Resolution of inflammation is an active process that leads to tissue homeostasis and involves multiple cellular and molecular mechanisms. Myeloid-derived suppressor cells (MDSCs) have recently emerged as important cellular components in the resolution of inflammation because of their activities to suppress T cell activation. In this article, we show that HLA-DR-CD11b+CD33+CD14+ human MDSCs and CD11b+Ly6G-Ly6C+ mouse MDSCs markedly increased in patients and mice during and before the resolution phase of autoimmune uveoretinitis. CD11b+Ly6C+ monocytes isolated from autoimmune uveoretinitis mice were able to suppress T cell proliferation in culture, and adoptive transfer of the cells accelerated the remission of autoimmune uveoretinitis in mice. Alternatively, depletion of CD11b+Ly6C+ monocytes at the resolution phase, but not CD11b+Ly6G+ granulocytes, exacerbated the disease. These findings collectively indicate that monocytic MDSCs serve as regulatory cells mediating the resolution of autoimmune uveoretinitis.
Copyright © 2018 by The American Association of Immunologists, Inc.