Yeast-expressed classical swine fever virus glycoprotein E2 induces a protective immune response   总被引：4，自引：0，他引：4  

Guang-Jan Lin  Ting-Yu Liu  Yu-Yao Tseng  Zeng-Weng Chen  Chia-Chin You  Shih-Ling Hsuan  Maw-Sheng Chien  Chienjin Huang   《Veterinary microbiology》2009,139(3-4):369-374

Classical swine fever (CSF) is an economically important swine disease worldwide. The glycoprotein E2 of classical swine fever virus (CSFV) is a viral antigen that can induce a protective immune response against CSF. A recombinant E2 protein was constructed using the yeast Pichia pastoris expression system and evaluated for its vaccine efficacy. The yeast-expressed E2 (yE2) was shown to have N-linked glycosylation and to form homodimer molecules. Four 6-week-old specified-pathogen-free (SPF) piglets were intramuscularly immunized with yE2 twice at 3-week intervals. All yE2-vaccinated pigs could mount an anamnestic response after booster vaccination with neutralizing antibody titers ranging from 1:96 to 1:768. Neutralizing antibody titers at 10 weeks post booster vaccination ranged from 1:16 to 1:64. At this time, the pigs were subjected to challenge infection with a dose of 1 × 10⁵ TCID₅₀ (50% tissue culture infective dose) virulent CSFV strain. At 1 week post challenge infection, all of the yE2-immunized pigs were alive and without symptoms or signs of CSF. Neutralizing antibody titers at this time ranged from 1:4,800 to 1:12,800 and even to 1:51,200 one week later. In contrast, the control pigs continuously exhibited signs of CSF and had to be euthanized because of severe clinical symptoms at 6 days post challenge infection. All of the yE2-vaccinated pigs were E^rns antibody negative and had seroconverted against E^rns by post challenge day 11, suggesting that yE2 is a potential DIVA (differentiating infected from vaccinated animals) vaccine. The yeast-expressed E2 protein retains correct immunogenicity and is able to induce a protective immune response against CSFV infection.  相似文献   

GSK3-TIP60-ULK1 signaling pathway links growth factor deprivation to autophagy   总被引：1，自引：0，他引：1  

Lin SY  Li TY  Liu Q  Zhang C  Li X  Chen Y  Zhang SM  Lian G  Liu Q  Ruan K  Wang Z  Zhang CS  Chien KY  Wu J  Li Q  Han J  Lin SC 《Science (New York, N.Y.)》2012,336(6080):477-481

In metazoans, cells depend on extracellular growth factors for energy homeostasis. We found that glycogen synthase kinase-3 (GSK3), when deinhibited by default in cells deprived of growth factors, activates acetyltransferase TIP60 through phosphorylating TIP60-Ser(86), which directly acetylates and stimulates the protein kinase ULK1, which is required for autophagy. Cells engineered to express TIP60(S86A) that cannot be phosphorylated by GSK3 could not undergo serum deprivation-induced autophagy. An acetylation-defective mutant of ULK1 failed to rescue autophagy in ULK1(-/-) mouse embryonic fibroblasts. Cells used signaling from GSK3 to TIP60 and ULK1 to regulate autophagy when deprived of serum but not glucose. These findings uncover an activating pathway that integrates protein phosphorylation and acetylation to connect growth factor deprivation to autophagy.  相似文献   

Kinetic studies of cholesterol oxidation as inhibited by stearylamine during heating     

Chien JT  Huang DY  Chen BH 《Journal of agricultural and food chemistry》2004,52(23):7132-7138

The formation of cholesterol oxidation products (COPs) during heating in the presence of stearylamine at 140 degrees C was analyzed by high-performance liquid chromatography (HPLC) and kinetically studied by use of nonlinear regression models. Results indicated that the COPs concentration increased with increasing heating time, and stearylamine was shown to reduce both oxidation and degradation rates of cholesterol. Without stearylamine, the highest rate constant (per hour) was observed for epoxidation (545.4), followed by free radical chain reaction (251.0), reduction (147.3), dehydration (95.8), triol dehydrogenation (4.7), degradation (0.34), triol formation (0.31), and dehydrogenation (0.13). With stearylamine, the epoxidation and free radical chain reaction rates could be reduced by about 800- and 3.4-fold, respectively, and triol formation during oxidation could be completely inhibited. In addition, the reactions for reduction, dehydration, degradation, and dehydrogenation could proceed slower in the presence of stearylamine. The kinetic model developed in this study can be used to predict the inhibition of COPs formation by stearylamine during heating of cholesterol.  相似文献   

Plant litter decomposition influenced by soil animals and disturbance in a subtropical rainforest of Taiwan     

Ping-Chun L. Hou  Xiaoming Zou  Ching-Yu Huang  Hao-Jian Chien 《Pedobiologia》2005,49(6):315-547

Soil fauna has been postulated as one of the paramount determinants of decomposition in the humid tropics. However, its effect on litter decomposition has only been demonstrated in few forest sites in Central America. In addition, landslide is a common disturbance associated with heavy rainfall brought by tropical cyclones in the tropics and can potentially alter abundance and structure of soil animals and thus affect litter decomposition. In this study, we examined the effect of soil animals on litter decomposition in an Asian subtropical monsoon forest and compared the animal effects in landslide-disturbed (2 years old) and undisturbed sites. Animal exclusion by naphthalene treatment significantly reduced the density and diversity of litterbag animals and slowed down the rate of decomposition in both landslide-disturbed and undisturbed sites. However, density (per unit area) and diversity of the litter animals and litter decomposition rate did not differ between the landslide-disturbed and undisturbed sites for both control and animal-excluded treatments. Our data suggest that the abundance of soil animals is not limited by litter mass. Furthermore, soil fauna recover quickly from landslides, and fauna's facilitative effect on litter decomposition is not altered after their recovery.  相似文献   

Antigen recognition determinants of gammadelta T cell receptors     

Shin S  El-Diwany R  Schaffert S  Adams EJ  Garcia KC  Pereira P  Chien YH 《Science (New York, N.Y.)》2005,308(5719):252-255

The molecular basis of gammadelta T cell receptor (TCR) recognition is poorly understood. Here, we analyze the TCR sequences of a natural gammadelta T cell population specific for the major histocompatibility complex class Ib molecule T22. We find that T22 recognition correlates strongly with a somatically recombined TCRdelta complementarity-determining region 3 (CDR3) motif derived from germ line-encoded residues. Sequence diversity around these residues modulates TCR ligand-binding affinities, whereas V gene usage correlates mainly with tissue origin. These results show how an antigen-specific gammadelta TCR repertoire can be generated at a high frequency and suggest that gammadelta T cells recognize a limited number of antigens.  相似文献   

The outcome of acute hepatitis C predicted by the evolution of the viral quasispecies     

Farci P  Shimoda A  Coiana A  Diaz G  Peddis G  Melpolder JC  Strazzera A  Chien DY  Munoz SJ  Balestrieri A  Purcell RH  Alter HJ 《Science (New York, N.Y.)》2000,288(5464):339-344

The mechanisms by which hepatitis C virus (HCV) induces chronic infection in the vast majority of infected individuals are unknown. Sequences within the HCV E1 and E2 envelope genes were analyzed during the acute phase of hepatitis C in 12 patients with different clinical outcomes. Acute resolving hepatitis was associated with relative evolutionary stasis of the heterogeneous viral population (quasispecies), whereas progressing hepatitis correlated with genetic evolution of HCV. Consistent with the hypothesis of selective pressure by the host immune system, the sequence changes occurred almost exclusively within the hypervariable region 1 of the E2 gene and were temporally correlated with antibody seroconversion. These data indicate that the evolutionary dynamics of the HCV quasispecies during the acute phase of hepatitis C predict whether the infection will resolve or become chronic.  相似文献   

Identification of virus-encoded microRNAs   总被引：1，自引：0，他引：1  

Pfeffer S  Zavolan M  Grässer FA  Chien M  Russo JJ  Ju J  John B  Enright AJ  Marks D  Sander C  Tuschl T 《Science (New York, N.Y.)》2004,304(5671):734-736

RNA silencing processes are guided by small RNAs that are derived from double-stranded RNA. To probe for function of RNA silencing during infection of human cells by a DNA virus, we recorded the small RNA profile of cells infected by Epstein-Barr virus (EBV). We show that EBV expresses several microRNA (miRNA) genes. Given that miRNAs function in RNA silencing pathways either by targeting messenger RNAs for degradation or by repressing translation, we identified viral regulators of host and/or viral gene expression.  相似文献   

astray, a zebrafish roundabout homolog required for retinal axon guidance     

Fricke C  Lee JS  Geiger-Rudolph S  Bonhoeffer F  Chien CB 《Science (New York, N.Y.)》2001,292(5516):507-510

As growing retinotectal axons navigate from the eye to the tectum, they sense guidance molecules distributed along the optic pathway. Mutations in the zebrafish astray gene severely disrupt retinal axon guidance, causing anterior-posterior pathfinding defects, excessive midline crossing, and defasciculation of the retinal projection. Eye transplantation experiments show that astray function is required in the eye. We identify astray as zebrafish robo2, a member of the Roundabout family of axon guidance receptors. Retinal ganglion cells express robo2 as they extend axons. Thus, robo2 is required for multiple axon guidance decisions during establishment of the vertebrate visual projection.  相似文献   

Effects of pH values and application methods of potassium silicate on nutrient uptake and bacterial spot of tomato     

Chien  Yi-Chun  Huang  Cheng-Hua 《European journal of plant pathology / European Foundation for Plant Pathology》2022,162(1):119-130

European Journal of Plant Pathology - Bacterial spot is a destructive disease of tomato that is caused by four taxonomically distinct Xanthomonas species. This study aimed to evaluate the effects...  相似文献   

Failure to regulate TNF-induced NF-kappaB and cell death responses in A20-deficient mice     

Lee EG  Boone DL  Chai S  Libby SL  Chien M  Lodolce JP  Ma A 《Science (New York, N.Y.)》2000,289(5488):2350-2354

A20 is a cytoplasmic zinc finger protein that inhibits nuclear factor kappaB (NF-kappaB) activity and tumor necrosis factor (TNF)-mediated programmed cell death (PCD). TNF dramatically increases A20 messenger RNA expression in all tissues. Mice deficient for A20 develop severe inflammation and cachexia, are hypersensitive to both lipopolysaccharide and TNF, and die prematurely. A20-deficient cells fail to terminate TNF-induced NF-kappaB responses. These cells are also more susceptible than control cells to undergo TNF-mediated PCD. Thus, A20 is critical for limiting inflammation by terminating TNF-induced NF-kappaB responses in vivo.  相似文献