Effects of Imatinib mesylate on the development of dendritic cells derived from bone marrow mononuclear cells of patients with chronic myeloid leukemia

Abstract

To investigate the effects of Imatinib mesylate (STI571) on the development of dendritic cells (DC) derived from the bone marrow mononuclear cells of patients with chronic myeloid leukemia (CML). Bone marrow mononuclear cells (BMMNC) from CML patients were cultured initially using multiple cytokine combinations as follows: recombined human granulocyte/macrophage colony-stimulating-factor (rhGM-CSF) plus recombined human interleukin-4 (rhIL-4) as control groups, rhGM-CSF plus rhIL-4 and STI571 as experimental groups, and from day 8 added recombined human tumor necrosis factor-alpha (rhTNF-alpha) for stimulating maturation. The morphologic features of cells were observed by Wright's staining, Cytogenetic analysis was performed by Fluorescence in-situ hybridization (FISH), phenotypes were assessed by flow cytometry, and the functions of antigen-presenting were assayed by mixed lymphocyte reaction (MLR). The concentration of VEGF was detected by enzyme-linked immunosorbent assay (ELISA). NF-kappaB activation was evaluated by TransAM(TM) ELISA kit. CML experimental groups treated with STI571 displayed features in morphology which were similar to those of control groups with delicate membrane projections. FISH confirmed the DC of both CML groups were leukemic origin. In comparison with the CML control groups, the CML experimental groups showed an increased expression of CD80, CD86, CD83 and HLA-DR and showed more intense abilities of allogeneic antigen presentation. The concentration of VEGF was dramatically reduced, and yet NF-kappaB activation was increased in experimental groups. STI571 could promote the activation/maturation of DC derived from BMMNCs of patients with CML in vitro, which might be partially responsible for the fact that the inhibitory effect of VEGF on DC NF-kappaB activation was relieved through STI571 inhibiting the overproduction of VEGF in CML.