Expression of adhesion molecules and cell markers by Gr1highneutrophils from naive and influenza virus-infected mice. Uninfected mice were euthanized and neutrophils in the blood or BAL from pools of 5 mice were examined for expression of cell markers (grey histograms) and appropriate isotype controls (white histograms) via fluorescence intensity. Mice infected with 105 PFU of HKx31 were euthanized at day 3 post-infection and neutrophils in pooled BAL samples were also examined for expression of (A) cell surface adhesion molecules (B) other markers associated with neutrophil activation including (i) granularity, (ii) cell surface expression of LAMP-1 and (iii) intracellular H2O2 production. A minimum of 50,000 living cells (PI-) were collected and analyzed from each sample and numbers shown beside each histogram represent the MFI of each surface marker on the neutrophil populations indicated, except for H2O2 production, where numbers shown represent the fold increase in MFI between samples incubated at 4°C and those incubated at 37°C. The data is representative of at least 2 independent experiments.