Fig. 1.

Types of virus nano-particle vaccines produced in plants. a VLPs are assembled by expression of a viral capsid protein. b Chimaeric VLPs are similarly assembled by expression of a modified viral capsid protein encoded by a capsid sequence containing an inserted sequence encoding a heterologous epitope/antigen. c Antigen-display particles are assembled by expression of a particle capsid protein sequence fused to ST or SC. Antigens fused to SC or ST are expressed and added to the ST- or SC-fused particles for their display. d RICs are assembled by co-expression of an Ab HC fused at the C terminus with its cognate antigen sequence, and the corresponding Ab LC sequence. Purification of the fused Abs results in Ab-Ag complexes forming. Ab antibody, HC heavy chain, LC light chain, RIC recombinant immune complex, SC SpyCatcher, ST SpyTag, VLP virus-like particle