[Cytotoxicity induced by HBsAg gene modified-dendritic cells against hepatocellular carcinoma cell HepG2.2.15].

Background & Objective: Up to now, there is no efficient immunotherapy for hepatocellular carcinoma (HCC). Dendritic cell (DC) vaccine could be a potential tool for HCC immunotherapy. This study was to evaluate the effect of dendritic cells (DCs) transfected with recombinant plasmid bearing hepatitis B virus surface antigen (HBsAg) gene, and the capability of generating specific cytotoxic T lymphocytes (CTL) response against HepG2.2.15 in vitro, which were induced by genetically modified DCs.

Methods: After cultured for 5 days, the DCs were transfected with pCR3.1-S by liposome. The HBsAg gene expression on pCR3.1-transfected DCs was identified by Western blot analysis, and immunofluorescence methods. The cytotoxicity against HepG2.2.15, which were induced by DCs, was tested by MTT assay.

Results: DCs up-regulated the expression of CD1a (55.0%), CD11c (98.6%), CD86 (86.1%), CD80 (66.1%), and HLA-DR (88.9%) after cultured for 5 days. Indirect immunofluorescence, and Western blot analysis showed that HBsAg gene was expressed on transfected DCs. The death rates of HepG2.2.15 cells induced by DCs transfected with pCR3.1-S were (52.3+/-2.8)% (E:T=5:1), (64.6+/-2.4)% (10:1), (78.8+/-2.6) (20:1), (82.1+/-2.4)% (40:1), while the pCR3.1- transfected and non-transfected DCs only induced relatively lower cytotoxicity (P< 0.05, n=4).

Conclusion: DCs transfected with recombined plasmid expressed HBsAg efficiently, and the genetically modified DCs evoke a higher CTL response in vitro.