The myeloid-related protein S100A9 reprograms Gr1+CD11b+ myeloid precursors into myeloid-derived suppressor cells (MDSCs) during murine sepsis. Here, we show that the immunosuppressive cytokine IL-10 supports S100A9 expression and its nuclear localization in MDSCs to function as immune repressors. To support this new concept, we showed that antibody mediated IL-10 blockade in wild-type mice after sepsis induction inhibited MDSC expansion during late sepsis, and that ectopic expression of S100A9 in Gr1+CD11b+ cells from S100A9 knockout mice switched them into the MDSC phenotype only in the presence of IL-10. Knockdown of S100A9 in MDSCs from wild-type mice with late sepsis confirmed our findings in the S100A9 knockout mice. We also found that while both IL-6 and IL-10 can activate S100A9 expression in naive Gr1+CD11b+ cells, only IL-10 can induce S100A9 nuclear localization. These results support that IL-10 drives the molecular path that generates MDSCs and enhances immunosuppression during late sepsis, and inform that targeting this immune repressor path may improve sepsis survival in mice.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-11479 |
| Date | 01 October 2018 |
| Creators | Bah, Isatou, Kumbhare, Ajinkya, Nguyen, Lam, McCall, Charles E., El Gazzar, Mohamed |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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