Fusion of antigen to chemokine CCL20 or CXCL13 strategy to enhance DNA vaccine potency.

DNA vaccination is a promising method to induce specific immune responses. However, it remains challenging to enhance DNA vaccine potency. Chemokines were used as adjuvants to improve the efficacy of DNA vaccination. Herein, we fused murine chemokine CCL20 or CXCL13 to a model antigen green fluorescent protein (GFP). The fusion DNA vaccines enhanced specific anti-GFP immune responses in mice compared with vector pEGFP-N1. Co-immunization with both of chemokine-GFP fusion constructs induced the significantly highest level of humoral immune responses. CCL20-GFP or CXCL13-GFP fusion DNA vaccine induced predominant IgG2a or IgG1 response respectively. However, co-immunization with both of these fusion DNA vaccines induced a predominant IgG2a response. Therefore, fusing chemokine CXCL13 or CCL20 to antigen provides new attractive strategy to enhance the immunogenicity of DNA vaccine and modulate immune responses.