Expression Of Hepatitis B Surface Antigen In Ginseng Cell

Hepatits B virus infection is one of the most widespread viral infections of humans, especially in China. A highly effective and safe hepatitis B vaccine was licensed in the U.S. in 1986. It has a great commercial success, with sales in the industrialized world exceeding $ 1 billion every year. Why have we pursued to an alternative vaccine against hepatitis B virus (HBV) infections? The answer lies in finding an equivalent or improved vaccine to serve for developing countries of the world, where the HBV disease burden remains at epidemic levels, and the price of vaccine has precluded its popularity. The existing vaccine against HBV infection is a biotechnological product that falls in the category of"subunit vaccines". The gene coding the hepatitis B surface antigen (HBsAg) was expressed in yeast or CHO cells. The resulting vaccine is the epitome of modern macromolecular pharmaceuticals derived from recombinant DNA technology; it is a good product that contains only a"subunit"of HBV. However, it is technology-intensive and expensive that the vaccine could not be a health-care product for developing countries.HBsAg-S gene was obtained from C28 cell containing the HBsAg-S DNA fragment using PCR and inserted into vector pMD18-T, to form pMDBs. The recombinant plasmid pMDBS was digested with XhoI and reaction of filling the ends with T4 DNA polymerase was carried out, then degested again Hepatits B virus infection is one of the most widespread viral infections of humans, especially in China. A highly effective and safe hepatitis B vaccine was licensed in the U.S. in 1986. It has a great commercial success, with sales in the industrialized world exceeding $ 1 billion every year. Why have we pursued to an alternative vaccine against hepatitis B virus (HBV) infections?The answer lies in finding an equivalent or improved vaccine to serve for developing countries of the world, where the HBV disease burden remains at epidemic levels, and the price of vaccine has precluded its popularity.The existing vaccine against HBV infection is a biotechnological product that falls in the category of"subunit vaccines". The gene coding the hepatitis B surface antigen (HBsAg) was expressed in yeast or CHO cells. The resulting vaccine is the epitome of modern macromolecular pharmaceuticals derived from recombinant DNA technology; it is a good product that contains only a"subunit"of HBV. However, it is technology-intensive and expensive that the vaccine could not be a health-care product for developing countries.HBsAg-S gene was obtained from C28 cell containing the HBsAg-S DNA fragment using PCR and inserted into vector pMD18-T, to form pMDBs. The recombinant plasmid pMDBS was digested with XhoI and reaction of filling the ends with T4 DNA polymerase was carried out, then degested again Over the past decade, increasing endeavors have been directed towards how to augment expression levels of foreign genes in transgenic plant cells. Some modifications of expression vectors have been successfully assayed to have the function to lead to improve levels of expression of the recombinant genes, including the use of stronger promoters, plant-optimized synthetic genes, plant-derived leader sequences, signal peptides which can target the protein for retention in intercellular compartments etc.In conclusion, more and more attentions have been paid to the study on vaccine using transgenic plants in the recent years, and many great achievements have been attained in this field. However, many problems still need to be solved. There is a long way to go before practical use of plant-derived vaccine.