Effects of interleukin-13 on cytokine secretion by human acute myelogenous leukemia blasts

Blast cells derived from patients with acute myelogenous leukemia (AML) were cultured in the presence of interleukin-13 (IL-13). IL-13 did not cause statistically significant alterations of AML blast proliferation when cells were cultured in medium alone or together with IL-4, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. In contrast, IL-13 inhibited constitutive AML blast secretion of IL-1 alpha, IL-1 beta, IL-6, tumor necrosis factor alpha, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. IL-4 caused a similar inhibition of constitutive cytokine secretion as IL-13, but IL-13 caused no additive inhibition in the presence of IL-4. In contrast to IL-4 which increased AML blast release of IL-1 receptor antagonist, IL-13 caused no significant alteration of blast release of the receptor antagonist. IL-13 inhibited cytokine secretion also in the presence. of neutralizing IL-4 and IL-10 antibodies and when AML blasts were cultures in serum-free conditions. We conclude that IL-13 has a direct and nontoxic inhibitory effect on constitutive AML blast cytokine secretion.