EPO treatment increased numbers of Treg cells and reduced numbers of Th17 cells in MOG-EAE mouse spinal cord.

<p>MOG-immunized C57 mice received daily EPO or PBS treatment for 6 days (day 1–6). Spinal cords were obtained at two different time points (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) EPO therapy induced a substantial increase in Foxp3+ Treg cells in EAE spinal cords. The EPO induced expansion of Tregs in the CNS became even more evident in late stages of the disease and correlated with less severe neurologic deficit. b–c) Foxp3⁺ labeled Treg cells in PBS or EPO treated MOG-EAE spinal cord by IHC. Panel b shows a sham treated EAE spinal cord section reacted with Foxp3 antibody containing few labeled cells. By contrast, many more Foxp3+ cells were present in the infiltrates of EPO treated EAE spinal cord (panel c). d) Significantly increased numbers of Th17 cells occurred in sham treated EAE mouse spinal cord and this correlated with more severe clinical neurologic deficits whereas EPO therapy suppressed the number of spinal cord Th17 cells. e) Increased MOG antigen-specific T cells occurred within untreated EAE spinal cord, and EPO induced large reductions in MOG-specific T effector cells within the CNS. Data represents mean±SEM for 6 individual mice. *, p<0.05; **, P<0.001.