Identification of neutrophil surface marker changes in health and inflammation using high-throughput screening flow cytometry.

Neutrophils are the most abundant white blood cell and are an essential component of the innate immune system. A complete cataloguing of cell surface markers has not been undertaken for neutrophils isolated from circulation as well as healthy and inflamed tissues. To identify cell-surface markers specific to human neutrophils, we used high-throughput flow cytometry to screen neutrophil populations isolated from blood and oral rinses from healthy and chronic periodontitis patients against a panel of 374 known cluster of differentiation (CD) antibodies. This screen identified CD11b, CD16, and CD66b as markers that are consistently expressed on neutrophils independent of the cell location, level of activation and disease state. Cell sorting against CD11b, CD16 and CD66b allowed for the enrichment of mature neutrophils, yielding neutrophil populations with up to 99% purity. These findings suggest an ideal surface marker set for isolating mature neutrophils from humans. The screen also demonstrated that tissue neutrophils from chronically inflamed tissue display a unique surface marker set compared to tissue neutrophils present in healthy, non-inflamed tissues.