Expression of Human Hepatitis B Virus Surface Antigen Middle Protein Gene in Transgenic Tobacco: Potential for Edible Vaccines

Abstract

Hepatitis B virus is responsible for significant morbidity and mortality despite the availability of safe and effective injectable vaccines. Transgenic plants are a novel system for expression and oral delivery of subunit vaccine antigens. In this paper, plant expression vector pBIS2S, which contains the HBsAg gene with precursor sequence preS2, was reconstructed based on pBI121 and was introduced into tobacco by the co-cultivating leaf-section method via Agrobacterium tumefaciens LBA4404. After selection by kanamycin and confirmation by PCR and Southern blot, it was found that the objective fragment had integrated into the tobacco genome. ELISA analysis showed that the hepatitis B surface antigen (HbsAg) was expressed in transgenic tobacco plants. These results indicate that the production of HbsAg with PreS2 extended to food plants as a source of edible vaccines is possible.

Key Words:

• HBsAg
• preS2
• transgenic tobacco
• expression

ACKNOWLEDGEMENT

This research was supported by Natural Science Foundation of Guangdong Province of China (Grant #001212).

Notes

∗ “+” means the OD₄₅₀ was higher than the cutoff value and the HbsAg protein is positive in the transgenic line. “−” means the OD₄₅₀ was lower than the cutoff value and the HbsAg protein is negative in the transgenic line.