Variability of ectosome activity among a group of 5 donors/kinetic of cytokine release by HMDMs dependent on zymosan and/or ectosomes. (A) HMDMs isolated from 5 different healthy blood donors were tested separately for their response to zymosan (zym., 5 μg/mL) in the presence or absence of ectosomes (ectos.) derived from PMN activated with either fMLP or C5a. fMLP-derived ectosomes were used at 5 μg/mL, and ectosome amounts released from equal numbers of PMN were used for fMLP- and C5a-ectosomes. Each dot represents one donor. Bars indicate the mean cytokine concentrations. Arrowheads indicate TGFβ1 “nonproducers”; arrows, donor who reacted strangely to C5a-ectosomes; lines link the cytokine response of this donor to zymosan in the presence and absence of C5a-ectosomes. (B) HMDMs were incubated with medium alone (Ø) with or without ectosomes and with medium supplemented with zymosan with or without ectosomes for up to 24 hours. Supernatants were harvested after 1, 2, 4, 8, and 24 hours and analyzed for IL-8, IL-10, TNFα and TGFβ1. HMDM alone (♦); HMDM + zymosan (▪); HMDM + ectosomes (▴); HMDM + ectosomes + zymosan (×). Error bars equal standard deviation of the mean.