Effects of dendritic cells transfected with full length wild type P53 and modified by gastric cancer lysate on immune response.

To investigate the effects of dendritic cells (DCs) transfected with full length wild type p53 and modified by gastric cancer lysates on immune response, the wild type P53 was transducted to DCs with adenovirus, and the DCs were modified by gastric cancer lysates (Lywt-P53DC). The concentration of the surface molecules (B7-1, B7-2, MHC-I , MHC-II) of all DCs was determined by FACS, and the ability of the DCs to induce efficient and specific immunological response in anti-51Cr-labeled target cells studied. BALB/c mice model infected with DCs and Mk28 was established. CTL response in mice immunized with Lywt-p53DC and the effectiveness of Lywt-p53DC in the treatment of tumor-bearing mice was assayed. FACS revealed that the surface molecules of Ly-wt-P53 DC had a high expression: for B7-1 86.70% +/- 0.07%, B7-2 18.77% +/- 0.08%, MHC-I 87.20% +/- 0.05%, MHC-II 56.70%+/-0.07%; The T lymphocytes had a specific CTL lysing ability induced by Lywt-P53DC with the CTL lysis rate being 81%. The immune protective effect of Lywt-p53DC group was more obvious than any other groups (P<0.05). The tumor diameter in Lywt-p53DC group was 3.10+/-0.31 mm, 2.73+/-0.23 mm, 3.70+/-0.07 mm on the day 13, 16 and 19, smaller than DC, wtp53DC and LyDC groups (P<0.05). On the other hand, the growth rate of tumor in Lywt-p53DC group was slower than any other groups (P<0.05). It was suggested that DCs transfected with wild type P53 and modified by gastric cancer lysates had specific CTL killing capability.