Improvement of Bombyx mori Nuclear Polyhedrosis Virus Expression Vectors and Their Application in the Synthesis of Hepatitis B Surface Antigen.

• Main Authors: Chang Ming Chuan, 張銘傳
• Other Authors: Roger F. Hou;Nien-Tai Hu
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/81799926882644469718

碩士 === 國立中興大學 === 昆蟲學系 === 81 === Bombyx mori nuclear polyhedrosis virus (BmNPV) transplacement vectors, carrying E. coli β-galactosidase gene as the marker gene, were constructed in order to improve the screening process of recombinant viruses. The D. melanogaster heat-shock (hsp70) promoter was utilized to express the marker gene. The marker gene was inserted in two different orientations, relative to the polyhedrin gene. This study chose hepatitis B surface antigen gene as the foreign gene to investigate the production of foreign gene product from BmNPV recombinant viruses. Depending upon different combinations of vectors and the inserted HBsAg genes, five recombinant viruses were constructed, each designated BmHBs1109、BmHBs1266、BmHBs4276、 BmHBs1303 and BmHBs1406, respectively. These five viruses were compared with three previously constructed recombinant viruses (BmHBs324P、BmHBs524B and BmHBs524s) in the production of the hepatitis B surface antigen. The polyhedrin promoters are not complete in the latter three viruses. Enzyme-linked immuno- sorbent assay (ELISA) was conducted to show that the production of the hepatitis B surface antigen, utilizing the complete polyhedrin promoter, was four times of those utilizing the incomplete polyhedrin promoter. The relative position of the marker gene with respect to the foreign gene did not affect the expression of the hepatitis B surface antigen gene. The deletion of 111 nucleotide sequence, which is upstream of the coding sequences of the major S and rich in G and C,did not effectively increase the production of the major S protein. The recombinat viruses expressing the pre-S2 region and major S gene released more HBsAg to the medium, compared with those expressing the major S gene only.