Antitumor effects produced by transduction of dendritic cells-derived heterodimeric cytokine genes in murine colon carcinoma cells.

Interleukin (IL)-23 and IL-27 have been recently identified as members of the IL-12 heterodimeric cytokine family. The cytokines are released from activated dentritic cells and play a crucial role in cell-mediated immunity. Expression profiles of the cytokines' receptors suggest that target cells of the cytokines are distinct depending on T cell maturation and differentiation. We first examined whether murine colon carcinoma cells (Colon 26) expressing IL-27 (Colon 26/IL-27) could produce antitumor effects in syngeneic mice. The mice developed small Colon 26/IL-27 tumors and subsequently rejected them, whereas parent tumors continued to grow. Since Colon 26/IL-12 and Colon 26/IL-23 cells were also rejected in syngeneic mice, we then investigated the combinatory antitumor effects of the cytokines. We inoculated Colon 26/IL-12, Colon 26/IL-23, Colon 26/IL-27 cells or mixed populations of the cytokine producers into one flank of the mice that simultaneously received parent tumors in the other flank. The parent tumor growth influenced by the cytokine producers was similar to each other. Combinatory antitumor effects were not produced by the cytokine producers and application of the cytokines did not show any synergistic effects.