Replication-incompetent adenoviruses expressing three major glycoproteins (gB, gC, and gD) of pseudorabies virus (PrV) were constructed and used to examine the ability of these glycoproteins to induce protective immunity against a lethal challenge. Among three constructs, recombinant adenovirus expressing gB (rAd-gB) was found to induce the most potent immunity biased to Th1-type, as determined by the IgG isotype ratio and the profile of the Th1/Th2 cytokine production. Conversely, the gC-expressing adenovirus (rAd-gC) revealed Th2-type immunity and the gD-expressing adenovirus (rAd-gD) induced lower levels of IFN-gamma and IL-4 production than other constructs, except IL-2 production. Mucosal delivery of rAd-gB induced mucosal IgA and serum IgG responses and biased toward Th2-type immune responses. However, these effects were not observed in response to systemic delivery of rAd-gB. In addition, rAd-gB appeared to induce effective protective immunity against a virulent viral infection, regardless of whether it was administered via the muscular or systemic route. These results suggest that administration of replication-incompetent adenoviruses can induce different types of immunity depending on the expressed antigen and that recombinant adenoviruses expressing gB induced the most potent Th1-biased humoral and cellular immunity and provided effective protection against PrV infection.
Adenoviridae/genetics/*immunology/metabolism ; Animals ; Antibody Formation ; Cell Line ; Cytokines/immunology ; Female ; Glycoproteins/biosynthesis/genetics/*immunology ; Herpesvirus 1, Suid/genetics/*immunology/physiology ; Immunity, Cellular ; Immunoglobulin G/immunology ; Mice ; Mice, Inbred C57BL ; Pseudorabies/*immunology/prevention & control ; Pseudorabies Vaccines/administration & dosage/*immunology ; Swine ; Th1 Cells/immunology ; Th2 Cells/immunology ; *Virus Replication