[Dendritic cells derived from hematopoietic stem cells pulsed with p53 induce a specific immune response against HMCC97 hepatocellular carcinoma cells]

To evaluate dendritic cells induced immune response against hepatocellular carcinoma by pulsed CD34+ hematopoietic stem cells originated dendritic cells with p53 gene.

CD34+ hematopoietic stem cells were harvested after mobilization by chemotherapy and G-CSF. CD34+ hematopoietic stem cell apheresis was induced to differentiate into dendritic cells by cytokine cocktail IL-4,GM-CSF and TNF-alpha. On day 7, dendritic cells were transfected with plasmid pEGFP-C3/p53 DNA. The CTL response triggered by p53 pulsed dendritic cells was assayed by MTT method.

Dendritic cells originated from CD34+ cell apheresis had typical dendritic stick and expressed high level CD1a, CD11c, CD80, CD86, and HLA-DR molecules. After being pulsed with p53 gene, dendritic cells expressed green fluorescence protein and immunofluorescence assay (Cy3 labeled anti-P53 antibody) showed that transfected dendritic cells emitted red fluorescence. Dendritic cells inducing CTL response against HMCC97 cells (P53 positive) and HepG2 cells (P53 negative) were assessed by MTT method. P53 pulsed dendritic cells could induce P53 specific immune response against HMCC97 cells and the cytotoxin rate was (49.3+/-4.6)% compared with pEGFP-C3 transfection group [(25.4+/-4.1)%] and control group [(24.8+/-3.8)%] (P < 0.05). However, P53 pulsed dendritic cells could not induce specific CTL against P53 expression negative HepG2 cells, which the cytotoxin rates were (30.8+/-4.6)%, (27.3+/-4.3)%, and (28.5+/-5.1)% respectively in pEGFP-C3/P53 transfection group, pEGFP-C3 transfection group and control group (P > 0.05).

P53 gene transfecting hematopoietic stem cell apheresis originated dendritic cells could induce specific CTL response against P53-expressing hepatocellular carcinoma cells. P53 may be a potential candidate for dendritic cell based immunotherapy of cancer.