Non-cytolytic antigen clearance in DNA-vaccinated mice with electroporation.
Acta pharmacologica Sinica 2007 Jul 1; 28(7):1024-30
Peng J JL, Zhao Y YG, Mai J JH, Pang W WK, Guo W W, Chen G GM,
Schools of Life Sciences and Technology, Shanghai Jiao Tong University, Shanghai 200240, China. yhxu
Aim: To explore the potential of electroporation (EP)-mediated hepatitis B virus (HBV) DNA vaccination for the treatment of chronic HBV infection. Methods: BALB/c mice were vaccinated with HBV DNA vaccine encoding for the HBV preS(2)-S antigen, combined with or without EP. HBV surface antigen expression plasmid was administered into mice liver via a hydrodynamic injection to mimic HBV infection. The clearance of antigen in the serum and liver was detected by ELISA assay and immunohistochemical staining. The histopathology of the liver tissues was examined by HE staining and serum alanine aminotransferase assay. Results: The immunogenicity of HBV DNA vaccine encoding for the HBV preS(2)- S antigen can be improved by EP-mediated vaccine delivery. The elicited immune responses can indeed reduce the expression of HBV surface antigen (HBsAg) in hepatocytes of the mouse model that was transfected to express HBsAg using the hydrodynamic injection method. The antigen clearance process did not cause significant toxicity to liver tissue, suggesting a non-cytolytic mechanism. Conclusion: The EP-aided DNA vaccination may have potential in mediating viral clearance in chronic hepatitis B patients.