Two-step maturation of immature DCs with proinflammatory cytokine cocktail and poly(I:C) enhances migratory and T cell stimulatory capacity.

Effective induction of cell-mediated immune responses strongly depends on the ability of dendritic cells (DCs) to produce Th1-polarizing cytokines, migrate to lymph nodes and stimulate T cells through antigen-presenting complex and costimulatory molecules. While various protocols for optimizing DC maturation with single or multiple stimuli mimicking infections or inflammatory milieu have been proposed for the generation of DCs with features desired for clinical application, stepwise maturation of DCs by these multiple stimuli has not been systemically assessed. Among the combinations of several immune-modulating factors with known effects on DC maturation, we found that stepwise DC maturation with cytokine cocktail (TNF-alpha+IL-6+IL-1 beta+PGE(2)) followed by poly(I:C) stimulation enhanced the production of IL-12 with strong allostimulatory capacity.