IL-27 attenuates IL-23 mediated inflammatory arthritis

Interleukin 27 has both pro-inflammatory and anti-inflammatory properties in autoimmunity. The anti-inflammatory effects of IL-27 are linked with inhibition of Th17 differentiation but the IL-27 effect on myeloid cells is less studied. Herein we demonstrate that IL-27 inhibits IL-23-induced inflammation associated not only with Th17 cells but also with myeloid cell infiltration in the joints and splenic myeloid populations of CD11b+ GR1+ and CD3−CD11b+CD11c−GR1− cells. The IL-27 anti-inflammatory response was associated with reduced levels of myeloid cells in the spleen and bone marrow. Overall, our data demonstrate that IL-27 has an immunosuppressive role that affects IL-23-dependent myelopoiesis in the bone marrow and its progression to inflammatory arthritis and plays a crucial role in controlling IL-23 driven joint inflammation by negatively regulating the expansion of myeloid cell subsets. •IL-27 exhibits both pro and anti-inflammatory properties.•IL-27 attenuates IL-23-induced synovitis and bone destruction.•IL-27 inhibits pathogenic myelopoiesis, neutrophilia and osteoclastogenesis.•IL-27 has anti-inflammatory properties in IL-23-induced experimental arthritis.