Effects of IL-17 on functional activity of peripheral blood cells

Interleukin-17 (IL-17) is a proinflammatory cytokine produced mainly by activated CD4(+) and CD8(+) T cells, while its specific receptor is ubiquitously distributed, The inflammatory capacity of IL-17 is based on its ability to stimulate a wide range of stromal cells to produce and release a number of proinflammatory mediators, some with a known impact on hematopoiesis, particularly granulopoiesis. Recent data indicate a role for IL-17 in the pathogenesis of several inflammatory diseases, transplant rejection and tumor growth. The purpose of this study was to determine functional responses, including the respiratory burst, nitric oxide (NO) production, adhesiveness and metabolical activity/viability of human peripheral blood leukocytes (total white blood cells, mononuclear cells and granulocytes) from healthy donors in the presence of recombinant human (rh)IL-17. The obtained results showed that rhIL-17 did not induce significant changes in the respiratory burst, NO production, and metabolical activity of each peripheral blood cell fraction the tested, while a slight increase in phorbol-12-myristate-13-acetate (PMA) stimulated adhesiveness of granulocytes and mononuclear cells was noted. The absence of significant changes in tested functional activities of various peripheral blood cells suggests that IL-17 does not express its proinflammatory ability in steady-state, since the requirement for its action really does not exist.