Morphology and regulatory features of HGF-differentiated monocytes. (A) GM4-DCs and ^HGFMo were stained with May-Grunwald-Giemsa and visualized under an AX70 optical microscope (Olympus, Tokyo, Japan) equipped with a 100 ×/1.25 NA objective lens. Image acquisition was performed with an Optronics digital camera (Olympus) and ImagePro Plus software (Media Cybernetics, Silver Spring, MD). Similar to conventional GM4-DCs, ^HGFMo displayed an eccentric nucleus and an irregular cytoplasmic outline with tiny projections. (B) Expression of ILT3 and CCR6 in monocytes exposed to GM-CSF and IL-4 or to HGF. Numbers indicate MFI of mAb staining measured in a representative experiment of 9 with similar results. (C) After 6 days of culture, DCs were treated with 1 μg/mL lipopolysaccharide (LPS) for 24 hours. Culture supernatants were harvested and used for ELISAs. Results are expressed as the mean ± SD recorded in 8 independent experiments performed in duplicate and depict IL-12p70, IL-10, and TGF-β release by GM4-DCs, ^HGFMo, or monocytes maintained in the presence of BIT serum substitute alone. ^*P < .001 compared with immunogenic GM4-DCs. (D) Semiquantitative RT-PCR for IL-10 in GM4-DCs, ^HGFMo, and monocytes maintained in the presence of BIT serum substitute alone. Th1-like and Th2-like human T cells, differentiated as previously detailed, were used as controls for IL-10 expression levels.¹³