Preliminary study on the influence of enhancer Ⅰ upon the immune response of HBV DNA vaccine / 解放军医学杂志

ABSTRACT

Objective To study the influence of ENH Ⅰ of HBV on immune response of HBV DNA vaccine. Methods DNA fragments of HBsAg and HBsAg-ENH Ⅰ region of HBV, after being amplified by PCR using the complete genome DNA of HBV adr subtype, were inserted into VR1012 vectors. The recombinant plasmids were transfected into COS-7 cells and HepG2 cells, and injected into Balb/C mice. The expression of COS-7 cells, HepG2 cells and the cellular and humoral immune response of mice were determined with Western blot, ELISA and ELSPOT. Results HBsAg was expressed by transfected HepG2 cells and COS-7 cells. The quantity of expression by HepG2 cells increased apparently when transfected by that combined with ENH Ⅰ. In transfected COS-7 cells, there was no significant difference in the expression of HBsAg between those transfected by two recombinant plasmids. The HBsAb and the HBsAg specific CTL were found in mice in the second week after immunization, and there was no marked difference between those immunized by two recombinant plasmids. Conclusions When inserted into HBV DNA vaccine, ENH Ⅰ can promote the expression of HBsAg in transfected HepG2 cells, but can not affect the expression of transfected COS-7 cells and the immune response of immunized Balb/C mice.