The disease burden of sepsis continues to increase, with intraabdominal contamination being a signif-icant source of infection. Sepsis is a syndrome involving both an increase in systemic inflammation as well as a regulatory component. We have previously demonstrated that neutrophils are significant IL-10 producers in the abdomen during sepsis. Here, we sought to further characterize these neutrophils and elucidate potential underlying mechanisms resulting in IL-10 generation. Using transcriptional reporter mice, we observed that IL-10 producing neutrophils were activated, non-apoptotic, and expressed C-X-C chemokine receptor type 4-expressing. Further, we observed that active Signal Transducer and Activator of Transcription 1 expression was significantly increased in IL-10 producing versus non-IL-10 producing neutrophils. During sepsis, IFN-gamma blockade lead to a decrease of neutrophil IL-10 production, while peritoneal CD4 T cells were found to be the most numerous acute producers of IFN-gamma. Altogether, this report demonstrates that during sepsis, mature neutrophils can potentially dampen local inflammation by IL-10 production and this can be orchestrated by CD4 T cells through an IFN-gamma dependent manner. (C) 2020 Elsevier Inc. All rights reserved.