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 v...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.展开更多
Using plants to produce heterologous proteins makes it very attractive due to the potentially low costs. Using this procedure it is possible to produce medicinal protein for clinical applications with the plants biore...Using plants to produce heterologous proteins makes it very attractive due to the potentially low costs. Using this procedure it is possible to produce medicinal protein for clinical applications with the plants bioreactors increasing gradually. The paper proposes the five major systems of the plant bioreactor as well as their advantage and disadvantage and the development of each system. Focuses on the five major systems of the plant bioreactor to produce vaccines, antibodies and medical protein and the research achievement at the present stage and the research on my laboratory. The key technology research of plant bioreactor such as new genes, new biological components, new technologies and new research methods related with plant bioreactor offer a work foundation for a long-term development in future.展开更多
The complexes excreted by VerticiUium dahliae are phytotoxins, which are responsible for most of the symptoms associated with Verticillium wilt disease. Verticillium dahliae toxins （VD-toxins） can be purified by dif...The complexes excreted by VerticiUium dahliae are phytotoxins, which are responsible for most of the symptoms associated with Verticillium wilt disease. Verticillium dahliae toxins （VD-toxins） can be purified by different methods. In the present study, we reported a simpler, more effective method to purify VD-toxins. The supematant of V. dahliae culture was frozen, lyophilized and dialyzed by 1 kDa Dialysis Membranes （MWCO）. We also partially identified the characteristics of the purified VD-toxins. The results showed that the components of VD-toxins include glycoprotein within 35.8-83.2 kDa. The phytotoxic activity of VD-toxins was remained after VD-toxins were pretreated by high temperature, Concanavalin-A, and proteinase E, respectively. These data suggest that VD-toxins are heat-stable, and the protein fraction and glycosyl are both important contributors to the phytotoxic activity. VD-toxins purified effectively from the culture filtrates of V. dahliae may help in further understanding the mechanisms of interactions between V. dahliae and plants.展开更多
The human pathogen, group A rotavirus, is the most prevalent cause of acute infantile and pediatric gastroenteritis worldwide, especially in developing countries. There is an urgent demand for safer, more effective an...The human pathogen, group A rotavirus, is the most prevalent cause of acute infantile and pediatric gastroenteritis worldwide, especially in developing countries. There is an urgent demand for safer, more effective and cheaper vaccines against rotavirus infection. Plant-derived antigens may provide an exclusive way to produce economical subunit vaccines. Virus-like particles, constituting viral capsid proteins without viral nucleic acids, are considered a far safer candidate compared with live attenuated viral vaccines. In this study, the rotavirus capsid proteins VP2, VP6 and VP7 were co-expressed in transgenic tobacco plants, and their expression levels, formation of rotavirus-like particles (RV VLPs) and immunogenicity were extensively studied. Quantitative real-time RT-PCR and Western blot analysis revealed that the expression level of vp6 was the highest while vp7 was expressed at the lowest levels. The RV VLPs were purified from transgenic tobacco plants and analyzed by electron microscopy and Western blot. Results indicated that the plant-derived VP2, VP6 and VP7 proteins self-assembled into 2/6 or 2/6/7 RV VLPs with a diameter of 60-80 nm. When orally delivered into mice with cholera toxin as an adjuvant, the total soluble protein extracted from transgenic tobacco plants induced rotavirus-specific antibodies comparable with those of attenuated rotavirus vaccines, while VP 2/6/7 induced higher serum IgG and fecal IgA titers compared with VP 2/6.展开更多
基金Indo-Swiss Joint research Program (ISJRP)#17/2011
文摘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.
基金National Ministry of Science and Technology "836" Project grant number:2007AA100503
文摘Using plants to produce heterologous proteins makes it very attractive due to the potentially low costs. Using this procedure it is possible to produce medicinal protein for clinical applications with the plants bioreactors increasing gradually. The paper proposes the five major systems of the plant bioreactor as well as their advantage and disadvantage and the development of each system. Focuses on the five major systems of the plant bioreactor to produce vaccines, antibodies and medical protein and the research achievement at the present stage and the research on my laboratory. The key technology research of plant bioreactor such as new genes, new biological components, new technologies and new research methods related with plant bioreactor offer a work foundation for a long-term development in future.
基金Acknowledgments： This research was supported by National Natural Science Foundation of China （No. 3017555）, （No. 30170087）.
文摘The complexes excreted by VerticiUium dahliae are phytotoxins, which are responsible for most of the symptoms associated with Verticillium wilt disease. Verticillium dahliae toxins （VD-toxins） can be purified by different methods. In the present study, we reported a simpler, more effective method to purify VD-toxins. The supematant of V. dahliae culture was frozen, lyophilized and dialyzed by 1 kDa Dialysis Membranes （MWCO）. We also partially identified the characteristics of the purified VD-toxins. The results showed that the components of VD-toxins include glycoprotein within 35.8-83.2 kDa. The phytotoxic activity of VD-toxins was remained after VD-toxins were pretreated by high temperature, Concanavalin-A, and proteinase E, respectively. These data suggest that VD-toxins are heat-stable, and the protein fraction and glycosyl are both important contributors to the phytotoxic activity. VD-toxins purified effectively from the culture filtrates of V. dahliae may help in further understanding the mechanisms of interactions between V. dahliae and plants.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2007AA100505)
文摘The human pathogen, group A rotavirus, is the most prevalent cause of acute infantile and pediatric gastroenteritis worldwide, especially in developing countries. There is an urgent demand for safer, more effective and cheaper vaccines against rotavirus infection. Plant-derived antigens may provide an exclusive way to produce economical subunit vaccines. Virus-like particles, constituting viral capsid proteins without viral nucleic acids, are considered a far safer candidate compared with live attenuated viral vaccines. In this study, the rotavirus capsid proteins VP2, VP6 and VP7 were co-expressed in transgenic tobacco plants, and their expression levels, formation of rotavirus-like particles (RV VLPs) and immunogenicity were extensively studied. Quantitative real-time RT-PCR and Western blot analysis revealed that the expression level of vp6 was the highest while vp7 was expressed at the lowest levels. The RV VLPs were purified from transgenic tobacco plants and analyzed by electron microscopy and Western blot. Results indicated that the plant-derived VP2, VP6 and VP7 proteins self-assembled into 2/6 or 2/6/7 RV VLPs with a diameter of 60-80 nm. When orally delivered into mice with cholera toxin as an adjuvant, the total soluble protein extracted from transgenic tobacco plants induced rotavirus-specific antibodies comparable with those of attenuated rotavirus vaccines, while VP 2/6/7 induced higher serum IgG and fecal IgA titers compared with VP 2/6.
