Effector mechanisms of interleukin-17 in collagen-induced arthritis in the absence of interferon-γ and counteraction by interferon-γ

In the absence of IFN-gamma, IL-17 mediates its pro-inflammatory effects mainly through stimulatory effects on granulopoiesis, neutrophil infiltration and bone destruction. In vitro IFN-gamma profoundly inhibits the effector function of IL-17. Thus, aside from the well-known inhibition of the development of Th17 cells by IFN-gamma, this may be an additional mechanism through which IFN-gamma attenuates autoimmune diseases.