Figure 5.

Effects of attachment on different extracellular substrates or β3-specific antibodies on J774 macrophage apoptotic cell or OS binding and internalization. J774 macrophages were seeded on coated coverslips in serum-free medium for 30 min. Particles were added for 30 min (a) or 90 min (b) in the presence or absence of inhibitory antibodies or peptides. White (a) and gray (b) bars, hatched or not, represent mean binding plus internalization indices ± SEM (n = 6). Black bars represent mean internalization indices ± SEM (n = 3). Note that cells seeded for 30 min before particle challenge, as studied in this experiment, bound fewer particles than cells which had attached overnight (see Fig. 2). Results represent data from OS challenges. Identical results were obtained challenging with apoptotic cells. Cell adhesion or morphology did not notably change due to attachment to the β3 antibody or to different substrates (LN, laminin; Fb, fibrinogen; VN, vitronectin). Attachment to αvβ5 or β1 antibody had no effect on particle binding (data not shown).