Dendritic cell (DC)-tumor cell hybrids are currently being evaluated as a novel anti-tumor
vaccination strategy. We here explored in an animal model whether administration of
DCs fused with poorly immunogenic carcinoma cells could elicit an anti-tumor response.
Fusion of C57BL/6 mice bone marrow derived DCs with Lewis Lung Carcinoma (LLC1) cells
resulted in around 50% fusion efficiency. Hybrid cells (HC) were used to explore three
potential tumor-therapy strategies: protective immunization, vaccination and adoptive
cellular therapy. Immunization with HCs induced activation of proliferating and cytotoxic
T cells and significantly retarded tumor growth, also confirmed by upregulated expression
of distinct cytokines genes. The same observations accented by vaccination with HCs
in the tumor bearing host. Finally, when T cells from HCs vaccinated mice were transferred
into naive tumor-bearing mice, tumor growth was most strongly retarded and an efficient
proliferative and cytotoxic T cell response was observed. Tumor growth was reduced
by over 50%, and tumor development was significantly delayed. Taken together, we demonstrate
that HCs offer for an effective immunotherapy of poorly immunogenic carcinomas. This
is independent of whether the HCs are taken for adoptive transfer or as a vaccine.
