DEVELOPMENT OF AN ANTIGEN PRESENTATION SYSTEM BASED ON PLUM POX POTYVIRUS

The development of an antigen presentation system based on the plum po x potyvirus (PPV) is here described. The amino-terminal part of PPV ca psid protein was chosen as the site for expression of foreign antigeni c peptides, Modifications in this site were engineered to avoid the ca pability of natural transmission by aphids of this PPV vector. As a fi rst practical attempt, different forms of an antigenic peptide (single and tandem repetition) from the VP2 capsid protein of canine parvovir us (CPV) were expressed. Both chimeras are able to infect Nicotiana cl evelandii plants with similar characteristics to wild-type virus and r emain genetically stable after several plant passages, The antigenicit y of purified chimeric virions was demonstrated, proving the suitabili ty of this system for diagnostic purposes. Moreover, mice and rabbits immunized with chimeric virions developed CPV-specific antibodies, whi ch showed neutralizing activity. (C) 1998 Federation of European Bioch emical Societies.