Dendritic cells (DCs) are antigen presenting cells which trace origin from bone marrow cells. These cells are discovered and described by Steinman i Cohn (1973) in peripheral lymphoid organs of mice. The cellular membrane of DCs are place of expression of plenty immunoregulatory molecules such as MHC class I and II, co stimulatory, and adhesion molecules, as well as many receptors for different cytokines. Armed on this way, DCs are one of the most effective antigen presenting and immunoregulatory cells. Moreover, role of DCs in development of immune reaction can be crucial due to they are one of the most important cellular “link” between native and adaptive immunity. DCs are engaged in mechanisms of antigen processing and presentation, induction of immune reaction, establishing immune tolerance and immune reaction regulation, balancing the immune reaction between autodestruction and protection of “self” cells. These functions makes that DCs play very important role in development of some pathological conditions and diseases such as autoimmunity, allergies and quality of anti-tumor and anti-microbe defense. Unbalanced immune reaction is hallmark of all cited diseases and immunopatological conditions, so that the function of DCs should be explored on the better way.

In regulation of specific immune responses the most important role play interleukin-2, IL-4, IL-5, IL-13, inter feron- (INF- ), transforming growth factor- (TGF- ) and lymphotoxin (LT). These signal molecules are produced mainly by T-lymphocytes after recognition of foreign antigens by specific receptors (TCR) placed on plasmalema. Some of mentioned cytokines stimulate proliferation and differentiation of various lymphocyte populations in the activation phase of T cell-de pendent immune responses, while the others activate and regulate the function of specialized effector cells, such as mono nuclear phagocytes, eosinophils, and neutrophils, to eliminate antigens in the effector phase of immune responses. In con trast to most of cytokines which have stimulating action on an initiation and course of humoral and cell-mediated immune responses, TGF- has an inhibitory effect on the activation and proliferation of T-lymphocytes and the other leukocyts