Maturation of dendritic cells following exposure to different maturational stimuli

Abstract

Dendritic cells (DCs) are professional antigen-presenting cells that are highly effective to immunize against pathogens and tumor antigens. In order to obtain mature DCs several in vitro methods have been reported. Selecting the most efficient and effective method of generating morphologic and phenotypic DCs within 7 days of culture is an essential prerequisite for success in immunotherapy strategies. Herein, we report a method of obtaining an enriched monocyte population from blood donors and performed a comparison of DC maturation in response to four agents. Monocyte populations with 91% ± 5 of purity were obtained from 15 healthy donors. The resulting monocyte populations were cultured in the presence of GM-CSF and IL-4 during 5 days. At day 5 different maturation conditions were performed and morphological and phenotypical changes were analyzed. Our study demonstrates that TNF-α or PGE1 by themselves can induce the expression of CD1a 2.4 and 2.7 times respectively more than DC cultures in the absence of maturing agents. On the other hand, for other costimulatory or accessory molecules (CD80, CD86, CD83 and CD40) TNF-α was more potent in the induction of expression than PGE1, although in the presence of TNF-α plus PGE1 this effect is more pronounced compared to TNF-α alone. Under TNF-α plus PGE1 treatment the phenotypical maturation of immature DCs are comparable to LPS and therefore TNF-α+ PGE1 might be useful for generating ex-vivo DCs to use in protocols of cell vaccination. Further functional evaluation of these mature DCs is warranted.