A single injection of immature dendritic cells is able to induce antitumour response against a murine colon adenocarcinoma with a low apoptotic index

Abstract

Dendritic cells can induce an immune response as competent antigen presenting cells. It has been reported that immature bone marrow derived dendritic cells are capable of inducing an immune response against tumours displaying significant apoptosis. It is still controversial, however whether immature dendritic cells can also induce an immune response against tumours with a low apoptotic index. C-26 adenocarcinoma cells were injected into the footpad of Balb/c mice. One million immature dendritic cells cultured in vitro using GM-CSF and IL-4 were injected into the tumour-bearing footpad on day 6 after tumour cell inoculation. Tumour volume was measured starting from day 5 after tumour cell inoculation. Mice were observed daily for survival. The growing tumours were characterized by a low apoptotic index. There was a statistically significant delay in the tumour growth and a significant prolongation of the survival time in DC treated group as compared with controls (p<0.05). Immature dendritic cells injected into the site of tumour growth are able to induce a potent antitumour response which leads to the retardation of the tumour growth and the prolongation of the life survival time. Here we show that even a single injection of immature dendritic cells is able to induce a significant immune response against tumours with low apoptotic index.