High-yield rapid production of hepatitis B surface antigen in plant leaf by a viral expression system
Article first published online: 13 DEC 2007
Plant Biotechnology Journal
Volume 6, Issue 2, pages 202–209, February 2008
How to Cite
Huang, Z., LePore, K., Elkin, G., Thanavala, Y. and Mason, H. S. (2008), High-yield rapid production of hepatitis B surface antigen in plant leaf by a viral expression system. Plant Biotechnology Journal, 6: 202–209. doi: 10.1111/j.1467-7652.2007.00316.x
- Issue published online: 13 DEC 2007
- Article first published online: 13 DEC 2007
- Received 9 July 2007; revised 25 September 2007; accepted 1 October 2007.
- hepatitis B surface antigen;
- Nicotiana benthamiana;
- transient expression;
- viral vector
Recombinant hepatitis B surface antigen (HBsAg) constitutes currently used vaccines against hepatitis B virus, and has been successfully employed as a carrier for foreign epitopes. With the aim of developing an inexpensive, easily administered vaccine source for global immunization, several groups have expressed HBsAg in plant systems. Transgenic plant-derived HBsAg assembles into virus-like particles (VLPs) and is immunogenic in both mice and humans. However, HBsAg expression is relatively low in transgenic plant systems. The time-consuming and labour-intensive process of generating transgenic plants also significantly limits high-throughput analyses of various HBsAg fusion antigens. In this paper, the high-yield rapid production of HBsAg in plant leaf using a novel viral transient expression system is described. Nicotiana benthamiana leaves infiltrated with the MagnICON viral vectors produced HBsAg at high levels, averaging 295 µg/g leaf fresh weight at 10 days post-infection, as measured by a polyclonal enzyme-linked immunosorbent assay. Transiently expressed HBsAg accumulated as the full-length product, formed disulphide-linked dimers, displayed the conformational ‘a’ antigenic determinant and assembled into VLPs. Immunization of mice with partially purified HBsAg elicited HBsAg-specific antibodies. Furthermore, it was found that transient production of HBsAg using vacuum infiltration of whole plants, rather than syringe infiltration of leaves, was readily scalable, and greatly improved the accumulation of correctly folded HBsAg that displays the protective ‘a’ determinant.