New Jersey, USA -
There are many studies discuss immune modulation by stem cells by mechanisms such as IDO production, soluble HLA-G, and hepatocyte growth factor. An interesting question is whether stimulators of various stem cell activities may have immune modulatory activity as well. For example, we know that GM-CSF, a cytokine that stimulates production of granulocytes and macrophages can protect from autoimmune diabetes in the mouse. The study above describes erythropoietin as having immune modulatory activity.
The authors showed EPO:
1. Suppresses TNF-alpha production
2. Downregulates in vitro and in vivo antigen-specific recall responses to myelin oligodendrocyte protein (MOG) derived peptides
3. Inhibits EAE induction
4. Stimulates Treg (as detected by FoxP3 staining)
5 Inhibits Th17
Overcoming the hematopoietic effects by specific dosing or different forms of EPO will be necessary before using it as an immune modulator. However, this immune suppressive activity of IDO may have implications in patients with anemia of chronic disease that are taking EPO.