Inhibition of cell adhesion by anti-4 Fab fragments does not inhibit VCAM-1 induction on endothelial cells.
(A) Confluent H-end80 monolayers were incubated with media alone or with media containing 10 ng/mL TNF-α for 16 hours and rinsed with DMEM. NQ22 cells (2 × 105) in DMEM were added for 20 minutes at 37°C under static conditions either in the absence or in the presence of PS/2 anti-integrin α4 subunit IgG (10 μg/mL) or Fab fragment (5 or 15 μg/mL). At the end of the incubation period, the nonadherent cells were removed as detailed in “Materials and methods.” The purity of the IgG and of the Fab fragment, analyzed by SDS-PAGE on a 10% gel under reducing conditions, is shown in the inset, lane 1 and lane 2, respectively. (B) Expression of VCAM-1 on H-end80 cells was evaluated after 7 hours of cocultivation with NQ22 cells obtained from infiltrated spleen either in the presence or in the absence of 50 μg/mL Fab fragment.
