Current Researchers: R. N. Beachy. T. Woodford-Thomas, E. Semenyuk
Previous Researchers: J. Fitchen, M. Koo, G. Lettieri, Y. Yin,  T. Moravec

Because of advances in biotechnology, scientists can now make plant viruses work for us. Methods have been developed for using plant viruses as platforms for delivery of vaccines.

Researchers in Roger Beachy's Laboratory are developing altered strains of tobacco mosaic virus (TMV) that carry antigens derived from human and animal pathogens on its surface. When exposed to the mouse immune system, these antigens illicit an immune response that can confer immunity to the host.

Tobacco mosaic virus makes an ideal candidate for delivery of such vaccines. The virus is harmless to human and other animal hosts, and the hybrid antigen-carrying virus can be produced inexpensively and cleanly in plant hosts.

Researchers incorporate epitopes (small pieces of antigen proteins) derived from disease-causing viruses into the coat protein of TMV. An assembled particle of TMV would then possess a protein coat with these epitopes placed uniformly on its surface. Studies have shown that mice exposed to TMV containing an immuno-protective epitope from murine hepatitis virus (MHV) develop antigens specific to the epitope and are able to withstand challenge with a normally lethal dose of MHV. Work is progressing to isolate mutants of TMV coat protein that optimize the production of virus particles in the host plant. Ongoing studies are investigating the incorporation into TMV of epitopes from the surface of Pseudomonas aeruginosa (a bacterium that leads to life threatening infections in weakened individuals--it is the leading cause of death in cystic fibrosis patients).