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Antiviral Vaccines (antiviral + vaccine)
Selected AbstractsAnchorage to the cytosolic face of the endoplasmic reticulum membrane: a new strategy to stabilize a cytosolic recombinant antigen in plantsPLANT BIOTECHNOLOGY JOURNAL, Issue 6 2008Alessandra Barbante Summary The levels of accumulation of recombinant vaccines in transgenic plants are protein specific and strongly influenced by the subcellular compartment of destination. The human immunodeficiency virus protein Nef (negative factor), a promising target for the development of an antiviral vaccine, is a cytosolic protein that accumulates to low levels in transgenic tobacco and is even more unstable when introduced into the secretory pathway, probably because of folding defects in the non-cytosolic environment. To improve Nef accumulation, a new strategy was developed to anchor the molecule to the cytosolic face of the endoplasmic reticulum (ER) membrane. For this purpose, the Nef sequence was fused to the C-terminal domain of mammalian ER cytochrome b5, a long-lived, tail-anchored (TA) protein. This consistently increased Nef accumulation by more than threefold in many independent transgenic tobacco plants. Real-time polymerase chain reaction of mRNA levels and protein pulse-chase analysis indicated that the increase was not caused by higher transcript levels but by enhanced protein stability. Subcellular fractionation and immunocytochemistry indicated that Nef-TA accumulated on the ER membrane. Over-expression of mammalian or plant ER cytochrome b5 caused the formation of stacked membrane structures, as observed previously in similar experiments performed in mammalian cells; however, Nef-TA did not alter membrane organization in tobacco cells. Finally, Nef could be removed in vitro by its tail-anchor, taking advantage of an engineered thrombin cleavage site. These results open up the way to use tail-anchors to improve foreign protein stability in the plant cytosol without perturbing cellular functions. [source] Processing of Infectious Bursal Disease Virus (IBDV) Polyprotein and Self-Assembly of IBDV-Like Particles in Hi-5 CellsBIOTECHNOLOGY PROGRESS, Issue 3 2006Meng-Shiou Lee The capsid of infectious bursal disease virus (IBDV), with a size of 60,65 nm, is formed by an initial processing of polyprotein (pVP2-VP4-VP3) by VP4, subsequent assemblage of pVP2 and VP3, and the maturation of VP2. In Sf9 cells, the processing of polyprotein expressed was restrained in the stage of VP2 maturation, leading to a limited production of capsid, i.e., IBDV-like particles (VLPs). In the present study, another insect cell line, High-Five (Hi-5) cells, was demonstrated to efficiently produce VLPs. Meanwhile, in this system, polyprotein was processed to pVP2 and VP3 protein and pVP2 was further processed to the matured form of VP2. Consequently, Hi-5 cells are better in terms of polyprotein processing and formation of VLPs than Sf9. In addition to the processing of pVP2, VP3 was also degraded. With insufficient intact VP3 protein present for the formation of VLPs, the excessive VP2 form subviral particles (SVPs) with a size of about 25 nm. The ratio of VLPs to SVPs is dependent on the multiplicity of infections (MOIs) used, and an optimal MOI is found for the production of both particles. VLPs were separated from SVPs with a combination of ultracentrifugation and gel-filtration chromatography, and a large number of purified particles of both were obtained. In conclusion, the insect cell lines and MOIs were optimized for the production of VLPs, and pure VLPs with morphology similar to that of the wild-type viruses can be effectively prepared. The efficient production and purification of VLPs benefits not only the development of an antiviral vaccine against IBDV but also the understanding of the structure of this avian virus that is economically important. [source] Transgenic mice replicating hepatitis B virus but lacking expression of the major HBsAg,JOURNAL OF MEDICAL VIROLOGY, Issue 4 2008Leonie Halverscheid Abstract Hepatitis B Virus (HBV) transgenic mice replicating the viral genome at high level but lacking expression of the small envelope protein (HBsAg) have been produced using a terminally redundant viral DNA construct (HBV 1.4). The generation of viable infectious progeny was dependent on sex and age of mice. Viral mRNA was abundant in liver and kidneys and at low levels in other organs of the mice. No viral particles or HBV envelope proteins could be detected in sera of mice. Despite expression of non-secreted LHBs and MHBs proteins in the liver, there was no accumulation of viral particles in the endoplasmic reticulum of hepatocytes and no necroinflammatory hepatitis was observed. Therefore, these mice represent an excellent model for studies of the role of HBsAg in viral assembly, antiviral immune responses, the further understanding of HBV immunopathogenesis, and the development of antiviral vaccines. J. Med. Virol. 80:583,590, 2008. © 2008 Wiley-Liss, Inc. [source] Glycopeptide dendrimers, Part III,a review: Use of glycopeptide dendrimers in immunotherapy and diagnosis of cancer and viral diseasesJOURNAL OF PEPTIDE SCIENCE, Issue 5 2008Petr Niederhafner Abstract Glycopeptide dendrimers containing different types of tumor associated-carbohydrate antigens (TN, TF, sialyl-TN, sialyl-TF, sialyl-Lex, sialyl-Lea etc.) were used in diagnosis and therapy of different sorts of cancer. These dendrimeric structures with incorporated T-cell epitopes and adjuvants can be used as antitumor vaccines. Best results were obtained with multiantigenic vaccines, containing, e.g. five or six different TAAs. The topic of TAAs and their dendrimeric forms at molecular level are reviewed, including structure, syntheses, and biological activities. Use of glycopeptide dendrimers as antiviral vaccines against HIV and influenza is also described. Their syntheses, physico-chemical properties, and biological activities are given with many examples. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd. [source] Bronchiectasis in children: Orphan disease or persistent problem?,PEDIATRIC PULMONOLOGY, Issue 6 2002Charles W. Callahan DO Abstract More than a decade ago, bronchiectasis unrelated to cystic fibrosis was termed an "orphan disease", because it had become an uncommon clinical entity among children in the developed world. Bronchiectasis is more common among children in lower socioeconomic classes and in developing countries, presumably due to more frequent and recurrent respiratory infections, environmental airway irritants, poor immunization rates, and malnutrition. Reports from the Southern Pacific and from Alaska Native children reveal persistently high rates of childhood bronchiectasis. Better epidemiologic data throughout the world are needed to reassess the importance of this condition. The pathophysiology includes airway inflammation, mucus production, and regional airway obstruction, yet the reasons why some children develop bronchiectasis while other do not is unclear. The coexistence of asthma with bronchiectasis is associated with more severe disease, yet the impact of asthma therapy in children with both disorders has not been studied. Similarly, the pattern of antibiotic use for children with bronchiectasis varies by region with little data to justify one particular approach. It may be that public health measures aimed at improving living conditions for children and prevention of respiratory infections with antiviral vaccines will have more impact on childhood bronchiectasis than medical treatments in the future. Pediatr Pulmonol. 2002; 33:492,496. © 2002 Wiley-Liss, Inc. [source] | ||||||||||