Dendritic cells are one of the major populations of immune cells. Due to the presence of specific receptors dendritic cells (DCs) are able to respond to both intra- and extracellular antigens. The diversity of this cell population is a result of differences in localization, stage of maturation, phenotype and function. In recent years there has been a shift in perception of DCs not only as inducers of immune reactivity but also as crucial regulators of immunity, which include ability to induce and maintain tolerance and also as effector cells, which are capable to kill tumor cells (NKDCs).

Current ideas concerning various aspects of the biology of dendritic cells (DC) were presented, including subdivision on two subsets and follow-ups of their activation. The issue of DC cross-presenta- tion (cross-priming) was discussed in detail as an important facet of their immunobiological function. The relevant role of DC in immunoregulation was underlined, particularly the action of immunosuppressive cytokines such as IL-10 and TGF-β and the enzyme indoleamine 2,3-dioxygenase (IDO). Attention was paid to the significance of DC in the induction of immunological tolerance.

During the last two decades treatment based on selective stimulation of immune system has became a promising anti-neoplastic strategy, testing in several clinical centers all over the world. Vac- cination with dendritic cells previously exposed to tumor antigens seems to be one of the most attrac- tive approaches of immunotherapy. Dendritic cell-based vaccines were tested in many early phase clinical trials in patients with solid tumors, including malignant melanoma.

During the last two decades treatment based on selective stimulation of immune system has became a promising anti-neoplastic strategy, testing in several clinical centers all over the world. Vac- cination with dendritic cells previously exposed to tumor antigens seems to be one of the most attrac- tive approaches of immunotherapy. Dendritic cell-based vaccines were tested in many early phase clinical trials in patients with solid tumors, including malignant melanoma.

Dendritic cells are professional antigen-presenting cells. They are found in the skin, blood, lymph nodes and other organs. Two their subpopulations are present in an organism myeloblastic and lymphoblastic, and this is the only example that we know. Dendritic cells play a key role in immunological response. The clinical and experimental studies suggest their use in tumor treatment, viral infections and autoimmunological disorders. In this review the biology of dendritic cells, their physiology, in vitro culturing methods and clinical use is described.

Cancer immunotherapy is not a standard in clinical treatment of tumors, while first attempts were made several years ago. The appearance of tumor specific antigens (TSA) e.g. Bcr/abl, or tumor associated antigens (TAA) in cancer cells may be used theoreticaly in cancer therapy. Tumor cells in transformation process accumulate products of oncogenes and/or loss the functional products of tumor suppressor genes. This processes change intracellular signaling roads regulating cell proliferation and/or apoptosis of cancer cells and effect the tumor growth progression.