Immunotherapy of HPV 16-associated tumours with tumour cell line/dendritic cell line (TC-1/DC2.4) hybrid vaccines

Hybridization of established dendritic cell lines with tumour cells represents a prospective technology for the construction of antitumour vaccines. Experiments were designed to examine whether administration of cell populations prepared by fusion of HPV 16-associated tumour TC-1 cells with dendritic cell line DC2.4 could be used for treatment of TC-1 tumours growing in syngeneic mice. The therapeutic potency of TC-1/DC2.4 fusion vaccine administered 24 h after fusion and that of TC-1/DC2.4 hybrid cells selected for 3 weeks in HAT-containing medium was tested. It has been found that administration of both types of fusion vaccines at the site of growing TC-1 tumour transplants significantly inhibited tumour growth with regard to the percentage of tumour-bearing mice and to the size of the transplanted tumours. Peritumoral administration of the DC2.4 cells alone also reduced the size of growing TC-1 tumours, but not the percentage of the tumour-bearing mice. Although in the groups of mice treated with fusion vaccines the size of the tumours was reproducibly smaller than that in the mice treated with parental DC2.4 cells, the difference was not statistically significant.