Cells of innate immunity form a heterogeneous group of myeloid and lymphoid populations includes cells that serve as the first line of defense of the organism against pathogens - granulocytes, monocytes, macrophages. Furthermore, cells that protect against external influences or disorders of internal balance and intracellular infections - NK cells and dendritic cells (DCs). Due to their ability to respond to subtle changes in the body (e.g. during tumor transformation or the initial stage of infection). DCs and NK cells can translate this information but also receive it through receptor interactions and chemokines, lymphokines and neurotransmitters. Although the individual subpopulations of innate immune cells are somehow specialized, the ability to recognize and the cytotoxic executive function are common to all cells. In this review, we describe the functions of dendritic cells in mammals. DCs play an important role in infectious immunity and autoimmunity.