Figure 1. CD13 surface expression on PMA-stimulated PBT induced by co-culture with HGF. PBT were incubated in the absence (A,C) or presence (B,D) of 0.5 µg/mL PMA for 24 hrs. After being washed, PBT and HGF were cultured for 24 hrs in the same wells of a six-well culture plate without (A,B) or with (C,D) direct contact, as described in MATERIALS & METHODS. (E-J) In another experiment, PMA-stimulated PBT were co-cultured with HGF for the indicated times. PBT were stained with biotin-conjugated 22A5 (anti-CD13) followed by PE-conjugated SAv, and subjected to flow cytometric analysis. Dotted lines represent flow cytometric profiles of PBT with PE-conjugated SAv only as negative control. Shaded histograms represent flow cytometric profiles of PBT stained with 22A5.