Maturation of dendritic cells in the presence of living, apoptotic and necrotic tumour cells derived from squamous cell carcinoma of head and neck.

Dendritic cells (DC) have been recently used as vaccines for stimulation of tumour-specific immunity in various types of cancer. Since data about interactions of DC with tumour cells derived from head and neck cancer are not available, in our study we investigated the effects of head and neck squamous cell carcinoma (HNSCC) cell lines on the maturation of DC. We found that immature DC efficiently internalise necrotic cells, but not living and apoptotic tumour cells. Although apoptotic cells induced a partial maturation of DC, they were not able to stimulate the secretion of IL-12. In contrast, necrotic tumour cell preparations from all three HNSCC cell lines induced the mature phenotype and IL-12 production by DC. Moreover, necrotic cells synergistically augmented stimulatory effects of monocyte-conditioned medium on the maturation of DC. Thus, DC-based vaccination utilizing necrotic tumour cells as a source of tumour antigens, even in combination with inflammatory stimulus, seems to be a suitable strategy for adjuvant immunotherapy in HNSCC.