Plasmid-encoded GM-CSF induces priming of the F4(K88)-specific serum IgA response by FaeG DNA vaccination in pigs

We have used FaeG DNA to immunise piglets by the intradermal (ID) and the intramuscular (IM) route in a heterologous prime/boost model. ID immunisation with DNA resulted in a better induction of cellular immunity, whereas only the IM immunisation could prime an F4(K88)-specific serum IgA response. However, ID administration of plasmid-encoded GM-CSF 1 week before the ID immunisation enhanced the F4-specific humoral and cellular immune response and even primed the F4-specific IgA response more efficiently than the IM immunisation did.