Figure 3

Phenotype of lung endothelial cells after enzymatic digestion. A) Flow cytometry light scatter characteristics of the digested lung cells. Gate 1 was used for subsequent dual parameter analyses. The green population in panels A-D reflect Gate 2 defined in panel B. B) Dual parameter histogram of lung cells stained with directly conjugated anti-CD31 (390, FITC) and anti-CD11b (M1/70, PE) monoclonal antibodies. C) Consistent with an endothelial phenotype, the CD31⁺/CD11b^- cells in Gate 2 were also negative for the leukocyte antigen CD45 (30-F11, PE). D) Isotype control of the anti-CD31 antibody. E-F) Surface expression of the Flt1 (VEGFR1) and Pecam1 (CD31) gene products of the endothelial cell population presented as a single parameter histogram. Gray reflects the surface staining of the isotype control of each antibody; MFI = mean fluorescence intensity. The CD31⁺ cells (Gate 2) were defined as endothelial cells for subsequent experiments.