Genetically modified cellular vaccines against human papillomavirus type 16 (HPV16)-associated tumors: adjuvant treatment of minimal residual disease after surgery/chemotherapy.

Local recurrences at the site of tumor resection or after chemotherapy, as well as distant micrometastases represent major problems in oncology. Therapeutic strategies based on insertion of immunostimulatory genes into the genome of tumor cells followed by vaccination with the resulting genetically modified and irradiated cellular vaccines represent a new potential prospect for the treatment of cancer patients. These strategies are based on the presumption that many, if not all tumors, possess cell surface antigens capable of being recognized by defence effectors of the immune system, as well as on the presumption that local treatment of primary tumors can, due to its immunizing potential, result also in the inhibition of distant metastases. Genetically modified cellular vaccines were found to be efficient against cancer both in experimental models and in tumor-bearing patients. It was also shown in various systems that the efficacy of conventional therapeutic modalities can be supported by adjuvant administration of genetically modified vaccines, as well as by depletion of immunosuppressive immunocyte subsets. The purpose of this review was to summarize and evaluate the results obtained with the administration of genetically modified cellular vaccines as well as with depletion of immunosuppressive immunocytes performed as treatment of minimal residual disease after surgery / chemotherapy in the experimental model of murine tumors mimicking human HPV16-associated neoplasms. The prospects and limitations of these adjuvant immunotherapeutic modalities are discussed.