The Induction of Dendritic Cells with IFN-alpha and GM-CSF from Bone Marrow Mononuclear Cells from Patients with Chronic Myeloid Leukemia.

Chronic myelogenous leukemia (CML) is a malignant myeloproliferative disease arising from the clonal expansion of a stem cell with the typical Philadelphia (Ph) chromosome cytogenetic abnormality. IFN-a has been proven to be effective for patients in the chronic phase of myelogenous leukemia (CML), yet the mechanisms of the antitumor action of these cytokines are still a matter of debate. Dendritc cells (DCs) are potent antigen-presenting cells that prime effective T-cell response aginst tumour antigens. Recent studies have shown that IFN-a can exert a variety of effects on dendritic cells (DCs), which may play an important role in the induction of an antitumor immunity. Human DCs can be generated in vitro from peripheral blood(PB) monocytes or from CD34+ haematopoietic precursor cells in culture medium containing human granulocyte macrophage-colony stimulating factor (GM-CSF), IL-4 and some other cytokines. Previous studies have shown a new effective protocol for the generation of human DCs from unseparated BM aspirate cells with excellent functional capacity of antigen uptake and of stimulating naive and memory T cell responses superior to that of DCs from peripheral blood(PB) monocytes. We, therefore, explored whether treatment with IFN-a may influence the CML bone marrow mononuclear cells(BMMNCs) derived DCs in vitro. Treatment BMMNCs of 12 patients with CML in chronic phase with IFN-a+rhGM-CSF(IFN-a-DC) generated DCs with more mature phenotype properties expressing higher of CD80,CD86,HLA-DR,CD83 compared to the CML- BMMNCs treated with rhGM-CSF+IL-4(IL-4-DC). And in parallel with phenotypes, IFN-a-DC also showed more effective than IL-4-DC in eliciting an allogeneic mixed lymphocyte reaction by MTT assay. FISH confirmed the DCs of both groups were leukemic origin. These findings demonstrate that IFN-a promotes the differentiation/maturation of DCs derived from BMMNCs of patients with CML in vitro, these studies also broaden the clinical scope of IFN-a as a promising agent in the immunotherapy of CML.