Interleukin 15 (IL-15) is a cytokine with strong impact on immunological system, that affects pathogenesis of multiple human disorders. Naturally, it participates in antiviral defence. Infected peripheral blood mononuclear cells secrete IL-15 which, via its impact on NK cells and T lymphocytes, exerts antiviral properties. IL-15 may find its application in HIV infection treatment. Stimulating proliferation of antigen- activated T cells and inhibiting their apoptosis, IL-15 may counteract AIDS-associated lymphocytopaenia.

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.