FIG 7.

The phenotypic effects of pLL on GM-CSF–BMDCs do not require phagocytosis. GM-CSF–BMDCs were exposed to pLL, LPS (the usual 10 ng/ml or in the indicated case 1 ng/ml), or both stimuli together for 18 h in the absence or presence of inhibitors of PI3K class III (Vps34-IN1 and SAR405), and the cell surface expression of CD40 (a) and CD86 (b), as well as the levels of IL-10 (c) and IL-12p70 (d), in supernatants was measured. Also, GM-CSF–BMDCs were exposed to pLL selected for nonphagocytosable particle size range (“pLL^NP”), LPS, or both stimuli together for 18 h, and maturation parameters were measured as described above. (e) Bright-field microscopy images of two representative nonphagocytosable pLL particles incubated with GM-CSF–BMDCs under assay conditions are shown. Insets highlight the contour of each particle (empty outline) and those of selected cells (outlines filled in gray). (f to i) Maturation parameters of GM-CSF–BMDCs responding to pLL^NP with or without LPS: CD40 (f) and CD86 (g) expression, as well as IL-10 (h) and IL-12p70 (i) production. All values plotted correspond to means ± the SD of triplicate wells. The results shown are representative of at least three independent experiments.