Presentation of heterologous peptides on plant viruses: genetics, structure, and function.

Capsid proteins of a number of plant viruses are permissive to genetic modifications in which foreign polypeptides are inserted in exposed loops or at their C termini. Plant viruses with these genetic alterations often grow at wild-type levels, providing gram quantities of modified viruses. Presented polypeptides studied most extensively correspond to antigenic epitopes of animal viruses and in some cases appropriately altered plant viruses generate neutralizing antibodies to the cognate animal virus when the plant virus is used as a vaccine. Structure-based analyses of these animal-plant virus chimeras have led to rational alterations to the presentation in efforts to increase the efficacy of the presented peptide.