Suppressive activity of neutrophils (N) results in a population of small nonresponsive T cells. (A) Gating of FSC^low (red) and large (green) T cells on FSC/SSC plots of (representative) flow cytometric analysis of purified T cells cultured with or without neutrophils in the presence of IL-15 and TNF-α (n = 3). (B) The surface marker expression of indicated proteins was measured by flow cytometric analysis of unstimulated T cells (purple bars), T cells stimulated for 2 days with IL-15 (blue bars), and T cells stimulated for 2 days with IL-15 in the presence of activated neutrophils. The latter T cells were separated into large (green bars) and small (red bars) groups (n = 3). (C) T cells cultured for 2 days in the presence of IL-15 and TNF-α–activated neutrophils were sorted into small and large T cells and cultured separately in the presence of anti-CD3/CD28 antibodies or phytohemagglutinin-L (PHA-L). Cells were harvested after 4 to 6 days and were analyzed by flow cytometry for CFSE dilution (n = 5-9). Error bars indicate SEM. ****P < .0001; ***P < .001; **P < .01; *P < .05.