Plant produced porcine circovirus pseudovirion

A method for producing a porcine circovirus (PCV) pseudovirion in a plant cell, the method comprising the steps of:

• (i) introducing into the plant cell:
• (a) an expression vector comprising a first nucleic acid encoding a PCV capsid polypeptide;
• and
• (b) a replicating vector derived from a ssDNA virus comprising at least two origin of replication (Ori) sequences recognised by a viral replication regulatory protein, the replicating vector further comprising a second nucleic acid encoding a heterologous polypeptide, and
• (c) a third nucleic acid encoding a viral replication regulatory protein, wherein replication of the replicating vector is initiated by the viral replication regulatory protein, and wherein the second nucleic acid is operably linked to a regulatory sequence which allows for the expression of the heterologous polypeptide in a mammalian cell;
• (ii) expressing the PCV capsid polypeptide and the viral replication regulatory protein in the plant cell, and
• (iii) replicating the replicating vector from the Ori sequence recognised by the viral replication regulatory protein in the plant cell, in order to produce a high copy number of a pseudogenome comprising the second nucleic acid,
• wherein the expressed PCV capsid polypeptides assemble, together with a single-stranded copy of the pseudogenome and encapsidate the pseudogenome to produce a PCV pseudovirion.