[Experimental study of the specific immunoresponse induced by p53 modified dendritic cells]

To explore the specific cytotoxic T lymphocyte (CTL) induced by dendritic cells (DC), which were transfected by the plasmid pC53-SN3 encoding p53 gene.

DC derived from HLA-A2(+) mononuclear cells of the 24-lung cancer patients was transfected with the plasmid pC53-SN3 by lipofectamine and then co-cultured with auto-unpurified T cells to induce potent CTL (T-pC53-SN3). The cytolysis of specific CTL against Calu-6, a HLA-A2(+) human lung cancer cell line, was measured by using lactate dehydrogenase (LDH) releasing assay.

The expression of CD(1a) and CD(83), the correlative markers of DC, increased apparently after transfected with plasmid pC53-SN3, the expression rate was (5.45 +/- 0.89)% and (3.26 +/- 0.47)% versus (52.15 +/- 11.56)% and (25.78 +/- 12.35)%. CD(14) decreased apparently, but other DC correlative markers of CD(1a), CD(40), CD(86), and HLA-DR remained almost the same as that before transfection. Compared with T-IL-2, the CTL derived from PBMNC stimulated by IL-2 (100 U/ml), the cytolytic activity of T-pC53-SN3 against Calu-6 cell line showed a significant increase, but cytolytic activity was 56.79 +/- 15.67 and 39.33 +/- 9.88, respectively, when effect cells: target cells was 10:1. The expression of the CD(8), CD(69), and CD(45)RO/CD(8) of T-pC53-SN3 cells increased significantly, but that of CD(3), CD(4), CD(86), ect, was not significantly different from those of T-pCMV-neo.

It showed that DC transfected by p53 gene could induce potent HLA-A(2) restrictive CTL to kill tumor cell efficiently.