A Case Study on Expression of Single-Chain Variable Fragment of Anti-HER2 Antibody by Using Recombinant Baculovirus in Silkworms

摘要

HER2 (Epidermal Human Growth Factor Receptor), is one of receptors in the epidermal growth factor receptor family. The overexpression of HER2 was determined in 25% to 35% of patients which were positive with breast cancer and in some of different cancers such as ovary cancer, uterus cancer... Due to this characteristic, HER2 has become an effective molecular marker for pre-diagnosis as well as a strike target for immune therapeutically treatment. Currently, there are different types of monoclonal antibodies (mAbs) specific to HER2 which produced based on recombinant DNA technology. These recombinant mAbs are bringing many benefits for diagnosis and making more effective in the treatment of breast cancer. In this research, the pair of primers (BacHER2F/BacHER2R) was designed to amplify antiHER2 antibody (antiHER2 Ab) fragment (Single-chain variable fragment, scFv) which had been moved into a cloning vector and confirmed by sequencing. An expression vector containing this fragment (vector Bacmid/AntiHER2) has been constructed and transfected into a cultured Sf9 insect cells to produce recombinant baculovirus (r-BV). The virus then infected to silkworm Bombyx mori and the recombinant antiHER2 Ab (r-antiHER2 Ab) was expressed successfully. The expressed protein was confirmed by Western blot analysis. We obtained r-antiHER2 Ab using Ni-NTA affinity chromatography. Our result verified that we received purified r-antiHER2 Ab with 95% purity, which can be used for next experiments.