Distinct Epitopes on CD13 Mediate Opposite Consequences for Cell Adhesion

Figure 4

Binding of mAbs C and E to CD13 do not induce changes in membrane expression of CD13. (a, b) Human U-937 monocytic cells were incubated for 3 h at 4°C (a) or at 37°C (b), with mAbs C and E or a control IgG, at concentrations at which C and E cause total inhibition of HA. Later, cells were transferred to 4°C and fixed. After fixation, CD13 expression was assessed by the binding of mAb 452-FITC, evaluated by flow cytometry. Data is presented as the average Mean Fluorescence Intensity + SD (). (c, d) U-937 cells were incubated for 3 h at 4°C (c) or at 37°C (d), with mAb 452 (at the optimal concentration for inducing HA), or a control IgG. Later, cells were transferred to 4°C and fixed. After fixation, CD13 expression was assessed by the binding of mAb C-FITC, which was evaluated by flow cytometry. Data is presented as the average Mean Fluorescence Intensity ± SD (). No significant differences were found by ANOVA.

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