The role of eosinophils in interleukin-2/lymphokine-activated killer cell therapy.

Abstract

When interleukin-2 alone or in combination with lymphokine-activated killer (LAK) cells is administered to patients with cancer, peripheral or local eosinophilia is frequently seen. To evaluate the role of eosinophils in this setting, we studied the functional changes of human eosinophils induced by the supernatant of LAK cell cultures. The chemotactic activity, change in chemiluminescence, superoxide production, expression of leukocyte integrins (CD11/CD18 family), and adherent activity to plastic dishes were investigated after stimulation of eosinophils with LAK cell culture supernatant. The chemotactic activity of eosinophils in the supernatant of LAK cell cultures was increased significantly, and this activity was chemotactic rather than chemokinetic by checkerboard analysis. Both chemiluminescence and superoxide production of stimulated eosinophils increased significantly compared with resting. In addition, eosinophil-adherent activity to plastic dishes was also increased. Among leukocyte integrins, CD11b expression on stimulated eosinophils increased. Moreover, eosinophil antibody-dependent cellular cytotoxicity against Raji cells was enhanced after stimulation with the supernatant of LAK cell cultures. These results suggest that the eosinophils activated by LAK cells may play an important role in the antitumor effect of interleukin-2/LAK cell therapy.