Figure 2. CD13 expression by PMA-stimulated PBT cultured with HGF but separated by a microporous membrane. (A) Schematic illustration of the chamber system in which cylindrical wells with collagen-treated microporous membranes were assembled and introduced. In this culture system, PBT and HGF were cultured in the same wells of a six-well culture plate without direct contact, as described in MATERIALS & METHODS. PMA-stimulated PBT were cultured on HGF (B) or on porous membrane (C) for 24 hrs. PBT were stained with biotin-conjugated 22A5 (anti-CD13) followed by PE-conjugated SAv, and then 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. (D) Gene expression of CD13. PMA-stimulated PBT were cultured on plate, or on either HGF monolayer or porous membrane, for 2 hrs in the same well as shown in (A). Total RNA was prepared from each cultured PBT, and cDNA syntheses by RT and PCR were performed as described in MATERIALS & METHODS. The results were a representative profile of three independent experiments.