Plant-derived Vaccine by Fusion Molecules

Filed in archive Drugs, Vaccines and Therapeutics on March 14, 2006

Using genetically modified tobacco, scientists have developed a new kind of molecule which has the potential to ultimately lead to the development of an anti-HIV vaccine. The research team from St. George's University of London headed by Dr. Patricia Obregon claimed to have overcome a major barrier in frustrated attempts to turn plants into economically viable "bioreactors" for vaccines.

By creating fusion molecules, the researchers have found a way to make plants produce more of the molecules (antigens) needed for vaccines. At the same time, they may also have discovered a way of producing better targeted vaccines. Obregon and her colleagues in Dr Julian Ma's laboratory are working with the p24 core protein of the Human Immunodeficiency Virus (HIV). This protein plays a central role in eliciting the immune response to HIV infection, and is therefore likely to be an integral part of any multicomponent vaccine for HIV.

Although plants have been used to produce many types of vaccine molecules, the consistent problem encountered is achieving adequate levels of protein expression in order to make them viable as bioreactors for vaccines. Through fusion molecules, Dr. Obregon and her team have found a way to significantly boost HIV-1 p24 protein production in plants by producing an entirely new molecule (a fusion of the HIV-1 p24 protein and part of another protein, human immunoglobulin A (IgA)-a major component of the immune system). The team found that the HIV-1p24 antigen produced in this way elicited appropriate immune response in mice.

These results have important implications for the economic viability of using plants as bioreactors to produce vaccines against HIV and other diseases. This could be the start of cheaper and effective biopharmaceuticals.

Source: [EurekAlert]