FIG 2

Surface expression of CEACAM5 on mammalian cells. (A) The indicated human cell lines were fixed in 4% paraformaldehyde and immunolabeled for surface DPP4 and CEACAM5 expression. The shaded curves and the open curves represent isotype- and antigen-specific staining, respectively. Horizontal lines represent the gating for DPP4⁺ or CEACAM5⁺ cells. The numbers represent the percentage of positive cells. (B and C) The same fixation and immunostaining procedures were performed for human primary T cells (B) and a number of nonhuman mammalian cells (C). (D) Average percentages of DPP4/CEACAM5-positive cells. (E) Average DPP4/CEACAM5 MFIs were quantified. Rabbit isotype IgG was used in place of antigen-specific antibodies for the controls. (D and E) Shown are means and standard deviations of the results of three independent experiments.