性抗病蛋白质的初步鉴定

稻瘟病抗病品种“地优63”的组织蛋白提取液对稻瘟菌株A_(15)的孢子萌发有显著抑制作用,而感病品种“索马里稻V_(41)B”则否,此抑制作用与“地优63”的蛋白质组成有关。IEF电泳显示,在“索马里稻V_(41)B”中有一pI为5.4的蛋白质与孢子吸附后消失。

用免疫组织化学染色法检测棉花幼苗根尖的枯萎病抗性蛋白质

我们实验室在棉花枯萎病的工作中从川-52128等抗病棉花品种里纯化、鉴定了一个具有生理小种(生理型)特异性的、组成型表达的抗病蛋白质R,其特异性与这个棉花品种在田间的抗病表型一致。蛋白质R在体外(7μg/ml)能抑制不亲和的棉枯萎病镰刀菌[Fusarium oxysporum f.sp.vasinfectum(ATK)Snyder & Hansen]孢子的萌发和菌丝体的生长。从感病棉花品种中也纯化了一个与蛋白质R相对应的蛋白质S。

玉米抗大斑病菌品种特异性抗病蛋白的初步研究

采用有机溶剂提取和聚丙烯酰胺等电聚焦电泳方法，从玉米抗大斑病菌品种“苏玉四号”叶片中初步鉴定了其特异性抗病蛋白。通过与大斑病菌孢子的孵育实验，确认该特异性蛋白质能与孢子产生吸附，并对孢子的萌发有较强的抑制作用，并对兔红细胞有凝集作用，该特异性抗病蛋白质的等电点为５．０。

参与植物防御反应的LRR型蛋白结构与功能

植物含有多种富含亮氨酸重复(LRRs)结构的蛋白质,它们在植物生长、发育和抗病反应等方面发挥着重要作用。综述了这类具有LRRs结构蛋白质家族的结构特征及其参与植物防御反应的功能。参与植物防御反应LRR型蛋白质家族包括:抗病基因编码蛋白质、类受体蛋白激酶、多聚半乳糖醛酸酶抑制蛋白和伸展蛋白家族。这四大蛋白质家族成员主要通过LRRs结构识别并结合病原物蛋白质,参与抗病信号传递,诱导植物防卫基因的表达,使植物获得系统抗性。其中LRRs序列中氨基酸的不同和单位重复数目的差异决定了蛋白识别的特异性和结合能力。

Negative feedback regulation of cellular antiviral signaling by RBCKl-mediated degradation of IRF3

Viral infection causes host cells to produce type I interferons （IFNs）, which are critically involved in viral clearance. Previous studies have demonstrated that activation of the transcription factor interferon regulatory factor （IRF）3 is essential for virus-triggered induction of type I IFNs. Here we show that the E3 ubiquitin ligase RBCC protein interacting with PKC1 （RBCK1） catalyzes the ubiquitination and degradation of IRF3. Overexpression of RBCK1 negatively regulates Sendai virus-triggered induction of type I IFNs, while knockdown of RBCK1 has the opposite effect. Plaque assays consistently demonstrate that RBCKI negatively regulates the cellular antiviral response. Furthermore, viral infection leads to induction of RBCK1 and subsequent degradation of IRF3. These findings suggest that the cellular antiviral response is controlled by a negative feedback regulatory mechanism involving RBCKl-mediated ubiquitination and degradation of IRF3.

Ribosome Inactivating Proteins from Plants Inhibiting Viruses

Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.

Analysis of the human Atox 1 homologue in Wilson patients

AIM: To analyze the metallochaperone antioxidant-1 (Atox1) gene sequence in Wilson disease patients. METHODS: Mutation analysis of the four exons of the Atox1 gene including the intron- exon boundaries was performed in 63 Wilson disease patients by direct sequencing. RESULTS: From 63 selected patients no mutations were identified after the entire coding region including the intron- exon boundaries of Atox1 were sequenced. One known polymorphism within the Atox1 gene (5’UTR -99 T>C) in 31 (49%) of the Wilson patients as well as one previously undescribed variation (5’UTR -68 C>T) in 2 of the Wilson patients could be detected. Statistical analyses revealed that the existence of a variation within the Atox1- gene showed a tendency towards an earlier onset of the disease. CONCLUSION: Based on the data of this study, no major role can be attributed to Atox1 in the pathophysiology or clinical variation of Wilson disease.

Survivin Antisense Oligodeoxy-Nucleotid Induces Apoptosis in Leukaemia Cell Line K562

OBJECTIVE To investigate the effects of survivin antisense oligodeoxy-nucleotid (ASODN) on proliferation and apoptosis in the chronic myeloid leukemia cell line K562. METHODS Different concentrations of an antisense oligodeoxy-nucleotid and control sequence (scrambled ODN) targeting the survivin gene were transferred into K562 by a lipofectin reagent. The MTT assay was used to measure the growth inhibitory rate, IC50, and to observe the cytotoxicity of survivin ASODN in the K562 cells. The morphologic changes in the nucleus and the apoptotic rate were observed by Hoechst33342/PI staining. Caspase-3 activity was evaluated by a kinase activity assay. The changes of survivin protein expression after transfection were detected by Western blots. RESULTS Eight hours after transfection, fluorescence in the K562 cells was well distributed. Treatment of the cells for 44 h with different concentrations of survivin ASODN produced a IC50 of 800 nmol/L. The growth inhibitory rate with 200, 400, 600 and 1000 nmol/L of survivin ASODN was 15.8±1.6%, 23.8±5.9%, 37.1±5.6% and 77.3±2.5% respectively. After 36 h of of survivin ASODN treatment, distinct morphologic changes characteristic of cell apoptosis such as karyopyknosis and conglomeration were observed by Hoechst33342/PI staining. Caspase-3 activity increased significantly after treatment of the cells with different concentrations of survivin ASODN(P<0.01)and following treatment with 800 nmol/L survivin ASODN, survivin expression decreased significantly. CONCLUSION Survivin ASODN exerts an anti-cancer effect by inducing apoptosis in K562 leukaemia cells. Up-regulated expression of caspase-3 may play a role in this process.

Comparison between surgical outcomes of colorectal cancer in younger and elderly patients

AIM:To compare the outcome of surgical treatment of colorectal adenocarcinoma in elderly and younger patients.METHODS:The outcomes of 122 patients with colorectal adenocarcinoma who underwent surgical treatment between January 2004 and June 2009 were analyzed.The clinicopathological and blood biochemistry data of the younger group(<75 years) and the elderly group (≥75 years) were compared.RESULTS:There were no significant differences between the two groups in operation time,intraoperative blood loss,hospital stay,time to resumption of oral intake,or morbidity.The elderly group had a significantly higher rate of hypertension and cardiovascular disease.The perioperative serum total protein and albumin levels were significantly lower in the elderly than in the younger group.The serum carcinoembryonic antigen level was lower in the elderly than in the younger group,and there was a significant decreasing trend after the operation in the elderly group.CONCLUSION:The short-term outcomes of surgical treatment in elderly patients with colorectal adenocarcinoma were acceptable.Surgical treatment in elderly patients was considered a selectively effective approach.

Isolation and Identification of Canine Parvovirus Serotype 2a and Its VP2 Protein Expression in Transgenic Tobacco

A strain of canine parvovirus(CPV)was isolated from feces of an ill puppy in an animal hospital in Wuhan, China. It was designated as CPV/WH02/06. This isolate was identified as serotype CPV-2a by the hemagglutination test, CPV Ag detection strip, electron microscopy, and PCR. The vp2 gene was cloned and sequenced and assigned GenBank accession number EU377537. A 1242 bp segment of the 5' region of the vp2 gene was cloned and inserted into the binary vector pBI121 and used for Agrobacterium-mediated tobacco transformation. Transgenic tobacco plants were selected on MS medium supplemented with 100 μg/mL kanamycin and 100 μg/mL timentin. Integration of the vp2 gene into the tobacco genome was confirmed by PCR using T1 progeny plants, and the expression of the VP2 protein was confirmed by Western blotting.

Herpes Simplex Virus Type 1 ICP27 Protein:Its Expression, Purification and Specific Antiserum Production

Herpes simplex virus type 1 (HSV-1) is the causative agent of cold sores and other more serious diseases. HSV-1 infected-cell protein 27 (ICP27) is an immediate-early regulatory phosphoprotein homologous to gene products identified in all classes of herpesviruses so far. To raise the antiserum to ICP27 for further characterization of its biological function, the ICP27 gene was cloned into the pET-28a (+) vector, then ICP27 protein was expressed in E. coli and purified by nickel-nitrilotriacetic acid (Ni 2+ -NTA) affinity resin column, finally the purified protein was used to raise antiserum. Western blot analysis demonstrated that the antiserum recognized the recombinant protein, and the antiserum was able to probe the ICP27 in HSV-1 infected cells with high specificity by immunofluorescence assay (IFA). Therefore, the specific antiserum will provide a valuable tool for further studies investigating ICP27's biological function during HSV-1 infection.

Subcellular Localization Analysis of Bovine Foamy Virus Borf1 Protein

The Borfl protein is encoded by an immediate-early gene of the bovine foamy virus （BFV） and plays a key role in the viral life cycle. Borfl is a DNA binding protein which can transactivate both the long terminal repeat （LTR） and the internal promoter （IP） of BFV by specifically binding to the transactivation responsive element （TRE）. To analyze the subcellular localization of Borfl during the BFV life cycle, this gene was cloned into a prokaryotic expression vector and expressed in a soluble form. After the purification and immunization, we raised the mouse anti-Borfl serum with a high titer based on ELISA results. Western blot analysis showed that the antiserum could specifically recognize the Borfl protein that was expressed in 293T cells. With this specific serum, we revealed the nuclear and cytoplasmic localization of Borfl in HeLa cells that was transfected with Borfl. Moreover, the immuno-fluorescence assay also showed that the localization of Borfl during the infection and transfection of BFV was identical.

Effects of Chinese Herbmedicines as Feed Additives on Resistance of Trionyx sinensis to Diseases

In the-comparison between two experimental turtle (Trionyx sinensis) groups fed on the feed containing 1 % or 2% Chinese medicinal herb powder and the contrast group to which no Chinese herb was fed,no obvious difference of γ-globulin level in the turtles' serum was found,but the survival rate of the experimental groups was obviously higher than that of the contrast group,and cell immunity of the experimental groups was significantly higher when tested by subcutaneous injection of PHA.Meanwhile,the Chinese herb promoted the growth of the turtles.

Stress Granule Formation is One of the Early Antiviral Mechanisms for Host Cells Against Coxsackievirus B Infection

Stress granules(SGs) are intracellular granules formed when cellular translation is blocked and have been reported to be involved in a variety of viral infections. Our previous studies revealed that SGs are involved in the coxsackievirus B(CVB)infection process, but the role of SGs in CVB infection has not been fully explored. In this study, we found that CVB type 3(CVB3) could induce SG formation in the early phase of infection. Results showed that levels of CVB3 RNA and protein were significantly inhibited during the early stage of CVB3 infection by the elevated formation of SGs, while viral RNA and protein synthesis were significantly promoted when SG formation was blocked. Our findings suggest that SG formation is one of the early antiviral mechanisms for host cells against CVB infection.