BACKGROUND: Dendritic cells (DCs) are the most potent antigen-presenting cells and are actively used in cancer immunotherapy. Wild-type p53 can be recognized as an antigen and can induce specific cytotoxic T lymphocytes (CTLs) in the host body. The aim of this study was to investigate the effects of DCs transfected with full length wild-type p53 and modified by bile duct lysates on immune response.
METHODS: The wild-type p53 was transducted to DCs with adenovirus, which were modified by bile duct lysates (Lywtp53DC). The concentration  of the  surface molecules (B7-1, B7-2, MHC-Ⅰ, MHC-Ⅱ) of all DCs was detected with fluorescence activated cell sorter (FACS), and the ability of the DCs to induce efficient and specific immunological response in anti51Cr-labeled target cells was studied. BALB/c mice infected with the DCs and QBC939 were used. CTL response in mice immunized with Lywtp53DC and treatment of tumor-bearing mice with Lywtp53DC and CTL response in these mice were studied.
RESULTS: The surface molecules of Lywtp53DC had a high expression  B7-1 (86.70%±0.07%), B7-2 (18.77%±0.08%), MHC-Ⅰ(87.20%±0.05%), MHC-Ⅱ(56.70%±0.07%) with FACS. The T lymphocytes had a specific CTL lysing ability induced by Lywtp53DC, with a CTL lysis rate of 81%. The immune protection of Lywtp53DC group was obvious, and the tumor diameter of the Lywtp53DC group was 3.10±0.31 mm, 2.73±0.23 mm, 3.70±0.07 mm on days 13, 16 and 19, smaller than those of any control groups (P<0.05), DC, wtp53DC and LyDC. On the other hand, the growth rate of tumor of the Lywtp53DC group was slower than that of any other groups (P<0.05).
CONCLUSION: Dendritic cells transfected with wild-type p53 and modified by bile duct lysates have specific CTL killing capability.