Figure 5. EPO treatment induced peripheral Treg cell expansion while reducing MOG-specific T cells and Th17 positive cells in peripheral lymphoid tissues.

Mice were immunized with MOG and received daily EPO treatment for 6 days (day1–6). DILNs and spinal cords were obtained at three different time points (day 7, day 16 and day 45) from mice treated with EPO or sham treated with PBS. Cells were quantified for number of Tregs (CD4⁺Foxp3⁺), Th17 and MOG-antigen specific T cells by flow cytometry. a) There were reduced numbers of Treg cells in DILNs from sham treated EAE mice at early stages (day 7) as well as at the peak of clinical signs (d16), and during recovery (day 45) compared to normal healthy control animals. b) Numbers of peripheral Th17 cells increased in sham treated EAE mice, whereas EPO therapy sharply reduced the number of peripheral Th17 cells in MOG-immunized animals. c) EPO treatment significantly reduced peripheral MOG_40–54/H-2Db specific T effector cell population compared to sham treated EAE mice. Data represents mean±SEM for 6 individual mice. *, p<0.05; **, p<0.001.