Of the 23 mAbs with different sequences, eight clones were used in the FCM analysis for three different cell lines, HepG2 (hepatocarcinoma), Caco-2 (colonic carcinoma), and SKOv3 (ovarian carcinoma). Fig. 1 indicated the results. In FCM analysis, the degree of peak shift should reflect the amount of Ag, the accessibility of Ab, and the strength of binding. The width and shape of peak should reflect the degree of heterogeneity of expressed Ags in the cell population. The results of HepG2 indicated that
Temsirolimus the epitopes recognized by these eight mAbs were well and homogeneously expressed on the cell surface. The differences in MFI (mean fluorescence intensity) might be due to those in the binding activity. The patterns of Caco-2 were also similar to each other among the eight samples but the width of the peak was wider than that of HepG2. This suggested that CADM1 was well expressed in Caco-2 and similarly accessible by the eight mAbs but the degree of
expression was heterogeneous in the cell population. SKOv3 gave very much different patterns from those of the other two cells. Since all the eight mAbs bound to CADM1, these differences should have reflected those in the epitopes recognized by respective clones. The patterns could be classified into at least the following three groups: 015-024 and 035-116; 076-048 and 040-131; the rest four clones.
