Figure 7.

S1-RBD supports cell adhesion and phosphotyrosine signaling in human small airway epithelial cells. hSAECs (6.7 × 10⁴ cells/cm²) were seeded in the presence of 1 mM MnCl₂ on wells precoated with S1-RBD, laminin, FNIII10, or 1% bovine serum albumin (BSA). Representative images of SAECs adherent of S1-RBD (A) or laminin (B) are shown. The scale bar represents 50 μm. C, cell adhesion after 2 h was determined by crystal violet staining. Data are presented as mean absorbance ± SEM. ∗p < 0.05 versus BSA by one-way ANOVA with Bonferroni’s posttest. D, cell lysates were obtained after 4 h of adhesion and analyzed by immunoblotting with the indicated phosphospecific antibodies. Vinculin was used as a loading control. Molecular mass markers are shown on the left. Control cells were maintained suspended in medium before lysing. SAEC, small airway epithelial cell.