The Impact of ATRA on Shaping Human Myeloid Cell Responses to Epithelial Cell-Derived Stimuli and on T-Lymphocyte Polarization

Figure 4

ATRA promotes the expression of CD103⁺ cells in in vitro differentiated myeloid cells. Monocytes were differentiated in the presence of GM-CSF+IL-4 or M-CSF, respectively. The differentiated cells were treated by the supernatants of Caco2 cells preactivated by IL-1β or TNF-α in the presence or absence of ATRA. The phenotype of the myeloid cells was characterized by measuring the cell surface expression of α4β7/CD103 and CX3CR1 on day 3 of in vitro myeloid cell differentiation by flow cytometry. Histograms show the cell surface expression of CD103 in cells differentiated by GM-CSF+IL-4 (or M-CSF) and stimulated by the supernatants of Caco2 cells pretreated by IL-1β (a) or TNF-α (b) and the cell surface expression of CX3CR1 in cells differentiated by M-CSF (or GM-CSF+IL-4) and stimulated by the supernatants of Caco2 cells prestimulated by IL-1β (c) or TNF-α (d). MFI of a typical measurement out of 3–5 independent experiments is shown. Red line depicts untreated cells, green is for cells pretreated with the supernatant of Caco2 cells activated by IL-1β or TNF-α, blue is for myeloid cells pretreated with the supernatant of Caco2 cells activated by IL-1β or TNF-α in combination with ATRA, and brown corresponds to cells treated by the supernatant of unstimulated Caco2 cells and ATRA.

(a)

(b)

(c)

(d)