MUC1 Limits Helicobacter pylori Infection both by Steric Hindrance and by Acting as a Releasable Decoy
Figure 3
MUC1 is released from the epithelial surface upon adherence of MUC1-binding beads.
105 fluorescent beads coated with the BC2 antibody against the extracellular domain of MUC1 or an isotype control (IC) were added to 96 well plates with confluent MKN7 epithelial cells and cultured for up to 50 h. Binding was assessed after 4.5, 24 and 50 h by determining fluorescence of washed monolayers (A) and culture supernatants (B). Statistics: Mean ± SEM, n = 9; ***p<0.001 vs 24 h. (C) The amount of MUC1 α-subunit (extracellular domain) in cells treated with anti-MUC1 coated beads compared to isotype control (IC) coated beads was detected by double determinant ELISA using the BC2 (capture) and BC3 (detection) antibodies (***p<0.001). Western blotting (D) was used to detect the MUC1 extracellular domain (using the BC2 antibody) in cell lysates from cells treated with anti-MUC1 coated beads compared to IC for 50 h (top panel, MUC1 has an apparent mobility in the range of 280–440 kDa due to its polydisperse glycosylation). β-actin as a loading/cell density control in the same gel is shown in the middle panel. Concentrated culture supernatants from the same cell monolayers run on a separate SDS-PAGE/Western blot are shown in the lower panel. Origins of the gels are indicated (O).