RECOMBINANT HUMAN INTERLEUKIN-11 DOES NOT AFFECT FUNCTIONS OF PURIFIED HUMAN NEUTROPHILS IN-VITRO

Recombinant human interleukin-11 (rHu-IL-11) is a multifunctional cyto kine with thrombopoietic activity and demonstrated clinical efficacy i n treating chemotherapy-induced thrombocytopenia. rHu-IL-11 also exhib its anti-inflammatory activity and is currently in clinical trials for the treatment of several inflammatory diseases. As neutrophils are in volved in both innate immunity and an acute inflammatory response, the effect of rHU-IL-11 on the function of human peripheral blood neutrop hils in vitro was examined, rHu-IL-11 was not cytotoxic and did not in duce superoxide anion production or the release of granular enzymes fr om resting neutrophils. Phagocytosis and chemotaxis were unaffected. r Hu-IL-11 treatment did not block the response of neutrophils to stimul ation. Pretreatment with rHu-IL-11 did not reduce production of IL-8 f ollowing activation with lipopolysaccharide (LPS) or zymosan A particl es. Pretreatment with rHu-IL-11 did not affect the release of lysozyme and P-glucuronidase in response to A23187 or PMA-stimulated productio n of superoxide anion. These results indicate that rHu-IL-11 does not directly modulate key functions of neutrophils in vitro.