Generation of dendritic cells from peripheral blood monocytes from patients with chronic lymphocytic leukemia using GM-CSF, IL-4 and TNF does not induce their tolerogenic properties

Abstract

The aim of this study was to evaluate the tolerogenic properties of dendritic cells generated in vitro from peripheral blood monocytes in patients with chronic lymphocytic leukemia (CLL) using cytokines such as GM-CSF, IL-4 and TNF. There were no significant differences in the concentration of tolerogenic cytokines, IL-10 and TGF-β in supernatants from cultures of mature dendritic cells of CLL patients and healthy donors and the concentration of mentioned cytokines in the serum of CLL patients. There was no induction of regulatory T cells in cultures containing autologous T cells and dendritic cells generated from CLL patients. We have also evaluated the intracellular expression of indoleamine 2,3-dioxygenase (IDO) protein in generated dendritic cells. IDO inhibits proliferation and induces death of effector T cells, and induces the formation of regulatory T cells. There was no or only a trace amount of this enzyme in generated dendritic cells and the no correlation between the percentage of T regulatory cells, and the percentage of cells with phenotype CD83+IDO+. The results obtained in our study show that DC generated with GM-CSF, IL-4 and TNF have no tolerogenic properties.