Figure 3

HCl treatment enhanced monocyte adhesion to lung epithelial cells via crosstalking between LAF-1 and ICAM-1. Human BEAS-2B cells were treated for 30 min with serum-free DMEM either alone (pH 7.4) or containing HCl (pH 4.0). The medium was replaced with complete DMEM at pH 7.4. The cells were then incubated with the LFA-1 peptide CD11a_237–246 (PeptCD11a), CD18_112–122 (PeptCD18), or both in combination (PeptCD11a + CD18) with scrambled peptides (PeptScrambled) as control at 0.1 or 1.0 mM for 30 min, human U937 cells (10⁵ cells) labeled with Calcein-AM were then added onto the monolayer of the BEAS-2B cells and cocultured for 48 h. Monocyte adhesion was evaluated by measurement of Calcein-AM density. Data shown are in triplicate from three experiments. ^*P < 0.05 vs. vehicle control (far left bar).