Many studies on medical application of adipose-derived mesenchymal stem cells are currently performed. Regenerative and immunomodulatory properties of these cells are very promising. In this paper we review the literature concerning differentiation potential of adipose-derived stem cells and their effects on immune response. We demonstrate the clinical application of these cells and, shortly, their phenotype and isolation methods.

Natural exogenous immunostimulators are preparations isolated from bacteria, plants or fungi that activate immunological system. Present research is aimed at understanding the exact mechanism of their action and improving their efficacy in parallel with reducing minor side effects. It appears that in the majority therapeutical effects of the bacterial and fungal preparations result from the activation of Toll- like receptors (TLR). However, biologically active substances isolated from plants can activate cells through non-specific interaction with their surface.

Interleukin 15 (IL-15) is a cytokine that reveals multiple actions on immune system. Initially it was thought to resemble IL-2, but there is still growing evidence that IL-15 has multiple, unique properties, in some cases acting opposingly to IL-2. IL-15 influences mechanisms of both innate and acquired immunity. It induces differentiation and proliferation of NK cells, increases their cytotoxic properties and ability of IFN-γ secretion and also serves as chemoattractant for them. IL-15 acts also on macrophages/monocytes as well as on neutrophils.