Enhanced anti-tumor effect of dendritic cells modified by CIITA gene in hepatocellular carcinoma-bearing mice]

AIM: To study the effect of MHC class II transactivator(CIITA ) on the expression of MHC class I/II molecules, CD80 and CD86 molecules on dendritic cells(DCs), and explor the use of DCs modified by CIITA gene in the biotherapy of tumors. METHODS: We transfected the mouse CIITA gene by lipofectamine into DCs drived from mouse bone marrow. The expression of MHC class I/II, CD80, and CD86 molecules was detected by flow cytometry. 40 mice bearing hepatcellular carcinoma were divided into 4 groups: group 1 were treated with a para-tumor injection of PBS, group 2 DCs, group 3 modified DCs, and group 4 modified DCs pulsed with H22 tumor antigen. Then the anti-tumor effect of DCs modified by mCIITA was evaluated by measuring the tumor size. RESULTS: After transfection of mCIITA, the expression rate of MHC class I/II molecules of DCs increased from 74.2%/66.7% to 93.6%/91.4%, and that of CD80/CD86 increased from 52.3%/60.5% to 89.7%/91.5%. After immunization, the growth of H22 tumors in group 4 mice was significantly inhibited compared with that in other three groups (P<0.05 at 3, 4, 5, 6, and 7 weeks versus groups 1, 2; P<0.05 at 5, 6, 7 weeks versus group 3). CONCLUSION: The expression of MHC I/II, CD80 and CD86 on DCs was regulated markedly by transfection of mCIITA. mCIITA transfection also enhanced the anti-tumor effect of DCs. Our results provided a new method for biotherapy of tumors with DCs.