Fig. 4.

Antigen density is important for phagocytosis. The MCF-7 breast cancer cell line was transfected with pcDNA HER2, and individual clones were selected by serial dilution. a Characterization of the protein expression by flow cytometry. Filled histogram is pcDNA HER2, bold line is empty vector, and normal line is unstained control. b Phagocytosis was performed as previously described in Fig. 1. Phagocytosis was performed in triplicate; means ± SEM and regression line are plotted on the graph. Two-way ANOVA with Sidak’s multiple comparisons test was used to determine significance. Asterisk represents significance between MCF7-HER2 and MCF7-Vector