[Immunization with dendritic cells infected with mTERT adenovirus vector effectively elicits immunity against mouse H22 hepatoma in vivo].

OBJECTIVE

To investigate the effects of dendritic cells (DCs) infected with adenovirus vector encoding mTERT on induction of mTERT antigen specific immunity against H22 hepatoma in vivo.

METHODS

Forty Bal B/c mice were subcutaneously immunized with Ad-mTERT infected DC. Cytotoxicity of mTERT specific CTL was determined by 51Cr release assay. IL-2 and IFN-gamma were tested by ELISA. IFN-gamma ELISPOT assays were performed for measuring antigen specific IFN-gamma production by T cells. Tumor size and survival of the immunized mice were recorded and evaluated whether preexisting hepatoma metastases could be supressed after immunization with mTERT-expressing DCs.

RESULTS

The lytic activity of CTL, IL-2 (871.25 pg/ml), IFN-gamma (169.15 ng/ml) and IFN-gamma secreting cells (378/10(6) spleen cells) elicited by the Ad-mTERT infected DCs were much stronger and higher than that by Ad-GFP group (131.6 pg/ml, 15.4 ng/ml, 36/10(6) spleen cells, P<0.05), DC group (71.3 pg/ml, 10.5 ng/ml, 21/10(6) spleen cells, P<0.05), PBS group (65.8 pg/ml, 7.4 ng/ml, 18/10(6) spleen cells, P<0.05). In prophylaxis and treatment experiment the Ad-mTERT/DCs immunized mice lived significantly longer than other groups, demonstrating that primary DCs were genetically modified to express the mTERT antigen and could suppress the tumor growth.

CONCLUSION

Adenovirus vector mediated mTERT infected DCs can effectively induce mTERT antigen specific antitumor activity, and can induce protective and therapeutic antitumor immunity.