Upregulated TCR Zeta and Improved the IFN-γ Secretion and Cytotoxicity in T Cell from Patients with AML after IL-2, IL-7 and IL-12 Stimulation

T cells from patients with acute myeloid leukemia (AML) display antigen receptor–mediated signaling aberrations associated with defective T cell receptor (TCR) zeta chain, a subunit of the TCR/CD3 complex. Up-regulate TCR signaling activation by TCR zeta recombinant vector transfection was showed to reverse IL-2 production and increased the activation in T cells from patients with chronic myeloid leukemia. This study was undertaken to explore the possibility that increased TCR zeta gene expression stimulated with immune cytokines may upregulate T cell receptor signaling activation in T cells from patients with AML. CD3⁺ T cells sorted from peripheral blood of 8 cases with AML were induced with different immune cytokines, including IL-2, IL-7, IL-12, anti-CD3 and anti-CD28 antibodies in vitro. The result showed that TCR zeta chain protein was significantly upregulated after stimulation with IL-2 + IL-7 at 72 hours (p<0.05) by western-blot analysis, the expression of Zap-70 which is TCR zeta-associated protein was increased apparently after stimulation by combined IL-7 and IL-12 at 72 hours (p<0.05). A higher level of interferon (IFN)-γ secretion was showed obviously with single stimulating factor or combination with different cytokines (p<0.05), especially in IL-12 + IL-7, CD3 + CD28 + IL-2 or CD3 + CD28 + IL-7 combination. In addition, the cytotoxicity of T cell from patients with AML was achieved after stimulation with different cytokines combinations at 7 days, especially in CD3 + CD28 + IL-2 group and CD3 + CD28 + IL-2 + IL-12 group. These result showed that downregulation of the TCR zeta chain in T cell from patients with AML is a reversible event. Combined different cytokines could restore TCR zeta chain deficiency and enhance IFN-γ production and cytotoxicity in T cells from AML patients. It is possible that upregulated TCR zeta chain expression in T cell from AML patients will effectively increase or recover their activation of antileukemia cytotoxicity.