Expression of hepatitis B virus surface antigen protein in a cell line and silkworm larvae with recombinant bombyx mori nuclear polyhedrosis virus

• Main Authors: Peng, Shu-Jen, 彭淑貞
• Other Authors: Roger F. Hou
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/30968026304372905037

碩士 === 國立中興大學 === 昆蟲學系 === 84 === Expression of Hepatitis B Virus Surface Antigen Protein in a Cell Line and Silkworm Larvae with Recombinant Bombyx mori Nuclear polyhedrosis virusThe silkworm (Bombyx mori) larvae and BmN cell line were infected with the recombinant virus BmYFHBs containing hepatitis B surface antigen (HBsAg) gene which was constructed from B. mori nuclear polyhedrosis virus (BmNPV). the cellular aberration was variable in infected cells. Histological sections of larval tissues stained with immunoenzymic method showed HBsAg protein at 48 hr post-infection and polyhedral inclusion bodies at 72 hr post-infection. The epidermal cells became swollen and lysed, and inclus-ion bodies liberated into body cavity at 84 hr post-infection. At frist, the recombinant virus formed in fat body, epidermis, trachea membrane and hemocytes. Later midgut, Malpighian tubules and silk glands were infected. The virus was not detected in muscles. Various silkworm strains were infected with BmYFHBs virus by feeding to the 5th instar. The more susceptible the more HBsAg protein were produced in hemolymph among these strains. The same was found among strains in the same group. Determination of susceptibility to the recombinant virus and production of HBsAg showed that the susceptibility of artificial diet-fed larvae and extracts from whole larva were higher than those fed on mulberry leaves but were not significantly different in hemolymph. Injection of different recombinant viruses into larvae showed increasing HBsAg production with incubation time until the peak on the 4th day post-infection. Microbial contamination in silkworms was measured under aseptically and non-aseptically rearingconditions.More samples were found contaminated under non-aseptically rearing condition. Decrease in feeding number of larvae and diet changing time under aseptical condition may lower microbial contamination. Injection of 5th instars with BmYFHBs resulted in similar HBsAg production in hemolymph and larval body extracts under aseptically and non-aseptically rearing conditions.