Effects of hypoxia on the differentiation of monocyte-derived DCs. (A) DCs express inducible HIF-1α in response to hypoxia. DCs were generated from monocytes cultured in the presence of IL-13 and GM-CSF under normoxic (Norm) and hypoxic (Hyp) conditions. Whole protein extracts were analyzed by Western blot at different time points as indicated. P indicates the protein extract from control Hela cells treated with the hypoxia-mimicking compound cobalt chloride (CoCl2).²³  Vertical lines between day 3 and day 6 have been inserted to indicate a repositioned gel lane. (B) Expression profiles of CD14 and CD1a in DCs differentiated in normoxia or hypoxia, as indicated. Freshly isolated monocytes (day 0) and DCs differentiating on day 3 and day 6 of culture were stained with CD14-APC and CD1a-FITC. The results shown are representative of 4 independent experiments. Q1: single-positive CD14⁺ cells; Q2: double-positive CD14⁺/CD1a⁺ cells; and Q4: single-positive CD1a⁺ cells. (C) Expression profiles of CD16 and CD68 in the single-positive CD14⁺ population (Q1) in normoxia and hypoxia. Results are means plus or minus standard deviation (SD) of 3 independent experiments.