[Dendritic cells and their applications in cancer immunotherapy--achievements and future prospects].

Dendritic cells (DC) are generally believed to play a key role in the initiation of immune response. A potential usefulness of these cells in antitumor immunotherapy is strongly considered in every stage of cancer treatment. Studies on tumor tissue infiltration by immune cells shown, that DC represented only a small percentage of leukocytes. The influence of tumor environment resulted in reduction of DC number, their inability to migrate across endothelial barriers, or impaired maturation and efficiency of tumor antigens presentation. Thus, decreased number of DC in tumors could be associated with a bad prognosis. Many attempts concentrate on the creation of the DC-based vaccines, which would generate strong anticancer cell mediated immunity. They include studies on stage of differentiation of the administered DC; effective way for antigen loading; optimum route and schedule of DC delivery into tumor bearing host; effective vectors for the therapeutic genes; effects of the therapy based on cytokine secreting DC; influence of DC on co-operation between innate and acquired immunity as well as on the generation of specific antitumor response. This review is focused on two important areas aiming for the preparation of DC vaccine for effective stimulation of immune response: loading of DC with tumor antigens (or other ways of DC preparation to successful antigen presentation)--as an encouraging evidence of therapeutic efficacy, and genetic modification of DC with cytokines resulting in the stimulation or alteration of the antitumor DC activity--as a promising anticancer strategy.