Production of highly concentrated, heat-stable hepatitis B surface antigen in maize

• Published in: Plant biotechnology journal 2012-10, Vol.10 (8), p.979-984
• Main Authors: Hayden, Celine A., Egelkrout, Erin M., Moscoso, Alessa M., Enrique, Cristina, Keener, Todd K., Jimenez-Flores, Rafael, Wong, Jeffrey C., Howard, John A.
• Format: Article
• Language: English
• Subjects: Animal vaccines; Antigens; bioencapsulation; Biological and medical sciences; Biotechnology; Celiac disease; Corn; Fundamental and applied biological sciences. Psychology; Heat; Hepatitis; Hepatitis B; Hepatitis B surface antigen; Hepatitis B Surface Antigens - analysis; Hepatitis B Surface Antigens - biosynthesis; Hepatitis B Vaccines - biosynthesis; Hexanes; immunogenicity; mucosal vaccine; Plant Extracts - analysis; Plant Extracts - immunology; Plant Oils - analysis; plant vaccine; Plants, Genetically Modified - metabolism; Proteins; Seeds; Seeds - chemistry; supercritical fluid extraction; Supercritical fluids; Thermal stability; Vaccines; Zea mays - immunology
• ISSN: 1467-7644; 1467-7652
• DOI: 10.1111/j.1467-7652.2012.00727.x

Summary Plant‐based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low‐cost, heat‐stable, oral alternative to parenterally administered commercial vaccines. Here, we describe high‐level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than fourfold higher than any previously reported lines. HBsAg expressed in maize seeds was extremely heat stable, tolerating temperatures up to 55 °C for 1 month without degradation. Optimal heat stability was achieved after oil extraction of ground maize material, either by supercritical fluid extraction or hexane treatment. The contributions of this material towards the development of a practical oral vaccine delivery system are discussed.