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

Abstract

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.

Interleukin 17 (IL-17) je proinflamatorni citokin koga produkuju aktivirane CD4+ i CD8+ T ćelije, dok je njegov receptor ubikvitarno distribuiran. Inflamatorni kapacitet IL-17 se zasniva na njegovoj sposobnosti da stimuliše širok spektar stromalnih ćelija da produkuju i oslobađaju različite proinflamatorne medijatore, među kojima neki imaju efekte na hematopoezu posebno granulopoezu. Dosadašnji podaci ukazuju na ulogu IL-17 u patogenezi različitih inflamatornih bolesti, odbacivanju transplanta i razvoju tumora. Cilj ovog rada je bio da se odrede funkcionalni odgovori, uključujući respiratorni prasak, produkciju azot monoksida (NO), adhezivnost i metaboličku aktivnost/vijabilnost različitih ćelija periferne krvi (ukupnih leukocita, mononuklearnih ćelija i granulocita) zdravih donora, u prisustvu IL-17. Dobijeni rezultati su ukazali da IL-17 ne dovodi do značajnih promena respiratornog praska, produkcije NO i metaboličke aktivnosti ćelija periferne krvi, ali da uzrokuje blago povećanje forbol-12-miristat-13-acetat (PMA) stimulisane adhezivnosti granulocita i mononuklearnih ćelija. Odsustvo značajnih promena u ispitivanim funkcionalnim aktivnostima različitih ćelija periferne krvi, ukazuje da IL-17 ne eksprimira proinflamatorno dejstvo kod zdravih osoba, jer najverovatnije i ne postoji potreba za njegovim delovanjem.