FIG 7.

Neutrophils from S. mitis-infected chambers either are healthy or have apoptotic features, while those from EP-infected chambers appear necrotic. Cells were collected from S. mitis- or EP-infected chambers at time points when a large proportion of the cells are identified as R1, R2, or R3 by PI/Ly6G FACS analysis. These cells were then applied to coverslips and stained with Wright stain or fixed and processed for TEM. (a) Wright-Giemsa staining; (b) TEM; (c) representative PI/Lyg6 staining of analyzed populations. Rows: 1, partially purified bone marrow neutrophils represent R1 cells; 2, cells collected from S. mitis-infected chambers at 24 h after infection are both R1 and R3; 3, cells collected from EP-infected chambers at 24 h are predominantly R2; 4, cells collected from S. mitis-infected chambers at 72 h represent the R3 population. R1 cells in row 2 were identified as distinct from cells with morphology similar to R3 cells identified in row 4. N, nucleus; arrows (a) and open arrowheads (b), phagocytosed bacteria; dashed arrows (a), extracellular strands consistent with NETs. Bars, 20 μm (a) and 5 μm (b).