Insect Cell Culture and Biotechnology

The continued development of new cell culture technology is essential for the future growth and application of insect cell and baculovirus biotechnology. The use of cell lines for academic research and for commercial applications is currently dominated by two cell lines; the Spodoptera frugiperda line, SF21 (and its clonal isolate, SF9), and the Trichoplusia ni line, BTI 5B1-4, commercially known as High Five cells. The long perceived prediction that the immense potential application of the baculovirus-insect cell system, as a tool in cell and molecular biology, agriculture, and animal health, has been achieved. The versatility and recent applications of this popular expression system has been demonstrated by both academia and industry and it is clear that this cell-based system has been widely accepted for biotechnological applications. Numerous small to midsize startup biotechnology companies in North America and the Europe are currently using the baculovirus-insect cell technology to produce custom recombinant proteins for research and commercial applications. The recent breakthroughs using the baculovirus-insect cell-based system for the development of several commercial products that will impact animal and human health will further enhance interest in this technology by pharma. Clearly, future progress in novel cell and engineering advances will lead to fundamental scientific discoveries and serve to enhance the utility and applications of this baculovirus-insect cell system.

Expression and Purification of Goose HSP70 and Compound Formation with Virus Polypeptide

The experiment was conducted to study the specific expression of HSP70 caused by heat shock, HSP70 purification and the characteristics of coalescence with antigenic peptide in the formation of the complex. Sixty healthy 6-week-old male Wulong geese were selected and randomly divided into three groups. The control group was slaughtered without heat treatment. Treatment group 1 was shocked with an acute heat treatment at （42 ± 1）℃ for 5 h before they were immediately slaughtered. Treatment group 2 was kept for 12 h after the heat treatment under normal conditions in order to recover and was then slaughtered. Cardiac tissue was taken in order to make paraffin sections for the immunohistochemistry experiment and the liver tissue was used to purify HSP70. The geese heart HSP70 expression differences in the three groups were determined and at the same time the experiments of HSP70 purification and appraisal in the liver tissue were carried on. HSP70 purification and synthesis of HBV PreS1 multi-peptides unified the complex, which was determined by bi-specific antibody enzyme-linked immune sandwich assay. The results indicated that widespread HSP70 positive pellets in the cardiac muscle were found under hot shock conditions. HSP70 expression in the treatment group 1 was centered in the karyotheca and its periphery, but in treatment group 2, it was centered in the surrounding cell membrane. The HSP70 purification could be obtained through two sets of purification plans; both the synthesis peptide and the HSP70 purification form the complex under certain conditions. The double antibody sandwich ELISA technique was applied to detect if the complex had been formed. Positive results showed that the complex was formed. The specific expression of HSP70 under heat shock shifted with time, suggesting that HSP70 possibly had some function in cell protection. High-purity HSP70 protein can be obtained under low-pressure chromatography conditions, and in comparison with each other, it was better in the flow of the molecular sieve preliminary separation, ConA-agarose chromatography and the ADP-agarose chromatography. Under certain condition in vitro, the synthetic peptide could combine with HSP70 to form the compound, thereby providing a further experimental foundation for the immunity function of the complex.