Granulocyte-macrophage colony-stimulating factor DNA prime-protein boost strategy to enhance efficacy of a recombinant pertussis DNA vaccine

摘要

Aim: To investigate a new strategy to enhance the efficacy of a recombinant pertussis DNA vaccine. The strategy is co-injection with cytokine plasmids as prime, and boosted with purified homologous proteins. Method: A recombinant pertussis DNA vaccine containing the pertussis toxin subunit 1 (PTS1), fragments of the filamentous hemagglutinin (FHA) gene and pertactin (PRN) gene encoding filamentous hemagglutinin and pertactin were constructed. Balb/c mice were immunized with several DNA vaccines and antigen-specific antibodies anti-PTSl, anti-PRN, anti-FHA, cytokines interleukin (IL)-10, IL-4, IFN-γ, TNF-oc, and spleno-cyte-proliferation assay were used to describe immune responses. Results: The recombinant DNA vaccine could elicit similar immune responses in mice as that of separate plasmids encoding the 3 fragments, respectively. Mice immunized with DNA and boosted with the corresponding protein elicited more antibodies than those that received DNA as boost. In particular, when the mice were co-immunized with murine granulocyte-macrophage colony-stimulating factor plasmids and boosted with proteins, all 4 cytokines and the 3 antigen-specific antibodies were significantly increased compared to the pVAXl group. Anti-PTSl, anti-FHA, IL-4 and TNF-α elicited in the colony stimulating factor (CSF) prime-protein boost group showed significant increase compared to all the other groups. Conclusion: This prime and boost strategy has proven to be very useful in improving the immunogenicity of DNA vaccines against pertussis.