The phenotype and functions of monocyte-derived dendritic cells (DCs), generated upon stimulation with GM-CSF and IFN-α, were investigated in pulmonary tuberculosis (TB). The most pronounced increase of IL-10 production, as well as the decrease of allostimulatory activity and the alteration of T1/T2 stimulatory activity of DCs were registered in patients with low PPD-induced proliferative response. The data obtained evidence the tolerogenic phenotype of monocyte-derived IFN-DCs and the association of DC impairment with decreased antigen-specific T cell response in TB patients.