Fig. 4

In vitro and in situ macrophages are responsive to IL-9. Human blood classical monocytes (Cl. Mo) of healthy donors were differentiated in macrophages (MΦ), and inflammatory macrophages (Infl. MΦ) in the presence of LPS and IFN-γ. IL-9R expression was analyzed by flow cytometry. Plots from a representative experiment are shown (a). Graph represents the frequency of IL-9R⁺ cells (b). IL-9R expression was analyzed by western blot. Results from a representative donor and cumulative data of 4 donors are reported (c). Mean ± SEM is shown for each group. Neuropathological assessment of IL-9 and IL-9R expression in post-mortem MS brain. Areas of microglia activation (e) in white matter (d), indicated with an asterisk, contain IL-9⁺ and IL-9R⁺ cells, mainly expressed in perivascular infiltrates (f, g). Scattered CD68⁺ IL-9R⁺ cells were found in the white matter tissue (h, i). Original magnifications: × 100 (d, e), × 200 (f, g), × 400 (h, i)