Figure 3.
Flow cytometry histograms demonstrating that humanized LM609 binds specifically to human integrin αvβ3 and can be blocked by mouse LM609. (A) Binding of humanized LM609 Fab to untransfected CS-1 hamster cells (fine line) and CS-1 hamster cells transfected with either human β3 (bold line) or β5 cDNA (dotted line). (B) Binding of humanized LM609 Fab to CS-1 hamster cells transfected with human β3 cDNA in the presence of a fourfold molar excess of mouse AP3 IgG (fine line) or mouse LM609 IgG (bold line). Clones 11, 7, 4, 24, and 2 represent the five humanized LM609 versions (cf. Fig. 2). Controls in A and B are based on identical experiments using buffer instead of humanized LM609 Fab. The y axis gives the number of events in linear scale, the x axis the fluorescence intensity in logarithmic scale.