FIG. 4.
Bacterial adherence to CHO cells in the presence or absence of exogenous GM1. (A) The percentage of CHO Lec-2 cells, preincubated with or without exogenous GM1 (n = 10,000), which had adherent PAO1 (labeled with GFP) was quantified by flow cytometry under control conditions. The amount of GM1 incorporation into the CHO cells was estimated by measuring the percentage of cells which could be labeled with FITC-conjugated CTB, a GM1-specific ligand. (B) Binding of 35S-labeled PAK, PAK/NP, PAK/fliC, and PAK/NP/fliC mutants to the CHO cells under control conditions or with added GM1 (as in panel A) was quantified. For these strains, the percent bound reflects the percentage of the bacterial inoculum added which bound to the CHO Lec-2 cells. The error bars are contained within the graph for many of the data points.