Abstract
Immune-suppressive effects of myeloid-derived suppressor cells (MDSCs) are well characterized during anti-tumor immunity. The complex mechanisms promoting MDSC development and their regulatory effects during autoimmune diseases are less understood. We demonstrate that the endogenous alarmin S100A8/A9 reprograms myeloid cells to a Tcell suppressing phenotype during autoimmune arthritis. Treatment of myeloid precursors with S100-alarmins during differentiation induces MDSCs in a Toll-like receptor 4-dependent manner. Consequently, knockout of S100A8/A9 aggravates disease activity in collagen-induced arthritis due to a deficit of MDSCs in local lymph nodes, which could be corrected by adoptive transfer of S100-induced MDSCs. Blockade of MDSC function invivo aggravates disease severity in arthritis. Therapeutic application of S100A8 induces MDSCs invivo and suppresses the inflammatory phenotype of S100A9ko mice. Accordingly, the interplay of Tcell-mediated autoimmunity with a defective innate immune regulation is crucial for autoimmune arthritis, which should be considered for future innovative therapeutic options.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have