Summary
Erythropoietin (EPO) is the principal cytokine regulating
erythropoiesis through its receptor, EPOR. Int
erestingly, EPORs are also found on immune cells with incompletely und
erstood functions. H
ere, we show that EPO inhibits the induction of proinflammatory genes including tumor necrosis factor (TNF)-α and inducible nitric oxide (NO) synthase in activated macrophages, which is mechanistically attributable to blockage of nuclear factor (NF)-κB p65 activation by EPO. Accordingly, in systemic Salmonella infection, treatment of mice with EPO results in reduced survival and impaired pathogen clearance because of diminished formation of anti-microbial effector molecules such as TNF-α and NO. Howev
er, neutralization of endogenous EPO or genetic ablation of Epor promotes Salmonella elimination. In contrast, in chemically induced colitis, EPO-EPOR int
eraction decreases the production of NF-κB-inducible immune mediators, thus limiting tissue damage and ameliorating disease sev
erity. These immune-modulatory effects of EPO may be of th
erapeutic relevance in infectious and inflammatory diseases.
PaperClip
erview"">