Neutrophils Are a Source of Gamma Interferon during Acute Salmonella enterica Serovar Typhimurium Colitis

Gamma interferon (IFN-gamma) is an important driver of intestinal inflammation during colitis caused by Salmonella enterica serovar Typhimurium. Here we used the mouse colitis model to investigate the cellular sources of IFN-gamma in the cecal mucosa during the acute phase of an S. Typhimurium infection. While IFN-gamma staining was detected in T cells, NK cells, and inflammatory monocytes at 2 days after infection, the majority of IFN-gamma-positive cells in the cecal mucosa were neutrophils. Furthermore, neutrophil depletion blunted mucosal Ifng expression and reduced the severity of intestinal lesions during S. Typhimurium infection. We conclude that neutrophils are a prominent cellular source of IFN-gamma during the innate phase of S. Typhimurium-induced colitis.