[Natural killer cells complot with dendritic cells]

Dendritic cells (DC) were initially considered as antigen presenting cells participating in the polarization of the immune response. Further understanding of their biology allowed determining their additional functions such as immunoregulatory and cytotoxicity. Until recently natural killer (NK) cells were known as a homogeneous population of lymphocytes capable of non-specific recognizing and eliminating target cells. Now it is widely accepted that NK cells, as a heterogeneous population, may also possess immunomodulatory functions. Moreover, the most recent analysis of the interactions between DC and NK cells revealed the exceptional functions of these cells. As a result of these studies the existence of bitypic cell population was postulated. The distinguishing features of these hybrid cells are: the expression of surface receptors typical for NK cells and DC, the cytotoxic activity, the production of interferons as well as their ability to present antigen after prior stimulation. Despite the lack of strong direct evidence that the same cell can be both cytotoxic and effectively present the antigen at the same time, there are experimental findings suggesting that generated ex vivo bitypic cells may be used in antitumor therapy.