Circulating N1 Neutrophils Are Proinflammatory Granulocytes That are First Responders at Sites of Inflammation

Neutrophils are the most abundant cellular component of the innate immune system. As first responders, they are rapidly recruited to sites of infection, where they eliminate invading pathogens. Although neutrophils are generally regarded as a homogeneous cellular population, recent research suggests that they may be made up of multiple subsets. In cancer, neutrophils present as multiple subsets, impacting tumour growth and metastases. We identified two subsets of neutrophils, N0 and N1, in na誰ve bone marrow and blood of healthy mice, based on the surface expression of 4 CD markers. The N1 neutrophils are first responders, with a proinflammatory phenotype, while the N0 population is the resting state subset. We show that the percent of N1 neutrophils in circulation changes during acute and chronic inflammation, suggesting that studying this population may allow us to better understand the role of neutrophils in maintaining health, and their role in regulating the inflammatory processes.M.Sc