Inducing and enhancing effects of IL-3, -5, and -6 and GM-CSF on histamine release from human basophils

The effects of interleukin (IL)-2, -3, -4, -5, -6, and -7 and granulocyte- macrophage colony-stimulating factor (GM-CSF) on histamine release from human basophils were evaluated. IL-3 was the only cytokine with histamine-releasing activity. This activity was observed predominantly on basophils from allergic patients (mean release ± SEM, 33.9 ± 9.5%; n = 12), whereas basophils from normal subjects responded less frequently to stimulation with IL-3 (mean release ± SEM, 2.8 ± 1.0%; n = 22). The effect of IL-3 was time and temperature dependent, since release was optimal after incubation for 120 min at 37°C. When cell-bound IgE were eluted at acid pH, basophils became unresponsive to IL-3; however, IL-3-induced histamine release correlated with anti-IgE-induced histamine release in allergics, but not in normals. IL-3, IL-5, IL-6, and GM-CSF enhanced significantly anti-IgE- and FMLP-induced histamine release. In contrast, IL-2, IL-4, and IL-7 were devoid of any significant histamine-releasing or -potentiating activity. These results indicate that IL-3 can induce and IL-3, -5, and -6 and GM-CSF can enhance histamine release from human basophils, suggesting a possible role of these cytokines in the expression of allergic reactions.