FL-MSCs drive monocyte differentiation to a TAM-like phenotype. (A) Early modulation of monocyte phenotype and secretory profile was evaluated after 24 hours of culture with or without FL-MSCs. HLA-DR, CD86, and CD14 expression was evaluated by flow cytometry on CD14^posCD105^negTOPRO-3^neg viable monocytes as the ratio of mean fluorescence intensity (rMFI) compared with isotype control (left). The production of TNF and IL-10 in the supernatant was simultaneously studied by ELISA (right). Results represent the mean ± SD from 5 experiments. *P < .05; ***P < .001; ND indicates not detectable. (B) Late modulation of macrophage gene expression profile was evaluated after 7 days of coculture of monocytes with or without FL-MSCs before cell sorting of CD14^posCD105^negTOPRO-3^neg viable macrophages. Expression of IL10, IL6, VEGFA, and PGF was then evaluated by RQ-PCR. Each data were normalized to GAPDH and compared with expression in macrophages alone. The results are the mean ± SD from 9 experiments. *P < .05; **P < .01; ***P < .001. (C) Monocytes were cultured during 7 days with or without FL-MSCs before stimulation or not by LPS during 5 hours. CD14^posCD105^negTOPRO-3^neg viable macrophages were then cell-sorted and expression of TNF, IL10, and IL12A was evaluated by RQ-PCR. Each sample was normalized to GAPDH and compared with expression in unstimulated macrophages. The results are the mean ± SD from 5 experiments. *P < .05. (D) Monocytes were preincubated or not (MEDIUM) with DAPT or its vehicle (DMSO) for 1 hour and cultured in the same conditions during 7 days with or without FL-MSCs. LPS was then added or not (CTRL) during 18 hours and TNF concentration was measured in cell supernatants by ELISA (n = 10). *P < .05; **P < .01; ns indicates not significant.