Polynucleotide vaccines in animals: enhancing and modulating responses.

We immunized cattle, the natural host for bovine herpesvirus 1 (BHV-1), with a polynucleotide vaccine encoding BHV-1 glycoprotein D. These cattle trials clearly indicate that large species can be immunized with polynucleotide vaccines. Recently, using a murine model, we demonstrated that: the cellular compartment to which the expressed antigen is delivered determines the type of immune response (type 1 or type 2), and that the magnitude and direction of the immune response can be modulated by coadministration of plasmid encoded cytokines and antigen. Finally, we demonstrated that immunization of mice with a polynucleotide vaccine encoding BHV-1 gD could circumvent preexisting passively transferred, gD specific, polyclonal antisera and lead to the development of an active immune response.